Outgoing byte stream type.

Flatten bytes-oriented Bigarray buffer.

Note. The rationale for using bytes instead of BA is to transparently transfer memory between the OCaml runtime and external functions, which are necessary for working with input/output.

A byte chunk is a non-empty consecutive range of bytes in a buffer value.

make ?buffer_size writer

Construct an outgoing byte stream using the writer function to output chunks to a bytes sink.

• parameter writer

  Function that accepting a chunk of buffer that always has an offset of zero and a variable length. Therefore, for you, it is enough to match only the buffer and length fields.

  let writer (~buffer, ~length, ..) = (* ... *)

• parameter ?buffer_size

  by default is 4096 bytes

Example

This example illustrates the basic concept of chunking.

(* Queue as a byte chunk sink. *)
let queue = Queue.create () in

(* Writer function that outputs chunks of text to the sink. *)
let writer (~buffer, ~length:len, ..) =
  Queue.add Bstr.(sub_string ~off:0 ~len buffer) queue
in

Bytream.Out.make writer

of_channel ?io_buffer_size oc make an outgoing stream from the channel.

Note. You can disable internal buffering for the channels to get the expected behavior: Out_channel.set_buffered oc false v.

with_into_string f make a stream that outgoing to buffer.

with_into_string f make a stream that outgoing to buffer and returns string value.

available_to_write out_stream

• returns

  Number of bytes that have not been written to the internal buffer.

shift out_stream n

Shift the buffer's offset by n bytes to account for the written bytes.

• raises Shifted_beyond_buffer

  if n is more than available space to write

writable_guard_bytes_at out_stream len

Guarantees that the buffer has enough space to write len bytes into it.

• returns

  the buffer's offset

Example

let write_hello_record out_stream hello =
  let off = Out.writable_guard_bytes_at out_stream 6 in
  Out.output_byte out_stream 5;
  Out.output_string out_stream "hello"

flush out_stream flush outgoing stream to sink.

with_flush out_stream f same as flush but with with-function.

output out_stream buffer off len

Output the buffer into outgoing byte stream.

output out_stream string

Output the string into outgoing byte stream.

output out_stream buffer off len

Output the buffer into outgoing byte stream with flushing.