ZStreamR Class Reference
[Streams]

Base interface for read streams. More...

#include <ZStream.h>

Inheritance diagram for ZStreamR:

List of all members.

Public Member Functions
Read raw data
Read data from this stream into memory.
void	Read (void *iDest, size_t iCount) const
	Read iCount bytes into memory starting at iDest.
void	Read (void *iDest, size_t iCount, size_t *oCountRead) const
Copy To
Read data from this stream and write it to iStreamW.
void	CopyAllTo (const ZStreamW &iStreamW) const
	Read data from this stream and write it to iStreamW until this stream reaches its end.
void	CopyAllTo (const ZStreamW &iStreamW, uint64 *oCountRead, uint64 *oCountWritten) const
	Read data from this stream and write it to iStreamW until one or other stream reaches its end.
void	CopyTo (const ZStreamW &iStreamW, uint64 iCount) const
	Read data from this stream and write it to iStreamW.
void	CopyTo (const ZStreamW &iStreamW, uint64 iCount, uint64 *oCountRead, uint64 *oCountWritten) const
	Read data from this stream and write it to iStreamW.
Skip
Skip over bytes from this stream without returning them to the caller.
void	Skip (uint64 iCount) const
	Skip over iCount bytes.
void	Skip (uint64 iCount, uint64 *oCountSkipped) const
void	SkipAll () const
void	SkipAll (uint64 *oCountSkipped) const
	Skip bytes until the end of the stream is reached, return the count actually skipped.
Read formatted data
Read data from the stream in standard formats.
int8	ReadInt8 () const
int16	ReadInt16 () const
int32	ReadInt32 () const
int64	ReadInt64 () const
float	ReadFloat () const
double	ReadDouble () const
int16	ReadInt16LE () const
int32	ReadInt32LE () const
int64	ReadInt64LE () const
float	ReadFloatLE () const
double	ReadDoubleLE () const
bool	ReadBool () const
uint8	ReadUInt8 () const
uint16	ReadUInt16 () const
uint32	ReadUInt32 () const
uint64	ReadUInt64 () const
uint16	ReadUInt16LE () const
uint32	ReadUInt32LE () const
uint64	ReadUInt64LE () const
Useful variants
Read single bytes without exceptions being thrown.
bool	ReadByte (uint8 &oResult) const
bool	ReadChar (char &oResult) const
Read standard string
std::string	ReadString (size_t iSize) const
Informational
size_t	CountReadable () const
Essential overrides
All ZStreamR functionality is implemented by calling this method.
virtual void	Imp_Read (void *iDest, size_t iCount, size_t *oCountRead)=0
Optionally overridable API
Default implementations that directly or indirectly call ZStreamR::Imp_Read are provided, but particular subclasses may have more efficient implementations available.
virtual size_t	Imp_CountReadable ()
	Returns the number of bytes guaranteed to be readable without blocking.
virtual void	Imp_CopyToDispatch (const ZStreamW &iStreamW, uint64 iCount, uint64 *oCountRead, uint64 *oCountWritten)
	Invoke iStreamW's Imp_CopyFrom method.
virtual void	Imp_CopyTo (const ZStreamW &iStreamW, uint64 iCount, uint64 *oCountRead, uint64 *oCountWritten)
	Actually copy data from this stream to iStreamW.
virtual void	Imp_Skip (uint64 iCount, uint64 *oCountSkipped)
	Read and discard iCount bytes.
Protected Member Functions
Canonical Methods
The canonical methods are protected, thus you cannot create, destroy or assign through a ZStreamR reference, you must work with some derived class.
	ZStreamR ()
	~ZStreamR ()
	ZStreamR (const ZStreamR &)
ZStreamR &	operator= (const ZStreamR &)

---

Detailed Description

Base interface for read streams.

See also:

Streams

The ZStreamR interface is heavily used by ZooLib entities that need to read formatted and unformatted data from arbitrary sources. It represents a continuous stream of bytes, with no a priori known limit. Subclasses that implement this interface may know ahead of time how much data will be readable, but this interface doesn't.

---

Member Function Documentation

void ZStreamR::Read	(	void *	iDest,
		size_t	iCount
	)			const

Read iCount bytes into memory starting at iDest.

Parameters:

	iDest	The address in memory at which read data is to be placed. It is the caller's responsibilty to ensure that iDest to iDest + iCount is correctly allocated and writeable.
	iCount	The number of bytes to read

If iCount bytes cannot be read from the stream an end of read stream exception will be thrown.

void ZStreamR::Read	(	void *	iDest,
		size_t	iCount,
		size_t *	oCountRead
	)			const [inline]

Read data into memory, returning the count actually read.

void ZStreamR::CopyAllTo	(	const ZStreamW &	iStreamW,
		uint64 *	oCountRead,
		uint64 *	oCountWritten
	)			const

Read data from this stream and write it to iStreamW until one or other stream reaches its end.

Parameters:

	iStreamW	The stream to which the data should be written.
	oCountRead	(optional output) The number of bytes that were actually read.
	oCountWritten	(optional output) The number of bytes that were actually written.

oCountWritten will be less than or equal to oCountRead. If oCountWritten is less than oCountRead it's a strong indication that iStreamW has reached its end, and a subsequent call to CopyTo or the iStreamW's Write will likely return zero in oCountWritten.

void ZStreamR::CopyTo	(	const ZStreamW &	iStreamW,
		uint64	iCount
	)			const

Read data from this stream and write it to iStreamW.

Parameters:

	iStreamW	The stream to which the data should be written.
	iCount	The number of bytes to be read from this stream and written to iStreamW.

If iCount bytes could not be read then an end of read stream exception is thrown. If iCount bytes could not be written then an end of write stream exception is thrown.

void ZStreamR::CopyTo	(	const ZStreamW &	iStreamW,
		uint64	iCount,
		uint64 *	oCountRead,
		uint64 *	oCountWritten
	)			const

Read data from this stream and write it to iStreamW.

Parameters:

	iStreamW	The stream to which the data should be written.
	iCount	The number of bytes to be read from this stream and written to iStreamW.
	oCountRead	(optional output) The number of bytes that were actually read.
	oCountWritten	(optional output) The number of bytes that were actually written.

void ZStreamR::Skip

(

uint64

iCount

)

const

Skip over iCount bytes.

Parameters:

iCount

The number of bytes to be skipped over. If the stream reaches its end prematurely then an end of read stream exception is thrown.

void ZStreamR::Skip	(	uint64	iCount,
		uint64 *	oCountSkipped
	)			const [inline]

Attempt to skip bytes, returning the count actually skipped.

void ZStreamR::SkipAll

(

)

const [inline]

Skip bytes until the end of the stream is reached.

void ZStreamR::SkipAll

(

uint64 *

oCountSkipped

)

const

Skip bytes until the end of the stream is reached, return the count actually skipped.

Parameters:

oCountSkipped

(optional output) The number of bytes actually skipped. If zero is returned then the end of the stream had already been reached.

int8 ZStreamR::ReadInt8

(

)

const

Read a single byte from the stream. May throw an end of read stream exception.

int16 ZStreamR::ReadInt16

(

)

const

Read a big endian 16 bit integer from the stream. May throw an end of read stream exception.

int32 ZStreamR::ReadInt32

(

)

const

Read a big endian 32 bit integer from the stream. May throw an end of read stream exception.

int64 ZStreamR::ReadInt64

(

)

const

Read a big endian 64 bit integer from the stream. May throw an end of read stream exception.

float ZStreamR::ReadFloat

(

)

const

Read a big endian IEEE754 single precision float from the stream. May throw an end of read stream exception.

double ZStreamR::ReadDouble

(

)

const

Read a big endian IEEE754 double precision float from the stream. May throw an end of read stream exception.

int16 ZStreamR::ReadInt16LE

(

)

const

Read a little endian 16 bit integer from the stream. May throw an end of read stream exception.

int32 ZStreamR::ReadInt32LE

(

)

const

Read a little endian 32 bit integer from the stream. May throw an end of read stream exception.

int64 ZStreamR::ReadInt64LE

(

)

const

Read a little endian 64 bit integer from the stream. May throw an end of read stream exception.

float ZStreamR::ReadFloatLE

(

)

const

Read a little endian IEEE754 single precision float from the stream. May throw an end of read stream exception.

double ZStreamR::ReadDoubleLE

(

)

const

Read a little endian IEEE754 double precision float from the stream. May throw an end of read stream exception.

bool ZStreamR::ReadBool

(

)

const

Read a single byte from the stream, returning true if it is non-zero. May throw an end of read stream exception.

bool ZStreamR::ReadByte

(

uint8 &

oResult

)

const

Read a single byte from the stream into oResult. If the stream reached its end return false, otherwise return true.

bool ZStreamR::ReadChar

(

char &

oResult

)

const

Read a single byte from the stream into oResult. If the stream reached its end return false, otherwise return true.

string ZStreamR::ReadString

(

size_t

iSize

)

const

Read iSize bytes from the stream and return them in a string. May throw an end of read stream exception.

size_t ZStreamR::CountReadable

(

)

const [inline]

Return the number of bytes guaranteed to be readable without blocking.

size_t ZStreamR::Imp_CountReadable

(

)

[virtual]

Returns the number of bytes guaranteed to be readable without blocking.

If the stream does not or cannot know this information it should return zero. A zero return thus does not mean no data is available, simply that a subsequent Read or Skip may block indefinitely.

Reimplemented in ZStreamRPos, ZStreamR_Buffered, ZStreamR_DynamicBuffered, ZStreamR_Count, ZStreamR_JNI, ZStreamR_Limited, ZStreamR_LZWEncodeNoPatent, ZStreamR_LZWDecode, ZStreamR_MD5, ZStreamRPos_Memory, ZStreamRPos_PageBuffered, ZStreamR_SHA1, ZStreamR_Tee, ZStreamR_Boundary, ZStreamR_Cat, ZStreamR_SkipAllOnDestroy, ZStreamRPos_StreamR, ZStreamRW_FIFO, ZStreamRW_FlushOnRead, ZStreamRW_MemoryPipe, and ZStreamRWPos_RAM.

void ZStreamR::Imp_CopyToDispatch	(	const ZStreamW &	iStreamW,
		uint64	iCount,
		uint64 *	oCountRead,
		uint64 *	oCountWritten
	)			[virtual]

Invoke iStreamW's Imp_CopyFrom method.

The first part of the two-stage dispatch initiated by ZStreamR::CopyTo and ZStreamR::CopyAllTo. Override this method if your stream's data is in memory and thus can be written to iStreamW by a single call to its Write method.

Reimplemented in ZStreamR_Null, ZStreamRPos_Null, ZStreamR_Count, ZStreamR_Limited, ZStreamR_Memory, ZStreamRPos_Memory, ZStreamR_SkipAllOnDestroy, ZStreamR_Source, ZStreamRW_FlushOnRead, and ZStreamRW_MemoryPipe.

void ZStreamR::Imp_CopyTo	(	const ZStreamW &	iStreamW,
		uint64	iCount,
		uint64 *	oCountRead,
		uint64 *	oCountWritten
	)			[virtual]

Actually copy data from this stream to iStreamW.

The second part of the two-stage dispatch initiated by ZStreamW::CopyFrom and ZStreamW::CopyAllFrom. The default implementation calls sCopyReadToWrite. Override this method if your stream's data is in memory and thus can be written to iStreamW by a single call to its Write method.

See also:

sCopyReadToWrite

Reimplemented in ZStreamR_Null, ZStreamRPos_Null, ZStreamR_Count, ZStreamR_Limited, ZStreamR_Memory, ZStreamRPos_Memory, ZStreamR_SkipAllOnDestroy, ZStreamR_Source, ZStreamRW_FlushOnRead, and ZStreamRW_MemoryPipe.

void ZStreamR::Imp_Skip	(	uint64	iCount,
		uint64 *	oCountSkipped
	)			[virtual]

Read and discard iCount bytes.

Override this method if your stream implementation can skip past bytes in the stream without actually reading them.

Parameters:

	iCount	Count of bytes to be skipped.
	oCountSkipped	Number of bytes that were actually skipped. If iCount is non zero and oCountSkipped is set to zero then this indicates that the stream has reached its end.

Reimplemented in ZStreamRPos, ZStreamR_Null, ZStreamRPos_Null, ZStreamR_Buffered, ZStreamR_Count, ZStreamR_Limited, ZStreamR_Memory, ZStreamRPos_Memory, ZStreamRPos_PageBuffered, ZStreamR_Cat, ZStreamR_SkipAllOnDestroy, ZStreamR_Source, ZStreamRW_FlushOnRead, ZStreamRW_MemoryPipe, and ZStreamRWPos_RAM.

---

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

• src/stream/ZStream.h
• src/stream/ZStream.cpp

---