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