Source
pub fn chunkedSendFile(w: *Writer, file_reader: *File.Reader, limit: std.Io.Limit) Writer.FileError!usize {
const bw: *BodyWriter = @alignCast(@fieldParentPtr("writer", w));
assert(!bw.isEliding());
const data_len = Writer.countSendFileLowerBound(w.end, file_reader, limit) orelse {
// If the file size is unknown, we cannot lower to a `sendFile` since we would
// have to flush the chunk header before knowing the chunk length.
return error.Unimplemented;
};
const out = bw.http_protocol_output;
l: switch (bw.state.chunk_len) {
0 => {
const header_buf = try out.writableArray(chunk_header_template.len);
@memcpy(header_buf, chunk_header_template);
writeHex(header_buf[0..chunk_len_digits], data_len);
bw.state.chunk_len = data_len + 2;
continue :l bw.state.chunk_len;
},
1 => unreachable, // Wrote more data than specified in chunk header.
2 => {
try out.writeAll("\r\n");
bw.state.chunk_len = 0;
assert(file_reader.atEnd());
return error.EndOfStream;
},
else => {
const chunk_limit: std.Io.Limit = .limited(bw.state.chunk_len - 2);
const n = if (chunk_limit.subtract(w.buffered().len)) |sendfile_limit|
try out.sendFileHeader(w.buffered(), file_reader, sendfile_limit.min(limit))
else
try out.write(chunk_limit.slice(w.buffered()));
bw.state.chunk_len -= n;
const ret = w.consume(n);
return ret;
},
}
}