Module Bigstring

module Bigstring: Bigstring


Types and exceptions

type t = (char, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t 
Type of bigstrings
exception IOError of int * exn
Type of I/O errors

The occurred exception (e.g. Unix_error, End_of_file)


Creation and string conversion

val create : ?max_mem_waiting_gc:Byte_units.t -> int -> t
create length
Returns a new bigstring having length. Content is undefined.
max_mem_waiting_gc : default = 256 M in OCaml <= 3.12, 1 G otherwise. As the total allocation of calls to create approach max_mem_waiting_gc, the pressure in the garbage collector to be more agressive will increase.
val init : int -> f:(int -> char) -> t
init n ~f creates a bigstring t of length n, with t.{i} = f i
val of_string : ?pos:int -> ?len:int -> string -> t
of_string ?pos ?len str
Returns a new bigstring that is equivalent to the substring of length len in str starting at position pos.
pos : default = 0
len : default = String.length str - pos
val to_string : ?pos:int -> ?len:int -> t -> string
to_string ?pos ?len bstr
Raises Invalid_argument if the string would exceed runtime limits.
Returns a new string that is equivalent to the substring of length len in bstr starting at position pos.
pos : default = 0
len : default = length bstr - pos

Checking

val check_args : loc:string -> pos:int -> len:int -> t -> unit
check_args ~loc ~pos ~len bstr checks the position and length arguments pos and len for bigstrings bstr.
Raises Invalid_argument if these arguments are illegal for the given bigstring using loc to indicate the calling context.
val get_opt_len : t -> pos:int -> int option -> int
get_opt_len bstr ~pos opt_len
Returns the length of a subbigstring in bstr starting at position pos and given optional length opt_len. This function does not check the validity of its arguments. Use Bigstring.check_args for that purpose.

Accessors

val length : t -> int
length bstr
Returns the length of bigstring bstr.
val sub : ?pos:int -> ?len:int -> t -> t
sub ?pos ?len bstr
Returns the sub-bigstring in bstr that starts at position pos and has length len. The sub-bigstring is a unique copy of the memory region, i.e. modifying it will not modify the original bigstring. Note that this is different than the behavior of the standard OCaml Array1.sub, which shares the memory.
pos : default = 0
len : default = Bigstring.length bstr - pos
val sub_shared : ?pos:int -> ?len:int -> t -> t
sub_shared ?pos ?len bstr
Returns the sub-bigstring in bstr that starts at position pos and has length len. The sub-bigstring shares the same memory region, i.e. modifying it will modify the original bigstring. Holding on to the sub-bigstring will also keep the (usually bigger) original one around.
pos : default = 0
len : default = Bigstring.length bstr - pos
val get : t -> int -> char
get t pos returns the character at pos
val set : t -> int -> char -> unit
set t pos sets the character at pos
val is_mmapped : t -> bool
is_mmapped bstr
Returns whether the bigstring bstr is memory-mapped.

Blitting

type ('src, 'dst) blit = src:'src ->
?src_pos:int -> ?src_len:int -> dst:'dst -> ?dst_pos:int -> unit -> unit
blit ~src ?src_pos ?src_len ~dst ?dst_pos () blits src_len characters from src starting at position src_pos to dst at position dst_pos.
Raises Invalid_argument if the designated ranges are out of bounds.
val blit : (t, t) blit
val blit_string_bigstring : (string, t) blit
val blit_bigstring_string : (t, string) blit

Input functions

val read : ?min_len:int -> Unix.file_descr -> ?pos:int -> ?len:int -> t -> int
read ?min_len fd ?pos ?len bstr reads at least min_len (must be greater than or equal zero) and at most len (must be greater than or equal to min_len) bytes from file descriptor fd, and writes them to bigstring bstr starting at position pos.
Raises Returns the number of bytes actually read.

NOTE: even if len is zero, there may still be errors when reading from the descriptor!

min_len : default = 0
pos : default = 0
len : default = length bstr - pos
val really_read : Unix.file_descr -> ?pos:int -> ?len:int -> t -> unit
really_read fd ?pos ?len bstr reads len bytes from file descriptor fd, and writes them to bigstring bstr starting at position pos.
Raises
pos : default = 0
len : default = length bstr - pos
val really_recv : Unix.file_descr -> ?pos:int -> ?len:int -> t -> unit
really_recv sock ?pos ?len bstr receives len bytes from socket sock, and writes them to bigstring bstr starting at position pos. If len is zero, the function returns immediately without performing the underlying system call.
Raises
pos : default = 0
len : default = length bstr - pos
val recvfrom_assume_fd_is_nonblocking : Unix.file_descr -> ?pos:int -> ?len:int -> t -> int * Unix.sockaddr
recvfrom_assume_fd_is_nonblocking sock ?pos ?len bstr reads up to len bytes into bigstring bstr starting at position pos from socket sock without yielding to other OCaml-threads.
Raises Returns the number of bytes actually read and the socket address of the client.
pos : default = 0
len : default = length bstr - pos
val read_assume_fd_is_nonblocking : Unix.file_descr -> ?pos:int -> ?len:int -> t -> int
read_assume_fd_is_nonblocking fd ?pos ?len bstr reads up to len bytes into bigstring bstr starting at position pos from file descriptor fd without yielding to other OCaml-threads.
Raises Returns the number of bytes actually read.
pos : default = 0
len : default = length bstr - pos
val input : ?min_len:int ->
Pervasives.in_channel -> ?pos:int -> ?len:int -> t -> int
input ?min_len ic ?pos ?len bstr tries to read len bytes (guarantees to read at least min_len bytes (must be greater than or equal to zero and smaller or equal to len), if possible, before returning) from input channel ic, and writes them to bigstring bstr starting at position pos.
Raises Returns the number of bytes actually read.

NOTE: even if len is zero, there may still be errors when reading from the descriptor, which will be done if the internal buffer is empty!

NOTE: if at least len characters are available in the input channel buffer and if len is not zero, data will only be fetched from the channel buffer. Otherwise data will be read until at least min_len characters are available.

min_len : default = 0
pos : default = 0
len : default = length bstr - pos
val really_input : Pervasives.in_channel -> ?pos:int -> ?len:int -> t -> unit
really_input ic ?pos ?len bstr reads exactly len bytes from input channel ic, and writes them to bigstring bstr starting at position pos.
Raises
pos : default = 0
len : default = length bstr - pos

Output functions

val really_write : Unix.file_descr -> ?pos:int -> ?len:int -> t -> unit
really_write fd ?pos ?len bstr writes len bytes in bigstring bstr starting at position pos to file descriptor fd.
Raises
pos : default = 0
len : default = length bstr - pos
val really_send_no_sigpipe : (Unix.file_descr -> ?pos:int -> ?len:int -> t -> unit) Or_error.t
really_send_no_sigpipe sock ?pos ?len bstr sends len bytes in bigstring bstr starting at position pos to socket sock without blocking and ignoring SIGPIPE.
Raises
val send_nonblocking_no_sigpipe : (Unix.file_descr -> ?pos:int -> ?len:int -> t -> int option)
Or_error.t
send_nonblocking_no_sigpipe sock ?pos ?len bstr tries to send len bytes in bigstring bstr starting at position pos to socket sock.
Raises Returns Some bytes_written, or None if the operation would have blocked.
val sendto_nonblocking_no_sigpipe : (Unix.file_descr ->
?pos:int -> ?len:int -> t -> Unix.sockaddr -> int option)
Or_error.t
sendto_nonblocking_no_sigpipe sock ?pos ?len bstr sockaddr tries to send len bytes in bigstring bstr starting at position pos to socket sock using address addr.
Raises Returns Some bytes_written, or None if the operation would have blocked.
val write : Unix.file_descr -> ?pos:int -> ?len:int -> t -> int
write fd ?pos ?len bstr writes len bytes in bigstring bstr starting at position pos to file descriptor fd.
Raises Returns the number of bytes actually written.
pos : default = 0
len : default = length bstr - pos
val write_assume_fd_is_nonblocking : Unix.file_descr -> ?pos:int -> ?len:int -> t -> int
write_assume_fd_is_nonblocking fd ?pos ?len bstr writes len bytes in bigstring bstr starting at position pos to file descriptor fd without yielding to other OCaml-threads.
Raises Returns the number of bytes actually written.
pos : default = 0
len : default = length bstr - pos
val writev : Unix.file_descr -> ?count:int -> t Unix.IOVec.t array -> int
writev fd ?count iovecs writes count iovecs of bigstrings to file descriptor fd.
Raises Returns the number of bytes written.
count : default = Array.length iovecs
val writev_assume_fd_is_nonblocking : Unix.file_descr -> ?count:int -> t Unix.IOVec.t array -> int
writev_assume_fd_is_nonblocking fd ?count iovecs writes count iovecs of bigstrings to file descriptor fd without yielding to other OCaml-threads.
Raises Returns the number of bytes actually written.
count : default = Array.length iovecs
val sendmsg_nonblocking_no_sigpipe : (Unix.file_descr ->
?count:int -> t Unix.IOVec.t array -> int option)
Or_error.t
sendmsg_nonblocking_no_sigpipe sock ?count iovecs sends count iovecs of bigstrings to socket sock.
Raises Returns Some bytes_written, or None if the operation would have blocked. This system call will not cause signal SIGPIPE if an attempt is made to write to a socket that was closed by the other side.
val output : ?min_len:int ->
Pervasives.out_channel -> ?pos:int -> ?len:int -> t -> int
output ?min_len oc ?pos ?len bstr tries to output len bytes (guarantees to write at least min_len bytes (must be equal to or greater than zero), if possible, before returning) from bigstring bstr starting at position pos to output channel oc.
Raises Returns the number of bytes actually written.

NOTE: you may need to flush oc to make sure that the data is actually sent.

NOTE: if len characters fit into the channel buffer completely, they will be buffered. Otherwise writes will be attempted until at least min_len characters have been sent.

min_len : default = 0
pos : default = 0
len : default = length bstr - pos
val really_output : Pervasives.out_channel -> ?pos:int -> ?len:int -> t -> unit
really_output oc ?pos ?len bstr outputs exactly len bytes from bigstring bstr starting at position pos to output channel oc.
Raises
pos : default = 0
len : default = length bstr - pos

Memory mapping

val map_file : shared:bool -> Unix.file_descr -> int -> t
map_file shared fd n memory-maps n characters of the data associated with descriptor fd to a bigstring. Iff shared is true, all changes to the bigstring will be reflected in the file.

Unsafe functions

val unsafe_blit : src:t ->
src_pos:int -> dst:t -> dst_pos:int -> len:int -> unit
unsafe_blit ~src ~src_pos ~dst ~dst_pos ~len similar to Bigstring.blit, but does not perform any bounds checks. Will crash on bounds errors! Owing to special handling for very large copies, bigstring_blit_stub may call Caml runtime functions, and hence cannot be flagged as noalloc.
val unsafe_blit_string_bigstring : src:string ->
src_pos:int -> dst:t -> dst_pos:int -> len:int -> unit
unsafe_blit_string_bigstring ~src ~src_pos ~dst ~dst_pos ~len similar to Bigstring.blit_string_bigstring, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_blit_bigstring_string : src:t ->
src_pos:int -> dst:string -> dst_pos:int -> len:int -> unit
unsafe_blit_bigstring_string ~src ~src_pos ~dst ~dst_pos ~len similar to Bigstring.blit_bigstring_string, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_read_assume_fd_is_nonblocking : Unix.file_descr -> pos:int -> len:int -> t -> int
unsafe_read_assume_fd_is_nonblocking fd ~pos ~len bstr similar to Bigstring.read_assume_fd_is_nonblocking, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_write : Unix.file_descr -> pos:int -> len:int -> t -> int
unsafe_write fd ~pos ~len bstr similar to Bigstring.write, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_write_assume_fd_is_nonblocking : Unix.file_descr -> pos:int -> len:int -> t -> int
unsafe_write_assume_fd_is_nonblocking fd ~pos ~len bstr similar to Bigstring.write_assume_fd_is_nonblocking, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_read : min_len:int -> Unix.file_descr -> pos:int -> len:int -> t -> int
unsafe_read ~min_len fd ~pos ~len bstr similar to Bigstring.read, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_really_recv : Unix.file_descr -> pos:int -> len:int -> t -> unit
unsafe_really_recv sock ~pos ~len bstr similar to Bigstring.really_recv, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_input : min_len:int ->
Pervasives.in_channel -> pos:int -> len:int -> t -> int
unsafe_input ~min_len ic ~pos ~len bstr similar to Bigstring.input, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_really_write : Unix.file_descr -> pos:int -> len:int -> t -> unit
unsafe_really_write fd ~pos ~len bstr similar to Bigstring.write, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_really_send_no_sigpipe : (Unix.file_descr -> pos:int -> len:int -> t -> unit) Or_error.t
unsafe_really_send_no_sigpipe sock ~pos ~len bstr similar to Bigstring.send, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_send_nonblocking_no_sigpipe : (Unix.file_descr -> pos:int -> len:int -> t -> int option)
Or_error.t
unsafe_send_nonblocking_no_sigpipe sock ~pos ~len bstr similar to Bigstring.send_nonblocking_no_sigpipe, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_output : min_len:int ->
Pervasives.out_channel -> pos:int -> len:int -> t -> int
unsafe_output ~min_len oc ~pos ~len bstr similar to Bigstring.output, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_writev : Unix.file_descr -> t Unix.IOVec.t array -> int -> int
unsafe_writev fd iovecs count similar to Bigstring.writev, but does not perform any bounds checks. Will crash on bounds errors!
val unsafe_sendmsg_nonblocking_no_sigpipe : (Unix.file_descr -> t Unix.IOVec.t array -> int -> int option)
Or_error.t
unsafe_sendmsg_nonblocking_no_sigpipe fd iovecs count similar to Bigstring.sendmsg_nonblocking_no_sigpipe, but does not perform any bounds checks. Will crash on bounds errors!


val find : ?pos:int -> ?len:int -> char -> t -> int option
find ?pos ?len char t returns Some i for the smallest i >= pos such that t.{i} = char, or None if there is no such i.
pos : default = 0
len : default = length bstr - pos

Destruction

val unsafe_destroy : t -> unit
unsafe_destroy bstr destroys the bigstring by deallocating its associated data or, if memory-mapped, unmapping the corresponding file, and setting all dimensions to zero. This effectively frees the associated memory or address-space resources instantaneously. This feature helps working around a bug in the current OCaml runtime, which does not correctly estimate how aggressively to reclaim such resources.

This operation is safe unless you have passed the bigstring to another thread that is performing operations on it at the same time. Access to the bigstring after this operation will yield array bounds exceptions.
Raises Failure if the bigstring has already been deallocated (or deemed "external", which is treated equivalently), or if it has proxies, i.e. other bigstrings referring to the same data.

val unsafe_get_int16_le : t -> pos:int -> int
val unsafe_get_int16_be : t -> pos:int -> int
val unsafe_set_int16_le : t -> pos:int -> int -> unit
val unsafe_set_int16_be : t -> pos:int -> int -> unit
val unsafe_get_uint16_le : t -> pos:int -> int
val unsafe_get_uint16_be : t -> pos:int -> int
val unsafe_set_uint16_le : t -> pos:int -> int -> unit
val unsafe_set_uint16_be : t -> pos:int -> int -> unit
val unsafe_get_int32_le : t -> pos:int -> int
val unsafe_get_int32_be : t -> pos:int -> int
val unsafe_set_int32_le : t -> pos:int -> int -> unit
val unsafe_set_int32_be : t -> pos:int -> int -> unit
val unsafe_get_int64_le_exn : t -> pos:int -> int
val unsafe_get_int64_be_exn : t -> pos:int -> int
val unsafe_set_int64_le : t -> pos:int -> int -> unit
val unsafe_set_int64_be : t -> pos:int -> int -> unit
val unsafe_get_int32_t_le : t -> pos:int -> Int32.t
val unsafe_get_int32_t_be : t -> pos:int -> Int32.t
val unsafe_set_int32_t_le : t -> pos:int -> Int32.t -> unit
val unsafe_set_int32_t_be : t -> pos:int -> Int32.t -> unit
val unsafe_get_int64_t_le : t -> pos:int -> Int64.t
val unsafe_get_int64_t_be : t -> pos:int -> Int64.t
val unsafe_set_int64_t_le : t -> pos:int -> Int64.t -> unit
val unsafe_set_int64_t_be : t -> pos:int -> Int64.t -> unit
val t_of_sexp : Sexplib.Sexp.t -> t
val sexp_of_t : t -> Sexplib.Sexp.t
val bin_t : t Bin_prot.Type_class.t
val bin_read_t : t Bin_prot.Read_ml.reader
val bin_read_t_ : t Bin_prot.Unsafe_read_c.reader
val bin_read_t__ : (int -> t) Bin_prot.Unsafe_read_c.reader
val bin_reader_t : t Bin_prot.Type_class.reader
val bin_size_t : t Bin_prot.Size.sizer
val bin_write_t : t Bin_prot.Write_ml.writer
val bin_write_t_ : t Bin_prot.Unsafe_write_c.writer
val bin_writer_t : t Bin_prot.Type_class.writer

Type of I/O errors

Number of bytes successfully read/written before error

The occurred exception (e.g. Unix_error, End_of_file)

Creation and string conversion


create length

init n ~f creates a bigstring t of length n, with t.{i} = f i

of_string ?pos ?len str

to_string ?pos ?len bstr

Checking


check_args ~loc ~pos ~len bstr checks the position and length arguments pos and len for bigstrings bstr.

get_opt_len bstr ~pos opt_len

Accessors


length bstr

sub ?pos ?len bstr

sub_shared ?pos ?len bstr

get t pos returns the character at pos

set t pos sets the character at pos

is_mmapped bstr

Blitting


blit ~src ?src_pos ?src_len ~dst ?dst_pos () blits src_len characters from src starting at position src_pos to dst at position dst_pos.

Input functions


read ?min_len fd ?pos ?len bstr reads at least min_len (must be greater than or equal zero) and at most len (must be greater than or equal to min_len) bytes from file descriptor fd, and writes them to bigstring bstr starting at position pos.

really_read fd ?pos ?len bstr reads len bytes from file descriptor fd, and writes them to bigstring bstr starting at position pos.

really_recv sock ?pos ?len bstr receives len bytes from socket sock, and writes them to bigstring bstr starting at position pos. If len is zero, the function returns immediately without performing the underlying system call.

recvfrom_assume_fd_is_nonblocking sock ?pos ?len bstr reads up to len bytes into bigstring bstr starting at position pos from socket sock without yielding to other OCaml-threads.

read_assume_fd_is_nonblocking fd ?pos ?len bstr reads up to len bytes into bigstring bstr starting at position pos from file descriptor fd without yielding to other OCaml-threads.

input ?min_len ic ?pos ?len bstr tries to read len bytes (guarantees to read at least min_len bytes (must be greater than or equal to zero and smaller or equal to len), if possible, before returning) from input channel ic, and writes them to bigstring bstr starting at position pos.

really_input ic ?pos ?len bstr reads exactly len bytes from input channel ic, and writes them to bigstring bstr starting at position pos.

Output functions


really_write fd ?pos ?len bstr writes len bytes in bigstring bstr starting at position pos to file descriptor fd.

really_send_no_sigpipe sock ?pos ?len bstr sends len bytes in bigstring bstr starting at position pos to socket sock without blocking and ignoring SIGPIPE.

send_nonblocking_no_sigpipe sock ?pos ?len bstr tries to send len bytes in bigstring bstr starting at position pos to socket sock.

sendto_nonblocking_no_sigpipe sock ?pos ?len bstr sockaddr tries to send len bytes in bigstring bstr starting at position pos to socket sock using address addr.

write fd ?pos ?len bstr writes len bytes in bigstring bstr starting at position pos to file descriptor fd.

write_assume_fd_is_nonblocking fd ?pos ?len bstr writes len bytes in bigstring bstr starting at position pos to file descriptor fd without yielding to other OCaml-threads.

writev fd ?count iovecs writes count iovecs of bigstrings to file descriptor fd.

writev_assume_fd_is_nonblocking fd ?count iovecs writes count iovecs of bigstrings to file descriptor fd without yielding to other OCaml-threads.

sendmsg_nonblocking_no_sigpipe sock ?count iovecs sends count iovecs of bigstrings to socket sock.

output ?min_len oc ?pos ?len bstr tries to output len bytes (guarantees to write at least min_len bytes (must be equal to or greater than zero), if possible, before returning) from bigstring bstr starting at position pos to output channel oc.

really_output oc ?pos ?len bstr outputs exactly len bytes from bigstring bstr starting at position pos to output channel oc.

Memory mapping


map_file shared fd n memory-maps n characters of the data associated with descriptor fd to a bigstring. Iff shared is true, all changes to the bigstring will be reflected in the file.

Unsafe functions


unsafe_blit ~src ~src_pos ~dst ~dst_pos ~len similar to Bigstring.blit, but does not perform any bounds checks. Will crash on bounds errors! Owing to special handling for very large copies, bigstring_blit_stub may call Caml runtime functions, and hence cannot be flagged as noalloc.

unsafe_blit_string_bigstring ~src ~src_pos ~dst ~dst_pos ~len similar to Bigstring.blit_string_bigstring, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_blit_bigstring_string ~src ~src_pos ~dst ~dst_pos ~len similar to Bigstring.blit_bigstring_string, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_read_assume_fd_is_nonblocking fd ~pos ~len bstr similar to Bigstring.read_assume_fd_is_nonblocking, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_write fd ~pos ~len bstr similar to Bigstring.write, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_write_assume_fd_is_nonblocking fd ~pos ~len bstr similar to Bigstring.write_assume_fd_is_nonblocking, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_read ~min_len fd ~pos ~len bstr similar to Bigstring.read, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_really_recv sock ~pos ~len bstr similar to Bigstring.really_recv, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_input ~min_len ic ~pos ~len bstr similar to Bigstring.input, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_really_write fd ~pos ~len bstr similar to Bigstring.write, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_really_send_no_sigpipe sock ~pos ~len bstr similar to Bigstring.send, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_send_nonblocking_no_sigpipe sock ~pos ~len bstr similar to Bigstring.send_nonblocking_no_sigpipe, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_output ~min_len oc ~pos ~len bstr similar to Bigstring.output, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_writev fd iovecs count similar to Bigstring.writev, but does not perform any bounds checks. Will crash on bounds errors!

unsafe_sendmsg_nonblocking_no_sigpipe fd iovecs count similar to Bigstring.sendmsg_nonblocking_no_sigpipe, but does not perform any bounds checks. Will crash on bounds errors!



find ?pos ?len char t returns Some i for the smallest i >= pos such that t.{i} = char, or None if there is no such i.

Destruction


unsafe_destroy bstr destroys the bigstring by deallocating its associated data or, if memory-mapped, unmapping the corresponding file, and setting all dimensions to zero. This effectively frees the associated memory or address-space resources instantaneously. This feature helps working around a bug in the current OCaml runtime, which does not correctly estimate how aggressively to reclaim such resources.

This operation is safe unless you have passed the bigstring to another thread that is performing operations on it at the same time. Access to the bigstring after this operation will yield array bounds exceptions.