Module Ocsigen_stream

module Ocsigen_stream : sig..end

Streams are a means to read data block by block


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 explicitely 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.

module StringStream : sig..end