Module Lwt_bytes

Access
Conversions
Copying
Filling
IOs
Memory mapped files

Instructions: Use this module in your project

In the IDE (CLion, Visual Studio Code, Xcode, etc.) you use for your DkSDK project:

Add the following to your project's dependencies/CMakeLists.txt:

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DkSDKProject_DeclareAvailable(lwt
    CONSTRAINT "= 5.6.1"
    FINDLIBS lwt lwt.unix)
DkSDKProject_MakeAvailable(lwt)

Add the Findlib::lwt library to any desired targets in src/*/CMakeLists.txt:

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target_link_libraries(YourPackage_YourLibraryName
     # ... existing libraries, if any ...
     Findlib::lwt)

Click your IDE's Build button

Not using DkSDK?

FIRST, do one or all of the following:

Run:
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```
opam install lwt.5.6.1
```

Edit your dune-project and add:

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(package
  (name YourExistingPackage)
  (depends
  ; ... existing dependenices ...
  (lwt (>= 5.6.1))))

Then run:

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dune build *.opam # if this fails, run: dune build

Edit your <package>.opam file and add:

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depends: [
  # ... existing dependencies ...
  "lwt" {>= "5.6.1"}
]

Then run:

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opam install . --deps-only

FINALLY, add the lwt.unix library to any desired (library)and/or (executable) targets in your **/dune files:

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(library
  (name YourLibrary)
  ; ... existing library options ...
  (libraries
    ; ... existing libraries ...
    lwt.unix))

(executable
  (name YourExecutable)
  ; ... existing executable options ...
  (libraries
    ; ... existing libraries ...
    lwt.unix))

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

Type of array of bytes.

valcreate : ``int-> t

Creates a new byte array of the given size.

vallength :t -> int

Returns the length of the given byte array.

Access

valget :t ->``int-> char

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

valset :t ->``int->``char-> unit

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

valunsafe_get :t ->``int-> char

Same as get but without bounds checking.

valunsafe_set :t ->``int->``char-> unit

Same as set but without bounds checking.

Conversions

valof_bytes : ``bytes-> t

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

valof_string : ``string-> t

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

valto_bytes :t -> bytes

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

valto_string :t -> string

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

Copying

valblit :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.

valblit_from_string : ``string->``int-> t ->``int->``int-> unit

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

valblit_from_bytes : ``bytes->``int-> t ->``int->``int-> unit

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

valblit_to_bytes :t ->``int->``bytes->``int->``int-> unit

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

valunsafe_blit :t ->``int-> t ->``int->``int-> unit

Same as blit but without bound checking.

valunsafe_blit_from_bytes : ``bytes->``int-> t ->``int->``int-> unit

Same as Lwt_bytes.blit_from_bytes but without bounds checking.

valunsafe_blit_from_string : ``string->``int-> t ->``int->``int-> unit

Same as Lwt_bytes.blit_from_string but without bounds checking.

valunsafe_blit_to_bytes :t ->``int->``bytes->``int->``int-> unit

Same as Lwt_bytes.blit_to_bytes but without bounds checking.

valproxy :t ->``int->``int-> t

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

valextract :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.

valcopy :t -> t

copy buffer creates a copy of the given byte array.

Filling

valfill :t ->``int->``int->``char-> unit

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

valunsafe_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 Bytes.t, and they never perform extra copies of the data.

valread :Lwt_unix.file_descr -> t ->``int->``int->``intLwt.t

valwrite :Lwt_unix.file_descr -> t ->``int->``int->``intLwt.t

valrecv :Lwt_unix.file_descr -> t ->``int->``int-> Unix.msg_flaglist``->``intLwt.t

Not implemented on Windows.

valsend :Lwt_unix.file_descr -> t ->``int->``int-> Unix.msg_flaglist``->``intLwt.t

Not implemented on Windows.

valrecvfrom :Lwt_unix.file_descr -> t ->``int->``int-> Unix.msg_flaglist``->``(int *Unix.sockaddr)`` Lwt.t

Not implemented on Windows.

valsendto :Lwt_unix.file_descr -> t ->``int->``int-> Unix.msg_flaglist``-> Unix.sockaddr ->``intLwt.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_vectorlist``->``(int *Unix.file_descrlist``)``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_vectorlist``-> ``fds:Unix.file_descrlist``->``intLwt.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.

valmapped :t -> bool

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

typeadvice`` =


| 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.

valmadvise :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.

valmincore :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.

valwait_mincore :t ->``int->``unitLwt.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.

Module Lwt_bytes

Contents

Not using DkSDK?

Access

Conversions

Copying

Filling

IOs

Memory mapped files

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