feat(core-clp)!: Migrate archive metadata file format to MessagePack.

components/core/src/clp/streaming_archive/ArchiveMetadata.cpp

@@ -1,5 +1,12 @@
 #include "ArchiveMetadata.hpp"
 
+#include <sys/stat.h>
+
+#include <fmt/core.h>
+
+#include "../Array.hpp"
+#include "../FileReader.hpp"
+
 namespace clp::streaming_archive {
 ArchiveMetadata::ArchiveMetadata(
         archive_format_version_t archive_format_version,
@@ -8,29 +15,29 @@ ArchiveMetadata::ArchiveMetadata(
 )
         : m_archive_format_version(archive_format_version),
           m_creator_id(std::move(creator_id)),
-          m_creation_idx(creation_idx) {
-    if (m_creator_id.length() > UINT16_MAX) {
-        throw OperationFailed(ErrorCode_BadParam, __FILENAME__, __LINE__);
+          m_creation_idx(creation_idx) {}
+
+auto ArchiveMetadata::create_from_file(std::string_view file_path) -> ArchiveMetadata {
+    FileReader file_reader{std::string(file_path)};
+    struct stat file_stat{};
+    if (auto const clp_rc = file_reader.try_fstat(file_stat);
+        clp::ErrorCode::ErrorCode_Success != clp_rc)
+    {
+        throw OperationFailed(clp_rc, __FILENAME__, __LINE__);
+    }
+
+    clp::Array<char> buf{static_cast<size_t>(file_stat.st_size)};
+    if (auto const clp_rc = file_reader.try_read_exact_length(buf.data(), buf.size());
+        clp::ErrorCode::ErrorCode_Success != clp_rc)
+    {
+        throw OperationFailed(clp_rc, __FILENAME__, __LINE__);
     }
-    m_creator_id_len = m_creator_id.length();
-
-    // NOTE: We set this to the size of this metadata on disk; when adding new members that will be
-    // written to disk, you must update this
-    m_compressed_size += sizeof(m_archive_format_version) + sizeof(m_creator_id_len)
-                         + m_creator_id.length() + sizeof(m_creation_idx)
-                         + sizeof(m_uncompressed_size) + sizeof(m_begin_timestamp)
-                         + sizeof(m_end_timestamp) + sizeof(m_compressed_size);
-}
 
-ArchiveMetadata::ArchiveMetadata(FileReader& file_reader) {
-    file_reader.read_numeric_value(m_archive_format_version, false);
-    file_reader.read_numeric_value(m_creator_id_len, false);
-    file_reader.read_string(m_creator_id_len, m_creator_id, false);
-    file_reader.read_numeric_value(m_creation_idx, false);
-    file_reader.read_numeric_value(m_uncompressed_size, false);
-    file_reader.read_numeric_value(m_compressed_size, false);
-    file_reader.read_numeric_value(m_begin_timestamp, false);
-    file_reader.read_numeric_value(m_end_timestamp, false);
+    ArchiveMetadata metadata;
+    msgpack::object_handle const obj_handle = msgpack::unpack(buf.data(), buf.size());
+    msgpack::object const obj = obj_handle.get();
+    obj.convert(metadata);
+    return metadata;
 }
 
 void ArchiveMetadata::expand_time_range(epochtime_t begin_timestamp, epochtime_t end_timestamp) {
@@ -43,13 +50,9 @@ void ArchiveMetadata::expand_time_range(epochtime_t begin_timestamp, epochtime_t
 }
 
 void ArchiveMetadata::write_to_file(FileWriter& file_writer) const {
-    file_writer.write_numeric_value(m_archive_format_version);
-    file_writer.write_numeric_value(m_creator_id_len);
-    file_writer.write_string(m_creator_id);
-    file_writer.write_numeric_value(m_creation_idx);
-    file_writer.write_numeric_value(m_uncompressed_size + m_dynamic_uncompressed_size);
-    file_writer.write_numeric_value(m_compressed_size + m_dynamic_uncompressed_size);
-    file_writer.write_numeric_value(m_begin_timestamp);
-    file_writer.write_numeric_value(m_end_timestamp);
+    std::ostringstream buf;
+    msgpack::pack(buf, *this);
+    auto const& string_buf = buf.str();
+    file_writer.write(string_buf.data(), string_buf.size());
 }
 }  // namespace clp::streaming_archive

components/core/src/clp/streaming_archive/ArchiveMetadata.hpp

@@ -2,9 +2,11 @@
 #define CLP_STREAMING_ARCHIVE_ARCHIVEMETADATA_HPP
 
 #include <cstdint>
+#include <string_view>
+
+#include <msgpack.hpp>
 
 #include "../Defs.h"
-#include "../FileReader.hpp"
 #include "../FileWriter.hpp"
 #include "Constants.hpp"
 
@@ -28,6 +30,10 @@ class ArchiveMetadata {
     };
 
     // Constructors
+    // We need a default constructor to convert from a msgpack::object in `create_from_file`. See
+    // https://github.com/msgpack/msgpack-c/wiki/v2_0_cpp_adaptor
+    ArchiveMetadata() = default;
+
     /**
      * Constructs a metadata object with the given parameters
      * @param archive_format_version
@@ -40,13 +46,20 @@ class ArchiveMetadata {
             uint64_t creation_idx
     );
 
+    // Methods
     /**
-     * Constructs a metadata object and initializes it from the given file reader
-     * @param file_reader
+     * Reads serialized MessagePack data from a file and unpacks it into an `ArchiveMetadata`
+     * instance.
+     *
+     * @param file_path
+     * @return The created instance.
+     * @throw `ArchiveMetadata::OperationFailed` if `stat` fails or the file couldn't be read.
+     * @throw `msgpack::unpack_error` if the data cannot be unpacked into a MessagePack object.
+     * @throw `msgpack::type_error` if the MessagePack object can't be converted to an
+     * `ArchiveMetadata` instance.
      */
-    explicit ArchiveMetadata(FileReader& file_reader);
+    [[nodiscard]] static auto create_from_file(std::string_view file_path) -> ArchiveMetadata;
 
-    // Methods
     [[nodiscard]] auto get_archive_format_version() const { return m_archive_format_version; }
 
     [[nodiscard]] auto get_creator_id() const -> std::string const& { return m_creator_id; }
@@ -86,13 +99,27 @@ class ArchiveMetadata {
      */
     void expand_time_range(epochtime_t begin_timestamp, epochtime_t end_timestamp);
 
+    /**
+     * Packs this instance into a MessagePack object and writes it to the open file.
+     *
+     * @param file_writer
+     */
     void write_to_file(FileWriter& file_writer) const;
 
+    MSGPACK_DEFINE_MAP(
+            MSGPACK_NVP("archive_format_version", m_archive_format_version),
+            MSGPACK_NVP("creator_id", m_creator_id),
+            MSGPACK_NVP("creation_idx", m_creation_idx),
+            MSGPACK_NVP("begin_timestamp", m_begin_timestamp),
+            MSGPACK_NVP("end_timestamp", m_end_timestamp),
+            MSGPACK_NVP("uncompressed_size", m_uncompressed_size),
+            MSGPACK_NVP("compressed_size", m_compressed_size)
+    );
+
 private:
     // Variables
     archive_format_version_t m_archive_format_version{cArchiveFormatVersion::Version};
     std::string m_creator_id;
-    uint16_t m_creator_id_len{0};
     uint64_t m_creation_idx{0};
     epochtime_t m_begin_timestamp{cEpochTimeMax};
     epochtime_t m_end_timestamp{cEpochTimeMin};

components/core/src/clp/streaming_archive/reader/Archive.cpp

@@ -37,8 +37,7 @@ void Archive::open(string const& path) {
     string metadata_file_path = path + '/' + cMetadataFileName;
     archive_format_version_t format_version{};
     try {
-        FileReader file_reader{metadata_file_path};
-        ArchiveMetadata const metadata{file_reader};
+        auto const metadata = ArchiveMetadata::create_from_file(metadata_file_path);
         format_version = metadata.get_archive_format_version();
     } catch (TraceableException& traceable_exception) {
         auto error_code = traceable_exception.get_error_code();