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This is an example of documentation generated by ZigDoc, an alternative to Zig's built-in Auto Doc feature. See also examples in other modes/formats. The project being documented here (as the example) is the Zig standard library. Public Function

extractTo

Public Function
std.zip.Iterator.Entry.extractTo
pub fn extractTo(self: Entry, stream: *File.Reader, w: *Writer) !void

Params

File

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        pub fn extractTo(self: Entry, stream: *File.Reader, w: *Writer) !void {
            switch (self.compression_method) {
                .store, .deflate => {},
                else => return error.UnsupportedCompressionMethod,
            }

            const local_data_header_offset: u64 = local_data_header_offset: {
                const local_header = blk: {
                    try stream.seekTo(self.file_offset);
                    break :blk try stream.interface.takeStruct(LocalFileHeader, .little);
                };
                if (!std.mem.eql(u8, &local_header.signature, &local_file_header_sig))
                    return error.ZipBadFileOffset;
                if (local_header.version_needed_to_extract != self.version_needed_to_extract)
                    return error.ZipMismatchVersionNeeded;
                if (local_header.last_modification_time != self.last_modification_time)
                    return error.ZipMismatchModTime;
                if (local_header.last_modification_date != self.last_modification_date)
                    return error.ZipMismatchModDate;

                if (@as(u16, @bitCast(local_header.flags)) != @as(u16, @bitCast(self.flags)))
                    return error.ZipMismatchFlags;
                if (local_header.crc32 != 0 and local_header.crc32 != self.crc32)
                    return error.ZipMismatchCrc32;
                var extents: FileExtents = .{
                    .uncompressed_size = local_header.uncompressed_size,
                    .compressed_size = local_header.compressed_size,
                    .local_file_header_offset = 0,
                };
                if (local_header.extra_len > 0) {
                    var extra_buf: [std.math.maxInt(u16)]u8 = undefined;
                    const extra = extra_buf[0..local_header.extra_len];

                    {
                        try stream.seekTo(self.file_offset + @sizeOf(LocalFileHeader) + local_header.filename_len);
                        try stream.interface.readSliceAll(extra);
                    }

                    var extra_offset: usize = 0;
                    while (extra_offset + 4 <= local_header.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 > local_header.extra_len)
                            return error.ZipBadExtraFieldSize;
                        const data = extra[extra_offset + 4 .. end];
                        switch (@as(ExtraHeader, @fromBackingInt(@intCast(header_id)))) {
                            .zip64_info => try readZip64FileExtents(LocalFileHeader, local_header, &extents, data),
                            else => {}, // ignore
                        }
                        extra_offset = end;
                    }
                }

                if (extents.compressed_size != 0 and
                    extents.compressed_size != self.compressed_size)
                    return error.ZipMismatchCompLen;
                if (extents.uncompressed_size != 0 and
                    extents.uncompressed_size != self.uncompressed_size)
                    return error.ZipMismatchUncompLen;

                if (local_header.filename_len != self.filename_len)
                    return error.ZipMismatchFilenameLen;

                break :local_data_header_offset @as(u64, local_header.filename_len) +
                    @as(u64, local_header.extra_len);
            };

            const local_data_file_offset: u64 =
                @as(u64, self.file_offset) +
                @as(u64, @sizeOf(LocalFileHeader)) +
                local_data_header_offset;
            try stream.seekTo(local_data_file_offset);

            // TODO limit based on self.compressed_size

            switch (self.compression_method) {
                .store => {
                    stream.interface.streamExact64(w, self.uncompressed_size) catch |err| switch (err) {
                        error.ReadFailed => |e| return stream.err orelse e,
                        error.WriteFailed => |e| return e,
                        error.EndOfStream => return error.ZipDecompressTruncated,
                    };
                },
                .deflate => {
                    var flate_buffer: [flate.max_window_len]u8 = undefined;
                    var decompress: flate.Decompress = .init(&stream.interface, .raw, &flate_buffer);
                    decompress.reader.streamExact64(w, self.uncompressed_size) catch |err| switch (err) {
                        error.ReadFailed => |e| return decompress.err orelse (stream.err orelse e),
                        error.WriteFailed => |e| return e,
                        error.EndOfStream => return error.ZipDecompressTruncated,
                    };
                },
                else => return error.UnsupportedCompressionMethod,
            }
        }