Source
pub fn next(self: *Iterator) !?Entry {
if (self.cd_record_index == self.cd_record_count) {
if (self.cd_record_offset != self.cd_size)
return if (self.cd_size > self.cd_record_offset)
error.ZipCdOversized
else
error.ZipCdUndersized;
return null;
}
const header_zip_offset = self.cd_zip_offset + self.cd_record_offset;
const input = self.input;
try input.seekTo(header_zip_offset);
const header = input.interface.takeStruct(CentralDirectoryFileHeader, .little) catch |err| switch (err) {
error.ReadFailed => return input.err.?,
error.EndOfStream => return error.EndOfStream,
};
if (!std.mem.eql(u8, &header.signature, ¢ral_file_header_sig))
return error.ZipBadCdOffset;
self.cd_record_index += 1;
self.cd_record_offset += @sizeOf(CentralDirectoryFileHeader) + header.filename_len + header.extra_len + header.comment_len;
// Note: checking the version_needed_to_extract doesn't seem to be helpful, i.e. the zip file
// at https://github.com/ninja-build/ninja/releases/download/v1.12.0/ninja-linux.zip
// has an undocumented version 788 but extracts just fine.
if (header.flags.encrypted)
return error.ZipEncryptionUnsupported;
// TODO: check/verify more flags
if (header.disk_number != 0)
return error.ZipMultiDiskUnsupported;
var extents: FileExtents = .{
.uncompressed_size = header.uncompressed_size,
.compressed_size = header.compressed_size,
.local_file_header_offset = header.local_file_header_offset,
};
if (header.extra_len > 0) {
var extra_buf: [std.math.maxInt(u16)]u8 = undefined;
const extra = extra_buf[0..header.extra_len];
try input.seekTo(header_zip_offset + @sizeOf(CentralDirectoryFileHeader) + header.filename_len);
input.interface.readSliceAll(extra) catch |err| switch (err) {
error.ReadFailed => return input.err.?,
error.EndOfStream => return error.EndOfStream,
};
var extra_offset: usize = 0;
while (extra_offset + 4 <= extra.len) {
const header_id = std.mem.readInt(u16, extra[extra_offset..][0..2], .little);
const data_size = std.mem.readInt(u16, extra[extra_offset..][2..4], .little);
const end = extra_offset + 4 + data_size;
if (end > extra.len)
return error.ZipBadExtraFieldSize;
const data = extra[extra_offset + 4 .. end];
switch (@as(ExtraHeader, @enumFromInt(header_id))) {
.zip64_info => try readZip64FileExtents(CentralDirectoryFileHeader, header, &extents, data),
else => {}, // ignore
}
extra_offset = end;
}
}
return .{
.version_needed_to_extract = header.version_needed_to_extract,
.flags = header.flags,
.compression_method = header.compression_method,
.last_modification_time = header.last_modification_time,
.last_modification_date = header.last_modification_date,
.header_zip_offset = header_zip_offset,
.crc32 = header.crc32,
.filename_len = header.filename_len,
.compressed_size = extents.compressed_size,
.uncompressed_size = extents.uncompressed_size,
.file_offset = extents.local_file_header_offset,
};
}