1 /* 2 * jmemnobs.c 3 * 4 * Copyright (C) 1992-1996, Thomas G. Lane. 5 * Modified 2019 by Guido Vollbeding. 6 * This file is part of the Independent JPEG Group's software. 7 * For conditions of distribution and use, see the accompanying README file. 8 * 9 * This file provides a really simple implementation of the system- 10 * dependent portion of the JPEG memory manager. This implementation 11 * assumes that no backing-store files are needed: all required space 12 * can be obtained from malloc(). 13 * This is very portable in the sense that it'll compile on almost anything, 14 * but you'd better have lots of main memory (or virtual memory) if you want 15 * to process big images. 16 * Note that the max_memory_to_use option is respected by this implementation. 17 */ 18 19 #define JPEG_INTERNALS 20 #include "jinclude.h" 21 #include "jpeglib.h" 22 #include "jmemsys.h" /* import the system-dependent declarations */ 23 24 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */ 25 extern void * malloc JPP((size_t size)); 26 extern void free JPP((void *ptr)); 27 #endif 28 29 30 /* 31 * Memory allocation and freeing are controlled by the regular library 32 * routines malloc() and free(). 33 */ 34 35 GLOBAL(void *) 36 jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject) 37 { 38 return (void *) malloc(sizeofobject); 39 } 40 41 GLOBAL(void) 42 jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject) 43 { 44 free(object); 45 } 46 47 48 /* 49 * "Large" objects are treated the same as "small" ones. 50 * NB: although we include FAR keywords in the routine declarations, 51 * this file won't actually work in 80x86 small/medium model; at least, 52 * you probably won't be able to process useful-size images in only 64KB. 53 */ 54 55 GLOBAL(void FAR *) 56 jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject) 57 { 58 return (void FAR *) malloc(sizeofobject); 59 } 60 61 GLOBAL(void) 62 jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject) 63 { 64 free(object); 65 } 66 67 68 /* 69 * This routine computes the total memory space available for allocation. 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 if (cinfo->mem->max_memory_to_use) 77 return cinfo->mem->max_memory_to_use - already_allocated; 78 79 /* Here we say, "we got all you want bud!" */ 80 return max_bytes_needed; 81 } 82 83 84 /* 85 * Backing store (temporary file) management. 86 * Since jpeg_mem_available always promised the moon, 87 * this should never be called and we can just error out. 88 */ 89 90 GLOBAL(void) 91 jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info, 92 long total_bytes_needed) 93 { 94 ERREXIT(cinfo, JERR_NO_BACKING_STORE); 95 } 96 97 98 /* 99 * These routines take care of any system-dependent initialization and 100 * cleanup required. Here, there isn't any. 101 */ 102 103 GLOBAL(long) 104 jpeg_mem_init (j_common_ptr cinfo) 105 { 106 return 0; /* just set max_memory_to_use to 0 */ 107 } 108 109 GLOBAL(void) 110 jpeg_mem_term (j_common_ptr cinfo) 111 { 112 /* no work */ 113 } 114