memory-0.7: memory and related abtraction stuff

LicenseBSD-style
MaintainerVincent Hanquez <vincent@snarc.org>
Stabilitystable
PortabilityGood
Safe HaskellNone
LanguageHaskell2010

Data.ByteArray

Contents

Description

Simple and efficient byte array types

This module should be imported qualified.

Synopsis

ByteArray Classes

class ByteArrayAccess ba where Source

Class to Access size properties and data of a ByteArray

Methods

length :: ba -> Int Source

Return the length in bytes of a bytearray

withByteArray :: ba -> (Ptr p -> IO a) -> IO a Source

Allow to use using a pointer

class (Eq ba, Ord ba, Monoid ba, ByteArrayAccess ba) => ByteArray ba where Source

Class to allocate new ByteArray of specific size

Methods

allocRet :: Int -> (Ptr p -> IO a) -> IO (a, ba) Source

ByteArray built-in types

data ScrubbedBytes Source

ScrubbedBytes is a memory chunk which have the properties of:

  • Being scrubbed after its goes out of scope.
  • A Show instance that doesn't actually show any content
  • A Eq instance that is constant time

data MemView Source

A simple abstraction to a piece of memory.

Do beware that garbage collection related to piece of memory could be triggered before this is used.

Only use with the appropriate handler has been used (e.g. withForeignPtr on ForeignPtr)

Constructors

MemView !(Ptr Word8) !Int 

memViewPlus :: MemView -> Int -> MemView Source

Increase the memory view while reducing the size of the window

this is useful as an abtraction to represent the current offset in a buffer, and the remaining bytes left.

data View bytes Source

a view on a given bytes

Equality test in constant time

Instances

ByteArrayAccess bytes => Eq (View bytes) 
ByteArrayAccess bytes => Ord (View bytes) 
ByteArrayAccess bytes => Show (View bytes) 
ByteArrayAccess bytes => ByteArrayAccess (View bytes) 

view Source

Arguments

:: ByteArrayAccess bytes 
=> bytes

the byte array we put a view on

-> Int

the offset to start the byte array on

-> Int

the size of the view

-> View bytes 

create a view on a given bytearray

This function update the offset and the size in order to guarantee:

  • offset >= 0
  • size >= 0
  • offset < length
  • size =< length - offset

takeView Source

Arguments

:: ByteArrayAccess bytes 
=> bytes

byte aray

-> Int

size of the view

-> View bytes 

create a view from the given bytearray

dropView Source

Arguments

:: ByteArrayAccess bytes 
=> bytes

byte array

-> Int

the number of bytes do dropped before creating the view

-> View bytes 

create a view from the given byte array starting after having dropped the fist n bytes

ByteArray methods

alloc :: ByteArray ba => Int -> (Ptr p -> IO ()) -> IO ba Source

Allocate a new bytearray of specific size, and run the initializer on this memory

allocAndFreeze :: ByteArray a => Int -> (Ptr p -> IO ()) -> a Source

similar to alloc but hide the allocation and initializer in a pure context

create :: ByteArray ba => Int -> (Ptr p -> IO ()) -> IO ba Source

Allocate a new bytearray of specific size, and run the initializer on this memory

unsafeCreate :: ByteArray a => Int -> (Ptr p -> IO ()) -> a Source

similar to create but hide the allocation and initializer in a pure context

pack :: ByteArray a => [Word8] -> a Source

Pack a list of bytes into a bytearray

unpack :: ByteArrayAccess a => a -> [Word8] Source

Un-pack a bytearray into a list of bytes

uncons :: ByteArray a => a -> Maybe (Word8, a) Source

returns the first byte, and the remaining bytearray if the bytearray is not null

empty :: ByteArray a => a Source

Create an empty byte array

null :: ByteArray a => a -> Bool Source

Check if a byte array is empty

replicate :: ByteArray ba => Int -> Word8 -> ba Source

Create a bytearray of a specific size containing a repeated byte value

zero :: ByteArray ba => Int -> ba Source

Create a bytearray of a specific size initialized to 0

copy :: (ByteArrayAccess bs1, ByteArray bs2) => bs1 -> (Ptr p -> IO ()) -> IO bs2 Source

Duplicate a bytearray into another bytearray, and run an initializer on it

take :: ByteArray bs => Int -> bs -> bs Source

Take the first @n byte of a bytearray

drop :: ByteArray bs => Int -> bs -> bs Source

drop the first @n byte of a bytearray

span :: ByteArray bs => (Word8 -> Bool) -> bs -> (bs, bs) Source

Split a bytearray at the point where @pred becomes invalid

convert :: (ByteArrayAccess bin, ByteArray bout) => bin -> bout Source

Convert a bytearray to another type of bytearray

copyRet :: (ByteArrayAccess bs1, ByteArray bs2) => bs1 -> (Ptr p -> IO a) -> IO (a, bs2) Source

Similar to copy but also provide a way to return a value from the initializer

copyAndFreeze :: (ByteArrayAccess bs1, ByteArray bs2) => bs1 -> (Ptr p -> IO ()) -> bs2 Source

Similiar to copy but expect the resulting bytearray in a pure context

splitAt :: ByteArray bs => Int -> bs -> (bs, bs) Source

Split a bytearray at a specific length in two bytearray

xor :: (ByteArrayAccess a, ByteArrayAccess b, ByteArray c) => a -> b -> c Source

Create a xor of bytes between a and b.

the returns byte array is the size of the smallest input.

index :: ByteArrayAccess a => a -> Int -> Word8 Source

return a specific byte indexed by a number from 0 in a bytearray

unsafe, no bound checking are done

eq :: (ByteArrayAccess bs1, ByteArrayAccess bs2) => bs1 -> bs2 -> Bool Source

Check if two bytearray are equals

This is not constant time, as soon some byte differs the function will returns. use constEq in sensitive context where timing matters.

constEq :: (ByteArrayAccess bs1, ByteArrayAccess bs2) => bs1 -> bs2 -> Bool Source

A constant time equality test for 2 ByteArrayAccess values.

If values are of 2 different sizes, the function will abort early without comparing any bytes.

compared to == , this function will go over all the bytes present before yielding a result even when knowing the overall result early in the processing.

append :: ByteArray bs => bs -> bs -> bs Source

append one bytearray to the other

concat :: (ByteArrayAccess bin, ByteArray bout) => [bin] -> bout Source

Concatenate bytearray into a larger bytearray