Z.IO.Buffered

This module provide buffered IO interface.

Input & Output device

class Input i where

Input device

readInput should return 0 on EOF.

Methods

readInput :: HasCallStack => i -> Ptr Word8 -> Int -> IO Int

Instances

Input File

Defined in Z.IO.FileSystem

Methods

readInput :: File -> Ptr Word8 -> Int -> IO Int

Input UVStream

Defined in Z.IO.UV.Manager

Methods

readInput :: UVStream -> Ptr Word8 -> Int -> IO Int

Input StdStream

Defined in Z.IO.StdStream

Methods

readInput :: StdStream -> Ptr Word8 -> Int -> IO Int

Input FileT

Defined in Z.IO.FileSystem.Threaded

Methods

readInput :: FileT -> Ptr Word8 -> Int -> IO Int

class Output o where

Output device

writeOutput should not return until all data are written (may not necessarily flushed to hardware, that should be done in device specific way).

Methods

writeOutput :: HasCallStack => o -> Ptr Word8 -> Int -> IO ()

Instances

Output File

Defined in Z.IO.FileSystem

Methods

writeOutput :: File -> Ptr Word8 -> Int -> IO ()

Output UVStream

Defined in Z.IO.UV.Manager

Methods

writeOutput :: UVStream -> Ptr Word8 -> Int -> IO ()

Output StdStream

Defined in Z.IO.StdStream

Methods

writeOutput :: StdStream -> Ptr Word8 -> Int -> IO ()

Output FileT

Defined in Z.IO.FileSystem.Threaded

Methods

writeOutput :: FileT -> Ptr Word8 -> Int -> IO ()

Buffered Input

data BufferedInput i

Input device with buffer, NOT THREAD SAFE!

• A BufferedInput should not be used in multiple threads, there's no locking mechanism to protect buffering state.
• A Input device should only be used with a single BufferedInput, If multiple BufferedInput s are opened on a same Input device, the behaviour is undefined.

newBufferedInput

Arguments

:: Int

Input buffer size

-> input

-> IO (BufferedInput input)

Open a new buffered input with given buffer size, e.g. defaultChunkSize.

readBuffer :: (HasCallStack, Input i) => BufferedInput i -> IO Bytes

Request bytes from BufferedInput.

The buffering logic is quite simple:

If we have pushed back bytes, directly return it, otherwise we read using buffer size. If we read N bytes, and N is larger than half of the buffer size, then we freeze buffer and return, otherwise we copy buffer into result and reuse buffer afterward.

unReadBuffer :: (HasCallStack, Input i) => Bytes -> BufferedInput i -> IO ()

Push bytes back into buffer.

readParser :: (HasCallStack, Input i) => Parser a -> BufferedInput i -> IO (Bytes, Either ParseError a)

Read buffer and parse with Parser.

This function will continuously draw data from input before parsing finish.

readExactly :: (HasCallStack, Input i) => Int -> BufferedInput i -> IO Bytes

Read exactly N bytes

If EOF reached before N bytes read, a ShortReadException will be thrown

readToMagic :: (HasCallStack, Input i) => Word8 -> BufferedInput i -> IO Bytes

Read until reach a magic bytes

If EOF is reached before meet a magic byte, partial bytes are returned.

readToMagic' :: (HasCallStack, Input i) => Word8 -> BufferedInput i -> IO Bytes

Read until reach a magic bytes

If EOF is reached before meet a magic byte, a ShortReadException will be thrown.

readLine :: (HasCallStack, Input i) => BufferedInput i -> IO Bytes

Read to a linefeed ('n' or 'rn'), return Bytes before it.

If EOF is reached before meet a magic byte, partial line is returned.

readLine' :: (HasCallStack, Input i) => BufferedInput i -> IO Bytes

Read to a linefeed ('n' or 'rn'), return Bytes before it.

If EOF reached before meet a 'n', a ShortReadException will be thrown.

readAll :: (HasCallStack, Input i) => BufferedInput i -> IO [Bytes]

Read all chunks from a BufferedInput.

readAll' :: (HasCallStack, Input i) => BufferedInput i -> IO Bytes

Read all chunks from a BufferedInput, and concat chunks together.

Buffered Output

data BufferedOutput o

Output device with buffer, NOT THREAD SAFE!

• A BufferedOutput should not be used in multiple threads, there's no locking mechanism to protect buffering state.
• A Output device should only be used with a single BufferedOutput, If multiple BufferedOutput s are opened on a same BufferedOutput device, the output will be interleaved.

newBufferedOutput

Arguments

:: Int

Output buffer size

-> output

-> IO (BufferedOutput output)

Open a new buffered output with given buffer size, e.g. defaultChunkSize.

writeBuffer :: Output o => BufferedOutput o -> Bytes -> IO ()

Write Bytes into buffered handle.

Copy Bytes to buffer if it can hold, otherwise write both buffer(if not empty) and Bytes.

writeBuilder :: Output o => BufferedOutput o -> Builder a -> IO ()

Write Bytes into buffered handle.

Copy Bytes to buffer if it can hold, otherwise write both buffer(if not empty) and Bytes.

flushBuffer :: Output f => BufferedOutput f -> IO ()

Flush the buffer into output device(if not empty).

Exceptions

data ShortReadException

Constructors

ShortReadException IOEInfo

Instances

Show ShortReadException

Defined in Z.IO.Buffered

Methods

showsPrec :: Int -> ShortReadException -> ShowS

show :: ShortReadException -> String

showList :: [ShortReadException] -> ShowS

Exception ShortReadException

Defined in Z.IO.Buffered

Methods

toException :: ShortReadException -> SomeException

fromException :: SomeException -> Maybe ShortReadException

displayException :: ShortReadException -> String

common buffer size

defaultChunkSize :: Int

smallChunkSize :: Int