adding more elaborate example

Author: lemire

cppcon2025/software/CMakeLists.txt

@@ -1,17 +1,53 @@
-
 cmake_minimum_required(VERSION 3.16)
 project(cppcon2025)
 
-set(CMAKE_CXX_STANDARD 23)
+add_compile_options(-freflection -fexpansion-statements 
+ $<$<COMPILE_LANGUAGE:CXX>:-stdlib=libc++>
+ $<$<COMPILE_LANGUAGE:CXX>:-std=c++26>)
+add_definitions(-DSIMDJSON_STATIC_REFLECTION=1)
 
 add_executable(player_demo main.cpp)
 
 
 include(cmake/CPM.cmake)
 CPMAddPackage("gh:nlohmann/[email protected]")
-CPMAddPackage("gh:fmtlib/fmt#11.2.0")
+CPMAddPackage(
+    NAME fmt
+    GITHUB_REPOSITORY fmtlib/fmt
+    GIT_TAG 18e160eb4c2e9f5c750f5eb11ab13be44aa8de78
+)
+
+CPMAddPackage(
+    NAME simdjson
+    GITHUB_REPOSITORY simdjson/simdjson
+    GIT_TAG 015daad6a95a4f67c08ed5980d24b57be221c38f
+    OPTIONS "SIMDJSON_STATIC_REFLECTION=ON"
+)
+
+CPMAddPackage(
+    NAME cURL
+    VERSION 8.15.0
+    GIT_TAG tags/curl-8_15_0
+    GITHUB_REPOSITORY curl/curl
+    OPTIONS
+        "BUILD_CURL_EXE OFF"
+        "CURL_USE_OPENSSL ON"
+        "CURL_ENABLE_SSL ON"
+        "CURL_DISABLE_INSTALL ON"
+        "CURL_DISABLE_DIGEST_AUTH ON"
+        "CURL_DISABLE_KERBEROS_AUTH ON"
+        "CURL_DISABLE_NEGOTIATE_AUTH ON"
+        "CURL_USE_LIBPSL OFF"
+)
 
 target_link_libraries(player_demo PRIVATE nlohmann_json::nlohmann_json)
+target_link_libraries(player_demo PRIVATE simdjson)
 
 
 target_link_libraries(player_demo PRIVATE fmt::fmt)
+add_executable(webservice webservice.cpp)
+#@target_compile_options(webservice PRIVATE -freflection -fexpansion-statements -stdlib=libc++ -std=c++26)
+target_link_libraries(webservice PRIVATE libcurl)
+target_link_libraries(webservice PRIVATE fmt::fmt)
+target_link_libraries(webservice PRIVATE simdjson::simdjson)
+#target_compile_definitions(webservice PRIVATE SIMDJSON_STATIC_REFLECTION=1)

cppcon2025/software/Dockerfile

@@ -0,0 +1,46 @@
+# Stage 1. Check out LLVM source code and run the build.
+FROM debian:12 AS builder
+# First, Update the apt's source list and include the sources of the packages.
+RUN grep deb /etc/apt/sources.list | \
+    sed 's/^deb/deb-src /g' >> /etc/apt/sources.list
+# Install compiler, python and subversion.
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends ca-certificates gnupg \
+           build-essential cmake make python3 zlib1g wget subversion unzip ninja-build git linux-perf && \
+    rm -rf /var/lib/apt/lists/*
+ARG CLANG_COMMIT=d77eff1cbd78fd065668acf93b1f5f400d39134d
+RUN git clone --depth=1 https://github.com/bloomberg/clang-p2996.git /tmp/clang-source && \
+    cd /tmp/clang-source && \
+    git fetch origin $CLANG_COMMIT --depth=1 && \
+    git checkout $CLANG_COMMIT
+RUN cmake -S /tmp/clang-source/llvm -B /tmp/clang-source/build-llvm -DCMAKE_BUILD_TYPE=Release \
+    -DLLVM_ENABLE_ASSERTIONS=ON \
+    -DLLVM_UNREACHABLE_OPTIMIZE=ON \
+    -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi;libunwind" \
+    -DCLANG_DEFAULT_CXX_STDLIB=libc++ \
+    -DLLVM_ENABLE_PROJECTS=clang -G Ninja
+RUN cmake --build /tmp/clang-source/build-llvm -j
+RUN cmake --install /tmp/clang-source/build-llvm --prefix /tmp/clang-install
+
+
+# Stage 2. Produce a minimal release image with build results.
+FROM debian:12
+ARG USER_NAME
+ARG USER_ID
+ARG GROUP_ID
+LABEL maintainer "LLVM Developers"
+# Install packages for minimal useful image.
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends build-essential  ca-certificates rust-all libcurl4-openssl-dev cmake make wget python3 python3-dev sudo curl ninja-build vim git binutils linux-perf && \
+    rm -rf /var/lib/apt/lists/*
+# Copy build results of stage 1 to /usr/local.
+COPY --from=builder /tmp/clang-install/ /usr/local/
+RUN P=`/usr/local/bin/clang++ -v 2>&1 | grep Target | cut -d' ' -f2-`; echo /usr/local/lib/$P > /etc/ld.so.conf.d/$P.conf
+RUN ldconfig
+RUN addgroup --gid $GROUP_ID user; exit 0
+RUN adduser --disabled-password --gecos '' --uid $USER_ID --gid $GROUP_ID $USER_NAME; exit 0
+RUN echo "$USER_NAME:$USER_NAME" | chpasswd && adduser $USER_NAME sudo
+RUN echo '----->'
+RUN echo 'root:Docker!' | chpasswd
+ENV TERM xterm-256color
+USER $USER_NAME

cppcon2025/software/README.md

@@ -12,19 +12,35 @@ struct Player {
 };
 ```
 
+## Use docker
+
+```sh
+./run_docker.sh
+```
+
+## Install OpenSLL
+
+Your password is your username.
+
+```
+sudo apt update
+sudo apt-get install libssl-dev -y
+```
+
 ## Compilation
 
+While in the `software` directory.
+
 ```sh
-cd software
-cmake -B build
+
+CXX=clang++ CC=clang cmake -B build
 cmake --build build
 ```
 
 ## Exécution
 
 ```sh
 ./build/player_demo
+./build/webservice
 ```
 
-## Dépendance
-La bibliothèque nlohmann/json est récupérée automatiquement via CMake FetchContent.

cppcon2025/software/run_docker.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+
+if [ -z "$1" ]
+  then
+    echo "The run-docker-station script takes a command as a argument. E.g., try ./run-docker-station 'ls' "
+    exit 1
+fi
+
+set -o noglob
+SCRIPTPATH="$( cd "$(dirname "$0")" ; pwd -P )"
+
+COMMAND=$@
+
+tuser=$(echo $USER | tr -dc 'a-z')
+
+container_name=${CONTAINER_NAME:-"debian12-clang-p2996-programming_station-for-$tuser-simdjson"}
+
+command -v docker >/dev/null 2>&1 || { echo >&2 "Please install docker. E.g., go to https://www.docker.com/products/docker-desktop Type 'docker' to diagnose the problem."; exit 1; }
+
+docker info >/dev/null 2>&1 || { echo >&2 "Docker server is not running? type 'docker info'."; exit 1; }
+
+SSHPARAM=""
+[ -e "${SSH_AUTH_SOCK}" ] && SSHPARAM="--volume /run/host-services/ssh-auth.sock:/run/host-services/ssh-auth.sock  --env SSH_AUTH_SOCK=/run/host-services/ssh-auth.sock"
+[ -e "${HOME}/.ssh" ] && SSHPARAM="--volume ${HOME}/.ssh:/home/$tuser/.ssh:ro"
+
+
+docker image inspect $container_name >/dev/null 2>&1 || ( echo "instantiating the container" ; docker build --no-cache -t $container_name -f $SCRIPTPATH/Dockerfile --build-arg USER_NAME="$tuser"  --build-arg USER_ID=$(id -u)  --build-arg GROUP_ID=$(id -g) .  )
+
+if [ -t 0 ]; then DOCKER_ARGS=-it; fi
+docker run --rm $DOCKER_ARGS -h $container_name $SSHPARAM -v $(pwd):$(pwd):Z --privileged  -w $(pwd)  $container_name sh -c "$COMMAND"

cppcon2025/software/webservice.cpp

@@ -0,0 +1,62 @@
+#include <string>
+#include <vector>
+#include <curl/curl.h>
+#include <cstdlib>
+#include <fmt/core.h>
+#include <fmt/format.h>
+#include <simdjson.h>
+
+#if !SIMDJSON_STATIC_REFLECTION
+#error "You need to enable static reflection for this to work"
+#endif
+
+
+struct weather_data {
+    std::vector<std::string> time;
+    std::vector<float> temperature_2m;
+    std::vector<float> relative_humidity_2m;
+    std::vector<float> winddirection_10m;
+    std::vector<float> precipitation;
+    std::vector<float> windspeed_10m;
+};
+
+std::string grab_weather_data(const std::string& latitude, const std::string& longitude) {
+    std::string url = fmt::format("https://api.open-meteo.com/v1/forecast?latitude={}&longitude={}&hourly=temperature_2m,relative_humidity_2m,winddirection_10m,precipitation,windspeed_10m", latitude, longitude);
+    CURL *curl = curl_easy_init();
+    if (!curl) {
+        throw std::runtime_error("Could not initialize cURL");
+    }
+    std::string response_data;
+    curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
+    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, +[](char *ptr, size_t size, size_t nmemb, void *userdata) -> size_t {
+        auto *str = static_cast<std::string*>(userdata);
+        str->append(ptr, size * nmemb);
+        return size * nmemb;
+    });
+    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response_data);
+    CURLcode res = curl_easy_perform(curl);
+    if (res != CURLE_OK) {
+        curl_easy_cleanup(curl);
+        throw std::runtime_error("Request failed cURL: " + std::string(curl_easy_strerror(res)));
+    }
+    curl_easy_cleanup(curl);
+    return response_data;
+}
+
+int main() {
+    std::string weather_data_str = grab_weather_data("45.5017", "-73.5673");
+    simdjson::ondemand::parser parser;
+    simdjson::ondemand::document doc = parser.iterate(simdjson::pad(weather_data_str));
+    weather_data wd = doc["hourly"].get<weather_data>();
+    // Assuming all vectors have the same length
+    for (size_t i = 0; i < wd.time.size(); ++i) {
+        fmt::print("Time: {}, Temperature: {:.1f}°C, Humidity: {:.1f}%, Wind Direction: {:.1f}°, Precipitation: {:.1f}mm, Wind Speed: {:.1f}km/h\n",
+            wd.time[i],
+            wd.temperature_2m[i],
+            wd.relative_humidity_2m[i],
+            wd.winddirection_10m[i],
+            wd.precipitation[i],
+            wd.windspeed_10m[i]);
+    }
+    return EXIT_SUCCESS;
+}