Home | History | Annotate | Download | only in jpeg 
      1 /*
      2  * jmemnobs.c
      3  *
      4  * Copyright (C) 1992-1996, Thomas G. Lane.
      5  * This file is part of the Independent JPEG Group's software.
      6  * For conditions of distribution and use, see the accompanying README file.
      7  *
      8  * This file provides a really simple implementation of the system-
      9  * dependent portion of the JPEG memory manager.  This implementation
     10  * assumes that no backing-store files are needed: all required space
     11  * can be obtained from malloc().
     12  * This is very portable in the sense that it'll compile on almost anything,
     13  * but you'd better have lots of main memory (or virtual memory) if you want
     14  * to process big images.
     15  * Note that the max_memory_to_use option is ignored by this implementation.
     16  */
     17 
     18 #define JPEG_INTERNALS
     19 #include "jinclude.h"
     20 #include "jpeglib.h"
     21 #include "jmemsys.h"		/* import the system-dependent declarations */
     22 
     23 #ifndef HAVE_STDLIB_H		/* <stdlib.h> should declare malloc(),free() */
     24 extern void * malloc JPP((size_t size));
     25 extern void free JPP((void *ptr));
     26 #endif
     27 
     28 
     29 /*
     30  * Memory allocation and freeing are controlled by the regular library
     31  * routines malloc() and free().
     32  */
     33 
     34 GLOBAL(void *)
     35 jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
     36 {
     37   return (void *) malloc(sizeofobject);
     38 }
     39 
     40 GLOBAL(void)
     41 jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
     42 {
     43   free(object);
     44 }
     45 
     46 
     47 /*
     48  * "Large" objects are treated the same as "small" ones.
     49  * NB: although we include FAR keywords in the routine declarations,
     50  * this file won't actually work in 80x86 small/medium model; at least,
     51  * you probably won't be able to process useful-size images in only 64KB.
     52  */
     53 
     54 GLOBAL(void FAR *)
     55 jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
     56 {
     57   return (void FAR *) malloc(sizeofobject);
     58 }
     59 
     60 GLOBAL(void)
     61 jpeg_free_large (j_common_ptr cinfo, void FAR * 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(long)
     73 jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
     74 		    long max_bytes_needed, long 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