Source
pub fn init(input: *File.Reader) !Iterator {
const end_record = try EndRecord.findFile(input);
if (!isMaxInt(end_record.record_count_disk) and end_record.record_count_disk > end_record.record_count_total)
return error.ZipDiskRecordCountTooLarge;
if (end_record.disk_number != 0 or end_record.central_directory_disk_number != 0)
return error.ZipMultiDiskUnsupported;
{
const counts_valid = !isMaxInt(end_record.record_count_disk) and !isMaxInt(end_record.record_count_total);
if (counts_valid and end_record.record_count_disk != end_record.record_count_total)
return error.ZipMultiDiskUnsupported;
}
var result: Iterator = .{
.input = input,
.cd_record_count = end_record.record_count_total,
.cd_zip_offset = end_record.central_directory_offset,
.cd_size = end_record.central_directory_size,
};
if (!end_record.need_zip64()) return result;
const locator_end_offset: u64 = @as(u64, end_record.comment_len) + @sizeOf(EndRecord) + @sizeOf(EndLocator64);
const stream_len = try input.getSize();
if (locator_end_offset > stream_len)
return error.ZipTruncated;
try input.seekTo(stream_len - locator_end_offset);
const locator = input.interface.takeStruct(EndLocator64, .little) catch |err| switch (err) {
error.ReadFailed => return input.err.?,
error.EndOfStream => return error.EndOfStream,
};
if (!std.mem.eql(u8, &locator.signature, &end_locator64_sig))
return error.ZipBadLocatorSig;
if (locator.zip64_disk_count != 0)
return error.ZipUnsupportedZip64DiskCount;
if (locator.total_disk_count != 1)
return error.ZipMultiDiskUnsupported;
try input.seekTo(locator.record_file_offset);
const record64 = input.interface.takeStruct(EndRecord64, .little) catch |err| switch (err) {
error.ReadFailed => return input.err.?,
error.EndOfStream => return error.EndOfStream,
};
if (!std.mem.eql(u8, &record64.signature, &end_record64_sig))
return error.ZipBadEndRecord64Sig;
if (record64.end_record_size < @sizeOf(EndRecord64) - 12)
return error.ZipEndRecord64SizeTooSmall;
if (record64.end_record_size > @sizeOf(EndRecord64) - 12)
return error.ZipEndRecord64UnhandledExtraData;
if (record64.version_needed_to_extract > 45)
return error.ZipUnsupportedVersion;
{
const is_multidisk = record64.disk_number != 0 or
record64.central_directory_disk_number != 0 or
record64.record_count_disk != record64.record_count_total;
if (is_multidisk)
return error.ZipMultiDiskUnsupported;
}
if (isMaxInt(end_record.record_count_total)) {
result.cd_record_count = record64.record_count_total;
} else if (end_record.record_count_total != record64.record_count_total)
return error.Zip64RecordCountTotalMismatch;
if (isMaxInt(end_record.central_directory_offset)) {
result.cd_zip_offset = record64.central_directory_offset;
} else if (end_record.central_directory_offset != record64.central_directory_offset)
return error.Zip64CentralDirectoryOffsetMismatch;
if (isMaxInt(end_record.central_directory_size)) {
result.cd_size = record64.central_directory_size;
} else if (end_record.central_directory_size != record64.central_directory_size)
return error.Zip64CentralDirectorySizeMismatch;
return result;
}