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 }