WvStreams
Public Member Functions | Protected Types | Protected Member Functions | Protected Attributes | List of all members
WvBufBaseCommonImpl< T > Class Template Reference

An abstract generic buffer template. More...

#include <wvbufbase.h>

Inheritance diagram for WvBufBaseCommonImpl< T >:
Inheritance graph
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Public Member Functions

virtual ~WvBufBaseCommonImpl ()
 Destroys the buffer.
 
WvBufStoregetstore ()
 Returns a pointer to the underlying storage class object. More...
 
bool isreadable () const
 Returns true if the buffer supports reading. More...
 
size_t used () const
 Returns the number of elements in the buffer currently available for reading. More...
 
const T * get (size_t count)
 Reads exactly the specified number of elements and returns a pointer to a storage location owned by the buffer. More...
 
void skip (size_t count)
 Skips exactly the specified number of elements. More...
 
size_t optgettable () const
 Returns the optimal maximum number of elements in the buffer currently available for reading without incurring significant overhead. More...
 
void unget (size_t count)
 Ungets exactly the specified number of elements by returning them to the buffer for subsequent reads. More...
 
size_t ungettable () const
 Returns the maximum number of elements that may be ungotten at this time. More...
 
const T * peek (int offset, size_t count)
 Returns a const pointer into the buffer at the specified offset to the specified number of elements without actually adjusting the current get() index. More...
 
size_t peekable (int offset)
 
size_t optpeekable (int offset)
 
void zap ()
 Clears the buffer. More...
 
get ()
 Reads the next element from the buffer. More...
 
peek (int offset=0)
 Returns the element at the specified offset in the buffer. More...
 
void move (T *buf, size_t count)
 Efficiently copies the specified number of elements from the buffer to the specified UNINITIALIZED storage location and removes the elements from the buffer. More...
 
void copy (T *buf, int offset, size_t count)
 Efficiently copies the specified number of elements from the buffer to the specified UNINITIALIZED storage location but does not remove the elements from the buffer. More...
 
bool iswritable () const
 Returns true if the buffer supports writing. More...
 
size_t free () const
 Returns the number of elements that the buffer can currently accept for writing. More...
 
T * alloc (size_t count)
 Allocates exactly the specified number of elements and returns a pointer to an UNINITIALIZED storage location owned by the buffer. More...
 
size_t optallocable () const
 Returns the optimal maximum number of elements that the buffer can currently accept for writing without incurring significant overhead. More...
 
void unalloc (size_t count)
 Unallocates exactly the specified number of elements by removing them from the buffer and releasing their storage. More...
 
size_t unallocable () const
 Returns the maximum number of elements that may be unallocated at this time. More...
 
T * mutablepeek (int offset, size_t count)
 Returns a non-const pointer info the buffer at the specified offset to the specified number of elements without actually adjusting the current get() index. More...
 
void put (const T *data, size_t count)
 Writes the specified number of elements from the specified storage location into the buffer at its tail. More...
 
void poke (const T *data, int offset, size_t count)
 Efficiently copies the specified number of elements from the specified storage location into the buffer at a particular offset. More...
 
void put (T &value)
 Writes the element into the buffer at its tail. More...
 
void poke (T &value, int offset)
 Writes the element into the buffer at the specified offset. More...
 
void merge (Buffer &inbuf, size_t count)
 Efficiently moves count bytes from the specified buffer into this one. More...
 
void merge (Buffer &inbuf)
 Efficiently merges the entire contents of a buffer into this one. More...
 

Protected Types

typedef T Elem
 
typedef WvBufBase< T > Buffer
 

Protected Member Functions

 WvBufBaseCommonImpl (const WvBufBaseCommonImpl &other)
 
 WvBufBaseCommonImpl (WvBufStore *store)
 Initializes the buffer. More...
 

Protected Attributes

WvBufStorestore
 

Detailed Description

template<class T>
class WvBufBaseCommonImpl< T >

An abstract generic buffer template.

Buffers are simple data queues designed to ease the construction of functions that must generate, consume, or transform large amount of data in pipeline fashion. Concrete buffer subclases define the actual storage mechanism and queuing machinery. In addition they may provide additional functionality for accomplishing particular tasks.

The base component is split into two parts, WvBufBaseCommonImpl that defines the common API for all buffer types, and WvBufBase that allows specializations to be defined to add functionality to the base type. When passing around buffer objects, you should use the WvBufBase<T> type rather than WvBufBaseCommonImpl<T>.

See WvBufBase<T> "T" is the type of object to store, must be a primitive or a struct without special initialization, copy, or assignment semantics

Definition at line 36 of file wvbufbase.h.

Constructor & Destructor Documentation

◆ WvBufBaseCommonImpl()

template<class T >
WvBufBaseCommonImpl< T >::WvBufBaseCommonImpl ( WvBufStore store)
inlineexplicitprotected

Initializes the buffer.

Note: Does not take ownership of the storage object.

"store" is the low-level storage object

Definition at line 57 of file wvbufbase.h.

Member Function Documentation

◆ getstore()

template<class T >
WvBufStore* WvBufBaseCommonImpl< T >::getstore ( )
inline

Returns a pointer to the underlying storage class object.

Returns: the low-level storage class object pointer, non-null

Definition at line 69 of file wvbufbase.h.

◆ isreadable()

template<class T >
bool WvBufBaseCommonImpl< T >::isreadable ( ) const
inline

Returns true if the buffer supports reading.

Returns: true if reading is supported

Definition at line 81 of file wvbufbase.h.

◆ used()

template<class T >
size_t WvBufBaseCommonImpl< T >::used ( ) const
inline

◆ get() [1/2]

template<class T >
const T* WvBufBaseCommonImpl< T >::get ( size_t  count)
inline

Reads exactly the specified number of elements and returns a pointer to a storage location owned by the buffer.

The pointer is only valid until the next non-const buffer member is called. eg. alloc(size_t)

If count == 0, a NULL pointer may be returned.

It is an error for count to be greater than the number of available elements in the buffer.

For maximum efficiency, call this function multiple times with count no greater than optgettable() each time.

After this operation, at least count elements may be ungotten.

Definition at line 114 of file wvbufbase.h.

Referenced by WvXOREncoder::_encode(), WvBackslashEncoder::_encode(), WvRateAdjust::_encode(), WvCounterModeEncoder::_encode(), WvEVPMDDigest::_encode(), WvBlowfishEncoder::_encode(), WvTripleDESEncoder::_encode(), WvBackslashDecoder::_encode(), WvRSAEncoder::_encode(), WvHMACDigest::_encode(), WvCrc32Digest::_encode(), WvAdler32Digest::_encode(), WvSyslog::_end_line(), WvLogBuffer::_end_line(), WvStream::blocking_getline(), WvDBusMsg::demarshal(), WvStream::read(), WvSSLStream::uwrite(), WvStream::write(), and wvtcl_getword().

◆ skip()

template<class T >
void WvBufBaseCommonImpl< T >::skip ( size_t  count)
inline

Skips exactly the specified number of elements.

This is equivalent to invoking get(size_t) with the count and discarding the result, but may be faster for certain types of buffers. As with get(size_t), the call may be followed up by an unget(size_t).

It is an error for count to be greater than the number of available elements in the buffer.

"count" is the number of elements

Definition at line 136 of file wvbufbase.h.

◆ optgettable()

template<class T >
size_t WvBufBaseCommonImpl< T >::optgettable ( ) const
inline

Returns the optimal maximum number of elements in the buffer currently available for reading without incurring significant overhead.

Invariants:

Returns: the number of elements

Definition at line 154 of file wvbufbase.h.

Referenced by WvXOREncoder::_encode(), WvBackslashEncoder::_encode(), WvEVPMDDigest::_encode(), WvCounterModeEncoder::_encode(), WvBackslashDecoder::_encode(), WvHMACDigest::_encode(), WvCrc32Digest::_encode(), and WvAdler32Digest::_encode().

◆ unget()

template<class T >
void WvBufBaseCommonImpl< T >::unget ( size_t  count)
inline

Ungets exactly the specified number of elements by returning them to the buffer for subsequent reads.

This operation may always be safely performed with count less than or equal to that specified in the last get(size_t) if no non-const buffer members have been called since then.

If count == 0, nothing happens.

It is an error for count to be greater than ungettable().

"count" is the number of elements

Definition at line 177 of file wvbufbase.h.

Referenced by WvBackslashEncoder::_encode(), WvGzipEncoder::_encode(), WvBackslashDecoder::_encode(), WvSSLStream::uwrite(), WvStream::write(), and wvtcl_getword().

◆ ungettable()

template<class T >
size_t WvBufBaseCommonImpl< T >::ungettable ( ) const
inline

Returns the maximum number of elements that may be ungotten at this time.

Returns: the number of elements

Definition at line 188 of file wvbufbase.h.

◆ peek() [1/2]

template<class T >
const T* WvBufBaseCommonImpl< T >::peek ( int  offset,
size_t  count 
)
inline

Returns a const pointer into the buffer at the specified offset to the specified number of elements without actually adjusting the current get() index.

The pointer is only valid until the next non-const buffer member is called. eg. alloc(size_t)

If count == 0, a NULL pointer may be returned.

If offset is greater than zero, then elements will be returned beginning with the with the offset'th element that would be returned by get(size_t).

If offset equals zero, then elements will be returned beginning with the next one available for get(size_t).

If offset is less than zero, then elements will be returned beginning with the first one that would be returned on a get(size_t) following an unget(-offset).

It is an error for count to be greater than peekable(offset).

For maximum efficiency, call this function multiple times with count no greater than that returned by optpeekable(size_t) at incremental offsets.

"offset" is the buffer offset "count" is the number of elements Returns: the element storage pointer

Definition at line 225 of file wvbufbase.h.

Referenced by WvDBusMsg::demarshal(), WvDBusMsg::demarshal_bytes_needed(), WvHttpStream::execute(), WvBufBaseCommonImpl< unsigned char >::peek(), WvX509Mgr::sign(), and WvX509::verify().

◆ zap()

template<class T >
void WvBufBaseCommonImpl< T >::zap ( )
inline

Clears the buffer.

For many types of buffers, calling zap() will increased the amount of free space available for writing (see below) by an amount greater than used(). Hence it is wise to zap() a buffer just before writing to it to maximize free space.

After this operation, used() == 0, and often ungettable() == 0.

Definition at line 257 of file wvbufbase.h.

Referenced by WvRSAEncoder::_encode(), WvNullEncoder::_encode(), WvSyslog::_end_line(), WvLogBuffer::_end_line(), WvBackslashDecoder::_reset(), WvStream::unread(), WvSSLStream::uread(), and WvSSLStream::uwrite().

◆ get() [2/2]

template<class T >
T WvBufBaseCommonImpl< T >::get ( )
inline

Reads the next element from the buffer.

It is an error to invoke this method if used() == 0.

After this operation, at least 1 element may be ungotten.

Returns: the element

Definition at line 272 of file wvbufbase.h.

Referenced by WvBufBaseCommonImpl< unsigned char >::get().

◆ peek() [2/2]

template<class T >
T WvBufBaseCommonImpl< T >::peek ( int  offset = 0)
inline

Returns the element at the specified offset in the buffer.

It is an error to invoke this method if used() == 0.

"offset" is the offset, default 0 Returns: the element

Definition at line 286 of file wvbufbase.h.

◆ move()

template<class T >
void WvBufBaseCommonImpl< T >::move ( T *  buf,
size_t  count 
)
inline

Efficiently copies the specified number of elements from the buffer to the specified UNINITIALIZED storage location and removes the elements from the buffer.

It is an error for count to be greater than used().

For maximum efficiency, choose as large a count as possible.

The pointer buf may be NULL only if count == 0.

After this operation, an indeterminate number of elements may be ungotten.

"buf" is the buffer that will receive the elements "count" is the number of elements

Definition at line 309 of file wvbufbase.h.

◆ copy()

template<class T >
void WvBufBaseCommonImpl< T >::copy ( T *  buf,
int  offset,
size_t  count 
)
inline

Efficiently copies the specified number of elements from the buffer to the specified UNINITIALIZED storage location but does not remove the elements from the buffer.

It is an error for count to be greater than peekable(offset).

For maximum efficiency, choose as large a count as possible.

The pointer buf may be NULL only if count == 0.

"buf" is the buffer that will receive the elements "offset" is the buffer offset "count" is the number of elements

Definition at line 330 of file wvbufbase.h.

◆ iswritable()

template<class T >
bool WvBufBaseCommonImpl< T >::iswritable ( ) const
inline

Returns true if the buffer supports writing.

Returns: true if writing is supported

Definition at line 342 of file wvbufbase.h.

◆ free()

template<class T >
size_t WvBufBaseCommonImpl< T >::free ( ) const
inline

Returns the number of elements that the buffer can currently accept for writing.

Returns: the number of elements

Definition at line 353 of file wvbufbase.h.

Referenced by WvBackslashEncoder::_encode(), WvBackslashDecoder::_encode(), WvStream::read(), WvSSLStream::uread(), and WvSSLStream::uwrite().

◆ alloc()

template<class T >
T* WvBufBaseCommonImpl< T >::alloc ( size_t  count)
inline

Allocates exactly the specified number of elements and returns a pointer to an UNINITIALIZED storage location owned by the buffer.

The pointer is only valid until the next non-const buffer member is called. eg. alloc(size_t)

If count == 0, a NULL pointer may be returned.

It is an error for count to be greater than free().

For best results, call this function multiple times with count no greater than optallocable() each time.

After this operation, at least count elements may be unallocated.

"count" is the number of elements Returns: the element storage pointer

Definition at line 379 of file wvbufbase.h.

Referenced by WvXOREncoder::_encode(), WvRateAdjust::_encode(), WvBlowfishEncoder::_encode(), WvTripleDESEncoder::_encode(), WvRSAEncoder::_encode(), WvStream::blocking_getline(), WvDSAKey::getpem(), WvStream::read(), and WvSSLStream::uread().

◆ optallocable()

template<class T >
size_t WvBufBaseCommonImpl< T >::optallocable ( ) const
inline

Returns the optimal maximum number of elements that the buffer can currently accept for writing without incurring significant overhead.

Invariants:

Returns: the number of elements

Definition at line 397 of file wvbufbase.h.

◆ unalloc()

template<class T >
void WvBufBaseCommonImpl< T >::unalloc ( size_t  count)
inline

Unallocates exactly the specified number of elements by removing them from the buffer and releasing their storage.

This operation may always be safely performed with count less than or equal to that specified in the last alloc(size_t) or put(const T*, size_t) if no non-const buffer members have been called since then.

If count == 0, nothing happens.

It is an error for count to be greater than unallocable().

"count" is the number of elements

Definition at line 421 of file wvbufbase.h.

Referenced by WvRateAdjust::_encode(), WvCounterModeEncoder::_encode(), WvBackslashDecoder::_encode(), WvRSAEncoder::_encode(), WvStream::blocking_getline(), WvDSAKey::getpem(), WvStream::read(), and WvSSLStream::uread().

◆ unallocable()

template<class T >
size_t WvBufBaseCommonImpl< T >::unallocable ( ) const
inline

Returns the maximum number of elements that may be unallocated at this time.

For all practical purposes, this number will always be at least as large as the amount currently in use. It is provided primarily for symmetry, but also to handle cases where buffer reading (hence used()) is not supported by the implementation.

Invariants:

Returns: the number of elements

Definition at line 443 of file wvbufbase.h.

◆ mutablepeek()

template<class T >
T* WvBufBaseCommonImpl< T >::mutablepeek ( int  offset,
size_t  count 
)
inline

Returns a non-const pointer info the buffer at the specified offset to the specified number of elements without actually adjusting the current get() index.

Other than the fact that the returned storage is mutable, operates identically to peek(int, size_t).

"offset" is the buffer offset "count" is the number of elements Returns: the element storage pointer

Definition at line 461 of file wvbufbase.h.

Referenced by WvCounterModeEncoder::_encode(), and WvStream::blocking_getline().

◆ put() [1/2]

template<class T >
void WvBufBaseCommonImpl< T >::put ( const T *  data,
size_t  count 
)
inline

Writes the specified number of elements from the specified storage location into the buffer at its tail.

It is an error for count to be greater than free().

For maximum efficiency, choose as large a count as possible.

The pointer buf may be NULL only if count == 0.

After this operation, at least count elements may be unallocated.

"data" is the buffer that contains the elements "count" is the number of elements

Definition at line 483 of file wvbufbase.h.

◆ poke() [1/2]

template<class T >
void WvBufBaseCommonImpl< T >::poke ( const T *  data,
int  offset,
size_t  count 
)
inline

Efficiently copies the specified number of elements from the specified storage location into the buffer at a particular offset.

If offset <= used() and offset + count > used(), the remaining data is simply tacked onto the end of the buffer with put().

It is an error for count to be greater than free() - offset.

"data" is the buffer that contains the elements "count" is the number of elements "offset" is the buffer offset, default 0

Definition at line 504 of file wvbufbase.h.

Referenced by WvBufBaseCommonImpl< unsigned char >::poke().

◆ put() [2/2]

template<class T >
void WvBufBaseCommonImpl< T >::put ( T &  value)
inline

Writes the element into the buffer at its tail.

It is an error to invoke this method if free() == 0.

After this operation, at least 1 element may be unallocated.

"valid" is the element

Definition at line 519 of file wvbufbase.h.

◆ poke() [2/2]

template<class T >
void WvBufBaseCommonImpl< T >::poke ( T &  value,
int  offset 
)
inline

Writes the element into the buffer at the specified offset.

It is an error to invoke this method if free() == 0.

After this operation, at least 1 element may be unallocated.

"value" is the element "offset" is the buffer offset

Definition at line 535 of file wvbufbase.h.

◆ merge() [1/2]

template<class T >
void WvBufBaseCommonImpl< T >::merge ( Buffer inbuf,
size_t  count 
)
inline

Efficiently moves count bytes from the specified buffer into this one.

In some cases, this may be a zero-copy operation.

It is an error for count to be greater than inbuf.used().

For maximum efficiency, choose as large a count as possible.

After this operation, an indeterminate number of elements may be ungotten from inbuf.

"inbuf" is the buffer from which to read "count" is the number of elements

Definition at line 558 of file wvbufbase.h.

Referenced by WvPassthroughEncoder::_encode(), WvEncoderStream::finish_read(), WvEncoderStream::flush_read(), WvBufBaseCommonImpl< unsigned char >::merge(), WvStream::read(), and WvStream::unread().

◆ merge() [2/2]

template<class T >
void WvBufBaseCommonImpl< T >::merge ( Buffer inbuf)
inline

Efficiently merges the entire contents of a buffer into this one.

"inbuf" is the buffer from which to read

Definition at line 568 of file wvbufbase.h.


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