add c++ example

examples/cpp/CMakeLists.txt

@@ -2,6 +2,7 @@ add_subdirectory(clock)
 add_subdirectory(custom_collection_adapter)
 add_subdirectory(dna)
 add_subdirectory(external_data_loader)
+add_subdirectory(log_file)
 add_subdirectory(minimal)
 add_subdirectory(shared_recording)
 add_subdirectory(spawn_viewer)
@@ -12,6 +13,7 @@ add_custom_target(examples)
 add_dependencies(examples example_clock)
 add_dependencies(examples example_custom_collection_adapter)
 add_dependencies(examples example_dna)
+add_dependencies(examples example_log_file)
 add_dependencies(examples example_minimal)
 add_dependencies(examples example_shared_recording)
 add_dependencies(examples example_spawn_viewer)

examples/cpp/log_file/CMakeLists.txt

@@ -0,0 +1,32 @@
+cmake_minimum_required(VERSION 3.16...3.27)
+
+# If you use the example outside of the Rerun SDK you need to specify
+# where the rerun_c build is to be found by setting the `RERUN_CPP_URL` variable.
+# This can be done by passing `-DRERUN_CPP_URL=<path to rerun_sdk_cpp zip>` to cmake.
+if(DEFINED RERUN_REPOSITORY)
+    add_executable(example_log_file main.cpp)
+    rerun_strict_warning_settings(example_log_file)
+else()
+    project(example_log_file LANGUAGES CXX)
+
+    add_executable(example_log_file main.cpp)
+
+    # Set the path to the rerun_c build.
+    set(RERUN_CPP_URL "https://github.com/rerun-io/rerun/releases/latest/download/rerun_cpp_sdk.zip" CACHE STRING "URL to the rerun_cpp zip.")
+    option(RERUN_FIND_PACKAGE "Whether to use find_package to find a preinstalled rerun package (instead of using FetchContent)." OFF)
+
+    if(RERUN_FIND_PACKAGE)
+        find_package(rerun_sdk REQUIRED)
+    else()
+        # Download the rerun_sdk
+        include(FetchContent)
+        FetchContent_Declare(rerun_sdk URL ${RERUN_CPP_URL})
+        FetchContent_MakeAvailable(rerun_sdk)
+    endif()
+
+    # Rerun requires at least C++17, but it should be compatible with newer versions.
+    set_property(TARGET example_log_file PROPERTY CXX_STANDARD 17)
+endif()
+
+# Link against rerun_sdk.
+target_link_libraries(example_log_file PRIVATE rerun_sdk)

examples/cpp/log_file/README.md

@@ -0,0 +1,12 @@
+<!--[metadata]
+title = "Log file example"
+-->
+
+Demonstrates how to log any file from the SDK using the [`DataLoader`](https://www.rerun.io/docs/howto/open-any-file) machinery.
+
+To build it from a checkout of the repository (requires a Rust toolchain):
+```bash
+cmake .
+cmake --build . --target example_log_file
+./examples/cpp/log_file/example_log_file examples/assets/
+```

examples/cpp/log_file/main.cpp

@@ -0,0 +1,73 @@
+#include <filesystem>
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <string>
+
+#include <rerun.hpp>
+#include <rerun/third_party/cxxopts.hpp>
+
+int main(int argc, char** argv) {
+    // Create a new `RecordingStream` which sends data over TCP to the viewer process.
+    const auto rec = rerun::RecordingStream("rerun_example_log_file");
+
+    cxxopts::Options options(
+        "rerun_example_log_file",
+        "Demonstrates how to log any file from the SDK using the `DataLoader` machinery."
+    );
+
+    // clang-format off
+    options.add_options()
+      ("h,help", "Print usage")
+      // Rerun
+      ("spawn", "Start a new Rerun Viewer process and feed it data in real-time")
+      ("connect", "Connects and sends the logged data to a remote Rerun viewer")
+      ("save", "Log data to an rrd file", cxxopts::value<std::string>())
+      ("stdout", "Log data to standard output, to be piped into a Rerun Viewer")
+      // Example
+      ("from-contents", "Log the contents of the file directly (files only -- not supported by external loaders)", cxxopts::value<bool>()->default_value("false"))
+      ("filepaths", "The filepaths to be loaded and logged", cxxopts::value<std::vector<std::string>>())
+    ;
+    // clang-format on
+
+    options.parse_positional({"filepaths"});
+
+    auto args = options.parse(argc, argv);
+
+    if (args.count("help")) {
+        std::cout << options.help() << std::endl;
+        exit(0);
+    }
+
+    // TODO(#4602): need common rerun args helper library
+    if (args["spawn"].as<bool>()) {
+        rec.spawn().exit_on_failure();
+    } else if (args["connect"].as<bool>()) {
+        rec.connect().exit_on_failure();
+    } else if (args["stdout"].as<bool>()) {
+        rec.to_stdout().exit_on_failure();
+    } else if (args.count("save")) {
+        rec.save(args["save"].as<std::string>()).exit_on_failure();
+    } else {
+        rec.spawn().exit_on_failure();
+    }
+
+    const auto from_contents = args["from-contents"].as<bool>();
+    if (args.count("filepaths")) {
+        const auto filepaths = args["filepaths"].as<std::vector<std::string>>();
+        for (const auto& filepath : filepaths) {
+            if (!from_contents) {
+                // Either log the file using its path…
+                rec.log_file_from_path(filepath);
+            } else {
+                // …or using its contents if you already have them loaded for some reason.
+                if (std::filesystem::is_regular_file(filepath)) {
+                    std::ifstream file(filepath);
+                    std::stringstream contents;
+                    contents << file.rdbuf();
+                    rec.log_file_from_contents(filepath, contents.str());
+                }
+            }
+        }
+    }
+}