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      1 /*
      2  * jmemnobs.c
      3  *
      4  * This file was part of the Independent JPEG Group's software:
      5  * Copyright (C) 1992-1996, Thomas G. Lane.
      6  * It was modified by The libjpeg-turbo Project to include only code and
      7  * information relevant to libjpeg-turbo.
      8  * For conditions of distribution and use, see the accompanying README.ijg
      9  * file.
     10  *
     11  * This file provides a really simple implementation of the system-
     12  * dependent portion of the JPEG memory manager.  This implementation
     13  * assumes that no backing-store files are needed: all required space
     14  * can be obtained from malloc().
     15  * This is very portable in the sense that it'll compile on almost anything,
     16  * but you'd better have lots of main memory (or virtual memory) if you want
     17  * to process big images.
     18  * Note that the max_memory_to_use option is ignored by this implementation.
     19  */
     20 
     21 #define JPEG_INTERNALS
     22 #include "jinclude.h"
     23 #include "jpeglib.h"
     24 #include "jmemsys.h"            /* import the system-dependent declarations */
     25 
     26 #ifndef HAVE_STDLIB_H           /* <stdlib.h> should declare malloc(),free() */
     27 extern void *malloc (size_t size);
     28 extern void free (void *ptr);
     29 #endif
     30 
     31 
     32 /*
     33  * Memory allocation and freeing are controlled by the regular library
     34  * routines malloc() and free().
     35  */
     36 
     37 GLOBAL(void *)
     38 jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
     39 {
     40   return (void *) malloc(sizeofobject);
     41 }
     42 
     43 GLOBAL(void)
     44 jpeg_free_small (j_common_ptr cinfo, void *object, size_t sizeofobject)
     45 {
     46   free(object);
     47 }
     48 
     49 
     50 /*
     51  * "Large" objects are treated the same as "small" ones.
     52  */
     53 
     54 GLOBAL(void *)
     55 jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
     56 {
     57   return (void *) malloc(sizeofobject);
     58 }
     59 
     60 GLOBAL(void)
     61 jpeg_free_large (j_common_ptr cinfo, void *object, size_t sizeofobject)
     62 {
     63   free(object);
     64 }
     65 
     66 
     67 /*
     68  * This routine computes the total memory space available for allocation.
     69  * Here we always say, "we got all you want bud!"
     70  */
     71 
     72 GLOBAL(size_t)
     73 jpeg_mem_available (j_common_ptr cinfo, size_t min_bytes_needed,
     74                     size_t max_bytes_needed, size_t already_allocated)
     75 {
     76   return max_bytes_needed;
     77 }
     78 
     79 
     80 /*
     81  * Backing store (temporary file) management.
     82  * Since jpeg_mem_available always promised the moon,
     83  * this should never be called and we can just error out.
     84  */
     85 
     86 GLOBAL(void)
     87 jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
     88                          long total_bytes_needed)
     89 {
     90   ERREXIT(cinfo, JERR_NO_BACKING_STORE);
     91 }
     92 
     93 
     94 /*
     95  * These routines take care of any system-dependent initialization and
     96  * cleanup required.  Here, there isn't any.
     97  */
     98 
     99 GLOBAL(long)
    100 jpeg_mem_init (j_common_ptr cinfo)
    101 {
    102   return 0;                     /* just set max_memory_to_use to 0 */
    103 }
    104 
    105 GLOBAL(void)
    106 jpeg_mem_term (j_common_ptr cinfo)
    107 {
    108   /* no work */
    109 }
    110