170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * jmemsys.h 370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Copyright (C) 1992-1997, Thomas G. Lane. 570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This file is part of the Independent JPEG Group's software. 670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * For conditions of distribution and use, see the accompanying README file. 770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This include file defines the interface between the system-independent 970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * and system-dependent portions of the JPEG memory manager. No other 1070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * modules need include it. (The system-independent portion is jmemmgr.c; 1170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * there are several different versions of the system-dependent portion.) 1270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 1370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This file works as-is for the system-dependent memory managers supplied 1470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * in the IJG distribution. You may need to modify it if you write a 1570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * custom memory manager. If system-dependent changes are needed in 1670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * this file, the best method is to #ifdef them based on a configuration 1770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * symbol supplied in jconfig.h, as we have done with USE_MSDOS_MEMMGR 1870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * and USE_MAC_MEMMGR. 1970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 2070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 2170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 2270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* Short forms of external names for systems with brain-damaged linkers. */ 2370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 2470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifdef NEED_SHORT_EXTERNAL_NAMES 2570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define jpeg_get_small jGetSmall 2670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define jpeg_free_small jFreeSmall 2770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define jpeg_get_large jGetLarge 2870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define jpeg_free_large jFreeLarge 2970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define jpeg_mem_available jMemAvail 3070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define jpeg_open_backing_store jOpenBackStore 3170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define jpeg_mem_init jMemInit 3270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define jpeg_mem_term jMemTerm 3370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif /* NEED_SHORT_EXTERNAL_NAMES */ 3470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 3570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 3670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 3770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * These two functions are used to allocate and release small chunks of 3870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * memory. (Typically the total amount requested through jpeg_get_small is 3970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * no more than 20K or so; this will be requested in chunks of a few K each.) 4070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Behavior should be the same as for the standard library functions malloc 4170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * and free; in particular, jpeg_get_small must return NULL on failure. 4270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * On most systems, these ARE malloc and free. jpeg_free_small is passed the 4370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * size of the object being freed, just in case it's needed. 4470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * On an 80x86 machine using small-data memory model, these manage near heap. 4570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 4670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 4770a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineEXTERN(void *) jpeg_get_small JPP((j_common_ptr cinfo, size_t sizeofobject)); 4870a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineEXTERN(void) jpeg_free_small JPP((j_common_ptr cinfo, void * object, 4970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine size_t sizeofobject)); 5070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 5170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 5270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * These two functions are used to allocate and release large chunks of 5370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * memory (up to the total free space designated by jpeg_mem_available). 5470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * The interface is the same as above, except that on an 80x86 machine, 5570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * far pointers are used. On most other machines these are identical to 5670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * the jpeg_get/free_small routines; but we keep them separate anyway, 5770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * in case a different allocation strategy is desirable for large chunks. 5870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 5970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 6070a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineEXTERN(void FAR *) jpeg_get_large JPP((j_common_ptr cinfo, 6170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine size_t sizeofobject)); 6270a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineEXTERN(void) jpeg_free_large JPP((j_common_ptr cinfo, void FAR * object, 6370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine size_t sizeofobject)); 6470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 6570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 6670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * The macro MAX_ALLOC_CHUNK designates the maximum number of bytes that may 6770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * be requested in a single call to jpeg_get_large (and jpeg_get_small for that 6870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * matter, but that case should never come into play). This macro is needed 6970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * to model the 64Kb-segment-size limit of far addressing on 80x86 machines. 7070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * On those machines, we expect that jconfig.h will provide a proper value. 7170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * On machines with 32-bit flat address spaces, any large constant may be used. 7270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 7370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * NB: jmemmgr.c expects that MAX_ALLOC_CHUNK will be representable as type 7470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * size_t and will be a multiple of sizeof(align_type). 7570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 7670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 7770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifndef MAX_ALLOC_CHUNK /* may be overridden in jconfig.h */ 7870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define MAX_ALLOC_CHUNK 1000000000L 7970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif 8070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 8170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 8270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This routine computes the total space still available for allocation by 8370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * jpeg_get_large. If more space than this is needed, backing store will be 8470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * used. NOTE: any memory already allocated must not be counted. 8570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 8670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * There is a minimum space requirement, corresponding to the minimum 8770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * feasible buffer sizes; jmemmgr.c will request that much space even if 8870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * jpeg_mem_available returns zero. The maximum space needed, enough to hold 8970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * all working storage in memory, is also passed in case it is useful. 9070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Finally, the total space already allocated is passed. If no better 9170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * method is available, cinfo->mem->max_memory_to_use - already_allocated 9270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * is often a suitable calculation. 9370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 9470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * It is OK for jpeg_mem_available to underestimate the space available 9570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * (that'll just lead to more backing-store access than is really necessary). 9670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * However, an overestimate will lead to failure. Hence it's wise to subtract 9770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * a slop factor from the true available space. 5% should be enough. 9870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 9970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * On machines with lots of virtual memory, any large constant may be returned. 10070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Conversely, zero may be returned to always use the minimum amount of memory. 10170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 10270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 10370a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineEXTERN(long) jpeg_mem_available JPP((j_common_ptr cinfo, 10470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine long min_bytes_needed, 10570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine long max_bytes_needed, 10670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine long already_allocated)); 10770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 10870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 10970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 11070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This structure holds whatever state is needed to access a single 11170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * backing-store object. The read/write/close method pointers are called 11270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * by jmemmgr.c to manipulate the backing-store object; all other fields 11370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * are private to the system-dependent backing store routines. 11470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 11570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 11670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define TEMP_NAME_LENGTH 64 /* max length of a temporary file's name */ 11770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 11870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 11970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifdef USE_MSDOS_MEMMGR /* DOS-specific junk */ 12070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 12170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinetypedef unsigned short XMSH; /* type of extended-memory handles */ 12270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinetypedef unsigned short EMSH; /* type of expanded-memory handles */ 12370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 12470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinetypedef union { 12570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine short file_handle; /* DOS file handle if it's a temp file */ 12670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine XMSH xms_handle; /* handle if it's a chunk of XMS */ 12770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine EMSH ems_handle; /* handle if it's a chunk of EMS */ 12870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} handle_union; 12970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 13070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif /* USE_MSDOS_MEMMGR */ 13170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 13270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifdef USE_MAC_MEMMGR /* Mac-specific junk */ 13370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#include <Files.h> 13470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif /* USE_MAC_MEMMGR */ 13570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 13670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 13770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinetypedef struct backing_store_struct * backing_store_ptr; 13870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 13970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinetypedef struct backing_store_struct { 14070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Methods for reading/writing/closing this backing-store object */ 14170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JMETHOD(void, read_backing_store, (j_common_ptr cinfo, 14270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine backing_store_ptr info, 14370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine void FAR * buffer_address, 14470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine long file_offset, long byte_count)); 14570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JMETHOD(void, write_backing_store, (j_common_ptr cinfo, 14670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine backing_store_ptr info, 14770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine void FAR * buffer_address, 14870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine long file_offset, long byte_count)); 14970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JMETHOD(void, close_backing_store, (j_common_ptr cinfo, 15070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine backing_store_ptr info)); 15170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 15270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Private fields for system-dependent backing-store management */ 15370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifdef USE_MSDOS_MEMMGR 15470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* For the MS-DOS manager (jmemdos.c), we need: */ 15570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine handle_union handle; /* reference to backing-store storage object */ 15670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine char temp_name[TEMP_NAME_LENGTH]; /* name if it's a file */ 15770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#else 15870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifdef USE_MAC_MEMMGR 15970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* For the Mac manager (jmemmac.c), we need: */ 16070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine short temp_file; /* file reference number to temp file */ 16170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine FSSpec tempSpec; /* the FSSpec for the temp file */ 16270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine char temp_name[TEMP_NAME_LENGTH]; /* name if it's a file */ 16370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#else 16470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifdef USE_ANDROID_ASHMEM 16570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine short temp_file; /* file reference number to temp file */ 16670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine unsigned char* addr; /* the memory address mapped to ashmem */ 16770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine long size; /* the requested ashmem size */ 16870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#else 16970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* For a typical implementation with temp files, we need: */ 17070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine FILE * temp_file; /* stdio reference to temp file */ 17170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine char temp_name[TEMP_NAME_LENGTH]; /* name of temp file */ 17270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif 17370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif 17470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif 17570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} backing_store_info; 17670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 17770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 17870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 17970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Initial opening of a backing-store object. This must fill in the 18070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * read/write/close pointers in the object. The read/write routines 18170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * may take an error exit if the specified maximum file size is exceeded. 18270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * (If jpeg_mem_available always returns a large value, this routine can 18370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * just take an error exit.) 18470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 18570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 18670a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineEXTERN(void) jpeg_open_backing_store JPP((j_common_ptr cinfo, 18770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine backing_store_ptr info, 18870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine long total_bytes_needed)); 18970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 19070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 19170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 19270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * These routines take care of any system-dependent initialization and 19370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * cleanup required. jpeg_mem_init will be called before anything is 19470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * allocated (and, therefore, nothing in cinfo is of use except the error 19570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * manager pointer). It should return a suitable default value for 19670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * max_memory_to_use; this may subsequently be overridden by the surrounding 19770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * application. (Note that max_memory_to_use is only important if 19870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * jpeg_mem_available chooses to consult it ... no one else will.) 19970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * jpeg_mem_term may assume that all requested memory has been freed and that 20070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * all opened backing-store objects have been closed. 20170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 20270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 20370a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineEXTERN(long) jpeg_mem_init JPP((j_common_ptr cinfo)); 20470a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineEXTERN(void) jpeg_mem_term JPP((j_common_ptr cinfo)); 205