Eio.Flow
A flow can be used to read or write bytes.
Flows are used to represent byte streams, such as open files and network sockets. A source
provides a stream of bytes. A sink
consumes a stream. A two_way
can do both.
To read structured data (e.g. a line at a time), wrap a source using Buf_read
.
type 'a shutdown = [> shutdown_ty ] as 'a Std.r
single_read src buf
reads one or more bytes into buf
.
It returns the number of bytes read (which may be less than the buffer size even if there is more data to be read).
read_exact
instead if you want to fill buf
completely.Buf_read.line
to read complete lines.copy
to stream data directly from a source to a sink.buf
must not be zero-length.
read_exact src dst
keeps reading into dst
until it is full.
cstruct_source cs
is a source that gives the bytes of cs
.
type read_method +=
| Read_source_buffer of 't -> (Cstruct.t list -> int) -> unit
If a source offers Read_source_buffer rsb
then the user can call rsb t fn
to borrow a view of the source's buffers. fn
returns the number of bytes it consumed.
rsb
will raise End_of_file
if no more data will be produced. If no data is currently available, rsb
will wait for some to become available before calling fn
.
fn
must not continue to use the buffers after it returns.
single_write dst bufs
writes at least one byte from bufs
and returns the number of bytes written.
val copy_string : string -> _ sink -> unit
copy_string s = copy (string_source s)
buffer_sink b
is a sink that adds anything sent to it to b
.
To collect data as a cstruct, use Buf_read
instead.
type 'a two_way = [> two_way_ty ] as 'a Std.r
val shutdown : _ two_way -> shutdown_command -> unit
shutdown t cmd
indicates that the caller has finished reading or writing t
(depending on cmd
).
This is useful in some protocols to indicate that you have finished sending the request, and that the remote peer should now send the response.
Flows are usually attached to switches and closed automatically when the switch finishes. However, it can be useful to close them sooner manually in some cases.
val close : [> `Close ] Std.r -> unit
Alias of Resource.close
.
module Pi : sig ... end
val read_all : _ source -> string
read_all src
is a convenience wrapper to read an entire flow.
It is the same as Buf_read.(parse_exn take_all) src ~max_size:max_int