LibArchive: Use designated initializers

Benefits:
- Braced-initialization prevents unknown narrowing conversions.
- Using designated initializers will result in a compiler error when a
  member is skipped or forgotten.

Userland/Libraries/LibArchive/Zip.cpp

@@ -68,17 +68,17 @@ Optional<Zip> Zip::try_create(ReadonlyBytes buffer)
         member_offset += central_directory_record.size();
     }
 
-    Zip zip;
-    zip.m_input_data = buffer;
-    zip.member_count = end_of_central_directory.total_records_count;
-    zip.members_start_offset = end_of_central_directory.central_directory_offset;
-    return zip;
+    return Zip {
+        end_of_central_directory.total_records_count,
+        end_of_central_directory.central_directory_offset,
+        buffer,
+    };
 }
 
 bool Zip::for_each_member(Function<IterationDecision(const ZipMember&)> callback)
 {
-    size_t member_offset = members_start_offset;
-    for (size_t i = 0; i < member_count; i++) {
+    size_t member_offset = m_members_start_offset;
+    for (size_t i = 0; i < m_member_count; i++) {
         CentralDirectoryRecord central_directory_record {};
         VERIFY(central_directory_record.read(m_input_data.slice(member_offset)));
         LocalFileHeader local_file_header {};
@@ -108,6 +108,12 @@ ZipOutputStream::ZipOutputStream(OutputStream& stream)
 {
 }
 
+static u16 minimum_version_needed(ZipCompressionMethod method)
+{
+    // Deflate was added in PKZip 2.0
+    return method == ZipCompressionMethod::Deflate ? 20 : 10;
+}
+
 void ZipOutputStream::add_member(const ZipMember& member)
 {
     VERIFY(!m_finished);
@@ -115,20 +121,21 @@ void ZipOutputStream::add_member(const ZipMember& member)
     VERIFY(member.compressed_data.size() <= UINT32_MAX);
     m_members.append(member);
 
-    LocalFileHeader local_file_header {};
-    local_file_header.minimum_version = member.compression_method == ZipCompressionMethod::Deflate ? 20 : 10; // Deflate was added in PKZip 2.0
-    local_file_header.general_purpose_flags = 0;
-    local_file_header.compression_method = static_cast<u16>(member.compression_method);
-    local_file_header.modification_time = 0; // TODO: support modification time
-    local_file_header.modification_date = 0;
-    local_file_header.crc32 = member.crc32;
-    local_file_header.compressed_size = member.compressed_data.size();
-    local_file_header.uncompressed_size = member.uncompressed_size;
-    local_file_header.name_length = member.name.length();
-    local_file_header.extra_data_length = 0;
-    local_file_header.name = (const u8*)(member.name.characters());
-    local_file_header.extra_data = nullptr;
-    local_file_header.compressed_data = member.compressed_data.data();
+    LocalFileHeader local_file_header {
+        .minimum_version = minimum_version_needed(member.compression_method),
+        .general_purpose_flags = 0,
+        .compression_method = static_cast<u16>(member.compression_method),
+        .modification_time = 0, // TODO: support modification time
+        .modification_date = 0,
+        .crc32 = member.crc32,
+        .compressed_size = static_cast<u32>(member.compressed_data.size()),
+        .uncompressed_size = member.uncompressed_size,
+        .name_length = static_cast<u16>(member.name.length()),
+        .extra_data_length = 0,
+        .name = reinterpret_cast<u8 const*>(member.name.characters()),
+        .extra_data = nullptr,
+        .compressed_data = member.compressed_data.data(),
+    };
     local_file_header.write(m_stream);
 }
 
@@ -137,44 +144,46 @@ void ZipOutputStream::finish()
     VERIFY(!m_finished);
     m_finished = true;
 
-    auto file_header_offset = 0;
-    auto central_directory_size = 0;
+    auto file_header_offset = 0u;
+    auto central_directory_size = 0u;
     for (const ZipMember& member : m_members) {
-        CentralDirectoryRecord central_directory_record {};
-        auto zip_version = member.compression_method == ZipCompressionMethod::Deflate ? 20 : 10; // Deflate was added in PKZip 2.0
-        central_directory_record.made_by_version = zip_version;
-        central_directory_record.minimum_version = zip_version;
-        central_directory_record.general_purpose_flags = 0;
-        central_directory_record.compression_method = static_cast<u16>(member.compression_method);
-        central_directory_record.modification_time = 0; // TODO: support modification time
-        central_directory_record.modification_date = 0;
-        central_directory_record.crc32 = member.crc32;
-        central_directory_record.compressed_size = member.compressed_data.size();
-        central_directory_record.uncompressed_size = member.uncompressed_size;
-        central_directory_record.name_length = member.name.length();
-        central_directory_record.extra_data_length = 0;
-        central_directory_record.comment_length = 0;
-        central_directory_record.start_disk = 0;
-        central_directory_record.internal_attributes = 0;
-        central_directory_record.external_attributes = member.is_directory ? zip_directory_external_attribute : 0;
-        central_directory_record.local_file_header_offset = file_header_offset; // FIXME: we assume the wrapped output stream was never written to before us
+        auto zip_version = minimum_version_needed(member.compression_method);
+        CentralDirectoryRecord central_directory_record {
+            .made_by_version = zip_version,
+            .minimum_version = zip_version,
+            .general_purpose_flags = 0,
+            .compression_method = member.compression_method,
+            .modification_time = 0, // TODO: support modification time
+            .modification_date = 0,
+            .crc32 = member.crc32,
+            .compressed_size = static_cast<u32>(member.compressed_data.size()),
+            .uncompressed_size = member.uncompressed_size,
+            .name_length = static_cast<u16>(member.name.length()),
+            .extra_data_length = 0,
+            .comment_length = 0,
+            .start_disk = 0,
+            .internal_attributes = 0,
+            .external_attributes = member.is_directory ? zip_directory_external_attribute : 0,
+            .local_file_header_offset = file_header_offset, // FIXME: we assume the wrapped output stream was never written to before us
+            .name = reinterpret_cast<u8 const*>(member.name.characters()),
+            .extra_data = nullptr,
+            .comment = nullptr,
+        };
         file_header_offset += sizeof(LocalFileHeader::signature) + (sizeof(LocalFileHeader) - (sizeof(u8*) * 3)) + member.name.length() + member.compressed_data.size();
-        central_directory_record.name = (const u8*)(member.name.characters());
-        central_directory_record.extra_data = nullptr;
-        central_directory_record.comment = nullptr;
         central_directory_record.write(m_stream);
         central_directory_size += central_directory_record.size();
     }
 
-    EndOfCentralDirectory end_of_central_directory {};
-    end_of_central_directory.disk_number = 0;
-    end_of_central_directory.central_directory_start_disk = 0;
-    end_of_central_directory.disk_records_count = m_members.size();
-    end_of_central_directory.total_records_count = m_members.size();
-    end_of_central_directory.central_directory_size = central_directory_size;
-    end_of_central_directory.central_directory_offset = file_header_offset;
-    end_of_central_directory.comment_length = 0;
-    end_of_central_directory.comment = nullptr;
+    EndOfCentralDirectory end_of_central_directory {
+        .disk_number = 0,
+        .central_directory_start_disk = 0,
+        .disk_records_count = static_cast<u16>(m_members.size()),
+        .total_records_count = static_cast<u16>(m_members.size()),
+        .central_directory_size = central_directory_size,
+        .central_directory_offset = file_header_offset,
+        .comment_length = 0,
+        .comment = nullptr,
+    };
     end_of_central_directory.write(m_stream);
 }
 

Userland/Libraries/LibArchive/Zip.h

@@ -221,8 +221,14 @@ public:
 private:
     static bool find_end_of_central_directory_offset(ReadonlyBytes, size_t& offset);
 
-    u16 member_count { 0 };
-    size_t members_start_offset { 0 };
+    Zip(u16 member_count, size_t members_start_offset, ReadonlyBytes input_data)
+        : m_member_count { member_count }
+        , m_members_start_offset { members_start_offset }
+        , m_input_data { input_data }
+    {
+    }
+    u16 m_member_count { 0 };
+    size_t m_members_start_offset { 0 };
     ReadonlyBytes m_input_data;
 };