Package: libzenohc Version: 0.11.0 Architecture: arm64 Maintainer: zenoh-dev@eclipse.org Installed-Size: 16875 Filename: 0.11.0/libzenohc_0.11.0_arm64.deb Size: 4101712 MD5sum: 20bae538da3c9550ee1ea9ec5d6ff52b SHA1: 3367e672b8b412d8a1d02f87661a298c0d751bb9 SHA256: 26e55e9edb29583baa206f0dd219bb06942b6e2e021a77f34194e8a754a72d25 Section: net Priority: optional Homepage: http://zenoh.io Description: The Zenoh C API . [![CI](https://github.com/eclipse-zenoh/zenoh-c/workflows/CI/badge.svg)](https://github.com/eclipse-zenoh/zenoh-c/actions?query=workflow%3A%22CI%22) [![Documentation Status](https://readthedocs.org/projects/zenoh-c/badge/?version=latest)](https://zenoh-c.readthedocs.io/en/latest/?badge=latest) [![Discussion](https://img.shields.io/badge/discussion-on%20github-blue)](https://github.com/eclipse-zenoh/roadmap/discussions) [![Discord](https://img.shields.io/badge/chat-on%20discord-blue)](https://discord.gg/2GJ958VuHs) [![License](https://img.shields.io/badge/License-EPL%202.0-blue)](https://choosealicense.com/licenses/epl-2.0/) [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0) . # Eclipse Zenoh . The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute. . Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and computations. It carefully blends traditional pub/sub with geo-distributed storages, queries and computations, while retaining a level of time and space efficiency that is well beyond any of the mainstream stacks. . Check the website [zenoh.io](http://zenoh.io) and the [roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed information. . ------------------------------- . # C API . This repository provides a C binding based on the main [Zenoh implementation written in Rust](https://github.com/eclipse-zenoh/zenoh). . ------------------------------- . ## How to build it . > :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active development. When you build from git, make sure you also build from git any other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.). It may happen that some changes in git are not compatible with the most recent packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in maintaining compatibility between the various git repositories in the Zenoh project. . 1. Make sure that [Rust](https://www.rust-lang.org) is available on your platform. Please check [here](https://www.rust-lang.org/tools/install) to learn how to install it. If you already have the Rust toolchain installed, make sure it is up-to-date with: . ```bash rustup update ``` . 2. Clone the [source] with `git`: . ```bash git clone https://github.com/eclipse-zenoh/zenoh-c.git ``` . [source]: https://github.com/eclipse-zenoh/zenoh-c . 3. Build: . Good CMake practice is to perform build outside of source directory, leaving source tree untouched. The examples below demonstrates this mode of building. On the other hand VScode by default creates build directory named 'build' inside source tree. In this case build script slightly changes its behavior. See more about it in section 'VScode'. . By default build configuration is set to `Release`, it's not necessary to add `-DCMAKE_BUILD_TYPE=Release` option on configuration step. But if your platform uses multi-config generator by default (this is the case on Windows), you may need to add option `--config Release` on build step. See more in CMake [build-configurations] documentation. Option`--config Release` is skipped in further examples for brewity. It's actually necessary for [Visual Studio generators] only. For [Ninja Multi-Config] the build script is able to select `Release` as the default configuration. . ```bash mkdir -p build && cd build cmake ../zenoh-c cmake --build . --config Release ``` . The generator to use is selected with option `-G`. If Ninja is installed on your system, adding `-GNinja` to `cmake` command can greatly speed up the build time: . ```bash cmake ../zenoh-c -GNinja cmake --build . ``` . [build-configurations]: https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html#build-configurations [Visual Studio generators]: https://cmake.org/cmake/help/latest/manual/cmake-generators.7.html#id14 [Ninja Multi-Config]: https://cmake.org/cmake/help/latest/generator/Ninja%20Multi-Config.html . 4. Install: . To install zenoh-c library into system just build target `install`. You need root privileges to do it, as the default install location is `/usr/local`. . ```bash cmake --build . --target install ``` . If you want to install zenoh-c libraries locally, you can set the installation directory with `CMAKE_INSTALL_PREFIX` . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local cmake --build . --target install ``` . By default only dynamic library is installed. Set `ZENOHC_INSTALL_STATIC_LIBRARY` variable to true to install static library also: . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local -DZENOHC_INSTALL_STATIC_LIBRARY=TRUE cmake --build . --target install ``` . The result of installation is the header files in `include` directory, the library files in `lib` directory and cmake package configuration files for package `zenohc` in `lib/cmake` directory. The library later can be loaded with CMake command `find_package(zenohc)`. Add dependency in CMakeLists.txt on target . - `zenohc::shared` for linking dynamic library - `zenohc::static` for linking static library - `zenohc::lib` for linking static or dynamic library depending on boolean variable `ZENOHC_LIB_STATIC` . For `Debug` configuration the library package `zenohc_debug` is installed side-by-side with release `zenohc` library. Suffix `d` is added to names of library files (libzenohc**d**.so). . 5. VScode . When zenoh-c project is opened in VSCode the build directory is set to `build` inside source tree (this is default behavior of Microsoft [CMake Tools]). The project build script detects this situation. In this case it places build files in `target` directory and `Cargo.toml` file (which is generated from `Cargo.toml.in`) into the root of source tree, as the rust developers used to and as the rust build tools expects by default. This behavior also can be explicitly enabled by setting `ZENOHC_BUILD_IN_SOURCE_TREE` variable to `TRUE`. . [CMake Tools]: https://marketplace.visualstudio.com/items?itemName=ms-vscode.cmake-tools . ## Building the Examples . The examples can be built in two ways. One is to select `examples` as a build target of zenoh-c project (assuming here that the current directory is side-by-side with zenoh-c directory): . ```bash cmake ../zenoh-c cmake --build . --target examples ``` . You may also use `--target ` if you wish to only build a specific example. . All build artifacts will be in the `target/release/examples` directory in this case. . The second way is to directly build `examples` as a root project: . ```bash cmake ../zenoh-c/examples cmake --build . ``` . In this case, the examples executables will be built in the current directory. . As a root project the `examples` project links `zenoh-c` with CMake's [add_subdirectory] command by default. There are also other ways to link `zenoh-c` - with [find_package] or [FetchContent]: . [add_subdirectory]: https://cmake.org/cmake/help/latest/command/add_subdirectory.html [find_package]: https://cmake.org/cmake/help/latest/command/find_package.html [FetchContent]: https://cmake.org/cmake/help/latest/module/FetchContent.html . Link with `zenoh-c` installed into default location in the system (with [find_package]): . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE ``` . Link with `zenoh-c` installed in `~/.local` directory: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE -DCMAKE_INSTALL_PREFIX=~/.local ``` . Download specific `zenoh-c` version from git with [FetchContent]: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=GIT_URL -DZENOHC_GIT_TAG=0.11.0-rc ``` . See also `configure_include_project` function in [helpers.cmake] for more information . [helpers.cmake]: cmake/helpers.cmake . ## Running the Examples . ### Basic Pub/Sub Example . ```bash ./target/release/examples/z_sub ``` . ```bash ./target/release/examples/z_pub ``` . ### Queryable and Query Example . ```bash ./target/release/examples/z_queryable ``` . ```bash ./target/release/examples/z_get ``` . ### Running the Throughput Examples . ```bash ./target/release/examples/z_sub_thr ``` . ```bash ./target/release/examples/z_pub_thr ``` . ## API conventions . Most of the types exposed by the `zenoh-c` API are types for which destruction is necessary. To help you spot these types, we name them with the convention that any destructible type must start by `z_owned`. . For maximum performance, we try to make as few copies as possible. Sometimes, this implies moving data that you `z_owned`. Any function that takes a non-const pointer to a `z_owned` type will perform its destruction. To make this pattern more obvious, we encourage you to use the `z_move` macro instead of a simple `&` to create these pointers. Rest assured that all `z_owned` types are double-free safe, and that you may check whether any `z_owned_X_t` typed value is still valid by using `z_X_check(&val)`, or the `z_check(val)` macro if you're using C11. . We hope this convention will help you streamline your memory-safe usage of zenoh, as following it should make looking for leaks trivial: simply search for paths where a value of a `z_owned` type hasn't been passed to a function using `z_move`. . Functions that simply need to borrow your data will instead take values of the associated `z_X_t` type. You may construct them using `z_X_loan(&val)` (or the `z_loan(val)` generic macro with C11). . Note that some `z_X_t` typed values can be constructed without needing to `z_borrow` their owned variants. This allows you to reduce the amount of copies realized in your program. . The examples have been written with C11 in mind, using the conventions we encourage you to follow. . Finally, we strongly advise that you refrain from using structure field that starts with `_`: . - We try to maintain a common API between `zenoh-c` and [`zenoh-pico`](https://github.com/eclipse-zenoh/zenoh-pico), such that porting code from one to the other is, ideally, trivial. However, some types must have distinct representations in either library, meaning that using these representations explicitly will get you in trouble when porting. - We reserve the right to change the memory layout of any type which has `_`-prefixed fields, so trying to use them might cause your code to break on updates. . ## Logging . By default, zenoh-c enables Zenoh's logging library upon using the `z_open` or `z_scout` functions. This behavior can be disabled by adding `-DDISABLE_LOGGER_AUTOINIT:bool=true` to the `cmake` configuration command. The logger may then be manually re-enabled with the `zc_init_logger` function. . ## Cross-Compilation . The following alternative options have been introduced to facilitate cross-compilation. > :warning: **WARNING** :warning: : Perhaps additional efforts are necessary, that will depend of your environment. . - `-DZENOHC_CARGO_CHANNEL="+nightly"|"+beta"|"+stable"`: refers to a specific rust toolchain release [[rust-channels](https://rust-lang.github.io/rustup/concepts/channels.html)] - `-DZENOHC_CARGO_FLAGS`: several optional flags can be used for compilation. [[cargo flags](https://doc.rust-lang.org/cargo/commands/cargo-build.html)] - `-DZENOHC_CUSTOM_TARGET`: specifies a crosscompilation target. Currently rust support several Tire-1, Tire-2 and Tire-3 targets [[targets](https://doc.rust-lang.org/nightly/rustc/platform-support.html)]. But keep in mind that zenoh-c only have support for following targets: `aarch64-unknown-linux-gnu`, `x86_64-unknown-linux-gnu`, `arm-unknown-linux-gnueabi` . Let's put all together in an example: Assuming you want to crosscompile for aarch64-unknown-linux-gnu. . 1. Install required packages - `sudo apt install gcc-aarch64-linux-gnu` 2. *(Only if you're using `nightly`) - `rustup component add rust-src --toolchain nightly` 3. Compile Zenoh-C. Assume that it's in `zenoh-c` directory. Notice that build in this sample is performed outside of source directory . ```bash export RUSTFLAGS="-Clinker=aarch64-linux-gnu-gcc -Car=aarch64-linux-gnu-ar" mkdir -p build && cd build cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+nightly" -DZENOHC_CARGO_FLAGS="-Zbuild-std=std,panic_abort" -DZENOHC_CUSTOM_TARGET="aarch64-unknown-linux-gnu" -DCMAKE_INSTALL_PREFIX=../aarch64/stage cmake --build . --target install ``` . Additionally you can use `RUSTFLAGS` environment variable for lead the compilation. . If all goes right the building files will be located at: `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` and release files will be located at `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` . ## Rust Version . The Rust version we use is defined in [rust-toolchain.toml](rust-toolchain.toml), which is `1.72.0`. There might be some memory mapping issue if you use the later version. . You can also specify the Rust version. . ```bash cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+1.72.0" ``` . ## Zenoh features support (enabling/disabling protocols, etc) . It's necessary sometimes to build zenoh-c library with set of features different from default. For example: enable TCP and UDP only. This can be done by changing `ZENOHC_CARGO_FLAGS` parameter for cmake (notice ";" instead of space due to cmake peculiarities) . Available features can be found in Zenoh [Cargo.toml](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/Cargo.toml) . ```bash cmake ../zenoh-c -DZENOHC_CARGO_FLAGS="--no-default-features;--features=zenoh/transport_tcp,zenoh/transport_udp" ``` Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-c Vcs-Git: https://github.com/eclipse-zenoh/zenoh-c Package: libzenohc Version: 0.11.0 Architecture: amd64 Maintainer: zenoh-dev@eclipse.org Installed-Size: 19367 Depends: libc6 (>= 2.29) Filename: 0.11.0/libzenohc_0.11.0_amd64.deb Size: 4627236 MD5sum: 887efce149d070c3f75c5286b824f0b6 SHA1: 3c8107e81f861c9cf6092e3b3b6e3249c9365a57 SHA256: d9b51937fd512947811e5026497fb742c530579bd22fd6805ea91952ee7b1dc3 Section: net Priority: optional Homepage: http://zenoh.io Description: The Zenoh C API . [![CI](https://github.com/eclipse-zenoh/zenoh-c/workflows/CI/badge.svg)](https://github.com/eclipse-zenoh/zenoh-c/actions?query=workflow%3A%22CI%22) [![Documentation Status](https://readthedocs.org/projects/zenoh-c/badge/?version=latest)](https://zenoh-c.readthedocs.io/en/latest/?badge=latest) [![Discussion](https://img.shields.io/badge/discussion-on%20github-blue)](https://github.com/eclipse-zenoh/roadmap/discussions) [![Discord](https://img.shields.io/badge/chat-on%20discord-blue)](https://discord.gg/2GJ958VuHs) [![License](https://img.shields.io/badge/License-EPL%202.0-blue)](https://choosealicense.com/licenses/epl-2.0/) [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0) . # Eclipse Zenoh . The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute. . Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and computations. It carefully blends traditional pub/sub with geo-distributed storages, queries and computations, while retaining a level of time and space efficiency that is well beyond any of the mainstream stacks. . Check the website [zenoh.io](http://zenoh.io) and the [roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed information. . ------------------------------- . # C API . This repository provides a C binding based on the main [Zenoh implementation written in Rust](https://github.com/eclipse-zenoh/zenoh). . ------------------------------- . ## How to build it . > :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active development. When you build from git, make sure you also build from git any other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.). It may happen that some changes in git are not compatible with the most recent packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in maintaining compatibility between the various git repositories in the Zenoh project. . 1. Make sure that [Rust](https://www.rust-lang.org) is available on your platform. Please check [here](https://www.rust-lang.org/tools/install) to learn how to install it. If you already have the Rust toolchain installed, make sure it is up-to-date with: . ```bash rustup update ``` . 2. Clone the [source] with `git`: . ```bash git clone https://github.com/eclipse-zenoh/zenoh-c.git ``` . [source]: https://github.com/eclipse-zenoh/zenoh-c . 3. Build: . Good CMake practice is to perform build outside of source directory, leaving source tree untouched. The examples below demonstrates this mode of building. On the other hand VScode by default creates build directory named 'build' inside source tree. In this case build script slightly changes its behavior. See more about it in section 'VScode'. . By default build configuration is set to `Release`, it's not necessary to add `-DCMAKE_BUILD_TYPE=Release` option on configuration step. But if your platform uses multi-config generator by default (this is the case on Windows), you may need to add option `--config Release` on build step. See more in CMake [build-configurations] documentation. Option`--config Release` is skipped in further examples for brewity. It's actually necessary for [Visual Studio generators] only. For [Ninja Multi-Config] the build script is able to select `Release` as the default configuration. . ```bash mkdir -p build && cd build cmake ../zenoh-c cmake --build . --config Release ``` . The generator to use is selected with option `-G`. If Ninja is installed on your system, adding `-GNinja` to `cmake` command can greatly speed up the build time: . ```bash cmake ../zenoh-c -GNinja cmake --build . ``` . [build-configurations]: https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html#build-configurations [Visual Studio generators]: https://cmake.org/cmake/help/latest/manual/cmake-generators.7.html#id14 [Ninja Multi-Config]: https://cmake.org/cmake/help/latest/generator/Ninja%20Multi-Config.html . 4. Install: . To install zenoh-c library into system just build target `install`. You need root privileges to do it, as the default install location is `/usr/local`. . ```bash cmake --build . --target install ``` . If you want to install zenoh-c libraries locally, you can set the installation directory with `CMAKE_INSTALL_PREFIX` . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local cmake --build . --target install ``` . By default only dynamic library is installed. Set `ZENOHC_INSTALL_STATIC_LIBRARY` variable to true to install static library also: . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local -DZENOHC_INSTALL_STATIC_LIBRARY=TRUE cmake --build . --target install ``` . The result of installation is the header files in `include` directory, the library files in `lib` directory and cmake package configuration files for package `zenohc` in `lib/cmake` directory. The library later can be loaded with CMake command `find_package(zenohc)`. Add dependency in CMakeLists.txt on target . - `zenohc::shared` for linking dynamic library - `zenohc::static` for linking static library - `zenohc::lib` for linking static or dynamic library depending on boolean variable `ZENOHC_LIB_STATIC` . For `Debug` configuration the library package `zenohc_debug` is installed side-by-side with release `zenohc` library. Suffix `d` is added to names of library files (libzenohc**d**.so). . 5. VScode . When zenoh-c project is opened in VSCode the build directory is set to `build` inside source tree (this is default behavior of Microsoft [CMake Tools]). The project build script detects this situation. In this case it places build files in `target` directory and `Cargo.toml` file (which is generated from `Cargo.toml.in`) into the root of source tree, as the rust developers used to and as the rust build tools expects by default. This behavior also can be explicitly enabled by setting `ZENOHC_BUILD_IN_SOURCE_TREE` variable to `TRUE`. . [CMake Tools]: https://marketplace.visualstudio.com/items?itemName=ms-vscode.cmake-tools . ## Building the Examples . The examples can be built in two ways. One is to select `examples` as a build target of zenoh-c project (assuming here that the current directory is side-by-side with zenoh-c directory): . ```bash cmake ../zenoh-c cmake --build . --target examples ``` . You may also use `--target ` if you wish to only build a specific example. . All build artifacts will be in the `target/release/examples` directory in this case. . The second way is to directly build `examples` as a root project: . ```bash cmake ../zenoh-c/examples cmake --build . ``` . In this case, the examples executables will be built in the current directory. . As a root project the `examples` project links `zenoh-c` with CMake's [add_subdirectory] command by default. There are also other ways to link `zenoh-c` - with [find_package] or [FetchContent]: . [add_subdirectory]: https://cmake.org/cmake/help/latest/command/add_subdirectory.html [find_package]: https://cmake.org/cmake/help/latest/command/find_package.html [FetchContent]: https://cmake.org/cmake/help/latest/module/FetchContent.html . Link with `zenoh-c` installed into default location in the system (with [find_package]): . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE ``` . Link with `zenoh-c` installed in `~/.local` directory: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE -DCMAKE_INSTALL_PREFIX=~/.local ``` . Download specific `zenoh-c` version from git with [FetchContent]: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=GIT_URL -DZENOHC_GIT_TAG=0.11.0-rc ``` . See also `configure_include_project` function in [helpers.cmake] for more information . [helpers.cmake]: cmake/helpers.cmake . ## Running the Examples . ### Basic Pub/Sub Example . ```bash ./target/release/examples/z_sub ``` . ```bash ./target/release/examples/z_pub ``` . ### Queryable and Query Example . ```bash ./target/release/examples/z_queryable ``` . ```bash ./target/release/examples/z_get ``` . ### Running the Throughput Examples . ```bash ./target/release/examples/z_sub_thr ``` . ```bash ./target/release/examples/z_pub_thr ``` . ## API conventions . Most of the types exposed by the `zenoh-c` API are types for which destruction is necessary. To help you spot these types, we name them with the convention that any destructible type must start by `z_owned`. . For maximum performance, we try to make as few copies as possible. Sometimes, this implies moving data that you `z_owned`. Any function that takes a non-const pointer to a `z_owned` type will perform its destruction. To make this pattern more obvious, we encourage you to use the `z_move` macro instead of a simple `&` to create these pointers. Rest assured that all `z_owned` types are double-free safe, and that you may check whether any `z_owned_X_t` typed value is still valid by using `z_X_check(&val)`, or the `z_check(val)` macro if you're using C11. . We hope this convention will help you streamline your memory-safe usage of zenoh, as following it should make looking for leaks trivial: simply search for paths where a value of a `z_owned` type hasn't been passed to a function using `z_move`. . Functions that simply need to borrow your data will instead take values of the associated `z_X_t` type. You may construct them using `z_X_loan(&val)` (or the `z_loan(val)` generic macro with C11). . Note that some `z_X_t` typed values can be constructed without needing to `z_borrow` their owned variants. This allows you to reduce the amount of copies realized in your program. . The examples have been written with C11 in mind, using the conventions we encourage you to follow. . Finally, we strongly advise that you refrain from using structure field that starts with `_`: . - We try to maintain a common API between `zenoh-c` and [`zenoh-pico`](https://github.com/eclipse-zenoh/zenoh-pico), such that porting code from one to the other is, ideally, trivial. However, some types must have distinct representations in either library, meaning that using these representations explicitly will get you in trouble when porting. - We reserve the right to change the memory layout of any type which has `_`-prefixed fields, so trying to use them might cause your code to break on updates. . ## Logging . By default, zenoh-c enables Zenoh's logging library upon using the `z_open` or `z_scout` functions. This behavior can be disabled by adding `-DDISABLE_LOGGER_AUTOINIT:bool=true` to the `cmake` configuration command. The logger may then be manually re-enabled with the `zc_init_logger` function. . ## Cross-Compilation . The following alternative options have been introduced to facilitate cross-compilation. > :warning: **WARNING** :warning: : Perhaps additional efforts are necessary, that will depend of your environment. . - `-DZENOHC_CARGO_CHANNEL="+nightly"|"+beta"|"+stable"`: refers to a specific rust toolchain release [[rust-channels](https://rust-lang.github.io/rustup/concepts/channels.html)] - `-DZENOHC_CARGO_FLAGS`: several optional flags can be used for compilation. [[cargo flags](https://doc.rust-lang.org/cargo/commands/cargo-build.html)] - `-DZENOHC_CUSTOM_TARGET`: specifies a crosscompilation target. Currently rust support several Tire-1, Tire-2 and Tire-3 targets [[targets](https://doc.rust-lang.org/nightly/rustc/platform-support.html)]. But keep in mind that zenoh-c only have support for following targets: `aarch64-unknown-linux-gnu`, `x86_64-unknown-linux-gnu`, `arm-unknown-linux-gnueabi` . Let's put all together in an example: Assuming you want to crosscompile for aarch64-unknown-linux-gnu. . 1. Install required packages - `sudo apt install gcc-aarch64-linux-gnu` 2. *(Only if you're using `nightly`) - `rustup component add rust-src --toolchain nightly` 3. Compile Zenoh-C. Assume that it's in `zenoh-c` directory. Notice that build in this sample is performed outside of source directory . ```bash export RUSTFLAGS="-Clinker=aarch64-linux-gnu-gcc -Car=aarch64-linux-gnu-ar" mkdir -p build && cd build cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+nightly" -DZENOHC_CARGO_FLAGS="-Zbuild-std=std,panic_abort" -DZENOHC_CUSTOM_TARGET="aarch64-unknown-linux-gnu" -DCMAKE_INSTALL_PREFIX=../aarch64/stage cmake --build . --target install ``` . Additionally you can use `RUSTFLAGS` environment variable for lead the compilation. . If all goes right the building files will be located at: `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` and release files will be located at `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` . ## Rust Version . The Rust version we use is defined in [rust-toolchain.toml](rust-toolchain.toml), which is `1.72.0`. There might be some memory mapping issue if you use the later version. . You can also specify the Rust version. . ```bash cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+1.72.0" ``` . ## Zenoh features support (enabling/disabling protocols, etc) . It's necessary sometimes to build zenoh-c library with set of features different from default. For example: enable TCP and UDP only. This can be done by changing `ZENOHC_CARGO_FLAGS` parameter for cmake (notice ";" instead of space due to cmake peculiarities) . Available features can be found in Zenoh [Cargo.toml](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/Cargo.toml) . ```bash cmake ../zenoh-c -DZENOHC_CARGO_FLAGS="--no-default-features;--features=zenoh/transport_tcp,zenoh/transport_udp" ``` Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-c Vcs-Git: https://github.com/eclipse-zenoh/zenoh-c Package: libzenohc Version: 0.11.0 Architecture: armel Maintainer: zenoh-dev@eclipse.org Installed-Size: 18203 Filename: 0.11.0/libzenohc_0.11.0_armel.deb Size: 4443840 MD5sum: 13e8c30ec52fc07d68106254c67ab2ce SHA1: 65a74f1a5ba7dddcf3de149cb3f4730416092bf4 SHA256: e3389d5d5a418e16c2c7eeefb5812f7c2c38f79d8e7e66ef31bbd0c4d2d296b2 Section: net Priority: optional Homepage: http://zenoh.io Description: The Zenoh C API . [![CI](https://github.com/eclipse-zenoh/zenoh-c/workflows/CI/badge.svg)](https://github.com/eclipse-zenoh/zenoh-c/actions?query=workflow%3A%22CI%22) [![Documentation Status](https://readthedocs.org/projects/zenoh-c/badge/?version=latest)](https://zenoh-c.readthedocs.io/en/latest/?badge=latest) [![Discussion](https://img.shields.io/badge/discussion-on%20github-blue)](https://github.com/eclipse-zenoh/roadmap/discussions) [![Discord](https://img.shields.io/badge/chat-on%20discord-blue)](https://discord.gg/2GJ958VuHs) [![License](https://img.shields.io/badge/License-EPL%202.0-blue)](https://choosealicense.com/licenses/epl-2.0/) [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0) . # Eclipse Zenoh . The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute. . Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and computations. It carefully blends traditional pub/sub with geo-distributed storages, queries and computations, while retaining a level of time and space efficiency that is well beyond any of the mainstream stacks. . Check the website [zenoh.io](http://zenoh.io) and the [roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed information. . ------------------------------- . # C API . This repository provides a C binding based on the main [Zenoh implementation written in Rust](https://github.com/eclipse-zenoh/zenoh). . ------------------------------- . ## How to build it . > :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active development. When you build from git, make sure you also build from git any other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.). It may happen that some changes in git are not compatible with the most recent packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in maintaining compatibility between the various git repositories in the Zenoh project. . 1. Make sure that [Rust](https://www.rust-lang.org) is available on your platform. Please check [here](https://www.rust-lang.org/tools/install) to learn how to install it. If you already have the Rust toolchain installed, make sure it is up-to-date with: . ```bash rustup update ``` . 2. Clone the [source] with `git`: . ```bash git clone https://github.com/eclipse-zenoh/zenoh-c.git ``` . [source]: https://github.com/eclipse-zenoh/zenoh-c . 3. Build: . Good CMake practice is to perform build outside of source directory, leaving source tree untouched. The examples below demonstrates this mode of building. On the other hand VScode by default creates build directory named 'build' inside source tree. In this case build script slightly changes its behavior. See more about it in section 'VScode'. . By default build configuration is set to `Release`, it's not necessary to add `-DCMAKE_BUILD_TYPE=Release` option on configuration step. But if your platform uses multi-config generator by default (this is the case on Windows), you may need to add option `--config Release` on build step. See more in CMake [build-configurations] documentation. Option`--config Release` is skipped in further examples for brewity. It's actually necessary for [Visual Studio generators] only. For [Ninja Multi-Config] the build script is able to select `Release` as the default configuration. . ```bash mkdir -p build && cd build cmake ../zenoh-c cmake --build . --config Release ``` . The generator to use is selected with option `-G`. If Ninja is installed on your system, adding `-GNinja` to `cmake` command can greatly speed up the build time: . ```bash cmake ../zenoh-c -GNinja cmake --build . ``` . [build-configurations]: https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html#build-configurations [Visual Studio generators]: https://cmake.org/cmake/help/latest/manual/cmake-generators.7.html#id14 [Ninja Multi-Config]: https://cmake.org/cmake/help/latest/generator/Ninja%20Multi-Config.html . 4. Install: . To install zenoh-c library into system just build target `install`. You need root privileges to do it, as the default install location is `/usr/local`. . ```bash cmake --build . --target install ``` . If you want to install zenoh-c libraries locally, you can set the installation directory with `CMAKE_INSTALL_PREFIX` . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local cmake --build . --target install ``` . By default only dynamic library is installed. Set `ZENOHC_INSTALL_STATIC_LIBRARY` variable to true to install static library also: . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local -DZENOHC_INSTALL_STATIC_LIBRARY=TRUE cmake --build . --target install ``` . The result of installation is the header files in `include` directory, the library files in `lib` directory and cmake package configuration files for package `zenohc` in `lib/cmake` directory. The library later can be loaded with CMake command `find_package(zenohc)`. Add dependency in CMakeLists.txt on target . - `zenohc::shared` for linking dynamic library - `zenohc::static` for linking static library - `zenohc::lib` for linking static or dynamic library depending on boolean variable `ZENOHC_LIB_STATIC` . For `Debug` configuration the library package `zenohc_debug` is installed side-by-side with release `zenohc` library. Suffix `d` is added to names of library files (libzenohc**d**.so). . 5. VScode . When zenoh-c project is opened in VSCode the build directory is set to `build` inside source tree (this is default behavior of Microsoft [CMake Tools]). The project build script detects this situation. In this case it places build files in `target` directory and `Cargo.toml` file (which is generated from `Cargo.toml.in`) into the root of source tree, as the rust developers used to and as the rust build tools expects by default. This behavior also can be explicitly enabled by setting `ZENOHC_BUILD_IN_SOURCE_TREE` variable to `TRUE`. . [CMake Tools]: https://marketplace.visualstudio.com/items?itemName=ms-vscode.cmake-tools . ## Building the Examples . The examples can be built in two ways. One is to select `examples` as a build target of zenoh-c project (assuming here that the current directory is side-by-side with zenoh-c directory): . ```bash cmake ../zenoh-c cmake --build . --target examples ``` . You may also use `--target ` if you wish to only build a specific example. . All build artifacts will be in the `target/release/examples` directory in this case. . The second way is to directly build `examples` as a root project: . ```bash cmake ../zenoh-c/examples cmake --build . ``` . In this case, the examples executables will be built in the current directory. . As a root project the `examples` project links `zenoh-c` with CMake's [add_subdirectory] command by default. There are also other ways to link `zenoh-c` - with [find_package] or [FetchContent]: . [add_subdirectory]: https://cmake.org/cmake/help/latest/command/add_subdirectory.html [find_package]: https://cmake.org/cmake/help/latest/command/find_package.html [FetchContent]: https://cmake.org/cmake/help/latest/module/FetchContent.html . Link with `zenoh-c` installed into default location in the system (with [find_package]): . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE ``` . Link with `zenoh-c` installed in `~/.local` directory: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE -DCMAKE_INSTALL_PREFIX=~/.local ``` . Download specific `zenoh-c` version from git with [FetchContent]: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=GIT_URL -DZENOHC_GIT_TAG=0.11.0-rc ``` . See also `configure_include_project` function in [helpers.cmake] for more information . [helpers.cmake]: cmake/helpers.cmake . ## Running the Examples . ### Basic Pub/Sub Example . ```bash ./target/release/examples/z_sub ``` . ```bash ./target/release/examples/z_pub ``` . ### Queryable and Query Example . ```bash ./target/release/examples/z_queryable ``` . ```bash ./target/release/examples/z_get ``` . ### Running the Throughput Examples . ```bash ./target/release/examples/z_sub_thr ``` . ```bash ./target/release/examples/z_pub_thr ``` . ## API conventions . Most of the types exposed by the `zenoh-c` API are types for which destruction is necessary. To help you spot these types, we name them with the convention that any destructible type must start by `z_owned`. . For maximum performance, we try to make as few copies as possible. Sometimes, this implies moving data that you `z_owned`. Any function that takes a non-const pointer to a `z_owned` type will perform its destruction. To make this pattern more obvious, we encourage you to use the `z_move` macro instead of a simple `&` to create these pointers. Rest assured that all `z_owned` types are double-free safe, and that you may check whether any `z_owned_X_t` typed value is still valid by using `z_X_check(&val)`, or the `z_check(val)` macro if you're using C11. . We hope this convention will help you streamline your memory-safe usage of zenoh, as following it should make looking for leaks trivial: simply search for paths where a value of a `z_owned` type hasn't been passed to a function using `z_move`. . Functions that simply need to borrow your data will instead take values of the associated `z_X_t` type. You may construct them using `z_X_loan(&val)` (or the `z_loan(val)` generic macro with C11). . Note that some `z_X_t` typed values can be constructed without needing to `z_borrow` their owned variants. This allows you to reduce the amount of copies realized in your program. . The examples have been written with C11 in mind, using the conventions we encourage you to follow. . Finally, we strongly advise that you refrain from using structure field that starts with `_`: . - We try to maintain a common API between `zenoh-c` and [`zenoh-pico`](https://github.com/eclipse-zenoh/zenoh-pico), such that porting code from one to the other is, ideally, trivial. However, some types must have distinct representations in either library, meaning that using these representations explicitly will get you in trouble when porting. - We reserve the right to change the memory layout of any type which has `_`-prefixed fields, so trying to use them might cause your code to break on updates. . ## Logging . By default, zenoh-c enables Zenoh's logging library upon using the `z_open` or `z_scout` functions. This behavior can be disabled by adding `-DDISABLE_LOGGER_AUTOINIT:bool=true` to the `cmake` configuration command. The logger may then be manually re-enabled with the `zc_init_logger` function. . ## Cross-Compilation . The following alternative options have been introduced to facilitate cross-compilation. > :warning: **WARNING** :warning: : Perhaps additional efforts are necessary, that will depend of your environment. . - `-DZENOHC_CARGO_CHANNEL="+nightly"|"+beta"|"+stable"`: refers to a specific rust toolchain release [[rust-channels](https://rust-lang.github.io/rustup/concepts/channels.html)] - `-DZENOHC_CARGO_FLAGS`: several optional flags can be used for compilation. [[cargo flags](https://doc.rust-lang.org/cargo/commands/cargo-build.html)] - `-DZENOHC_CUSTOM_TARGET`: specifies a crosscompilation target. Currently rust support several Tire-1, Tire-2 and Tire-3 targets [[targets](https://doc.rust-lang.org/nightly/rustc/platform-support.html)]. But keep in mind that zenoh-c only have support for following targets: `aarch64-unknown-linux-gnu`, `x86_64-unknown-linux-gnu`, `arm-unknown-linux-gnueabi` . Let's put all together in an example: Assuming you want to crosscompile for aarch64-unknown-linux-gnu. . 1. Install required packages - `sudo apt install gcc-aarch64-linux-gnu` 2. *(Only if you're using `nightly`) - `rustup component add rust-src --toolchain nightly` 3. Compile Zenoh-C. Assume that it's in `zenoh-c` directory. Notice that build in this sample is performed outside of source directory . ```bash export RUSTFLAGS="-Clinker=aarch64-linux-gnu-gcc -Car=aarch64-linux-gnu-ar" mkdir -p build && cd build cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+nightly" -DZENOHC_CARGO_FLAGS="-Zbuild-std=std,panic_abort" -DZENOHC_CUSTOM_TARGET="aarch64-unknown-linux-gnu" -DCMAKE_INSTALL_PREFIX=../aarch64/stage cmake --build . --target install ``` . Additionally you can use `RUSTFLAGS` environment variable for lead the compilation. . If all goes right the building files will be located at: `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` and release files will be located at `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` . ## Rust Version . The Rust version we use is defined in [rust-toolchain.toml](rust-toolchain.toml), which is `1.72.0`. There might be some memory mapping issue if you use the later version. . You can also specify the Rust version. . ```bash cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+1.72.0" ``` . ## Zenoh features support (enabling/disabling protocols, etc) . It's necessary sometimes to build zenoh-c library with set of features different from default. For example: enable TCP and UDP only. This can be done by changing `ZENOHC_CARGO_FLAGS` parameter for cmake (notice ";" instead of space due to cmake peculiarities) . Available features can be found in Zenoh [Cargo.toml](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/Cargo.toml) . ```bash cmake ../zenoh-c -DZENOHC_CARGO_FLAGS="--no-default-features;--features=zenoh/transport_tcp,zenoh/transport_udp" ``` Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-c Vcs-Git: https://github.com/eclipse-zenoh/zenoh-c Package: libzenohc Version: 0.11.0 Architecture: armhf Maintainer: zenoh-dev@eclipse.org Installed-Size: 17957 Filename: 0.11.0/libzenohc_0.11.0_armhf.deb Size: 4476988 MD5sum: 73afe304147a324c03174a9a81adc1f3 SHA1: d50d07f67399165e0c5a8796876caf2649441132 SHA256: 83e4bbb7a501c9d2c608590982f26e31fab6b0888c5b861e36910f85ed96a6f4 Section: net Priority: optional Homepage: http://zenoh.io Description: The Zenoh C API . [![CI](https://github.com/eclipse-zenoh/zenoh-c/workflows/CI/badge.svg)](https://github.com/eclipse-zenoh/zenoh-c/actions?query=workflow%3A%22CI%22) [![Documentation Status](https://readthedocs.org/projects/zenoh-c/badge/?version=latest)](https://zenoh-c.readthedocs.io/en/latest/?badge=latest) [![Discussion](https://img.shields.io/badge/discussion-on%20github-blue)](https://github.com/eclipse-zenoh/roadmap/discussions) [![Discord](https://img.shields.io/badge/chat-on%20discord-blue)](https://discord.gg/2GJ958VuHs) [![License](https://img.shields.io/badge/License-EPL%202.0-blue)](https://choosealicense.com/licenses/epl-2.0/) [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0) . # Eclipse Zenoh . The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute. . Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and computations. It carefully blends traditional pub/sub with geo-distributed storages, queries and computations, while retaining a level of time and space efficiency that is well beyond any of the mainstream stacks. . Check the website [zenoh.io](http://zenoh.io) and the [roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed information. . ------------------------------- . # C API . This repository provides a C binding based on the main [Zenoh implementation written in Rust](https://github.com/eclipse-zenoh/zenoh). . ------------------------------- . ## How to build it . > :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active development. When you build from git, make sure you also build from git any other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.). It may happen that some changes in git are not compatible with the most recent packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in maintaining compatibility between the various git repositories in the Zenoh project. . 1. Make sure that [Rust](https://www.rust-lang.org) is available on your platform. Please check [here](https://www.rust-lang.org/tools/install) to learn how to install it. If you already have the Rust toolchain installed, make sure it is up-to-date with: . ```bash rustup update ``` . 2. Clone the [source] with `git`: . ```bash git clone https://github.com/eclipse-zenoh/zenoh-c.git ``` . [source]: https://github.com/eclipse-zenoh/zenoh-c . 3. Build: . Good CMake practice is to perform build outside of source directory, leaving source tree untouched. The examples below demonstrates this mode of building. On the other hand VScode by default creates build directory named 'build' inside source tree. In this case build script slightly changes its behavior. See more about it in section 'VScode'. . By default build configuration is set to `Release`, it's not necessary to add `-DCMAKE_BUILD_TYPE=Release` option on configuration step. But if your platform uses multi-config generator by default (this is the case on Windows), you may need to add option `--config Release` on build step. See more in CMake [build-configurations] documentation. Option`--config Release` is skipped in further examples for brewity. It's actually necessary for [Visual Studio generators] only. For [Ninja Multi-Config] the build script is able to select `Release` as the default configuration. . ```bash mkdir -p build && cd build cmake ../zenoh-c cmake --build . --config Release ``` . The generator to use is selected with option `-G`. If Ninja is installed on your system, adding `-GNinja` to `cmake` command can greatly speed up the build time: . ```bash cmake ../zenoh-c -GNinja cmake --build . ``` . [build-configurations]: https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html#build-configurations [Visual Studio generators]: https://cmake.org/cmake/help/latest/manual/cmake-generators.7.html#id14 [Ninja Multi-Config]: https://cmake.org/cmake/help/latest/generator/Ninja%20Multi-Config.html . 4. Install: . To install zenoh-c library into system just build target `install`. You need root privileges to do it, as the default install location is `/usr/local`. . ```bash cmake --build . --target install ``` . If you want to install zenoh-c libraries locally, you can set the installation directory with `CMAKE_INSTALL_PREFIX` . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local cmake --build . --target install ``` . By default only dynamic library is installed. Set `ZENOHC_INSTALL_STATIC_LIBRARY` variable to true to install static library also: . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local -DZENOHC_INSTALL_STATIC_LIBRARY=TRUE cmake --build . --target install ``` . The result of installation is the header files in `include` directory, the library files in `lib` directory and cmake package configuration files for package `zenohc` in `lib/cmake` directory. The library later can be loaded with CMake command `find_package(zenohc)`. Add dependency in CMakeLists.txt on target . - `zenohc::shared` for linking dynamic library - `zenohc::static` for linking static library - `zenohc::lib` for linking static or dynamic library depending on boolean variable `ZENOHC_LIB_STATIC` . For `Debug` configuration the library package `zenohc_debug` is installed side-by-side with release `zenohc` library. Suffix `d` is added to names of library files (libzenohc**d**.so). . 5. VScode . When zenoh-c project is opened in VSCode the build directory is set to `build` inside source tree (this is default behavior of Microsoft [CMake Tools]). The project build script detects this situation. In this case it places build files in `target` directory and `Cargo.toml` file (which is generated from `Cargo.toml.in`) into the root of source tree, as the rust developers used to and as the rust build tools expects by default. This behavior also can be explicitly enabled by setting `ZENOHC_BUILD_IN_SOURCE_TREE` variable to `TRUE`. . [CMake Tools]: https://marketplace.visualstudio.com/items?itemName=ms-vscode.cmake-tools . ## Building the Examples . The examples can be built in two ways. One is to select `examples` as a build target of zenoh-c project (assuming here that the current directory is side-by-side with zenoh-c directory): . ```bash cmake ../zenoh-c cmake --build . --target examples ``` . You may also use `--target ` if you wish to only build a specific example. . All build artifacts will be in the `target/release/examples` directory in this case. . The second way is to directly build `examples` as a root project: . ```bash cmake ../zenoh-c/examples cmake --build . ``` . In this case, the examples executables will be built in the current directory. . As a root project the `examples` project links `zenoh-c` with CMake's [add_subdirectory] command by default. There are also other ways to link `zenoh-c` - with [find_package] or [FetchContent]: . [add_subdirectory]: https://cmake.org/cmake/help/latest/command/add_subdirectory.html [find_package]: https://cmake.org/cmake/help/latest/command/find_package.html [FetchContent]: https://cmake.org/cmake/help/latest/module/FetchContent.html . Link with `zenoh-c` installed into default location in the system (with [find_package]): . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE ``` . Link with `zenoh-c` installed in `~/.local` directory: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE -DCMAKE_INSTALL_PREFIX=~/.local ``` . Download specific `zenoh-c` version from git with [FetchContent]: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=GIT_URL -DZENOHC_GIT_TAG=0.11.0-rc ``` . See also `configure_include_project` function in [helpers.cmake] for more information . [helpers.cmake]: cmake/helpers.cmake . ## Running the Examples . ### Basic Pub/Sub Example . ```bash ./target/release/examples/z_sub ``` . ```bash ./target/release/examples/z_pub ``` . ### Queryable and Query Example . ```bash ./target/release/examples/z_queryable ``` . ```bash ./target/release/examples/z_get ``` . ### Running the Throughput Examples . ```bash ./target/release/examples/z_sub_thr ``` . ```bash ./target/release/examples/z_pub_thr ``` . ## API conventions . Most of the types exposed by the `zenoh-c` API are types for which destruction is necessary. To help you spot these types, we name them with the convention that any destructible type must start by `z_owned`. . For maximum performance, we try to make as few copies as possible. Sometimes, this implies moving data that you `z_owned`. Any function that takes a non-const pointer to a `z_owned` type will perform its destruction. To make this pattern more obvious, we encourage you to use the `z_move` macro instead of a simple `&` to create these pointers. Rest assured that all `z_owned` types are double-free safe, and that you may check whether any `z_owned_X_t` typed value is still valid by using `z_X_check(&val)`, or the `z_check(val)` macro if you're using C11. . We hope this convention will help you streamline your memory-safe usage of zenoh, as following it should make looking for leaks trivial: simply search for paths where a value of a `z_owned` type hasn't been passed to a function using `z_move`. . Functions that simply need to borrow your data will instead take values of the associated `z_X_t` type. You may construct them using `z_X_loan(&val)` (or the `z_loan(val)` generic macro with C11). . Note that some `z_X_t` typed values can be constructed without needing to `z_borrow` their owned variants. This allows you to reduce the amount of copies realized in your program. . The examples have been written with C11 in mind, using the conventions we encourage you to follow. . Finally, we strongly advise that you refrain from using structure field that starts with `_`: . - We try to maintain a common API between `zenoh-c` and [`zenoh-pico`](https://github.com/eclipse-zenoh/zenoh-pico), such that porting code from one to the other is, ideally, trivial. However, some types must have distinct representations in either library, meaning that using these representations explicitly will get you in trouble when porting. - We reserve the right to change the memory layout of any type which has `_`-prefixed fields, so trying to use them might cause your code to break on updates. . ## Logging . By default, zenoh-c enables Zenoh's logging library upon using the `z_open` or `z_scout` functions. This behavior can be disabled by adding `-DDISABLE_LOGGER_AUTOINIT:bool=true` to the `cmake` configuration command. The logger may then be manually re-enabled with the `zc_init_logger` function. . ## Cross-Compilation . The following alternative options have been introduced to facilitate cross-compilation. > :warning: **WARNING** :warning: : Perhaps additional efforts are necessary, that will depend of your environment. . - `-DZENOHC_CARGO_CHANNEL="+nightly"|"+beta"|"+stable"`: refers to a specific rust toolchain release [[rust-channels](https://rust-lang.github.io/rustup/concepts/channels.html)] - `-DZENOHC_CARGO_FLAGS`: several optional flags can be used for compilation. [[cargo flags](https://doc.rust-lang.org/cargo/commands/cargo-build.html)] - `-DZENOHC_CUSTOM_TARGET`: specifies a crosscompilation target. Currently rust support several Tire-1, Tire-2 and Tire-3 targets [[targets](https://doc.rust-lang.org/nightly/rustc/platform-support.html)]. But keep in mind that zenoh-c only have support for following targets: `aarch64-unknown-linux-gnu`, `x86_64-unknown-linux-gnu`, `arm-unknown-linux-gnueabi` . Let's put all together in an example: Assuming you want to crosscompile for aarch64-unknown-linux-gnu. . 1. Install required packages - `sudo apt install gcc-aarch64-linux-gnu` 2. *(Only if you're using `nightly`) - `rustup component add rust-src --toolchain nightly` 3. Compile Zenoh-C. Assume that it's in `zenoh-c` directory. Notice that build in this sample is performed outside of source directory . ```bash export RUSTFLAGS="-Clinker=aarch64-linux-gnu-gcc -Car=aarch64-linux-gnu-ar" mkdir -p build && cd build cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+nightly" -DZENOHC_CARGO_FLAGS="-Zbuild-std=std,panic_abort" -DZENOHC_CUSTOM_TARGET="aarch64-unknown-linux-gnu" -DCMAKE_INSTALL_PREFIX=../aarch64/stage cmake --build . --target install ``` . Additionally you can use `RUSTFLAGS` environment variable for lead the compilation. . If all goes right the building files will be located at: `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` and release files will be located at `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` . ## Rust Version . The Rust version we use is defined in [rust-toolchain.toml](rust-toolchain.toml), which is `1.72.0`. There might be some memory mapping issue if you use the later version. . You can also specify the Rust version. . ```bash cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+1.72.0" ``` . ## Zenoh features support (enabling/disabling protocols, etc) . It's necessary sometimes to build zenoh-c library with set of features different from default. For example: enable TCP and UDP only. This can be done by changing `ZENOHC_CARGO_FLAGS` parameter for cmake (notice ";" instead of space due to cmake peculiarities) . Available features can be found in Zenoh [Cargo.toml](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/Cargo.toml) . ```bash cmake ../zenoh-c -DZENOHC_CARGO_FLAGS="--no-default-features;--features=zenoh/transport_tcp,zenoh/transport_udp" ``` Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-c Vcs-Git: https://github.com/eclipse-zenoh/zenoh-c Package: libzenohc-dev Version: 0.11.0 Architecture: armhf Maintainer: zenoh-dev@eclipse.org Installed-Size: 173 Depends: libzenohc (=0.11.0) Filename: 0.11.0/libzenohc-dev_0.11.0_armhf.deb Size: 32324 MD5sum: 2e40b5e40a8e91f69f4fc50cc4cdb6e1 SHA1: 5b40bb2ccbdcee6b399546442c3f8af575a0b8e2 SHA256: d288eb6585ac24cee02cac15edd74aa42bb3284543e6e26890e97211a82daffb Section: net Priority: optional Homepage: http://zenoh.io Description: The Zenoh C API . [![CI](https://github.com/eclipse-zenoh/zenoh-c/workflows/CI/badge.svg)](https://github.com/eclipse-zenoh/zenoh-c/actions?query=workflow%3A%22CI%22) [![Documentation Status](https://readthedocs.org/projects/zenoh-c/badge/?version=latest)](https://zenoh-c.readthedocs.io/en/latest/?badge=latest) [![Discussion](https://img.shields.io/badge/discussion-on%20github-blue)](https://github.com/eclipse-zenoh/roadmap/discussions) [![Discord](https://img.shields.io/badge/chat-on%20discord-blue)](https://discord.gg/2GJ958VuHs) [![License](https://img.shields.io/badge/License-EPL%202.0-blue)](https://choosealicense.com/licenses/epl-2.0/) [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0) . # Eclipse Zenoh . The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute. . Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and computations. It carefully blends traditional pub/sub with geo-distributed storages, queries and computations, while retaining a level of time and space efficiency that is well beyond any of the mainstream stacks. . Check the website [zenoh.io](http://zenoh.io) and the [roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed information. . ------------------------------- . # C API . This repository provides a C binding based on the main [Zenoh implementation written in Rust](https://github.com/eclipse-zenoh/zenoh). . ------------------------------- . ## How to build it . > :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active development. When you build from git, make sure you also build from git any other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.). It may happen that some changes in git are not compatible with the most recent packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in maintaining compatibility between the various git repositories in the Zenoh project. . 1. Make sure that [Rust](https://www.rust-lang.org) is available on your platform. Please check [here](https://www.rust-lang.org/tools/install) to learn how to install it. If you already have the Rust toolchain installed, make sure it is up-to-date with: . ```bash rustup update ``` . 2. Clone the [source] with `git`: . ```bash git clone https://github.com/eclipse-zenoh/zenoh-c.git ``` . [source]: https://github.com/eclipse-zenoh/zenoh-c . 3. Build: . Good CMake practice is to perform build outside of source directory, leaving source tree untouched. The examples below demonstrates this mode of building. On the other hand VScode by default creates build directory named 'build' inside source tree. In this case build script slightly changes its behavior. See more about it in section 'VScode'. . By default build configuration is set to `Release`, it's not necessary to add `-DCMAKE_BUILD_TYPE=Release` option on configuration step. But if your platform uses multi-config generator by default (this is the case on Windows), you may need to add option `--config Release` on build step. See more in CMake [build-configurations] documentation. Option`--config Release` is skipped in further examples for brewity. It's actually necessary for [Visual Studio generators] only. For [Ninja Multi-Config] the build script is able to select `Release` as the default configuration. . ```bash mkdir -p build && cd build cmake ../zenoh-c cmake --build . --config Release ``` . The generator to use is selected with option `-G`. If Ninja is installed on your system, adding `-GNinja` to `cmake` command can greatly speed up the build time: . ```bash cmake ../zenoh-c -GNinja cmake --build . ``` . [build-configurations]: https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html#build-configurations [Visual Studio generators]: https://cmake.org/cmake/help/latest/manual/cmake-generators.7.html#id14 [Ninja Multi-Config]: https://cmake.org/cmake/help/latest/generator/Ninja%20Multi-Config.html . 4. Install: . To install zenoh-c library into system just build target `install`. You need root privileges to do it, as the default install location is `/usr/local`. . ```bash cmake --build . --target install ``` . If you want to install zenoh-c libraries locally, you can set the installation directory with `CMAKE_INSTALL_PREFIX` . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local cmake --build . --target install ``` . By default only dynamic library is installed. Set `ZENOHC_INSTALL_STATIC_LIBRARY` variable to true to install static library also: . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local -DZENOHC_INSTALL_STATIC_LIBRARY=TRUE cmake --build . --target install ``` . The result of installation is the header files in `include` directory, the library files in `lib` directory and cmake package configuration files for package `zenohc` in `lib/cmake` directory. The library later can be loaded with CMake command `find_package(zenohc)`. Add dependency in CMakeLists.txt on target . - `zenohc::shared` for linking dynamic library - `zenohc::static` for linking static library - `zenohc::lib` for linking static or dynamic library depending on boolean variable `ZENOHC_LIB_STATIC` . For `Debug` configuration the library package `zenohc_debug` is installed side-by-side with release `zenohc` library. Suffix `d` is added to names of library files (libzenohc**d**.so). . 5. VScode . When zenoh-c project is opened in VSCode the build directory is set to `build` inside source tree (this is default behavior of Microsoft [CMake Tools]). The project build script detects this situation. In this case it places build files in `target` directory and `Cargo.toml` file (which is generated from `Cargo.toml.in`) into the root of source tree, as the rust developers used to and as the rust build tools expects by default. This behavior also can be explicitly enabled by setting `ZENOHC_BUILD_IN_SOURCE_TREE` variable to `TRUE`. . [CMake Tools]: https://marketplace.visualstudio.com/items?itemName=ms-vscode.cmake-tools . ## Building the Examples . The examples can be built in two ways. One is to select `examples` as a build target of zenoh-c project (assuming here that the current directory is side-by-side with zenoh-c directory): . ```bash cmake ../zenoh-c cmake --build . --target examples ``` . You may also use `--target ` if you wish to only build a specific example. . All build artifacts will be in the `target/release/examples` directory in this case. . The second way is to directly build `examples` as a root project: . ```bash cmake ../zenoh-c/examples cmake --build . ``` . In this case, the examples executables will be built in the current directory. . As a root project the `examples` project links `zenoh-c` with CMake's [add_subdirectory] command by default. There are also other ways to link `zenoh-c` - with [find_package] or [FetchContent]: . [add_subdirectory]: https://cmake.org/cmake/help/latest/command/add_subdirectory.html [find_package]: https://cmake.org/cmake/help/latest/command/find_package.html [FetchContent]: https://cmake.org/cmake/help/latest/module/FetchContent.html . Link with `zenoh-c` installed into default location in the system (with [find_package]): . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE ``` . Link with `zenoh-c` installed in `~/.local` directory: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE -DCMAKE_INSTALL_PREFIX=~/.local ``` . Download specific `zenoh-c` version from git with [FetchContent]: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=GIT_URL -DZENOHC_GIT_TAG=0.11.0-rc ``` . See also `configure_include_project` function in [helpers.cmake] for more information . [helpers.cmake]: cmake/helpers.cmake . ## Running the Examples . ### Basic Pub/Sub Example . ```bash ./target/release/examples/z_sub ``` . ```bash ./target/release/examples/z_pub ``` . ### Queryable and Query Example . ```bash ./target/release/examples/z_queryable ``` . ```bash ./target/release/examples/z_get ``` . ### Running the Throughput Examples . ```bash ./target/release/examples/z_sub_thr ``` . ```bash ./target/release/examples/z_pub_thr ``` . ## API conventions . Most of the types exposed by the `zenoh-c` API are types for which destruction is necessary. To help you spot these types, we name them with the convention that any destructible type must start by `z_owned`. . For maximum performance, we try to make as few copies as possible. Sometimes, this implies moving data that you `z_owned`. Any function that takes a non-const pointer to a `z_owned` type will perform its destruction. To make this pattern more obvious, we encourage you to use the `z_move` macro instead of a simple `&` to create these pointers. Rest assured that all `z_owned` types are double-free safe, and that you may check whether any `z_owned_X_t` typed value is still valid by using `z_X_check(&val)`, or the `z_check(val)` macro if you're using C11. . We hope this convention will help you streamline your memory-safe usage of zenoh, as following it should make looking for leaks trivial: simply search for paths where a value of a `z_owned` type hasn't been passed to a function using `z_move`. . Functions that simply need to borrow your data will instead take values of the associated `z_X_t` type. You may construct them using `z_X_loan(&val)` (or the `z_loan(val)` generic macro with C11). . Note that some `z_X_t` typed values can be constructed without needing to `z_borrow` their owned variants. This allows you to reduce the amount of copies realized in your program. . The examples have been written with C11 in mind, using the conventions we encourage you to follow. . Finally, we strongly advise that you refrain from using structure field that starts with `_`: . - We try to maintain a common API between `zenoh-c` and [`zenoh-pico`](https://github.com/eclipse-zenoh/zenoh-pico), such that porting code from one to the other is, ideally, trivial. However, some types must have distinct representations in either library, meaning that using these representations explicitly will get you in trouble when porting. - We reserve the right to change the memory layout of any type which has `_`-prefixed fields, so trying to use them might cause your code to break on updates. . ## Logging . By default, zenoh-c enables Zenoh's logging library upon using the `z_open` or `z_scout` functions. This behavior can be disabled by adding `-DDISABLE_LOGGER_AUTOINIT:bool=true` to the `cmake` configuration command. The logger may then be manually re-enabled with the `zc_init_logger` function. . ## Cross-Compilation . The following alternative options have been introduced to facilitate cross-compilation. > :warning: **WARNING** :warning: : Perhaps additional efforts are necessary, that will depend of your environment. . - `-DZENOHC_CARGO_CHANNEL="+nightly"|"+beta"|"+stable"`: refers to a specific rust toolchain release [[rust-channels](https://rust-lang.github.io/rustup/concepts/channels.html)] - `-DZENOHC_CARGO_FLAGS`: several optional flags can be used for compilation. [[cargo flags](https://doc.rust-lang.org/cargo/commands/cargo-build.html)] - `-DZENOHC_CUSTOM_TARGET`: specifies a crosscompilation target. Currently rust support several Tire-1, Tire-2 and Tire-3 targets [[targets](https://doc.rust-lang.org/nightly/rustc/platform-support.html)]. But keep in mind that zenoh-c only have support for following targets: `aarch64-unknown-linux-gnu`, `x86_64-unknown-linux-gnu`, `arm-unknown-linux-gnueabi` . Let's put all together in an example: Assuming you want to crosscompile for aarch64-unknown-linux-gnu. . 1. Install required packages - `sudo apt install gcc-aarch64-linux-gnu` 2. *(Only if you're using `nightly`) - `rustup component add rust-src --toolchain nightly` 3. Compile Zenoh-C. Assume that it's in `zenoh-c` directory. Notice that build in this sample is performed outside of source directory . ```bash export RUSTFLAGS="-Clinker=aarch64-linux-gnu-gcc -Car=aarch64-linux-gnu-ar" mkdir -p build && cd build cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+nightly" -DZENOHC_CARGO_FLAGS="-Zbuild-std=std,panic_abort" -DZENOHC_CUSTOM_TARGET="aarch64-unknown-linux-gnu" -DCMAKE_INSTALL_PREFIX=../aarch64/stage cmake --build . --target install ``` . Additionally you can use `RUSTFLAGS` environment variable for lead the compilation. . If all goes right the building files will be located at: `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` and release files will be located at `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` . ## Rust Version . The Rust version we use is defined in [rust-toolchain.toml](rust-toolchain.toml), which is `1.72.0`. There might be some memory mapping issue if you use the later version. . You can also specify the Rust version. . ```bash cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+1.72.0" ``` . ## Zenoh features support (enabling/disabling protocols, etc) . It's necessary sometimes to build zenoh-c library with set of features different from default. For example: enable TCP and UDP only. This can be done by changing `ZENOHC_CARGO_FLAGS` parameter for cmake (notice ";" instead of space due to cmake peculiarities) . Available features can be found in Zenoh [Cargo.toml](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/Cargo.toml) . ```bash cmake ../zenoh-c -DZENOHC_CARGO_FLAGS="--no-default-features;--features=zenoh/transport_tcp,zenoh/transport_udp" ``` Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-c Vcs-Git: https://github.com/eclipse-zenoh/zenoh-c Package: libzenohc-dev Version: 0.11.0 Architecture: amd64 Maintainer: zenoh-dev@eclipse.org Installed-Size: 173 Depends: libzenohc (=0.11.0) Filename: 0.11.0/libzenohc-dev_0.11.0_amd64.deb Size: 32304 MD5sum: 40dd4ab9cba6a045082e11a8c88e0f0c SHA1: 087f0f5ab01e3f223fa29426c5c5397541050d7a SHA256: d2dcb632b009cbd9f6fb750213d7fa506a25647031a1f8be9eab229e0bdad32c Section: net Priority: optional Homepage: http://zenoh.io Description: The Zenoh C API . [![CI](https://github.com/eclipse-zenoh/zenoh-c/workflows/CI/badge.svg)](https://github.com/eclipse-zenoh/zenoh-c/actions?query=workflow%3A%22CI%22) [![Documentation Status](https://readthedocs.org/projects/zenoh-c/badge/?version=latest)](https://zenoh-c.readthedocs.io/en/latest/?badge=latest) [![Discussion](https://img.shields.io/badge/discussion-on%20github-blue)](https://github.com/eclipse-zenoh/roadmap/discussions) [![Discord](https://img.shields.io/badge/chat-on%20discord-blue)](https://discord.gg/2GJ958VuHs) [![License](https://img.shields.io/badge/License-EPL%202.0-blue)](https://choosealicense.com/licenses/epl-2.0/) [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0) . # Eclipse Zenoh . The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute. . Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and computations. It carefully blends traditional pub/sub with geo-distributed storages, queries and computations, while retaining a level of time and space efficiency that is well beyond any of the mainstream stacks. . Check the website [zenoh.io](http://zenoh.io) and the [roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed information. . ------------------------------- . # C API . This repository provides a C binding based on the main [Zenoh implementation written in Rust](https://github.com/eclipse-zenoh/zenoh). . ------------------------------- . ## How to build it . > :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active development. When you build from git, make sure you also build from git any other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.). It may happen that some changes in git are not compatible with the most recent packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in maintaining compatibility between the various git repositories in the Zenoh project. . 1. Make sure that [Rust](https://www.rust-lang.org) is available on your platform. Please check [here](https://www.rust-lang.org/tools/install) to learn how to install it. If you already have the Rust toolchain installed, make sure it is up-to-date with: . ```bash rustup update ``` . 2. Clone the [source] with `git`: . ```bash git clone https://github.com/eclipse-zenoh/zenoh-c.git ``` . [source]: https://github.com/eclipse-zenoh/zenoh-c . 3. Build: . Good CMake practice is to perform build outside of source directory, leaving source tree untouched. The examples below demonstrates this mode of building. On the other hand VScode by default creates build directory named 'build' inside source tree. In this case build script slightly changes its behavior. See more about it in section 'VScode'. . By default build configuration is set to `Release`, it's not necessary to add `-DCMAKE_BUILD_TYPE=Release` option on configuration step. But if your platform uses multi-config generator by default (this is the case on Windows), you may need to add option `--config Release` on build step. See more in CMake [build-configurations] documentation. Option`--config Release` is skipped in further examples for brewity. It's actually necessary for [Visual Studio generators] only. For [Ninja Multi-Config] the build script is able to select `Release` as the default configuration. . ```bash mkdir -p build && cd build cmake ../zenoh-c cmake --build . --config Release ``` . The generator to use is selected with option `-G`. If Ninja is installed on your system, adding `-GNinja` to `cmake` command can greatly speed up the build time: . ```bash cmake ../zenoh-c -GNinja cmake --build . ``` . [build-configurations]: https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html#build-configurations [Visual Studio generators]: https://cmake.org/cmake/help/latest/manual/cmake-generators.7.html#id14 [Ninja Multi-Config]: https://cmake.org/cmake/help/latest/generator/Ninja%20Multi-Config.html . 4. Install: . To install zenoh-c library into system just build target `install`. You need root privileges to do it, as the default install location is `/usr/local`. . ```bash cmake --build . --target install ``` . If you want to install zenoh-c libraries locally, you can set the installation directory with `CMAKE_INSTALL_PREFIX` . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local cmake --build . --target install ``` . By default only dynamic library is installed. Set `ZENOHC_INSTALL_STATIC_LIBRARY` variable to true to install static library also: . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local -DZENOHC_INSTALL_STATIC_LIBRARY=TRUE cmake --build . --target install ``` . The result of installation is the header files in `include` directory, the library files in `lib` directory and cmake package configuration files for package `zenohc` in `lib/cmake` directory. The library later can be loaded with CMake command `find_package(zenohc)`. Add dependency in CMakeLists.txt on target . - `zenohc::shared` for linking dynamic library - `zenohc::static` for linking static library - `zenohc::lib` for linking static or dynamic library depending on boolean variable `ZENOHC_LIB_STATIC` . For `Debug` configuration the library package `zenohc_debug` is installed side-by-side with release `zenohc` library. Suffix `d` is added to names of library files (libzenohc**d**.so). . 5. VScode . When zenoh-c project is opened in VSCode the build directory is set to `build` inside source tree (this is default behavior of Microsoft [CMake Tools]). The project build script detects this situation. In this case it places build files in `target` directory and `Cargo.toml` file (which is generated from `Cargo.toml.in`) into the root of source tree, as the rust developers used to and as the rust build tools expects by default. This behavior also can be explicitly enabled by setting `ZENOHC_BUILD_IN_SOURCE_TREE` variable to `TRUE`. . [CMake Tools]: https://marketplace.visualstudio.com/items?itemName=ms-vscode.cmake-tools . ## Building the Examples . The examples can be built in two ways. One is to select `examples` as a build target of zenoh-c project (assuming here that the current directory is side-by-side with zenoh-c directory): . ```bash cmake ../zenoh-c cmake --build . --target examples ``` . You may also use `--target ` if you wish to only build a specific example. . All build artifacts will be in the `target/release/examples` directory in this case. . The second way is to directly build `examples` as a root project: . ```bash cmake ../zenoh-c/examples cmake --build . ``` . In this case, the examples executables will be built in the current directory. . As a root project the `examples` project links `zenoh-c` with CMake's [add_subdirectory] command by default. There are also other ways to link `zenoh-c` - with [find_package] or [FetchContent]: . [add_subdirectory]: https://cmake.org/cmake/help/latest/command/add_subdirectory.html [find_package]: https://cmake.org/cmake/help/latest/command/find_package.html [FetchContent]: https://cmake.org/cmake/help/latest/module/FetchContent.html . Link with `zenoh-c` installed into default location in the system (with [find_package]): . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE ``` . Link with `zenoh-c` installed in `~/.local` directory: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE -DCMAKE_INSTALL_PREFIX=~/.local ``` . Download specific `zenoh-c` version from git with [FetchContent]: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=GIT_URL -DZENOHC_GIT_TAG=0.11.0-rc ``` . See also `configure_include_project` function in [helpers.cmake] for more information . [helpers.cmake]: cmake/helpers.cmake . ## Running the Examples . ### Basic Pub/Sub Example . ```bash ./target/release/examples/z_sub ``` . ```bash ./target/release/examples/z_pub ``` . ### Queryable and Query Example . ```bash ./target/release/examples/z_queryable ``` . ```bash ./target/release/examples/z_get ``` . ### Running the Throughput Examples . ```bash ./target/release/examples/z_sub_thr ``` . ```bash ./target/release/examples/z_pub_thr ``` . ## API conventions . Most of the types exposed by the `zenoh-c` API are types for which destruction is necessary. To help you spot these types, we name them with the convention that any destructible type must start by `z_owned`. . For maximum performance, we try to make as few copies as possible. Sometimes, this implies moving data that you `z_owned`. Any function that takes a non-const pointer to a `z_owned` type will perform its destruction. To make this pattern more obvious, we encourage you to use the `z_move` macro instead of a simple `&` to create these pointers. Rest assured that all `z_owned` types are double-free safe, and that you may check whether any `z_owned_X_t` typed value is still valid by using `z_X_check(&val)`, or the `z_check(val)` macro if you're using C11. . We hope this convention will help you streamline your memory-safe usage of zenoh, as following it should make looking for leaks trivial: simply search for paths where a value of a `z_owned` type hasn't been passed to a function using `z_move`. . Functions that simply need to borrow your data will instead take values of the associated `z_X_t` type. You may construct them using `z_X_loan(&val)` (or the `z_loan(val)` generic macro with C11). . Note that some `z_X_t` typed values can be constructed without needing to `z_borrow` their owned variants. This allows you to reduce the amount of copies realized in your program. . The examples have been written with C11 in mind, using the conventions we encourage you to follow. . Finally, we strongly advise that you refrain from using structure field that starts with `_`: . - We try to maintain a common API between `zenoh-c` and [`zenoh-pico`](https://github.com/eclipse-zenoh/zenoh-pico), such that porting code from one to the other is, ideally, trivial. However, some types must have distinct representations in either library, meaning that using these representations explicitly will get you in trouble when porting. - We reserve the right to change the memory layout of any type which has `_`-prefixed fields, so trying to use them might cause your code to break on updates. . ## Logging . By default, zenoh-c enables Zenoh's logging library upon using the `z_open` or `z_scout` functions. This behavior can be disabled by adding `-DDISABLE_LOGGER_AUTOINIT:bool=true` to the `cmake` configuration command. The logger may then be manually re-enabled with the `zc_init_logger` function. . ## Cross-Compilation . The following alternative options have been introduced to facilitate cross-compilation. > :warning: **WARNING** :warning: : Perhaps additional efforts are necessary, that will depend of your environment. . - `-DZENOHC_CARGO_CHANNEL="+nightly"|"+beta"|"+stable"`: refers to a specific rust toolchain release [[rust-channels](https://rust-lang.github.io/rustup/concepts/channels.html)] - `-DZENOHC_CARGO_FLAGS`: several optional flags can be used for compilation. [[cargo flags](https://doc.rust-lang.org/cargo/commands/cargo-build.html)] - `-DZENOHC_CUSTOM_TARGET`: specifies a crosscompilation target. Currently rust support several Tire-1, Tire-2 and Tire-3 targets [[targets](https://doc.rust-lang.org/nightly/rustc/platform-support.html)]. But keep in mind that zenoh-c only have support for following targets: `aarch64-unknown-linux-gnu`, `x86_64-unknown-linux-gnu`, `arm-unknown-linux-gnueabi` . Let's put all together in an example: Assuming you want to crosscompile for aarch64-unknown-linux-gnu. . 1. Install required packages - `sudo apt install gcc-aarch64-linux-gnu` 2. *(Only if you're using `nightly`) - `rustup component add rust-src --toolchain nightly` 3. Compile Zenoh-C. Assume that it's in `zenoh-c` directory. Notice that build in this sample is performed outside of source directory . ```bash export RUSTFLAGS="-Clinker=aarch64-linux-gnu-gcc -Car=aarch64-linux-gnu-ar" mkdir -p build && cd build cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+nightly" -DZENOHC_CARGO_FLAGS="-Zbuild-std=std,panic_abort" -DZENOHC_CUSTOM_TARGET="aarch64-unknown-linux-gnu" -DCMAKE_INSTALL_PREFIX=../aarch64/stage cmake --build . --target install ``` . Additionally you can use `RUSTFLAGS` environment variable for lead the compilation. . If all goes right the building files will be located at: `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` and release files will be located at `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` . ## Rust Version . The Rust version we use is defined in [rust-toolchain.toml](rust-toolchain.toml), which is `1.72.0`. There might be some memory mapping issue if you use the later version. . You can also specify the Rust version. . ```bash cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+1.72.0" ``` . ## Zenoh features support (enabling/disabling protocols, etc) . It's necessary sometimes to build zenoh-c library with set of features different from default. For example: enable TCP and UDP only. This can be done by changing `ZENOHC_CARGO_FLAGS` parameter for cmake (notice ";" instead of space due to cmake peculiarities) . Available features can be found in Zenoh [Cargo.toml](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/Cargo.toml) . ```bash cmake ../zenoh-c -DZENOHC_CARGO_FLAGS="--no-default-features;--features=zenoh/transport_tcp,zenoh/transport_udp" ``` Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-c Vcs-Git: https://github.com/eclipse-zenoh/zenoh-c Package: libzenohc-dev Version: 0.11.0 Architecture: armel Maintainer: zenoh-dev@eclipse.org Installed-Size: 173 Depends: libzenohc (=0.11.0) Filename: 0.11.0/libzenohc-dev_0.11.0_armel.deb Size: 32324 MD5sum: 196cc2693d549cae80f1fd9634f1b45d SHA1: b6cbf43c9560a182660f0268cb43a59b68c435f7 SHA256: 1ec9586f7788cb8e2d7db9562aa6fffb35470a7848156c81b730fb7151dd22db Section: net Priority: optional Homepage: http://zenoh.io Description: The Zenoh C API . [![CI](https://github.com/eclipse-zenoh/zenoh-c/workflows/CI/badge.svg)](https://github.com/eclipse-zenoh/zenoh-c/actions?query=workflow%3A%22CI%22) [![Documentation Status](https://readthedocs.org/projects/zenoh-c/badge/?version=latest)](https://zenoh-c.readthedocs.io/en/latest/?badge=latest) [![Discussion](https://img.shields.io/badge/discussion-on%20github-blue)](https://github.com/eclipse-zenoh/roadmap/discussions) [![Discord](https://img.shields.io/badge/chat-on%20discord-blue)](https://discord.gg/2GJ958VuHs) [![License](https://img.shields.io/badge/License-EPL%202.0-blue)](https://choosealicense.com/licenses/epl-2.0/) [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0) . # Eclipse Zenoh . The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute. . Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and computations. It carefully blends traditional pub/sub with geo-distributed storages, queries and computations, while retaining a level of time and space efficiency that is well beyond any of the mainstream stacks. . Check the website [zenoh.io](http://zenoh.io) and the [roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed information. . ------------------------------- . # C API . This repository provides a C binding based on the main [Zenoh implementation written in Rust](https://github.com/eclipse-zenoh/zenoh). . ------------------------------- . ## How to build it . > :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active development. When you build from git, make sure you also build from git any other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.). It may happen that some changes in git are not compatible with the most recent packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in maintaining compatibility between the various git repositories in the Zenoh project. . 1. Make sure that [Rust](https://www.rust-lang.org) is available on your platform. Please check [here](https://www.rust-lang.org/tools/install) to learn how to install it. If you already have the Rust toolchain installed, make sure it is up-to-date with: . ```bash rustup update ``` . 2. Clone the [source] with `git`: . ```bash git clone https://github.com/eclipse-zenoh/zenoh-c.git ``` . [source]: https://github.com/eclipse-zenoh/zenoh-c . 3. Build: . Good CMake practice is to perform build outside of source directory, leaving source tree untouched. The examples below demonstrates this mode of building. On the other hand VScode by default creates build directory named 'build' inside source tree. In this case build script slightly changes its behavior. See more about it in section 'VScode'. . By default build configuration is set to `Release`, it's not necessary to add `-DCMAKE_BUILD_TYPE=Release` option on configuration step. But if your platform uses multi-config generator by default (this is the case on Windows), you may need to add option `--config Release` on build step. See more in CMake [build-configurations] documentation. Option`--config Release` is skipped in further examples for brewity. It's actually necessary for [Visual Studio generators] only. For [Ninja Multi-Config] the build script is able to select `Release` as the default configuration. . ```bash mkdir -p build && cd build cmake ../zenoh-c cmake --build . --config Release ``` . The generator to use is selected with option `-G`. If Ninja is installed on your system, adding `-GNinja` to `cmake` command can greatly speed up the build time: . ```bash cmake ../zenoh-c -GNinja cmake --build . ``` . [build-configurations]: https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html#build-configurations [Visual Studio generators]: https://cmake.org/cmake/help/latest/manual/cmake-generators.7.html#id14 [Ninja Multi-Config]: https://cmake.org/cmake/help/latest/generator/Ninja%20Multi-Config.html . 4. Install: . To install zenoh-c library into system just build target `install`. You need root privileges to do it, as the default install location is `/usr/local`. . ```bash cmake --build . --target install ``` . If you want to install zenoh-c libraries locally, you can set the installation directory with `CMAKE_INSTALL_PREFIX` . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local cmake --build . --target install ``` . By default only dynamic library is installed. Set `ZENOHC_INSTALL_STATIC_LIBRARY` variable to true to install static library also: . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local -DZENOHC_INSTALL_STATIC_LIBRARY=TRUE cmake --build . --target install ``` . The result of installation is the header files in `include` directory, the library files in `lib` directory and cmake package configuration files for package `zenohc` in `lib/cmake` directory. The library later can be loaded with CMake command `find_package(zenohc)`. Add dependency in CMakeLists.txt on target . - `zenohc::shared` for linking dynamic library - `zenohc::static` for linking static library - `zenohc::lib` for linking static or dynamic library depending on boolean variable `ZENOHC_LIB_STATIC` . For `Debug` configuration the library package `zenohc_debug` is installed side-by-side with release `zenohc` library. Suffix `d` is added to names of library files (libzenohc**d**.so). . 5. VScode . When zenoh-c project is opened in VSCode the build directory is set to `build` inside source tree (this is default behavior of Microsoft [CMake Tools]). The project build script detects this situation. In this case it places build files in `target` directory and `Cargo.toml` file (which is generated from `Cargo.toml.in`) into the root of source tree, as the rust developers used to and as the rust build tools expects by default. This behavior also can be explicitly enabled by setting `ZENOHC_BUILD_IN_SOURCE_TREE` variable to `TRUE`. . [CMake Tools]: https://marketplace.visualstudio.com/items?itemName=ms-vscode.cmake-tools . ## Building the Examples . The examples can be built in two ways. One is to select `examples` as a build target of zenoh-c project (assuming here that the current directory is side-by-side with zenoh-c directory): . ```bash cmake ../zenoh-c cmake --build . --target examples ``` . You may also use `--target ` if you wish to only build a specific example. . All build artifacts will be in the `target/release/examples` directory in this case. . The second way is to directly build `examples` as a root project: . ```bash cmake ../zenoh-c/examples cmake --build . ``` . In this case, the examples executables will be built in the current directory. . As a root project the `examples` project links `zenoh-c` with CMake's [add_subdirectory] command by default. There are also other ways to link `zenoh-c` - with [find_package] or [FetchContent]: . [add_subdirectory]: https://cmake.org/cmake/help/latest/command/add_subdirectory.html [find_package]: https://cmake.org/cmake/help/latest/command/find_package.html [FetchContent]: https://cmake.org/cmake/help/latest/module/FetchContent.html . Link with `zenoh-c` installed into default location in the system (with [find_package]): . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE ``` . Link with `zenoh-c` installed in `~/.local` directory: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE -DCMAKE_INSTALL_PREFIX=~/.local ``` . Download specific `zenoh-c` version from git with [FetchContent]: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=GIT_URL -DZENOHC_GIT_TAG=0.11.0-rc ``` . See also `configure_include_project` function in [helpers.cmake] for more information . [helpers.cmake]: cmake/helpers.cmake . ## Running the Examples . ### Basic Pub/Sub Example . ```bash ./target/release/examples/z_sub ``` . ```bash ./target/release/examples/z_pub ``` . ### Queryable and Query Example . ```bash ./target/release/examples/z_queryable ``` . ```bash ./target/release/examples/z_get ``` . ### Running the Throughput Examples . ```bash ./target/release/examples/z_sub_thr ``` . ```bash ./target/release/examples/z_pub_thr ``` . ## API conventions . Most of the types exposed by the `zenoh-c` API are types for which destruction is necessary. To help you spot these types, we name them with the convention that any destructible type must start by `z_owned`. . For maximum performance, we try to make as few copies as possible. Sometimes, this implies moving data that you `z_owned`. Any function that takes a non-const pointer to a `z_owned` type will perform its destruction. To make this pattern more obvious, we encourage you to use the `z_move` macro instead of a simple `&` to create these pointers. Rest assured that all `z_owned` types are double-free safe, and that you may check whether any `z_owned_X_t` typed value is still valid by using `z_X_check(&val)`, or the `z_check(val)` macro if you're using C11. . We hope this convention will help you streamline your memory-safe usage of zenoh, as following it should make looking for leaks trivial: simply search for paths where a value of a `z_owned` type hasn't been passed to a function using `z_move`. . Functions that simply need to borrow your data will instead take values of the associated `z_X_t` type. You may construct them using `z_X_loan(&val)` (or the `z_loan(val)` generic macro with C11). . Note that some `z_X_t` typed values can be constructed without needing to `z_borrow` their owned variants. This allows you to reduce the amount of copies realized in your program. . The examples have been written with C11 in mind, using the conventions we encourage you to follow. . Finally, we strongly advise that you refrain from using structure field that starts with `_`: . - We try to maintain a common API between `zenoh-c` and [`zenoh-pico`](https://github.com/eclipse-zenoh/zenoh-pico), such that porting code from one to the other is, ideally, trivial. However, some types must have distinct representations in either library, meaning that using these representations explicitly will get you in trouble when porting. - We reserve the right to change the memory layout of any type which has `_`-prefixed fields, so trying to use them might cause your code to break on updates. . ## Logging . By default, zenoh-c enables Zenoh's logging library upon using the `z_open` or `z_scout` functions. This behavior can be disabled by adding `-DDISABLE_LOGGER_AUTOINIT:bool=true` to the `cmake` configuration command. The logger may then be manually re-enabled with the `zc_init_logger` function. . ## Cross-Compilation . The following alternative options have been introduced to facilitate cross-compilation. > :warning: **WARNING** :warning: : Perhaps additional efforts are necessary, that will depend of your environment. . - `-DZENOHC_CARGO_CHANNEL="+nightly"|"+beta"|"+stable"`: refers to a specific rust toolchain release [[rust-channels](https://rust-lang.github.io/rustup/concepts/channels.html)] - `-DZENOHC_CARGO_FLAGS`: several optional flags can be used for compilation. [[cargo flags](https://doc.rust-lang.org/cargo/commands/cargo-build.html)] - `-DZENOHC_CUSTOM_TARGET`: specifies a crosscompilation target. Currently rust support several Tire-1, Tire-2 and Tire-3 targets [[targets](https://doc.rust-lang.org/nightly/rustc/platform-support.html)]. But keep in mind that zenoh-c only have support for following targets: `aarch64-unknown-linux-gnu`, `x86_64-unknown-linux-gnu`, `arm-unknown-linux-gnueabi` . Let's put all together in an example: Assuming you want to crosscompile for aarch64-unknown-linux-gnu. . 1. Install required packages - `sudo apt install gcc-aarch64-linux-gnu` 2. *(Only if you're using `nightly`) - `rustup component add rust-src --toolchain nightly` 3. Compile Zenoh-C. Assume that it's in `zenoh-c` directory. Notice that build in this sample is performed outside of source directory . ```bash export RUSTFLAGS="-Clinker=aarch64-linux-gnu-gcc -Car=aarch64-linux-gnu-ar" mkdir -p build && cd build cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+nightly" -DZENOHC_CARGO_FLAGS="-Zbuild-std=std,panic_abort" -DZENOHC_CUSTOM_TARGET="aarch64-unknown-linux-gnu" -DCMAKE_INSTALL_PREFIX=../aarch64/stage cmake --build . --target install ``` . Additionally you can use `RUSTFLAGS` environment variable for lead the compilation. . If all goes right the building files will be located at: `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` and release files will be located at `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` . ## Rust Version . The Rust version we use is defined in [rust-toolchain.toml](rust-toolchain.toml), which is `1.72.0`. There might be some memory mapping issue if you use the later version. . You can also specify the Rust version. . ```bash cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+1.72.0" ``` . ## Zenoh features support (enabling/disabling protocols, etc) . It's necessary sometimes to build zenoh-c library with set of features different from default. For example: enable TCP and UDP only. This can be done by changing `ZENOHC_CARGO_FLAGS` parameter for cmake (notice ";" instead of space due to cmake peculiarities) . Available features can be found in Zenoh [Cargo.toml](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/Cargo.toml) . ```bash cmake ../zenoh-c -DZENOHC_CARGO_FLAGS="--no-default-features;--features=zenoh/transport_tcp,zenoh/transport_udp" ``` Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-c Vcs-Git: https://github.com/eclipse-zenoh/zenoh-c Package: libzenohc-dev Version: 0.11.0 Architecture: arm64 Maintainer: zenoh-dev@eclipse.org Installed-Size: 173 Depends: libzenohc (=0.11.0) Filename: 0.11.0/libzenohc-dev_0.11.0_arm64.deb Size: 32324 MD5sum: 5398380d8ec4b61ce7caddb47afc8fc6 SHA1: 3f51c2088c1716807a9e00ee8ed58c662ec8466d SHA256: 6d9a188472a51092f329d3595f90817d515f772af79245fe2c22ea7e42093689 Section: net Priority: optional Homepage: http://zenoh.io Description: The Zenoh C API . [![CI](https://github.com/eclipse-zenoh/zenoh-c/workflows/CI/badge.svg)](https://github.com/eclipse-zenoh/zenoh-c/actions?query=workflow%3A%22CI%22) [![Documentation Status](https://readthedocs.org/projects/zenoh-c/badge/?version=latest)](https://zenoh-c.readthedocs.io/en/latest/?badge=latest) [![Discussion](https://img.shields.io/badge/discussion-on%20github-blue)](https://github.com/eclipse-zenoh/roadmap/discussions) [![Discord](https://img.shields.io/badge/chat-on%20discord-blue)](https://discord.gg/2GJ958VuHs) [![License](https://img.shields.io/badge/License-EPL%202.0-blue)](https://choosealicense.com/licenses/epl-2.0/) [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0) . # Eclipse Zenoh . The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute. . Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and computations. It carefully blends traditional pub/sub with geo-distributed storages, queries and computations, while retaining a level of time and space efficiency that is well beyond any of the mainstream stacks. . Check the website [zenoh.io](http://zenoh.io) and the [roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed information. . ------------------------------- . # C API . This repository provides a C binding based on the main [Zenoh implementation written in Rust](https://github.com/eclipse-zenoh/zenoh). . ------------------------------- . ## How to build it . > :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active development. When you build from git, make sure you also build from git any other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.). It may happen that some changes in git are not compatible with the most recent packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in maintaining compatibility between the various git repositories in the Zenoh project. . 1. Make sure that [Rust](https://www.rust-lang.org) is available on your platform. Please check [here](https://www.rust-lang.org/tools/install) to learn how to install it. If you already have the Rust toolchain installed, make sure it is up-to-date with: . ```bash rustup update ``` . 2. Clone the [source] with `git`: . ```bash git clone https://github.com/eclipse-zenoh/zenoh-c.git ``` . [source]: https://github.com/eclipse-zenoh/zenoh-c . 3. Build: . Good CMake practice is to perform build outside of source directory, leaving source tree untouched. The examples below demonstrates this mode of building. On the other hand VScode by default creates build directory named 'build' inside source tree. In this case build script slightly changes its behavior. See more about it in section 'VScode'. . By default build configuration is set to `Release`, it's not necessary to add `-DCMAKE_BUILD_TYPE=Release` option on configuration step. But if your platform uses multi-config generator by default (this is the case on Windows), you may need to add option `--config Release` on build step. See more in CMake [build-configurations] documentation. Option`--config Release` is skipped in further examples for brewity. It's actually necessary for [Visual Studio generators] only. For [Ninja Multi-Config] the build script is able to select `Release` as the default configuration. . ```bash mkdir -p build && cd build cmake ../zenoh-c cmake --build . --config Release ``` . The generator to use is selected with option `-G`. If Ninja is installed on your system, adding `-GNinja` to `cmake` command can greatly speed up the build time: . ```bash cmake ../zenoh-c -GNinja cmake --build . ``` . [build-configurations]: https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html#build-configurations [Visual Studio generators]: https://cmake.org/cmake/help/latest/manual/cmake-generators.7.html#id14 [Ninja Multi-Config]: https://cmake.org/cmake/help/latest/generator/Ninja%20Multi-Config.html . 4. Install: . To install zenoh-c library into system just build target `install`. You need root privileges to do it, as the default install location is `/usr/local`. . ```bash cmake --build . --target install ``` . If you want to install zenoh-c libraries locally, you can set the installation directory with `CMAKE_INSTALL_PREFIX` . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local cmake --build . --target install ``` . By default only dynamic library is installed. Set `ZENOHC_INSTALL_STATIC_LIBRARY` variable to true to install static library also: . ```bash cmake ../zenoh-c -DCMAKE_INSTALL_PREFIX=~/.local -DZENOHC_INSTALL_STATIC_LIBRARY=TRUE cmake --build . --target install ``` . The result of installation is the header files in `include` directory, the library files in `lib` directory and cmake package configuration files for package `zenohc` in `lib/cmake` directory. The library later can be loaded with CMake command `find_package(zenohc)`. Add dependency in CMakeLists.txt on target . - `zenohc::shared` for linking dynamic library - `zenohc::static` for linking static library - `zenohc::lib` for linking static or dynamic library depending on boolean variable `ZENOHC_LIB_STATIC` . For `Debug` configuration the library package `zenohc_debug` is installed side-by-side with release `zenohc` library. Suffix `d` is added to names of library files (libzenohc**d**.so). . 5. VScode . When zenoh-c project is opened in VSCode the build directory is set to `build` inside source tree (this is default behavior of Microsoft [CMake Tools]). The project build script detects this situation. In this case it places build files in `target` directory and `Cargo.toml` file (which is generated from `Cargo.toml.in`) into the root of source tree, as the rust developers used to and as the rust build tools expects by default. This behavior also can be explicitly enabled by setting `ZENOHC_BUILD_IN_SOURCE_TREE` variable to `TRUE`. . [CMake Tools]: https://marketplace.visualstudio.com/items?itemName=ms-vscode.cmake-tools . ## Building the Examples . The examples can be built in two ways. One is to select `examples` as a build target of zenoh-c project (assuming here that the current directory is side-by-side with zenoh-c directory): . ```bash cmake ../zenoh-c cmake --build . --target examples ``` . You may also use `--target ` if you wish to only build a specific example. . All build artifacts will be in the `target/release/examples` directory in this case. . The second way is to directly build `examples` as a root project: . ```bash cmake ../zenoh-c/examples cmake --build . ``` . In this case, the examples executables will be built in the current directory. . As a root project the `examples` project links `zenoh-c` with CMake's [add_subdirectory] command by default. There are also other ways to link `zenoh-c` - with [find_package] or [FetchContent]: . [add_subdirectory]: https://cmake.org/cmake/help/latest/command/add_subdirectory.html [find_package]: https://cmake.org/cmake/help/latest/command/find_package.html [FetchContent]: https://cmake.org/cmake/help/latest/module/FetchContent.html . Link with `zenoh-c` installed into default location in the system (with [find_package]): . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE ``` . Link with `zenoh-c` installed in `~/.local` directory: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=PACKAGE -DCMAKE_INSTALL_PREFIX=~/.local ``` . Download specific `zenoh-c` version from git with [FetchContent]: . ```bash cmake ../zenoh-c/examples -DZENOHC_SOURCE=GIT_URL -DZENOHC_GIT_TAG=0.11.0-rc ``` . See also `configure_include_project` function in [helpers.cmake] for more information . [helpers.cmake]: cmake/helpers.cmake . ## Running the Examples . ### Basic Pub/Sub Example . ```bash ./target/release/examples/z_sub ``` . ```bash ./target/release/examples/z_pub ``` . ### Queryable and Query Example . ```bash ./target/release/examples/z_queryable ``` . ```bash ./target/release/examples/z_get ``` . ### Running the Throughput Examples . ```bash ./target/release/examples/z_sub_thr ``` . ```bash ./target/release/examples/z_pub_thr ``` . ## API conventions . Most of the types exposed by the `zenoh-c` API are types for which destruction is necessary. To help you spot these types, we name them with the convention that any destructible type must start by `z_owned`. . For maximum performance, we try to make as few copies as possible. Sometimes, this implies moving data that you `z_owned`. Any function that takes a non-const pointer to a `z_owned` type will perform its destruction. To make this pattern more obvious, we encourage you to use the `z_move` macro instead of a simple `&` to create these pointers. Rest assured that all `z_owned` types are double-free safe, and that you may check whether any `z_owned_X_t` typed value is still valid by using `z_X_check(&val)`, or the `z_check(val)` macro if you're using C11. . We hope this convention will help you streamline your memory-safe usage of zenoh, as following it should make looking for leaks trivial: simply search for paths where a value of a `z_owned` type hasn't been passed to a function using `z_move`. . Functions that simply need to borrow your data will instead take values of the associated `z_X_t` type. You may construct them using `z_X_loan(&val)` (or the `z_loan(val)` generic macro with C11). . Note that some `z_X_t` typed values can be constructed without needing to `z_borrow` their owned variants. This allows you to reduce the amount of copies realized in your program. . The examples have been written with C11 in mind, using the conventions we encourage you to follow. . Finally, we strongly advise that you refrain from using structure field that starts with `_`: . - We try to maintain a common API between `zenoh-c` and [`zenoh-pico`](https://github.com/eclipse-zenoh/zenoh-pico), such that porting code from one to the other is, ideally, trivial. However, some types must have distinct representations in either library, meaning that using these representations explicitly will get you in trouble when porting. - We reserve the right to change the memory layout of any type which has `_`-prefixed fields, so trying to use them might cause your code to break on updates. . ## Logging . By default, zenoh-c enables Zenoh's logging library upon using the `z_open` or `z_scout` functions. This behavior can be disabled by adding `-DDISABLE_LOGGER_AUTOINIT:bool=true` to the `cmake` configuration command. The logger may then be manually re-enabled with the `zc_init_logger` function. . ## Cross-Compilation . The following alternative options have been introduced to facilitate cross-compilation. > :warning: **WARNING** :warning: : Perhaps additional efforts are necessary, that will depend of your environment. . - `-DZENOHC_CARGO_CHANNEL="+nightly"|"+beta"|"+stable"`: refers to a specific rust toolchain release [[rust-channels](https://rust-lang.github.io/rustup/concepts/channels.html)] - `-DZENOHC_CARGO_FLAGS`: several optional flags can be used for compilation. [[cargo flags](https://doc.rust-lang.org/cargo/commands/cargo-build.html)] - `-DZENOHC_CUSTOM_TARGET`: specifies a crosscompilation target. Currently rust support several Tire-1, Tire-2 and Tire-3 targets [[targets](https://doc.rust-lang.org/nightly/rustc/platform-support.html)]. But keep in mind that zenoh-c only have support for following targets: `aarch64-unknown-linux-gnu`, `x86_64-unknown-linux-gnu`, `arm-unknown-linux-gnueabi` . Let's put all together in an example: Assuming you want to crosscompile for aarch64-unknown-linux-gnu. . 1. Install required packages - `sudo apt install gcc-aarch64-linux-gnu` 2. *(Only if you're using `nightly`) - `rustup component add rust-src --toolchain nightly` 3. Compile Zenoh-C. Assume that it's in `zenoh-c` directory. Notice that build in this sample is performed outside of source directory . ```bash export RUSTFLAGS="-Clinker=aarch64-linux-gnu-gcc -Car=aarch64-linux-gnu-ar" mkdir -p build && cd build cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+nightly" -DZENOHC_CARGO_FLAGS="-Zbuild-std=std,panic_abort" -DZENOHC_CUSTOM_TARGET="aarch64-unknown-linux-gnu" -DCMAKE_INSTALL_PREFIX=../aarch64/stage cmake --build . --target install ``` . Additionally you can use `RUSTFLAGS` environment variable for lead the compilation. . If all goes right the building files will be located at: `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` and release files will be located at `/path/to/zenoh-c/target/aarch64-unknown-linux-gnu/release` . ## Rust Version . The Rust version we use is defined in [rust-toolchain.toml](rust-toolchain.toml), which is `1.72.0`. There might be some memory mapping issue if you use the later version. . You can also specify the Rust version. . ```bash cmake ../zenoh-c -DZENOHC_CARGO_CHANNEL="+1.72.0" ``` . ## Zenoh features support (enabling/disabling protocols, etc) . It's necessary sometimes to build zenoh-c library with set of features different from default. For example: enable TCP and UDP only. This can be done by changing `ZENOHC_CARGO_FLAGS` parameter for cmake (notice ";" instead of space due to cmake peculiarities) . Available features can be found in Zenoh [Cargo.toml](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/Cargo.toml) . ```bash cmake ../zenoh-c -DZENOHC_CARGO_FLAGS="--no-default-features;--features=zenoh/transport_tcp,zenoh/transport_udp" ``` Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-c Vcs-Git: https://github.com/eclipse-zenoh/zenoh-c