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C:/temp/src/j2k/Beta/fast_alloc.h File Reference

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <malloc.h>

Go to the source code of this file.

Defines

#define __J2K__FAST_ALLOC_H__   1

#define MALLOC_MIN_OVERHEAD   sizeof( size_t )

#define MALLOC_MAX_THRESHOLD   sizeof( short )

#define MALLOC_MAX_THRESHOLD_BIT   16

Functions

size_t fast_mem_size (register size_t min_size)

void * fast_malloc (register size_t min_size)

void * fast_realloc (register void *buffer, register size_t buf_size, register size_t extra)

void fast_free (void *buffer)

Define Documentation

#define MALLOC_MAX_THRESHOLD sizeof( short )

Definition at line 35 of file fast_alloc.h.

#define MALLOC_MAX_THRESHOLD_BIT 16

Definition at line 36 of file fast_alloc.h.

#define MALLOC_MIN_OVERHEAD sizeof( size_t )

Definition at line 30 of file fast_alloc.h.

#define __J2K__FAST_ALLOC_H__ 1

Definition at line 2 of file fast_alloc.h.

Function Documentation

void fast_free ( void * buffer )

Definition at line 90 of file fast_alloc.c.
00091 { 00092 free( buffer ); 00093 }

void* fast_malloc ( register size_t min_size )

Definition at line 63 of file fast_alloc.c.
Referenced by JString_calloc(), and JString_malloc().

00064 { 00065 if ( min_size < 16 ) min_size = 16; 00066 00067 void* buffer = malloc( fast_mem_size( min_size ) ); 00068 00069 /* Make sure we have some memory allocated ! */ 00070 assert( buffer != NULL ); 00071 00072 return buffer; 00073 }

size_t fast_mem_size ( register size_t min_size )

Definition at line 24 of file fast_alloc.c.
Referenced by fast_malloc(), and fast_realloc().

00025 { 00026 register size_t alloc_size = 1; 00027 register size_t curr_size = min_size; 00028 00029 curr_size += MALLOC_MIN_OVERHEAD; 00030 00031 if ( curr_size >= MALLOC_MAX_THRESHOLD ) 00032 { 00033 curr_size >>= MALLOC_MAX_THRESHOLD_BIT; 00034 curr_size++; 00035 curr_size <<= MALLOC_MAX_THRESHOLD_BIT; 00036 alloc_size = curr_size; 00037 } 00038 else /* Too small, so exponential growth */ 00039 { 00040 while( curr_size > 0 ) 00041 { 00042 curr_size >>= 1; /* Get the highest power of two + 1 bit */ 00043 alloc_size <<= 1; 00044 } 00045 } 00046 00047 #ifdef __J2K__DEBUG_TRACE 00048 printf( "Wanted space: [%d]\n", min_size ); 00049 printf( "Allocated space: [%d]\n", alloc_size ); 00050 printf( "malloc'ed space: [%d]\n", alloc_size - MALLOC_MIN_OVERHEAD ); 00051 fflush( stdout ); 00052 #endif 00053 00054 alloc_size -= MALLOC_MIN_OVERHEAD; 00055 00056 /* Make sure what we allocate is big enough */ 00057 assert( alloc_size >= curr_size ); 00058 00059 return alloc_size; 00060 }

void* fast_realloc ( register void * buffer,

register size_t buf_size,

register size_t extra

)

Definition at line 76 of file fast_alloc.c.
00077 { 00078 if ( extra < 16 ) extra = 16; 00079 00080 register size_t sz = fast_mem_size( extra ) + buf_size; 00081 void* buffer = realloc( buffer, sz ); 00082 00083 /* Make sure we have some memory allocated ! */ 00084 assert( buffer != NULL ); 00085 00086 return buffer; 00087 }

Generated on Sun Oct 14 18:46:50 2001 for Standard J2K Library by

Defines
#define	__J2K__FAST_ALLOC_H__ 1
#define	MALLOC_MIN_OVERHEAD sizeof( size_t )
#define	MALLOC_MAX_THRESHOLD sizeof( short )
#define	MALLOC_MAX_THRESHOLD_BIT 16
Functions
size_t	fast_mem_size (register size_t min_size)
void *	fast_malloc (register size_t min_size)
void *	fast_realloc (register void *buffer, register size_t buf_size, register size_t extra)
void	fast_free (void *buffer)