SkMemoryStream Class Reference

#include <SkStream.h>

Inheritance diagram for SkMemoryStream:

Public Member Functions
	SkMemoryStream ()
	SkMemoryStream (size_t length)
	SkMemoryStream (const void *data, size_t length, bool copyData=false)
	SkMemoryStream (sk_sp< SkData > data)
virtual void	setMemory (const void *data, size_t length, bool copyData=false)
void	setMemoryOwned (const void *data, size_t length)
sk_sp< SkData >	getData () const override
void	setData (sk_sp< SkData > data)
const void *	getAtPos ()
size_t	read (void *buffer, size_t size) override
bool	isAtEnd () const override
size_t	peek (void *buffer, size_t size) const override
bool	rewind () override
std::unique_ptr< SkMemoryStream >	duplicate () const
size_t	getPosition () const override
bool	seek (size_t position) override
bool	move (long offset) override
std::unique_ptr< SkMemoryStream >	fork () const
size_t	getLength () const override
const void *	getMemoryBase () override
Public Member Functions inherited from SkStreamMemory
const void *	getMemoryBase () override=0
std::unique_ptr< SkStreamMemory >	duplicate () const
std::unique_ptr< SkStreamMemory >	fork () const
Public Member Functions inherited from SkStreamAsset
bool	hasLength () const override
size_t	getLength () const override=0
std::unique_ptr< SkStreamAsset >	duplicate () const
std::unique_ptr< SkStreamAsset >	fork () const
Public Member Functions inherited from SkStreamSeekable
std::unique_ptr< SkStreamSeekable >	duplicate () const
bool	hasPosition () const override
size_t	getPosition () const override=0
bool	seek (size_t position) override=0
bool	move (long offset) override=0
std::unique_ptr< SkStreamSeekable >	fork () const
Public Member Functions inherited from SkStreamRewindable
bool	rewind () override=0
std::unique_ptr< SkStreamRewindable >	duplicate () const
Public Member Functions inherited from SkStream
virtual	~SkStream ()
	SkStream ()
virtual size_t	read (void *buffer, size_t size)=0
size_t	skip (size_t size)
virtual size_t	peek (void *, size_t) const
virtual bool	isAtEnd () const =0
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 ()
std::unique_ptr< SkStream >	duplicate () const
std::unique_ptr< SkStream >	fork () const
virtual bool	hasPosition () const
virtual size_t	getPosition () const
virtual bool	seek (size_t)
virtual bool	move (long)
virtual bool	hasLength () const
virtual size_t	getLength () const
virtual const void *	getMemoryBase ()
virtual sk_sp< SkData >	getData () const

Static Public Member Functions
static std::unique_ptr< SkMemoryStream >	MakeCopy (const void *data, size_t length)
static std::unique_ptr< SkMemoryStream >	MakeDirect (const void *data, size_t length)
static std::unique_ptr< SkMemoryStream >	Make (sk_sp< SkData > data)
Static Public Member Functions inherited from SkStream
static std::unique_ptr< SkStreamAsset >	MakeFromFile (const char path[])

Detailed Description

Definition at line 361 of file SkStream.h.

Constructor & Destructor Documentation

SkMemoryStream() [1/4]

SkMemoryStream::SkMemoryStream

(

)

Definition at line 284 of file SkStream.cpp.

                               {
    fData = SkData::MakeEmpty();
    fOffset = 0;
}

SkMemoryStream() [2/4]

SkMemoryStream::SkMemoryStream

(

size_t

length

)

We allocate (and free) the memory. Write to it via getMemoryBase()

Definition at line 289 of file SkStream.cpp.

                                          {
    fData = SkData::MakeUninitialized(size);
    fOffset = 0;
}

SkMemoryStream() [3/4]

SkMemoryStream::SkMemoryStream	(	const void *	data,
		size_t	length,
		bool	copyData = false
	)

If copyData is true, the stream makes a private copy of the data.

Definition at line 294 of file SkStream.cpp.

                                                                          {
    fData = newFromParams(src, size, copyData);
    fOffset = 0;
}

SkMemoryStream() [4/4]

SkMemoryStream::SkMemoryStream

(

sk_sp< SkData >

data

)

Creates the stream to read from the specified data

Definition at line 299 of file SkStream.cpp.

                                                 : fData(std::move(data)) {
    if (nullptr == fData) {
        fData = SkData::MakeEmpty();
    }
    fOffset = 0;
}

Member Function Documentation

duplicate()

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

inline

Definition at line 407 of file SkStream.h.

                                                    {
        return std::unique_ptr<SkMemoryStream>(this->onDuplicate());
    }

fork()

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

inline

Definition at line 415 of file SkStream.h.

                                               {
        return std::unique_ptr<SkMemoryStream>(this->onFork());
    }

getAtPos()

const void * SkMemoryStream::getAtPos

(

)

Definition at line 403 of file SkStream.cpp.

                                     {
    return fData->bytes() + fOffset;
}

getData()

sk_sp< SkData > SkMemoryStream::getData ( ) const

inlineoverridevirtual

Reimplemented from SkStream.

Definition at line 395 of file SkStream.h.

{ return fData; }

getLength()

size_t SkMemoryStream::getLength ( ) const

overridevirtual

Returns the total length of the stream. If this cannot be done, returns 0.

Implements SkStreamAsset.

Definition at line 395 of file SkStream.cpp.

                                       {
    return fData->size();
}

getMemoryBase()

const void * SkMemoryStream::getMemoryBase ( )

overridevirtual

Returns the starting address for the data. If this cannot be done, returns NULL.

Implements SkStreamMemory.

Definition at line 399 of file SkStream.cpp.

                                          {
    return fData->data();
}

getPosition()

size_t SkMemoryStream::getPosition ( ) const

overridevirtual

Returns the current position in the stream. If this cannot be done, returns 0.

Implements SkStreamSeekable.

Definition at line 374 of file SkStream.cpp.

                                         {
    return fOffset;
}

isAtEnd()

bool SkMemoryStream::isAtEnd ( ) const

overridevirtual

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).

Implements SkStream.

Definition at line 361 of file SkStream.cpp.

                                   {
    return fOffset == fData->size();
}

Make()

std::unique_ptr< SkMemoryStream > SkMemoryStream::Make ( sk_sp< SkData >  data )

static

Returns a stream with a shared reference to the input data.

Definition at line 314 of file SkStream.cpp.

                                                                     {
    return std::make_unique<SkMemoryStream>(std::move(data));
}

MakeCopy()

std::unique_ptr< SkMemoryStream > SkMemoryStream::MakeCopy ( const void *  data, size_t  length  )

static

Returns a stream with a copy of the input data.

Definition at line 306 of file SkStream.cpp.

                                                                                      {
    return std::make_unique<SkMemoryStream>(data, length, true);
}

MakeDirect()

std::unique_ptr< SkMemoryStream > SkMemoryStream::MakeDirect ( const void *  data, size_t  length  )

static

Returns a stream with a bare pointer reference to the input data.

Definition at line 310 of file SkStream.cpp.

                                                                                        {
    return std::make_unique<SkMemoryStream>(data, length, false);
}

move()

bool SkMemoryStream::move ( long  )

overridevirtual

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).

Implements SkStreamSeekable.

Definition at line 385 of file SkStream.cpp.

                                     {
    return this->seek(fOffset + offset);
}

peek()

size_t SkMemoryStream::peek ( void *  , size_t    ) const

overridevirtual

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 from SkStream.

Definition at line 351 of file SkStream.cpp.

                                                           {
    SkASSERT(buffer != nullptr);
 
    const size_t currentOffset = fOffset;
    SkMemoryStream* nonConstThis = const_cast<SkMemoryStream*>(this);
    const size_t bytesRead = nonConstThis->read(buffer, size);
    nonConstThis->fOffset = currentOffset;
    return bytesRead;
}

read()

size_t SkMemoryStream::read ( void *  buffer, size_t  size  )

overridevirtual

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.

Implements SkStream.

Definition at line 337 of file SkStream.cpp.

                                                     {
    size_t dataSize = fData->size();
 
    SkASSERT(fOffset <= dataSize);
    if (size > dataSize - fOffset) {
        size = dataSize - fOffset;
    }
    if (buffer) {
        sk_careful_memcpy(buffer, fData->bytes() + fOffset, size);
    }
    fOffset += size;
    return size;
}

rewind()

bool SkMemoryStream::rewind ( )

overridevirtual

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

Implements SkStreamRewindable.

Definition at line 365 of file SkStream.cpp.

                            {
    fOffset = 0;
    return true;
}

seek()

bool SkMemoryStream::seek ( size_t  )

overridevirtual

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.

Implements SkStreamSeekable.

Definition at line 378 of file SkStream.cpp.

                                         {
    fOffset = position > fData->size()
            ? fData->size()
            : position;
    return true;
}

setData()

void SkMemoryStream::setData

(

sk_sp< SkData >

data

)

Definition at line 328 of file SkStream.cpp.

                                               {
    if (nullptr == data) {
        fData = SkData::MakeEmpty();
    } else {
        fData = data;
    }
    fOffset = 0;
}

setMemory()

void SkMemoryStream::setMemory ( const void *  data, size_t  length, bool  copyData = false  )

virtual

Resets the stream to the specified data and length, just like the constructor. if copyData is true, the stream makes a private copy of the data

Definition at line 323 of file SkStream.cpp.

                                                                          {
    fData = newFromParams(src, size, copyData);
    fOffset = 0;
}

setMemoryOwned()

void SkMemoryStream::setMemoryOwned	(	const void *	data,
		size_t	length
	)

Replace any memory buffer with the specified buffer. The caller must have allocated data with sk_malloc or sk_realloc, since it will be freed with sk_free.

Definition at line 318 of file SkStream.cpp.

                                                                {
    fData = SkData::MakeFromMalloc(src, size);
    fOffset = 0;
}

---

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

• third_party/skia/include/core/SkStream.h
• third_party/skia/src/core/SkStream.cpp