src/jpeg/jmemmac.c

   1 /*
   2  * jmemmac.c
   3  *
   4  * Copyright (C) 1992-1997, 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  * jmemmac.c provides an Apple Macintosh implementation of the system-
   9  * dependent portion of the JPEG memory manager.
  10  *
  11  * If you use jmemmac.c, then you must define USE_MAC_MEMMGR in the
  12  * JPEG_INTERNALS part of jconfig.h.
  13  *
  14  * jmemmac.c uses the Macintosh toolbox routines NewPtr and DisposePtr
  15  * instead of malloc and free.  It accurately determines the amount of
  16  * memory available by using CompactMem.  Notice that if left to its
  17  * own devices, this code can chew up all available space in the
  18  * application's zone, with the exception of the rather small "slop"
  19  * factor computed in jpeg_mem_available().  The application can ensure
  20  * that more space is left over by reducing max_memory_to_use.
  21  *
  22  * Large images are swapped to disk using temporary files and System 7.0+'s
  23  * temporary folder functionality.
  24  *
  25  * Note that jmemmac.c depends on two features of MacOS that were first
  26  * introduced in System 7: FindFolder and the FSSpec-based calls.
  27  * If your application uses jmemmac.c and is run under System 6 or earlier,
  28  * and the jpeg library decides it needs a temporary file, it will abort,
  29  * printing error messages about requiring System 7.  (If no temporary files
  30  * are created, it will run fine.)
  31  *
  32  * If you want to use jmemmac.c in an application that might be used with
  33  * System 6 or earlier, then you should remove dependencies on FindFolder
  34  * and the FSSpec calls.  You will need to replace FindFolder with some
  35  * other mechanism for finding a place to put temporary files, and you
  36  * should replace the FSSpec calls with their HFS equivalents:
  37  *
  38  *     FSpDelete     ->  HDelete
  39  *     FSpGetFInfo   ->  HGetFInfo
  40  *     FSpCreate     ->  HCreate
  41  *     FSpOpenDF     ->  HOpen      *** Note: not HOpenDF ***
  42  *     FSMakeFSSpec  ->  (fill in spec by hand.)
  43  *
  44  * (Use HOpen instead of HOpenDF.  HOpen is just a glue-interface to PBHOpen,
  45  * which is on all HFS macs.  HOpenDF is a System 7 addition which avoids the
  46  * ages-old problem of names starting with a period.)
  47  *
  48  * Contributed by Sam Bushell (jsam@iagu.on.net) and
  49  * Dan Gildor (gyld@in-touch.com).
  50  */
  51
  52 #define JPEG_INTERNALS
  53 #include "jinclude.h"
  54 #include "jpeglib.h"
  55 #include "jmemsys.h"    /* import the system-dependent declarations */
  56
  57 #ifndef USE_MAC_MEMMGR  /* make sure user got configuration right */
  58   You forgot to define USE_MAC_MEMMGR in jconfig.h. /* deliberate syntax error */
  59 #endif
  60
  61 #include <Memory.h>     /* we use the MacOS memory manager */
  62 #include <Files.h>      /* we use the MacOS File stuff */
  63 #include <Folders.h>    /* we use the MacOS HFS stuff */
  64 #include <Script.h>     /* for smSystemScript */
  65 #include <Gestalt.h>    /* we use Gestalt to test for specific functionality */
  66
  67 #ifndef TEMP_FILE_NAME          /* can override from jconfig.h or Makefile */
  68 #define TEMP_FILE_NAME  "JPG%03d.TMP"
  69 #endif
  70
  71 static int next_file_num;       /* to distinguish among several temp files */
  72
  73
  74 /*
  75  * Memory allocation and freeing are controlled by the MacOS library
  76  * routines NewPtr() and DisposePtr(), which allocate fixed-address
  77  * storage.  Unfortunately, the IJG library isn't smart enough to cope
  78  * with relocatable storage.
  79  */
  80
  81 GLOBAL(void *)
  82 jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
  83 {
  84   return (void *) NewPtr(sizeofobject);
  85 }
  86
  87 GLOBAL(void)
  88 jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
  89 {
  90   DisposePtr((Ptr) object);
  91 }
  92
  93
  94 /*
  95  * "Large" objects are treated the same as "small" ones.
  96  * NB: we include FAR keywords in the routine declarations simply for
  97  * consistency with the rest of the IJG code; FAR should expand to empty
  98  * on rational architectures like the Mac.
  99  */
 100
 101 GLOBAL(void FAR *)
 102 jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
 103 {
 104   return (void FAR *) NewPtr(sizeofobject);
 105 }
 106
 107 GLOBAL(void)
 108 jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
 109 {
 110   DisposePtr((Ptr) object);
 111 }
 112
 113
 114 /*
 115  * This routine computes the total memory space available for allocation.
 116  */
 117
 118 GLOBAL(long)
 119 jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
 120                     long max_bytes_needed, long already_allocated)
 121 {
 122   long limit = cinfo->mem->max_memory_to_use - already_allocated;
 123   long slop, mem;
 124
 125   /* Don't ask for more than what application has told us we may use */
 126   if (max_bytes_needed > limit && limit > 0)
 127     max_bytes_needed = limit;
 128   /* Find whether there's a big enough free block in the heap.
 129    * CompactMem tries to create a contiguous block of the requested size,
 130    * and then returns the size of the largest free block (which could be
 131    * much more or much less than we asked for).
 132    * We add some slop to ensure we don't use up all available memory.
 133    */
 134   slop = max_bytes_needed / 16 + 32768L;
 135   mem = CompactMem(max_bytes_needed + slop) - slop;
 136   if (mem < 0)
 137     mem = 0;                    /* sigh, couldn't even get the slop */
 138   /* Don't take more than the application says we can have */
 139   if (mem > limit && limit > 0)
 140     mem = limit;
 141   return mem;
 142 }
 143
 144
 145 /*
 146  * Backing store (temporary file) management.
 147  * Backing store objects are only used when the value returned by
 148  * jpeg_mem_available is less than the total space needed.  You can dispense
 149  * with these routines if you have plenty of virtual memory; see jmemnobs.c.
 150  */
 151
 152
 153 METHODDEF(void)
 154 read_backing_store (j_common_ptr cinfo, backing_store_ptr info,
 155                     void FAR * buffer_address,
 156                     long file_offset, long byte_count)
 157 {
 158   long bytes = byte_count;
 159   long retVal;
 160
 161   if ( SetFPos ( info->temp_file, fsFromStart, file_offset ) != noErr )
 162     ERREXIT(cinfo, JERR_TFILE_SEEK);
 163
 164   retVal = FSRead ( info->temp_file, &bytes,
 165                     (unsigned char *) buffer_address );
 166   if ( retVal != noErr || bytes != byte_count )
 167     ERREXIT(cinfo, JERR_TFILE_READ);
 168 }
 169
 170
 171 METHODDEF(void)
 172 write_backing_store (j_common_ptr cinfo, backing_store_ptr info,
 173                      void FAR * buffer_address,
 174                      long file_offset, long byte_count)
 175 {
 176   long bytes = byte_count;
 177   long retVal;
 178
 179   if ( SetFPos ( info->temp_file, fsFromStart, file_offset ) != noErr )
 180     ERREXIT(cinfo, JERR_TFILE_SEEK);
 181
 182   retVal = FSWrite ( info->temp_file, &bytes,
 183                      (unsigned char *) buffer_address );
 184   if ( retVal != noErr || bytes != byte_count )
 185     ERREXIT(cinfo, JERR_TFILE_WRITE);
 186 }
 187
 188
 189 METHODDEF(void)
 190 close_backing_store (j_common_ptr cinfo, backing_store_ptr info)
 191 {
 192   FSClose ( info->temp_file );
 193   FSpDelete ( &(info->tempSpec) );
 194 }
 195
 196
 197 /*
 198  * Initial opening of a backing-store object.
 199  *
 200  * This version uses FindFolder to find the Temporary Items folder,
 201  * and puts the temporary file in there.
 202  */
 203
 204 GLOBAL(void)
 205 jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
 206                          long total_bytes_needed)
 207 {
 208   short         tmpRef, vRefNum;
 209   long          dirID;
 210   FInfo         finderInfo;
 211   FSSpec        theSpec;
 212   Str255        fName;
 213   OSErr         osErr;
 214   long          gestaltResponse = 0;
 215
 216   /* Check that FSSpec calls are available. */
 217   osErr = Gestalt( gestaltFSAttr, &gestaltResponse );
 218   if ( ( osErr != noErr )
 219        || !( gestaltResponse & (1<<gestaltHasFSSpecCalls) ) )
 220     ERREXITS(cinfo, JERR_TFILE_CREATE, "- System 7.0 or later required");
 221   /* TO DO: add a proper error message to jerror.h. */
 222
 223   /* Check that FindFolder is available. */
 224   osErr = Gestalt( gestaltFindFolderAttr, &gestaltResponse );
 225   if ( ( osErr != noErr )
 226        || !( gestaltResponse & (1<<gestaltFindFolderPresent) ) )
 227     ERREXITS(cinfo, JERR_TFILE_CREATE, "- System 7.0 or later required.");
 228   /* TO DO: add a proper error message to jerror.h. */
 229
 230   osErr = FindFolder ( kOnSystemDisk, kTemporaryFolderType, kCreateFolder,
 231                        &vRefNum, &dirID );
 232   if ( osErr != noErr )
 233     ERREXITS(cinfo, JERR_TFILE_CREATE, "- temporary items folder unavailable");
 234   /* TO DO: Try putting the temp files somewhere else. */
 235
 236   /* Keep generating file names till we find one that's not in use */
 237   for (;;) {
 238     next_file_num++;            /* advance counter */
 239
 240     sprintf(info->temp_name, TEMP_FILE_NAME, next_file_num);
 241     strcpy ( (Ptr)fName+1, info->temp_name );
 242     *fName = strlen (info->temp_name);
 243     osErr = FSMakeFSSpec ( vRefNum, dirID, fName, &theSpec );
 244
 245     if ( (osErr = FSpGetFInfo ( &theSpec, &finderInfo ) ) != noErr )
 246       break;
 247   }
 248
 249   osErr = FSpCreate ( &theSpec, '????', '????', smSystemScript );
 250   if ( osErr != noErr )
 251     ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
 252
 253   osErr = FSpOpenDF ( &theSpec, fsRdWrPerm, &(info->temp_file) );
 254   if ( osErr != noErr )
 255     ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
 256
 257   info->tempSpec = theSpec;
 258
 259   info->read_backing_store = read_backing_store;
 260   info->write_backing_store = write_backing_store;
 261   info->close_backing_store = close_backing_store;
 262   TRACEMSS(cinfo, 1, JTRC_TFILE_OPEN, info->temp_name);
 263 }
 264
 265
 266 /*
 267  * These routines take care of any system-dependent initialization and
 268  * cleanup required.
 269  */
 270
 271 GLOBAL(long)
 272 jpeg_mem_init (j_common_ptr cinfo)
 273 {
 274   next_file_num = 0;
 275
 276   /* max_memory_to_use will be initialized to FreeMem()'s result;
 277    * the calling application might later reduce it, for example
 278    * to leave room to invoke multiple JPEG objects.
 279    * Note that FreeMem returns the total number of free bytes;
 280    * it may not be possible to allocate a single block of this size.
 281    */
 282   return FreeMem();
 283 }
 284
 285 GLOBAL(void)
 286 jpeg_mem_term (j_common_ptr cinfo)
 287 {
 288   /* no work */
 289 }