Utils: Add curl easy handle utility class

3 files changed, 265 insertions, 0 deletions

diff --git a/src/utils/cpp/TARGETS b/src/utils/cpp/TARGETS
index 82177208..e278210e 100644
--- a/src/utils/cpp/TARGETS
+++ b/src/utils/cpp/TARGETS
@@ -66,4 +66,17 @@
   , "stage": ["src", "utils", "cpp"]
   , "private-deps": [["src/buildtool/logging", "logging"], ["", "libcurl"]]
   }
+, "curl_easy_handle":
+  { "type": ["@", "rules", "CC", "library"]
+  , "name": ["curl_easy_handle"]
+  , "hdrs": ["curl_easy_handle.hpp"]
+  , "srcs": ["curl_easy_handle.cpp"]
+  , "deps": ["curl_context", ["@", "gsl-lite", "", "gsl-lite"]]
+  , "stage": ["src", "utils", "cpp"]
+  , "private-deps":
+    [ ["src/buildtool/logging", "logging"]
+    , ["src/buildtool/file_system", "file_system_manager"]
+    , ["", "libcurl"]
+    ]
+  }
 }
diff --git a/src/utils/cpp/curl_easy_handle.cpp b/src/utils/cpp/curl_easy_handle.cpp
new file mode 100644
index 00000000..c823890d
--- /dev/null
+++ b/src/utils/cpp/curl_easy_handle.cpp
@@ -0,0 +1,166 @@
+// Copyright 2022 Huawei Cloud Computing Technology Co., Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "src/utils/cpp/curl_easy_handle.hpp"
+
+#include <fstream>
+
+#include "src/buildtool/file_system/file_system_manager.hpp"
+#include "src/buildtool/logging/logger.hpp"
+
+#ifndef BOOTSTRAP_BUILD_TOOL
+extern "C" {
+#include "curl/curl.h"
+}
+#endif  // BOOTSTRAP_BUILD_TOOL
+
+void curl_easy_closer(gsl::owner<CURL*> curl) {
+#ifndef BOOTSTRAP_BUILD_TOOL
+    curl_easy_cleanup(curl);
+#endif  // BOOTSTRAP_BUILD_TOOL
+}
+
+auto CurlEasyHandle::Create() noexcept -> std::shared_ptr<CurlEasyHandle> {
+#ifdef BOOTSTRAP_BUILD_TOOL
+    return nullptr;
+#else
+    try {
+        auto curl = std::make_shared<CurlEasyHandle>();
+        auto* handle = curl_easy_init();
+        if (handle == nullptr) {
+            return nullptr;
+        }
+        curl->handle_.reset(handle);
+        return curl;
+    } catch (std::exception const& ex) {
+        Logger::Log(LogLevel::Error,
+                    "create curl easy handle failed with:\n{}",
+                    ex.what());
+        return nullptr;
+    }
+#endif  // BOOTSTRAP_BUILD_TOOL
+}
+
+auto CurlEasyHandle::EasyWriteToFile(gsl::owner<char*> data,
+                                     size_t size,
+                                     size_t nmemb,
+                                     gsl::owner<void*> userptr)
+    -> std::streamsize {
+#ifdef BOOTSTRAP_BUILD_TOOL
+    return 0;
+#else
+    auto actual_size = static_cast<std::streamsize>(size * nmemb);
+    auto* file = static_cast<std::ofstream*>(userptr);
+    file->write(data, actual_size);  // append chunk
+    return actual_size;
+#endif  // BOOTSTRAP_BUILD_TOOL
+}
+
+auto CurlEasyHandle::EasyWriteToString(gsl::owner<char*> data,
+                                       size_t size,
+                                       size_t nmemb,
+                                       gsl::owner<void*> userptr)
+    -> std::streamsize {
+#ifdef BOOTSTRAP_BUILD_TOOL
+    return 0;
+#else
+    (static_cast<std::string*>(userptr))->append(data, size * nmemb);
+    return static_cast<std::streamsize>(size * nmemb);
+#endif  // BOOTSTRAP_BUILD_TOOL
+}
+
+auto CurlEasyHandle::DownloadToFile(
+    std::string const& url,
+    std::filesystem::path const& file_path) noexcept -> int {
+#ifdef BOOTSTRAP_BUILD_TOOL
+    return 1;
+#else
+    try {
+        // set URL
+        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg, hicpp-vararg)
+        curl_easy_setopt(handle_.get(), CURLOPT_URL, url.c_str());
+
+        // set callback for writing to file
+        std::ofstream file(file_path.c_str(), std::ios::binary);
+
+        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg, hicpp-vararg)
+        curl_easy_setopt(handle_.get(), CURLOPT_WRITEFUNCTION, EasyWriteToFile);
+        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg, hicpp-vararg)
+        curl_easy_setopt(
+            handle_.get(), CURLOPT_WRITEDATA, static_cast<void*>(&file));
+
+        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg, hicpp-vararg)
+        curl_easy_setopt(handle_.get(), CURLOPT_VERBOSE, 1);
+
+        // perform download
+        auto res = curl_easy_perform(handle_.get());
+
+        // close file
+        file.close();
+
+        // check result
+        if (res != CURLE_OK) {
+            // cleanup failed downloaded file, if created
+            [[maybe_unused]] auto tmp_res =
+                FileSystemManager::RemoveFile(file_path);
+        }
+        return res;
+    } catch (std::exception const& ex) {
+        Logger::Log(LogLevel::Error,
+                    "curl download to file failed with:\n{}",
+                    ex.what());
+        return 1;
+    }
+#endif  // BOOTSTRAP_BUILD_TOOL
+}
+
+auto CurlEasyHandle::DownloadToString(std::string const& url) noexcept
+    -> std::optional<std::string> {
+#ifdef BOOTSTRAP_BUILD_TOOL
+    return std::nullopt;
+#else
+    try {
+        // set URL
+        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg, hicpp-vararg)
+        curl_easy_setopt(handle_.get(), CURLOPT_URL, url.c_str());
+
+        // set callback for writing to string
+        std::string content{};
+
+        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg, hicpp-vararg)
+        curl_easy_setopt(
+            handle_.get(), CURLOPT_WRITEFUNCTION, EasyWriteToString);
+        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg, hicpp-vararg)
+        curl_easy_setopt(
+            handle_.get(), CURLOPT_WRITEDATA, static_cast<void*>(&content));
+
+        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg, hicpp-vararg)
+        curl_easy_setopt(handle_.get(), CURLOPT_VERBOSE, 1);
+
+        // perform download
+        auto res = curl_easy_perform(handle_.get());
+
+        // check result
+        if (res != CURLE_OK) {
+            return std::nullopt;
+        }
+        return content;
+    } catch (std::exception const& ex) {
+        Logger::Log(LogLevel::Error,
+                    "curl download to string failed with:\n{}",
+                    ex.what());
+        return std::nullopt;
+    }
+#endif  // BOOTSTRAP_BUILD_TOOL
+}
diff --git a/src/utils/cpp/curl_easy_handle.hpp b/src/utils/cpp/curl_easy_handle.hpp
new file mode 100644
index 00000000..5f318887
--- /dev/null
+++ b/src/utils/cpp/curl_easy_handle.hpp
@@ -0,0 +1,86 @@
+// Copyright 2022 Huawei Cloud Computing Technology Co., Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef INCLUDED_SRC_OTHER_TOOLS_CURL_EASY_HANDLE_HPP
+#define INCLUDED_SRC_OTHER_TOOLS_CURL_EASY_HANDLE_HPP
+
+#include <filesystem>
+#include <functional>
+#include <memory>
+#include <optional>
+
+#include "gsl-lite/gsl-lite.hpp"
+#include "src/utils/cpp/curl_context.hpp"
+
+extern "C" {
+#if defined(BUILDING_LIBCURL) || defined(CURL_STRICTER)
+using CURL = struct Curl_easy;
+#else
+using CURL = void;
+#endif
+}
+
+void curl_easy_closer(gsl::owner<CURL*> curl);
+
+class CurlEasyHandle {
+  public:
+    CurlEasyHandle() noexcept = default;
+    ~CurlEasyHandle() noexcept = default;
+
+    // prohibit moves and copies
+    CurlEasyHandle(CurlEasyHandle const&) = delete;
+    CurlEasyHandle(CurlEasyHandle&& other) = delete;
+    auto operator=(CurlEasyHandle const&) = delete;
+    auto operator=(CurlEasyHandle&& other) = delete;
+
+    /// \brief Create a CurlEasyHandle object
+    [[nodiscard]] auto static Create() noexcept
+        -> std::shared_ptr<CurlEasyHandle>;
+
+    /// \brief Download file from URL into given file_path.
+    /// Will perform cleanup (i.e., remove empty file) in case download fails.
+    /// Returns 0 if successful.
+    [[nodiscard]] auto DownloadToFile(
+        std::string const& url,
+        std::filesystem::path const& file_path) noexcept -> int;
+
+    /// \brief Download file from URL into string as binary.
+    /// Returns the content or nullopt if download failure.
+    [[nodiscard]] auto DownloadToString(std::string const& url) noexcept
+        -> std::optional<std::string>;
+
+  private:
+    // IMPORTANT: the CurlContext must to be initialized before any curl object!
+    CurlContext curl_context_{};
+    std::unique_ptr<CURL, decltype(&curl_easy_closer)> handle_{
+        nullptr,
+        curl_easy_closer};
+
+    /// \brief Overwrites write_callback to redirrect to file instead of stdout.
+    [[nodiscard]] auto static EasyWriteToFile(gsl::owner<char*> data,
+                                              size_t size,
+                                              size_t nmemb,
+                                              gsl::owner<void*> userptr)
+        -> std::streamsize;
+
+    /// \brief Overwrites write_callback to redirect to string instead of
+    /// stdout.
+    [[nodiscard]] auto static EasyWriteToString(gsl::owner<char*> data,
+                                                size_t size,
+                                                size_t nmemb,
+                                                gsl::owner<void*> userptr)
+        -> std::streamsize;
+};
+
+#endif  // INCLUDED_SRC_OTHER_TOOLS_CURL_EASY_HANDLE_HPP
\ No newline at end of file