Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 1 | /* |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 2 | * jmemdos.c |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 3 | * |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 4 | * Copyright (C) 1992-1994, Thomas G. Lane. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 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 an MS-DOS-compatible implementation of the system- |
| 9 | * dependent portion of the JPEG memory manager. Temporary data can be |
| 10 | * stored in extended or expanded memory as well as in regular DOS files. |
| 11 | * |
| 12 | * If you use this file, you must be sure that NEED_FAR_POINTERS is defined |
| 13 | * if you compile in a small-data memory model; it should NOT be defined if |
| 14 | * you use a large-data memory model. This file is not recommended if you |
| 15 | * are using a flat-memory-space 386 environment such as DJGCC or Watcom C. |
Thomas G. Lane | cc7150e | 1993-02-18 00:00:00 +0000 | [diff] [blame] | 16 | * Also, this code will NOT work if struct fields are aligned on greater than |
| 17 | * 2-byte boundaries. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 18 | * |
| 19 | * Based on code contributed by Ge' Weijers. |
| 20 | */ |
| 21 | |
| 22 | /* |
| 23 | * If you have both extended and expanded memory, you may want to change the |
| 24 | * order in which they are tried in jopen_backing_store. On a 286 machine |
| 25 | * expanded memory is usually faster, since extended memory access involves |
| 26 | * an expensive protected-mode-and-back switch. On 386 and better, extended |
| 27 | * memory is usually faster. As distributed, the code tries extended memory |
| 28 | * first (what? not everyone has a 386? :-). |
| 29 | * |
| 30 | * You can disable use of extended/expanded memory entirely by altering these |
| 31 | * definitions or overriding them from the Makefile (eg, -DEMS_SUPPORTED=0). |
| 32 | */ |
| 33 | |
| 34 | #ifndef XMS_SUPPORTED |
| 35 | #define XMS_SUPPORTED 1 |
| 36 | #endif |
| 37 | #ifndef EMS_SUPPORTED |
| 38 | #define EMS_SUPPORTED 1 |
| 39 | #endif |
| 40 | |
| 41 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 42 | #define JPEG_INTERNALS |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 43 | #include "jinclude.h" |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 44 | #include "jpeglib.h" |
| 45 | #include "jmemsys.h" /* import the system-dependent declarations */ |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 46 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 47 | #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare these */ |
| 48 | extern void * malloc JPP((size_t size)); |
| 49 | extern void free JPP((void *ptr)); |
| 50 | extern char * getenv JPP((const char * name)); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 51 | #endif |
| 52 | |
| 53 | #ifdef NEED_FAR_POINTERS |
| 54 | |
| 55 | #ifdef __TURBOC__ |
| 56 | /* These definitions work for Borland C (Turbo C) */ |
| 57 | #include <alloc.h> /* need farmalloc(), farfree() */ |
| 58 | #define far_malloc(x) farmalloc(x) |
| 59 | #define far_free(x) farfree(x) |
| 60 | #else |
| 61 | /* These definitions work for Microsoft C and compatible compilers */ |
| 62 | #include <malloc.h> /* need _fmalloc(), _ffree() */ |
| 63 | #define far_malloc(x) _fmalloc(x) |
| 64 | #define far_free(x) _ffree(x) |
| 65 | #endif |
| 66 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 67 | #else /* not NEED_FAR_POINTERS */ |
| 68 | |
| 69 | #define far_malloc(x) malloc(x) |
| 70 | #define far_free(x) free(x) |
| 71 | |
| 72 | #endif /* NEED_FAR_POINTERS */ |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 73 | |
| 74 | #ifdef DONT_USE_B_MODE /* define mode parameters for fopen() */ |
| 75 | #define READ_BINARY "r" |
| 76 | #else |
| 77 | #define READ_BINARY "rb" |
| 78 | #endif |
| 79 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 80 | #if MAX_ALLOC_CHUNK >= 65535L /* make sure jconfig.h got this right */ |
| 81 | MAX_ALLOC_CHUNK should be less than 64K. /* deliberate syntax error */ |
| 82 | #endif |
| 83 | |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 84 | |
| 85 | /* |
| 86 | * Declarations for assembly-language support routines (see jmemdosa.asm). |
| 87 | * |
| 88 | * The functions are declared "far" as are all pointer arguments; |
| 89 | * this ensures the assembly source code will work regardless of the |
| 90 | * compiler memory model. We assume "short" is 16 bits, "long" is 32. |
| 91 | */ |
| 92 | |
| 93 | typedef void far * XMSDRIVER; /* actually a pointer to code */ |
| 94 | typedef struct { /* registers for calling XMS driver */ |
| 95 | unsigned short ax, dx, bx; |
| 96 | void far * ds_si; |
| 97 | } XMScontext; |
| 98 | typedef struct { /* registers for calling EMS driver */ |
| 99 | unsigned short ax, dx, bx; |
| 100 | void far * ds_si; |
| 101 | } EMScontext; |
| 102 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 103 | EXTERN short far jdos_open JPP((short far * handle, char far * filename)); |
| 104 | EXTERN short far jdos_close JPP((short handle)); |
| 105 | EXTERN short far jdos_seek JPP((short handle, long offset)); |
| 106 | EXTERN short far jdos_read JPP((short handle, void far * buffer, |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 107 | unsigned short count)); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 108 | EXTERN short far jdos_write JPP((short handle, void far * buffer, |
| 109 | unsigned short count)); |
| 110 | EXTERN void far jxms_getdriver JPP((XMSDRIVER far *)); |
| 111 | EXTERN void far jxms_calldriver JPP((XMSDRIVER, XMScontext far *)); |
| 112 | EXTERN short far jems_available JPP((void)); |
| 113 | EXTERN void far jems_calldriver JPP((EMScontext far *)); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 114 | |
| 115 | |
| 116 | /* |
| 117 | * Selection of a file name for a temporary file. |
| 118 | * This is highly system-dependent, and you may want to customize it. |
| 119 | */ |
| 120 | |
| 121 | static int next_file_num; /* to distinguish among several temp files */ |
| 122 | |
| 123 | LOCAL void |
| 124 | select_file_name (char * fname) |
| 125 | { |
| 126 | const char * env; |
| 127 | char * ptr; |
| 128 | FILE * tfile; |
| 129 | |
| 130 | /* Keep generating file names till we find one that's not in use */ |
| 131 | for (;;) { |
| 132 | /* Get temp directory name from environment TMP or TEMP variable; |
| 133 | * if none, use "." |
| 134 | */ |
| 135 | if ((env = (const char *) getenv("TMP")) == NULL) |
| 136 | if ((env = (const char *) getenv("TEMP")) == NULL) |
| 137 | env = "."; |
| 138 | if (*env == '\0') /* null string means "." */ |
| 139 | env = "."; |
| 140 | ptr = fname; /* copy name to fname */ |
| 141 | while (*env != '\0') |
| 142 | *ptr++ = *env++; |
| 143 | if (ptr[-1] != '\\' && ptr[-1] != '/') |
| 144 | *ptr++ = '\\'; /* append backslash if not in env variable */ |
| 145 | /* Append a suitable file name */ |
| 146 | next_file_num++; /* advance counter */ |
| 147 | sprintf(ptr, "JPG%03d.TMP", next_file_num); |
| 148 | /* Probe to see if file name is already in use */ |
| 149 | if ((tfile = fopen(fname, READ_BINARY)) == NULL) |
| 150 | break; |
| 151 | fclose(tfile); /* oops, it's there; close tfile & try again */ |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | |
| 156 | /* |
| 157 | * Near-memory allocation and freeing are controlled by the regular library |
| 158 | * routines malloc() and free(). |
| 159 | */ |
| 160 | |
| 161 | GLOBAL void * |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 162 | jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 163 | { |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 164 | return (void *) malloc(sizeofobject); |
| 165 | } |
| 166 | |
| 167 | GLOBAL void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 168 | jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 169 | { |
| 170 | free(object); |
| 171 | } |
| 172 | |
| 173 | |
| 174 | /* |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 175 | * "Large" objects are allocated in far memory, if possible |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 176 | */ |
| 177 | |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 178 | GLOBAL void FAR * |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 179 | jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 180 | { |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 181 | return (void FAR *) far_malloc(sizeofobject); |
| 182 | } |
| 183 | |
| 184 | GLOBAL void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 185 | jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 186 | { |
| 187 | far_free(object); |
| 188 | } |
| 189 | |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 190 | |
| 191 | /* |
| 192 | * This routine computes the total memory space available for allocation. |
| 193 | * It's impossible to do this in a portable way; our current solution is |
| 194 | * to make the user tell us (with a default value set at compile time). |
| 195 | * If you can actually get the available space, it's a good idea to subtract |
| 196 | * a slop factor of 5% or so. |
| 197 | */ |
| 198 | |
| 199 | #ifndef DEFAULT_MAX_MEM /* so can override from makefile */ |
| 200 | #define DEFAULT_MAX_MEM 300000L /* for total usage about 450K */ |
| 201 | #endif |
| 202 | |
| 203 | GLOBAL long |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 204 | jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed, |
| 205 | long max_bytes_needed, long already_allocated) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 206 | { |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 207 | return cinfo->mem->max_memory_to_use - already_allocated; |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 208 | } |
| 209 | |
| 210 | |
| 211 | /* |
| 212 | * Backing store (temporary file) management. |
| 213 | * Backing store objects are only used when the value returned by |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 214 | * jpeg_mem_available is less than the total space needed. You can dispense |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 215 | * with these routines if you have plenty of virtual memory; see jmemnobs.c. |
| 216 | */ |
| 217 | |
| 218 | /* |
| 219 | * For MS-DOS we support three types of backing storage: |
| 220 | * 1. Conventional DOS files. We access these by direct DOS calls rather |
| 221 | * than via the stdio package. This provides a bit better performance, |
| 222 | * but the real reason is that the buffers to be read or written are FAR. |
| 223 | * The stdio library for small-data memory models can't cope with that. |
| 224 | * 2. Extended memory, accessed per the XMS V2.0 specification. |
| 225 | * 3. Expanded memory, accessed per the LIM/EMS 4.0 specification. |
| 226 | * You'll need copies of those specs to make sense of the related code. |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 227 | * The specs are available by Internet FTP from the SIMTEL archives |
| 228 | * (oak.oakland.edu and its various mirror sites). See files |
| 229 | * pub/msdos/microsoft/xms20.arc and pub/msdos/info/limems41.zip. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 230 | */ |
| 231 | |
| 232 | |
| 233 | /* |
| 234 | * Access methods for a DOS file. |
| 235 | */ |
| 236 | |
| 237 | |
| 238 | METHODDEF void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 239 | read_file_store (j_common_ptr cinfo, backing_store_ptr info, |
| 240 | void FAR * buffer_address, |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 241 | long file_offset, long byte_count) |
| 242 | { |
| 243 | if (jdos_seek(info->handle.file_handle, file_offset)) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 244 | ERREXIT(cinfo, JERR_TFILE_SEEK); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 245 | /* Since MAX_ALLOC_CHUNK is less than 64K, byte_count will be too. */ |
| 246 | if (byte_count > 65535L) /* safety check */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 247 | ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 248 | if (jdos_read(info->handle.file_handle, buffer_address, |
| 249 | (unsigned short) byte_count)) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 250 | ERREXIT(cinfo, JERR_TFILE_READ); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 251 | } |
| 252 | |
| 253 | |
| 254 | METHODDEF void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 255 | write_file_store (j_common_ptr cinfo, backing_store_ptr info, |
| 256 | void FAR * buffer_address, |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 257 | long file_offset, long byte_count) |
| 258 | { |
| 259 | if (jdos_seek(info->handle.file_handle, file_offset)) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 260 | ERREXIT(cinfo, JERR_TFILE_SEEK); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 261 | /* Since MAX_ALLOC_CHUNK is less than 64K, byte_count will be too. */ |
| 262 | if (byte_count > 65535L) /* safety check */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 263 | ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 264 | if (jdos_write(info->handle.file_handle, buffer_address, |
| 265 | (unsigned short) byte_count)) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 266 | ERREXIT(cinfo, JERR_TFILE_WRITE); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 267 | } |
| 268 | |
| 269 | |
| 270 | METHODDEF void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 271 | close_file_store (j_common_ptr cinfo, backing_store_ptr info) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 272 | { |
| 273 | jdos_close(info->handle.file_handle); /* close the file */ |
| 274 | remove(info->temp_name); /* delete the file */ |
| 275 | /* If your system doesn't have remove(), try unlink() instead. |
| 276 | * remove() is the ANSI-standard name for this function, but |
| 277 | * unlink() was more common in pre-ANSI systems. |
| 278 | */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 279 | TRACEMSS(cinfo, 1, JTRC_TFILE_CLOSE, info->temp_name); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 280 | } |
| 281 | |
| 282 | |
| 283 | LOCAL boolean |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 284 | open_file_store (j_common_ptr cinfo, backing_store_ptr info, |
| 285 | long total_bytes_needed) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 286 | { |
| 287 | short handle; |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 288 | |
| 289 | select_file_name(info->temp_name); |
Thomas G. Lane | 88aeed4 | 1992-12-10 00:00:00 +0000 | [diff] [blame] | 290 | if (jdos_open((short far *) & handle, (char far *) info->temp_name)) { |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 291 | /* might as well exit since jpeg_open_backing_store will fail anyway */ |
| 292 | ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 293 | return FALSE; |
Thomas G. Lane | 88aeed4 | 1992-12-10 00:00:00 +0000 | [diff] [blame] | 294 | } |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 295 | info->handle.file_handle = handle; |
| 296 | info->read_backing_store = read_file_store; |
| 297 | info->write_backing_store = write_file_store; |
| 298 | info->close_backing_store = close_file_store; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 299 | TRACEMSS(cinfo, 1, JTRC_TFILE_OPEN, info->temp_name); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 300 | return TRUE; /* succeeded */ |
| 301 | } |
| 302 | |
| 303 | |
| 304 | /* |
| 305 | * Access methods for extended memory. |
| 306 | */ |
| 307 | |
| 308 | #if XMS_SUPPORTED |
| 309 | |
| 310 | static XMSDRIVER xms_driver; /* saved address of XMS driver */ |
| 311 | |
| 312 | typedef union { /* either long offset or real-mode pointer */ |
| 313 | long offset; |
| 314 | void far * ptr; |
| 315 | } XMSPTR; |
| 316 | |
| 317 | typedef struct { /* XMS move specification structure */ |
| 318 | long length; |
| 319 | XMSH src_handle; |
| 320 | XMSPTR src; |
| 321 | XMSH dst_handle; |
| 322 | XMSPTR dst; |
| 323 | } XMSspec; |
| 324 | |
| 325 | #define ODD(X) (((X) & 1L) != 0) |
| 326 | |
| 327 | |
| 328 | METHODDEF void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 329 | read_xms_store (j_common_ptr cinfo, backing_store_ptr info, |
| 330 | void FAR * buffer_address, |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 331 | long file_offset, long byte_count) |
| 332 | { |
| 333 | XMScontext ctx; |
| 334 | XMSspec spec; |
| 335 | char endbuffer[2]; |
| 336 | |
| 337 | /* The XMS driver can't cope with an odd length, so handle the last byte |
| 338 | * specially if byte_count is odd. We don't expect this to be common. |
| 339 | */ |
| 340 | |
| 341 | spec.length = byte_count & (~ 1L); |
| 342 | spec.src_handle = info->handle.xms_handle; |
| 343 | spec.src.offset = file_offset; |
| 344 | spec.dst_handle = 0; |
| 345 | spec.dst.ptr = buffer_address; |
| 346 | |
| 347 | ctx.ds_si = (void far *) & spec; |
| 348 | ctx.ax = 0x0b00; /* EMB move */ |
| 349 | jxms_calldriver(xms_driver, (XMScontext far *) & ctx); |
| 350 | if (ctx.ax != 1) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 351 | ERREXIT(cinfo, JERR_XMS_READ); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 352 | |
| 353 | if (ODD(byte_count)) { |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 354 | read_xms_store(cinfo, info, (void FAR *) endbuffer, |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 355 | file_offset + byte_count - 1L, 2L); |
| 356 | ((char FAR *) buffer_address)[byte_count - 1L] = endbuffer[0]; |
| 357 | } |
| 358 | } |
| 359 | |
| 360 | |
| 361 | METHODDEF void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 362 | write_xms_store (j_common_ptr cinfo, backing_store_ptr info, |
| 363 | void FAR * buffer_address, |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 364 | long file_offset, long byte_count) |
| 365 | { |
| 366 | XMScontext ctx; |
| 367 | XMSspec spec; |
| 368 | char endbuffer[2]; |
| 369 | |
| 370 | /* The XMS driver can't cope with an odd length, so handle the last byte |
| 371 | * specially if byte_count is odd. We don't expect this to be common. |
| 372 | */ |
| 373 | |
| 374 | spec.length = byte_count & (~ 1L); |
| 375 | spec.src_handle = 0; |
| 376 | spec.src.ptr = buffer_address; |
| 377 | spec.dst_handle = info->handle.xms_handle; |
| 378 | spec.dst.offset = file_offset; |
| 379 | |
| 380 | ctx.ds_si = (void far *) & spec; |
| 381 | ctx.ax = 0x0b00; /* EMB move */ |
| 382 | jxms_calldriver(xms_driver, (XMScontext far *) & ctx); |
| 383 | if (ctx.ax != 1) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 384 | ERREXIT(cinfo, JERR_XMS_WRITE); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 385 | |
| 386 | if (ODD(byte_count)) { |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 387 | read_xms_store(cinfo, info, (void FAR *) endbuffer, |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 388 | file_offset + byte_count - 1L, 2L); |
| 389 | endbuffer[0] = ((char FAR *) buffer_address)[byte_count - 1L]; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 390 | write_xms_store(cinfo, info, (void FAR *) endbuffer, |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 391 | file_offset + byte_count - 1L, 2L); |
| 392 | } |
| 393 | } |
| 394 | |
| 395 | |
| 396 | METHODDEF void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 397 | close_xms_store (j_common_ptr cinfo, backing_store_ptr info) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 398 | { |
| 399 | XMScontext ctx; |
| 400 | |
| 401 | ctx.dx = info->handle.xms_handle; |
| 402 | ctx.ax = 0x0a00; |
| 403 | jxms_calldriver(xms_driver, (XMScontext far *) & ctx); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 404 | TRACEMS1(cinfo, 1, JTRC_XMS_CLOSE, info->handle.xms_handle); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 405 | /* we ignore any error return from the driver */ |
| 406 | } |
| 407 | |
| 408 | |
| 409 | LOCAL boolean |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 410 | open_xms_store (j_common_ptr cinfo, backing_store_ptr info, |
| 411 | long total_bytes_needed) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 412 | { |
| 413 | XMScontext ctx; |
| 414 | |
| 415 | /* Get address of XMS driver */ |
| 416 | jxms_getdriver((XMSDRIVER far *) & xms_driver); |
| 417 | if (xms_driver == NULL) |
| 418 | return FALSE; /* no driver to be had */ |
| 419 | |
| 420 | /* Get version number, must be >= 2.00 */ |
| 421 | ctx.ax = 0x0000; |
| 422 | jxms_calldriver(xms_driver, (XMScontext far *) & ctx); |
| 423 | if (ctx.ax < (unsigned short) 0x0200) |
| 424 | return FALSE; |
| 425 | |
| 426 | /* Try to get space (expressed in kilobytes) */ |
| 427 | ctx.dx = (unsigned short) ((total_bytes_needed + 1023L) >> 10); |
| 428 | ctx.ax = 0x0900; |
| 429 | jxms_calldriver(xms_driver, (XMScontext far *) & ctx); |
| 430 | if (ctx.ax != 1) |
| 431 | return FALSE; |
| 432 | |
| 433 | /* Succeeded, save the handle and away we go */ |
| 434 | info->handle.xms_handle = ctx.dx; |
| 435 | info->read_backing_store = read_xms_store; |
| 436 | info->write_backing_store = write_xms_store; |
| 437 | info->close_backing_store = close_xms_store; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 438 | TRACEMS1(cinfo, 1, JTRC_XMS_OPEN, ctx.dx); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 439 | return TRUE; /* succeeded */ |
| 440 | } |
| 441 | |
| 442 | #endif /* XMS_SUPPORTED */ |
| 443 | |
| 444 | |
| 445 | /* |
| 446 | * Access methods for expanded memory. |
| 447 | */ |
| 448 | |
| 449 | #if EMS_SUPPORTED |
| 450 | |
Thomas G. Lane | cc7150e | 1993-02-18 00:00:00 +0000 | [diff] [blame] | 451 | /* The EMS move specification structure requires word and long fields aligned |
| 452 | * at odd byte boundaries. Some compilers will align struct fields at even |
| 453 | * byte boundaries. While it's usually possible to force byte alignment, |
| 454 | * that causes an overall performance penalty and may pose problems in merging |
| 455 | * JPEG into a larger application. Instead we accept some rather dirty code |
| 456 | * here. Note this code would fail if the hardware did not allow odd-byte |
| 457 | * word & long accesses, but all 80x86 CPUs do. |
| 458 | */ |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 459 | |
Thomas G. Lane | cc7150e | 1993-02-18 00:00:00 +0000 | [diff] [blame] | 460 | typedef void far * EMSPTR; |
| 461 | |
| 462 | typedef union { /* EMS move specification structure */ |
| 463 | long length; /* It's easy to access first 4 bytes */ |
| 464 | char bytes[18]; /* Misaligned fields in here! */ |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 465 | } EMSspec; |
| 466 | |
Thomas G. Lane | cc7150e | 1993-02-18 00:00:00 +0000 | [diff] [blame] | 467 | /* Macros for accessing misaligned fields */ |
| 468 | #define FIELD_AT(spec,offset,type) (*((type *) &(spec.bytes[offset]))) |
| 469 | #define SRC_TYPE(spec) FIELD_AT(spec,4,char) |
| 470 | #define SRC_HANDLE(spec) FIELD_AT(spec,5,EMSH) |
| 471 | #define SRC_OFFSET(spec) FIELD_AT(spec,7,unsigned short) |
| 472 | #define SRC_PAGE(spec) FIELD_AT(spec,9,unsigned short) |
| 473 | #define SRC_PTR(spec) FIELD_AT(spec,7,EMSPTR) |
| 474 | #define DST_TYPE(spec) FIELD_AT(spec,11,char) |
| 475 | #define DST_HANDLE(spec) FIELD_AT(spec,12,EMSH) |
| 476 | #define DST_OFFSET(spec) FIELD_AT(spec,14,unsigned short) |
| 477 | #define DST_PAGE(spec) FIELD_AT(spec,16,unsigned short) |
| 478 | #define DST_PTR(spec) FIELD_AT(spec,14,EMSPTR) |
| 479 | |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 480 | #define EMSPAGESIZE 16384L /* gospel, see the EMS specs */ |
| 481 | |
| 482 | #define HIBYTE(W) (((W) >> 8) & 0xFF) |
| 483 | #define LOBYTE(W) ((W) & 0xFF) |
| 484 | |
| 485 | |
| 486 | METHODDEF void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 487 | read_ems_store (j_common_ptr cinfo, backing_store_ptr info, |
| 488 | void FAR * buffer_address, |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 489 | long file_offset, long byte_count) |
| 490 | { |
| 491 | EMScontext ctx; |
| 492 | EMSspec spec; |
| 493 | |
| 494 | spec.length = byte_count; |
Thomas G. Lane | cc7150e | 1993-02-18 00:00:00 +0000 | [diff] [blame] | 495 | SRC_TYPE(spec) = 1; |
| 496 | SRC_HANDLE(spec) = info->handle.ems_handle; |
| 497 | SRC_PAGE(spec) = (unsigned short) (file_offset / EMSPAGESIZE); |
| 498 | SRC_OFFSET(spec) = (unsigned short) (file_offset % EMSPAGESIZE); |
| 499 | DST_TYPE(spec) = 0; |
| 500 | DST_HANDLE(spec) = 0; |
| 501 | DST_PTR(spec) = buffer_address; |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 502 | |
| 503 | ctx.ds_si = (void far *) & spec; |
| 504 | ctx.ax = 0x5700; /* move memory region */ |
| 505 | jems_calldriver((EMScontext far *) & ctx); |
| 506 | if (HIBYTE(ctx.ax) != 0) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 507 | ERREXIT(cinfo, JERR_EMS_READ); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 508 | } |
| 509 | |
| 510 | |
| 511 | METHODDEF void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 512 | write_ems_store (j_common_ptr cinfo, backing_store_ptr info, |
| 513 | void FAR * buffer_address, |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 514 | long file_offset, long byte_count) |
| 515 | { |
| 516 | EMScontext ctx; |
| 517 | EMSspec spec; |
| 518 | |
| 519 | spec.length = byte_count; |
Thomas G. Lane | cc7150e | 1993-02-18 00:00:00 +0000 | [diff] [blame] | 520 | SRC_TYPE(spec) = 0; |
| 521 | SRC_HANDLE(spec) = 0; |
| 522 | SRC_PTR(spec) = buffer_address; |
| 523 | DST_TYPE(spec) = 1; |
| 524 | DST_HANDLE(spec) = info->handle.ems_handle; |
| 525 | DST_PAGE(spec) = (unsigned short) (file_offset / EMSPAGESIZE); |
| 526 | DST_OFFSET(spec) = (unsigned short) (file_offset % EMSPAGESIZE); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 527 | |
| 528 | ctx.ds_si = (void far *) & spec; |
| 529 | ctx.ax = 0x5700; /* move memory region */ |
| 530 | jems_calldriver((EMScontext far *) & ctx); |
| 531 | if (HIBYTE(ctx.ax) != 0) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 532 | ERREXIT(cinfo, JERR_EMS_WRITE); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 533 | } |
| 534 | |
| 535 | |
| 536 | METHODDEF void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 537 | close_ems_store (j_common_ptr cinfo, backing_store_ptr info) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 538 | { |
| 539 | EMScontext ctx; |
| 540 | |
| 541 | ctx.ax = 0x4500; |
| 542 | ctx.dx = info->handle.ems_handle; |
| 543 | jems_calldriver((EMScontext far *) & ctx); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 544 | TRACEMS1(cinfo, 1, JTRC_EMS_CLOSE, info->handle.ems_handle); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 545 | /* we ignore any error return from the driver */ |
| 546 | } |
| 547 | |
| 548 | |
| 549 | LOCAL boolean |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 550 | open_ems_store (j_common_ptr cinfo, backing_store_ptr info, |
| 551 | long total_bytes_needed) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 552 | { |
| 553 | EMScontext ctx; |
| 554 | |
| 555 | /* Is EMS driver there? */ |
| 556 | if (! jems_available()) |
| 557 | return FALSE; |
| 558 | |
| 559 | /* Get status, make sure EMS is OK */ |
| 560 | ctx.ax = 0x4000; |
| 561 | jems_calldriver((EMScontext far *) & ctx); |
| 562 | if (HIBYTE(ctx.ax) != 0) |
| 563 | return FALSE; |
| 564 | |
| 565 | /* Get version, must be >= 4.0 */ |
| 566 | ctx.ax = 0x4600; |
| 567 | jems_calldriver((EMScontext far *) & ctx); |
| 568 | if (HIBYTE(ctx.ax) != 0 || LOBYTE(ctx.ax) < 0x40) |
| 569 | return FALSE; |
| 570 | |
| 571 | /* Try to allocate requested space */ |
| 572 | ctx.ax = 0x4300; |
| 573 | ctx.bx = (unsigned short) ((total_bytes_needed + EMSPAGESIZE-1L) / EMSPAGESIZE); |
| 574 | jems_calldriver((EMScontext far *) & ctx); |
| 575 | if (HIBYTE(ctx.ax) != 0) |
| 576 | return FALSE; |
| 577 | |
| 578 | /* Succeeded, save the handle and away we go */ |
| 579 | info->handle.ems_handle = ctx.dx; |
| 580 | info->read_backing_store = read_ems_store; |
| 581 | info->write_backing_store = write_ems_store; |
| 582 | info->close_backing_store = close_ems_store; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 583 | TRACEMS1(cinfo, 1, JTRC_EMS_OPEN, ctx.dx); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 584 | return TRUE; /* succeeded */ |
| 585 | } |
| 586 | |
| 587 | #endif /* EMS_SUPPORTED */ |
| 588 | |
| 589 | |
| 590 | /* |
| 591 | * Initial opening of a backing-store object. |
| 592 | */ |
| 593 | |
| 594 | GLOBAL void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 595 | jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info, |
| 596 | long total_bytes_needed) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 597 | { |
| 598 | /* Try extended memory, then expanded memory, then regular file. */ |
| 599 | #if XMS_SUPPORTED |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 600 | if (open_xms_store(cinfo, info, total_bytes_needed)) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 601 | return; |
| 602 | #endif |
| 603 | #if EMS_SUPPORTED |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 604 | if (open_ems_store(cinfo, info, total_bytes_needed)) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 605 | return; |
| 606 | #endif |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 607 | if (open_file_store(cinfo, info, total_bytes_needed)) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 608 | return; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 609 | ERREXITS(cinfo, JERR_TFILE_CREATE, ""); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 610 | } |
| 611 | |
| 612 | |
| 613 | /* |
| 614 | * These routines take care of any system-dependent initialization and |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 615 | * cleanup required. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 616 | */ |
| 617 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 618 | GLOBAL long |
| 619 | jpeg_mem_init (j_common_ptr cinfo) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 620 | { |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 621 | next_file_num = 0; /* initialize temp file name generator */ |
| 622 | return DEFAULT_MAX_MEM; /* default for max_memory_to_use */ |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 623 | } |
| 624 | |
| 625 | GLOBAL void |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame^] | 626 | jpeg_mem_term (j_common_ptr cinfo) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 627 | { |
Thomas G. Lane | cc7150e | 1993-02-18 00:00:00 +0000 | [diff] [blame] | 628 | /* Microsoft C, at least in v6.00A, will not successfully reclaim freed |
| 629 | * blocks of size > 32Kbytes unless we give it a kick in the rear, like so: |
| 630 | */ |
| 631 | #ifdef NEED_FHEAPMIN |
| 632 | _fheapmin(); |
| 633 | #endif |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 634 | } |