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EST_TBuffer.h
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/* Centre for Speech Technology Research */
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/**@name EST_TBuffer.h
* Extending buffers, ie arrays which grow as needed.
* I got fed up of writing equivalent code all over the place.
*
* @see EST_TBuffer
* @author Richard Caley <rjc@cstr.ed.ac.uk>
* @version $Id: EST_TBuffer.h,v 1.4 2004/09/29 08:24:17 robert Exp $
*/
//@{
#ifndef __EST_TBUFFER_H__
#define __EST_TBUFFER_H__
#include "EST_bool.h"
/// How many chunks of memory to keep around for re-use.
#define TBUFFER_N_OLD (10)
/// Initial size for buffers created with no size specified.
#define TBUFFER_DEFAULT_SIZE 0
/// Amount to increment buffer size by.
#define TBUFFER_DEFAULT_STEP 100
/** Structure to remember old buffers for re-use.
* @see EST_TBuffer.h
*/
struct old_tbuffer { void *mem; unsigned int size; };
/// Memory of old buffers
extern struct old_tbuffer EST_old_buffers[TBUFFER_N_OLD];
/** Extending buffer class.
* <p>
* This class provides the convenience of arrays which change in size
* at run time rather more efficiently than the full EST_TVector class
* would.
* <p>
* Buffers can only be expanded and when a buffer is no longer needed
* (i.e. when the variable goes out of scope) the memory is not deleted,
* rather it is saved for re-use as a new buffer.
* <p>
* A typical use would be a buffer to hold a windowed section of a signal
* inside a signal processing loop where the size of the window changes from
* iteration to iteration.
*
* @see EST_TBuffer.h, Associated definitions.
* @see EST_TVector, class to use for more general uses.
* @see lpc_analyse, example of use.
*/
template<class TYPE>
class EST_TBuffer {
private:
/// Pointer to memory.
TYPE *p_buffer;
/// Current size.
unsigned int p_size;
/// Amount to grow by (if negative it is a percentage).
int p_step;
private:
/// Setup code.
void init(unsigned int size, int step);
/// Expand the buffer.
void expand_to(unsigned int req_size, bool cpy);
/// Expand and set some of it to a known value.
void expand_to(unsigned int req_size, const TYPE &set_to, int howmany);
public:
/** Create with size and increment.
* Increment can be negative for percentage growth.
* <p>
* Tries to use a buffer from EST_old_buffers[] if there is one which
* is suitable
* @see EST_old_buffers
*/
EST_TBuffer(unsigned int size=TBUFFER_DEFAULT_SIZE, int step=TBUFFER_DEFAULT_STEP);
/// Destructor. Places the memory in EST_old_buffers[] for re-use if there is room.
~EST_TBuffer(void);
/// Current available space.
unsigned int length(void) const {return p_size;}
/// Set to the given value. By default sets all values.
void set(const TYPE &set_to, int howmany=-1);
/**@name Methods to make sure there is enough space. */
//@{
/// Extend if needed, copying existing data.
void ensure(unsigned int req_size)
{if (req_size > p_size) expand_to(req_size, (bool)TRUE);}
/// Make sure there is enough space, copying if requested.
void ensure(unsigned int req_size, bool copy)
{if (req_size > p_size) expand_to(req_size, copy,-1);}
/// Make sure there is enough space, setting to a known value.
void ensure(unsigned int req_size, const TYPE &set_to, int howmany=-1)
{if (req_size > p_size) expand_to(req_size, set_to, howmany);}
//@}
/**@name Access to the memory itself. */
//@{
/// Simple access as a pointer.
TYPE *b(void) {return p_buffer;}
/// Read-only access when the EST_TBuffer is a constant
const TYPE *b(void) const {return p_buffer;}
/// operator () is simple access
const TYPE &operator() (unsigned int i) const { return p_buffer[i];}
TYPE &operator[] (unsigned int i) { return p_buffer[i];}
const TYPE &operator[] (unsigned int i) const { return p_buffer[i];}
//@}
};
#endif
//@}
EST_TBuffer::ensure
void ensure(unsigned int req_size, bool copy)
Make sure there is enough space, copying if requested.
Definition EST_TBuffer.h:132
EST_TBuffer::ensure
void ensure(unsigned int req_size)
Extend if needed, copying existing data.
Definition EST_TBuffer.h:128
EST_TBuffer::ensure
void ensure(unsigned int req_size, const TYPE &set_to, int howmany=-1)
Make sure there is enough space, setting to a known value.
Definition EST_TBuffer.h:136
EST_TBuffer::~EST_TBuffer
~EST_TBuffer(void)
Destructor. Places the memory in EST_old_buffers[] for re-use if there is room.
Definition EST_TBuffer.cc:56
EST_TBuffer::b
TYPE * b(void)
Simple access as a pointer.
Definition EST_TBuffer.h:144
EST_TBuffer::b
const TYPE * b(void) const
Read-only access when the EST_TBuffer is a constant.
Definition EST_TBuffer.h:146
EST_TBuffer::length
unsigned int length(void) const
Current available space.
Definition EST_TBuffer.h:119
EST_TBuffer::set
void set(const TYPE &set_to, int howmany=-1)
Set to the given value. By default sets all values.
Definition EST_TBuffer.cc:149
EST_TBuffer::operator()
const TYPE & operator()(unsigned int i) const
operator () is simple access
Definition EST_TBuffer.h:149
EST_TBuffer::EST_TBuffer
EST_TBuffer(unsigned int size=TBUFFER_DEFAULT_SIZE, int step=TBUFFER_DEFAULT_STEP)
Definition EST_TBuffer.cc:49
old_tbuffer
Definition EST_TBuffer.h:60