SkStream Class Reference

SkStream – abstraction for a source of bytes. More...

#include <SkStream.h>

Inheritance diagram for SkStream:

Public Member Functions
virtual	~SkStream ()
	SkStream ()
virtual size_t	read (void *buffer, size_t size)=0
	Reads or skips size number of bytes. More...
size_t	skip (size_t size)
	Skip size number of bytes. More...
virtual size_t	peek (void *, size_t) const
	Attempt to peek at size bytes. More...
virtual bool	isAtEnd () const =0
	Returns true when all the bytes in the stream have been read. More...
bool	readS8 (int8_t *)
bool	readS16 (int16_t *)
bool	readS32 (int32_t *)
bool	readU8 (uint8_t *i)
bool	readU16 (uint16_t *i)
bool	readU32 (uint32_t *i)
bool	readBool (bool *b)
bool	readScalar (SkScalar *)
bool	readPackedUInt (size_t *)
virtual bool	rewind ()
	Rewinds to the beginning of the stream. More...
std::unique_ptr< SkStream >	duplicate () const
	Duplicates this stream. More...
std::unique_ptr< SkStream >	fork () const
	Duplicates this stream. More...
virtual bool	hasPosition () const
	Returns true if this stream can report its current position. More...
virtual size_t	getPosition () const
	Returns the current position in the stream. More...
virtual bool	seek (size_t)
	Seeks to an absolute position in the stream. More...
virtual bool	move (long)
	Seeks to an relative offset in the stream. More...
virtual bool	hasLength () const
	Returns true if this stream can report its total length. More...
virtual size_t	getLength () const
	Returns the total length of the stream. More...
virtual const void *	getMemoryBase ()
	Returns the starting address for the data. More...

Static Public Member Functions
static std::unique_ptr< SkStreamAsset >	MakeFromFile (const char path[])
	Attempts to open the specified file as a stream, returns nullptr on failure. More...

Detailed Description

SkStream – abstraction for a source of bytes.

Subclasses can be backed by memory, or a file, or something else.

Constructor & Destructor Documentation

~SkStream()

virtual SkStream::~SkStream ( )

inlinevirtual

SkStream()

SkStream::SkStream ( )

inline

Member Function Documentation

duplicate()

std::unique_ptr<SkStream> SkStream::duplicate ( ) const

inline

Duplicates this stream.

If this cannot be done, returns NULL. The returned stream will be positioned at the beginning of its data.

fork()

std::unique_ptr<SkStream> SkStream::fork ( ) const

inline

Duplicates this stream.

If this cannot be done, returns NULL. The returned stream will be positioned the same as this stream.

getLength()

virtual size_t SkStream::getLength ( ) const

inlinevirtual

Returns the total length of the stream.

If this cannot be done, returns 0.

Reimplemented in SkStreamAsset, SkMemoryStream, and SkFILEStream.

getMemoryBase()

virtual const void* SkStream::getMemoryBase ( )

inlinevirtual

Returns the starting address for the data.

If this cannot be done, returns NULL.

Reimplemented in SkStreamMemory, and SkMemoryStream.

getPosition()

virtual size_t SkStream::getPosition ( ) const

inlinevirtual

Returns the current position in the stream.

If this cannot be done, returns 0.

Reimplemented in SkStreamSeekable, SkMemoryStream, and SkFILEStream.

hasLength()

virtual bool SkStream::hasLength ( ) const

inlinevirtual

Returns true if this stream can report its total length.

Reimplemented in SkStreamAsset.

hasPosition()

virtual bool SkStream::hasPosition ( ) const

inlinevirtual

Returns true if this stream can report its current position.

Reimplemented in SkStreamSeekable.

isAtEnd()

virtual bool SkStream::isAtEnd ( ) const

pure virtual

Returns true when all the bytes in the stream have been read.

As SkStream represents synchronous I/O, isAtEnd returns false when the final stream length isn't known yet, even when all the bytes available so far have been read. This may return true early (when there are no more bytes to be read) or late (after the first unsuccessful read).

Implemented in SkMemoryStream, and SkFILEStream.

MakeFromFile()

static std::unique_ptr<SkStreamAsset> SkStream::MakeFromFile ( const char  path[] )

static

Attempts to open the specified file as a stream, returns nullptr on failure.

move()

virtual bool SkStream::move ( long  )

inlinevirtual

Seeks to an relative offset in the stream.

If this cannot be done, returns false. If an attempt is made to move to a position outside the stream, the position will be set to the closest point within the stream (beginning or end).

Reimplemented in SkStreamSeekable, SkMemoryStream, and SkFILEStream.

peek()

virtual size_t SkStream::peek ( void *  , size_t    ) const

inlinevirtual

Attempt to peek at size bytes.

If this stream supports peeking, copy min(size, peekable bytes) into buffer, and return the number of bytes copied. If the stream does not support peeking, or cannot peek any bytes, return 0 and leave buffer unchanged. The stream is guaranteed to be in the same visible state after this call, regardless of success or failure.

Parameters

buffer	Must not be NULL, and must be at least size bytes. Destination to copy bytes.
size	Number of bytes to copy.

Returns

The number of bytes peeked/copied.

Reimplemented in SkMemoryStream.

read()

virtual size_t SkStream::read ( void *  buffer, size_t  size  )

pure virtual

Reads or skips size number of bytes.

If buffer == NULL, skip size bytes, return how many were skipped. If buffer != NULL, copy size bytes into buffer, return how many were copied.

Parameters

buffer	when NULL skip size bytes, otherwise copy size bytes into buffer
size	the number of bytes to skip or copy

Returns

the number of bytes actually read.

Implemented in SkMemoryStream, and SkFILEStream.

readBool()

bool SkStream::readBool ( bool *  b )

inline

readPackedUInt()

bool SkStream::readPackedUInt

(

size_t *

)

readS16()

bool SkStream::readS16

(

int16_t *

)

readS32()

bool SkStream::readS32

(

int32_t *

)

readS8()

bool SkStream::readS8

(

int8_t *

)

readScalar()

bool SkStream::readScalar

(

SkScalar *

)

readU16()

bool SkStream::readU16 ( uint16_t *  i )

inline

readU32()

bool SkStream::readU32 ( uint32_t *  i )

inline

readU8()

bool SkStream::readU8 ( uint8_t *  i )

inline

rewind()

virtual bool SkStream::rewind ( )

inlinevirtual

Rewinds to the beginning of the stream.

Returns true if the stream is known to be at the beginning after this call returns.

Reimplemented in SkStreamRewindable, SkMemoryStream, and SkFILEStream.

seek()

virtual bool SkStream::seek ( size_t  )

inlinevirtual

Seeks to an absolute position in the stream.

If this cannot be done, returns false. If an attempt is made to seek past the end of the stream, the position will be set to the end of the stream.

Reimplemented in SkStreamSeekable, SkMemoryStream, and SkFILEStream.

skip()

size_t SkStream::skip ( size_t  size )

inline

Skip size number of bytes.

Returns

the actual number bytes that could be skipped.

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The documentation for this class was generated from the following file:

• /CHECKOUT/include/core/SkStream.h