# Module Ocsigen_stream

    module Ocsigen_stream: sig .. end

    exception Interrupted of exn

    exception Cancelled

    exception Already_read

    exception Finalized

Streams are a means to read data block by block

    type 'a stream

    type 'a step = private

`|` | `Finished of `'a stream option``
`|` | `Cont of `'a * 'a stream``

A stream may be composed by several substreams. Thus a stream is either something that contains the current buffer and a function to retrieve the following data, or a finished stream with possibly another stream following.

    type 'a t

    type outcome = [ `Failure | `Success ]

    val make : ?finalize:(outcome -> unit Lwt.t) ->
           (unit -> 'a step Lwt.t) -> 'a t

creates a new stream

    val get : 'a t -> 'a stream

call this function if you decide to start reading a stream.

- Raises `Already_read` if the stream has already been read.

    val next : 'a stream -> 'a step Lwt.t

get the next step of a stream. Fails with `Interrupted e` if reading the thread failed with exception `e`, and with `Cancelled` if the thread has been cancelled.

    val empty : (unit -> 'a step Lwt.t) option -> 'a step Lwt.t

creates an empty step. The parameter is the following substream, if any.

    val cont : 'a -> (unit -> 'a step Lwt.t) -> 'a step Lwt.t

creates a non empty step.

    val add_finalizer : 'a t -> (outcome -> unit Lwt.t) -> unit

Add a finalizer function. In the current version, finalizers must be called manually.

    val finalize : 'a t -> outcome -> unit Lwt.t

Finalize the stream. This function must be called explicitly after reading the stream, otherwise finalizers won't be called.

    val cancel : 'a t -> unit Lwt.t

Cancel the stream, i.e. read the stream until the end, without decoding. Further tries to read on the stream will fail with exception `Ocsigen_stream.Cancelled`

    val consume : 'a t -> unit Lwt.t

Consume without cancelling. Read the stream until the end, without decoding.

    exception Stream_too_small

possibly with the size of the stream

    exception Stream_error of string

    exception String_too_large

    val string_of_stream : int -> string stream -> string Lwt.t

Creates a string from a stream. The first argument is the upper limit of the string length

    val enlarge_stream : string step -> string step Lwt.t

Read more data in the buffer

    val stream_want : string step -> int -> string step Lwt.t

`stream_want s len` Returns a stream with at least len bytes in the buffer if possible

    val current_buffer : string step -> string

Returns the value of the current buffer

    val skip : string step -> int64 -> string step Lwt.t

Skips data. Raises `Stream_too_small (Some size)` if the stream is too small, where `size` is the size of the stream.

    val substream : string -> string step -> string step Lwt.t

Cut the stream at the position given by a string delimiter

    val of_file : string -> string t

returns a stream reading from a file. Do not forget to finalize the stream to close the file.

    val of_string : string -> string t

returns a stream containing a string.

    val of_lwt_stream : 'a Lwt_stream.t -> 'a t

Convert a `Lwt_stream.t` to an `Ocsigen_stream.t`.

    val to_lwt_stream : ?is_empty:('a -> bool) -> 'a t -> 'a Lwt_stream.t

Convert an `Ocsigen_stream.t` into a `Lwt_stream.t`.

`is_empty` : function to skip empty chunk.

    module StringStream: sig .. end