lwt 4.5.0 · OCaml Package

Byte arrays

type t =
  (char, Stdlib.Bigarray.int8_unsigned_elt, Stdlib.Bigarray.c_layout)
    Stdlib.Bigarray.Array1.t

Type of array of bytes.

val create : int -> t

Creates a new byte array of the given size.

val length : t -> int

Returns the length of the given byte array.

Access

val get : t -> int -> char

get buffer offset returns the byte at offset offset in buffer.

val set : t -> int -> char -> unit

get buffer offset value changes the value of the byte at offset offset in buffer to value.

val unsafe_get : t -> int -> char

Same as get but without bounds checking.

val unsafe_set : t -> int -> char -> unit

Same as set but without bounds checking.

Conversions

val of_bytes : bytes -> t

of_bytes buf returns a newly allocated byte array with the same contents as buf.

val of_string : string -> t

of_string buf returns a newly allocated byte array with the same contents as buf.

val to_bytes : t -> bytes

to_bytes buf returns newly allocated bytes with the same contents as buf.

val to_string : t -> string

to_string buf returns a newly allocated string with the same contents as buf.

Copying

val blit : t -> int -> t -> int -> int -> unit

blit buf1 ofs1 buf2 ofs2 len copies len bytes from buf1 starting at offset ofs1 to buf2 starting at offset ofs2.

val blit_from_bytes : bytes -> int -> t -> int -> int -> unit

Same as blit but the first buffer is a string instead of a byte array.

val blit_to_bytes : t -> int -> bytes -> int -> int -> unit

Same as blit but the second buffer is a string instead of a byte array.

val unsafe_blit : t -> int -> t -> int -> int -> unit

Same as blit but without bound checking.

val unsafe_blit_from_bytes : bytes -> int -> t -> int -> int -> unit

Same as Lwt_bytes.blit_from_bytes but without bounds checking.

val unsafe_blit_to_bytes : t -> int -> bytes -> int -> int -> unit

Same as Lwt_bytes.blit_to_bytes but without bounds checking.

val proxy : t -> int -> int -> t

proxy buffer offset length creates a ``proxy''. The returned byte array share the data of buffer but with different bounds.

val extract : t -> int -> int -> t

extract buffer offset length creates a new byte array of length length and copy the length bytes of buffer at offset into it.

val copy : t -> t

copy buffer creates a copy of the given byte array.

Filling

val fill : t -> int -> int -> char -> unit

fill buffer offset length value puts value in all length bytes of buffer starting at offset offset.

val unsafe_fill : t -> int -> int -> char -> unit

Same as fill but without bounds checking.

IOs

The following functions behave similarly to the ones in Lwt_unix, except they use byte arrays instead of strings, and they never perform extra copies of the data.

val read : Lwt_unix.file_descr -> t -> int -> int -> int Lwt.t

val write : Lwt_unix.file_descr -> t -> int -> int -> int Lwt.t

val recv : 
  Lwt_unix.file_descr ->
  t ->
  int ->
  int ->
  Unix.msg_flag list ->
  int Lwt.t

Not implemented on Windows.

val send : 
  Lwt_unix.file_descr ->
  t ->
  int ->
  int ->
  Unix.msg_flag list ->
  int Lwt.t

Not implemented on Windows.

val recvfrom : 
  Lwt_unix.file_descr ->
  t ->
  int ->
  int ->
  Unix.msg_flag list ->
  (int * Unix.sockaddr) Lwt.t

Not implemented on Windows.

val sendto : 
  Lwt_unix.file_descr ->
  t ->
  int ->
  int ->
  Unix.msg_flag list ->
  Unix.sockaddr ->
  int Lwt.t

Not implemented on Windows.

type io_vector = {

iov_buffer : t;
iov_offset : int;
iov_length : int;

}

val io_vector : buffer:t -> offset:int -> length:int -> io_vector

val recv_msg : 
  socket:Lwt_unix.file_descr ->
  io_vectors:io_vector list ->
  (int * Unix.file_descr list) Lwt.t

Not implemented on Windows.

deprecated
Use Lwt_unix.Versioned.recv_msg_2.

val send_msg : 
  socket:Lwt_unix.file_descr ->
  io_vectors:io_vector list ->
  fds:Unix.file_descr list ->
  int Lwt.t

Not implemented on Windows.

deprecated
Use Lwt_unix.Versioned.send_msg_2.

Memory mapped files

val map_file : 
  fd:Unix.file_descr ->
  ?pos:int64 ->
  shared:bool ->
  ?size:int ->
  unit ->
  t

map_file ~fd ?pos ~shared ?size () maps the file descriptor fd to an array of bytes.

val mapped : t -> bool

mapped buffer returns true iff buffer is a memory mapped file.

type advice =

| MADV_NORMAL
| MADV_RANDOM
| MADV_SEQUENTIAL
| MADV_WILLNEED
| MADV_DONTNEED
| MADV_MERGEABLE
| MADV_UNMERGEABLE
| MADV_HUGEPAGE
| MADV_NOHUGEPAGE

Type of advise that can be sent to the kernel by the program. See the manual madvise(2) for a description of each.

val madvise : t -> int -> int -> advice -> unit

madvise buffer pos len advice advises the kernel how the program will use the memory mapped file between pos and pos + len.

This call is not available on windows.

val page_size : int

Size of pages.

val mincore : t -> int -> bool array -> unit

mincore buffer offset states tests whether the given pages are in the system memory (the RAM). The offset argument must be a multiple of page_size. states is used to store the result; each cases is true if the corresponding page is in RAM and false otherwise.

This call is not available on windows and cygwin.

val wait_mincore : t -> int -> unit Lwt.t

wait_mincore buffer offset waits until the page containing the byte at offset offset is in RAM.

This functions is not available on windows and cygwin.

package lwt

Access

Conversions

Copying

Filling

IOs

Memory mapped files