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Diffstat (limited to 'jpeg/jmemdos.c')
| -rw-r--r-- | jpeg/jmemdos.c | 638 |
1 files changed, 0 insertions, 638 deletions
diff --git a/jpeg/jmemdos.c b/jpeg/jmemdos.c deleted file mode 100644 index 60b45c6..0000000 --- a/jpeg/jmemdos.c +++ /dev/null @@ -1,638 +0,0 @@ -/* - * jmemdos.c - * - * Copyright (C) 1992-1997, Thomas G. Lane. - * This file is part of the Independent JPEG Group's software. - * For conditions of distribution and use, see the accompanying README file. - * - * This file provides an MS-DOS-compatible implementation of the system- - * dependent portion of the JPEG memory manager. Temporary data can be - * stored in extended or expanded memory as well as in regular DOS files. - * - * If you use this file, you must be sure that NEED_FAR_POINTERS is defined - * if you compile in a small-data memory model; it should NOT be defined if - * you use a large-data memory model. This file is not recommended if you - * are using a flat-memory-space 386 environment such as DJGCC or Watcom C. - * Also, this code will NOT work if struct fields are aligned on greater than - * 2-byte boundaries. - * - * Based on code contributed by Ge' Weijers. - */ - -/* - * If you have both extended and expanded memory, you may want to change the - * order in which they are tried in jopen_backing_store. On a 286 machine - * expanded memory is usually faster, since extended memory access involves - * an expensive protected-mode-and-back switch. On 386 and better, extended - * memory is usually faster. As distributed, the code tries extended memory - * first (what? not everyone has a 386? :-). - * - * You can disable use of extended/expanded memory entirely by altering these - * definitions or overriding them from the Makefile (eg, -DEMS_SUPPORTED=0). - */ - -#ifndef XMS_SUPPORTED -#define XMS_SUPPORTED 1 -#endif -#ifndef EMS_SUPPORTED -#define EMS_SUPPORTED 1 -#endif - - -#define JPEG_INTERNALS -#include "jinclude.h" -#include "jpeglib.h" -#include "jmemsys.h" /* import the system-dependent declarations */ - -#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare these */ -extern void * malloc JPP((size_t size)); -extern void free JPP((void *ptr)); -extern char * getenv JPP((const char * name)); -#endif - -#ifdef NEED_FAR_POINTERS - -#ifdef __TURBOC__ -/* These definitions work for Borland C (Turbo C) */ -#include <alloc.h> /* need farmalloc(), farfree() */ -#define far_malloc(x) farmalloc(x) -#define far_free(x) farfree(x) -#else -/* These definitions work for Microsoft C and compatible compilers */ -#include <malloc.h> /* need _fmalloc(), _ffree() */ -#define far_malloc(x) _fmalloc(x) -#define far_free(x) _ffree(x) -#endif - -#else /* not NEED_FAR_POINTERS */ - -#define far_malloc(x) malloc(x) -#define far_free(x) free(x) - -#endif /* NEED_FAR_POINTERS */ - -#ifdef DONT_USE_B_MODE /* define mode parameters for fopen() */ -#define READ_BINARY "r" -#else -#define READ_BINARY "rb" -#endif - -#ifndef USE_MSDOS_MEMMGR /* make sure user got configuration right */ - You forgot to define USE_MSDOS_MEMMGR in jconfig.h. /* deliberate syntax error */ -#endif - -#if MAX_ALLOC_CHUNK >= 65535L /* make sure jconfig.h got this right */ - MAX_ALLOC_CHUNK should be less than 64K. /* deliberate syntax error */ -#endif - - -/* - * Declarations for assembly-language support routines (see jmemdosa.asm). - * - * The functions are declared "far" as are all their pointer arguments; - * this ensures the assembly source code will work regardless of the - * compiler memory model. We assume "short" is 16 bits, "long" is 32. - */ - -typedef void far * XMSDRIVER; /* actually a pointer to code */ -typedef struct { /* registers for calling XMS driver */ - unsigned short ax, dx, bx; - void far * ds_si; - } XMScontext; -typedef struct { /* registers for calling EMS driver */ - unsigned short ax, dx, bx; - void far * ds_si; - } EMScontext; - -extern short far jdos_open JPP((short far * handle, char far * filename)); -extern short far jdos_close JPP((short handle)); -extern short far jdos_seek JPP((short handle, long offset)); -extern short far jdos_read JPP((short handle, void far * buffer, - unsigned short count)); -extern short far jdos_write JPP((short handle, void far * buffer, - unsigned short count)); -extern void far jxms_getdriver JPP((XMSDRIVER far *)); -extern void far jxms_calldriver JPP((XMSDRIVER, XMScontext far *)); -extern short far jems_available JPP((void)); -extern void far jems_calldriver JPP((EMScontext far *)); - - -/* - * Selection of a file name for a temporary file. - * This is highly system-dependent, and you may want to customize it. - */ - -static int next_file_num; /* to distinguish among several temp files */ - -LOCAL(void) -select_file_name (char * fname) -{ - const char * env; - char * ptr; - FILE * tfile; - - /* Keep generating file names till we find one that's not in use */ - for (;;) { - /* Get temp directory name from environment TMP or TEMP variable; - * if none, use "." - */ - if ((env = (const char *) getenv("TMP")) == NULL) - if ((env = (const char *) getenv("TEMP")) == NULL) - env = "."; - if (*env == '\0') /* null string means "." */ - env = "."; - ptr = fname; /* copy name to fname */ - while (*env != '\0') - *ptr++ = *env++; - if (ptr[-1] != '\\' && ptr[-1] != '/') - *ptr++ = '\\'; /* append backslash if not in env variable */ - /* Append a suitable file name */ - next_file_num++; /* advance counter */ - sprintf(ptr, "JPG%03d.TMP", next_file_num); - /* Probe to see if file name is already in use */ - if ((tfile = fopen(fname, READ_BINARY)) == NULL) - break; - fclose(tfile); /* oops, it's there; close tfile & try again */ - } -} - - -/* - * Near-memory allocation and freeing are controlled by the regular library - * routines malloc() and free(). - */ - -GLOBAL(void *) -jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject) -{ - return (void *) malloc(sizeofobject); -} - -GLOBAL(void) -jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject) -{ - free(object); -} - - -/* - * "Large" objects are allocated in far memory, if possible - */ - -GLOBAL(void FAR *) -jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject) -{ - return (void FAR *) far_malloc(sizeofobject); -} - -GLOBAL(void) -jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject) -{ - far_free(object); -} - - -/* - * This routine computes the total memory space available for allocation. - * It's impossible to do this in a portable way; our current solution is - * to make the user tell us (with a default value set at compile time). - * If you can actually get the available space, it's a good idea to subtract - * a slop factor of 5% or so. - */ - -#ifndef DEFAULT_MAX_MEM /* so can override from makefile */ -#define DEFAULT_MAX_MEM 300000L /* for total usage about 450K */ -#endif - -GLOBAL(long) -jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed, - long max_bytes_needed, long already_allocated) -{ - return cinfo->mem->max_memory_to_use - already_allocated; -} - - -/* - * Backing store (temporary file) management. - * Backing store objects are only used when the value returned by - * jpeg_mem_available is less than the total space needed. You can dispense - * with these routines if you have plenty of virtual memory; see jmemnobs.c. - */ - -/* - * For MS-DOS we support three types of backing storage: - * 1. Conventional DOS files. We access these by direct DOS calls rather - * than via the stdio package. This provides a bit better performance, - * but the real reason is that the buffers to be read or written are FAR. - * The stdio library for small-data memory models can't cope with that. - * 2. Extended memory, accessed per the XMS V2.0 specification. - * 3. Expanded memory, accessed per the LIM/EMS 4.0 specification. - * You'll need copies of those specs to make sense of the related code. - * The specs are available by Internet FTP from the SIMTEL archives - * (oak.oakland.edu and its various mirror sites). See files - * pub/msdos/microsoft/xms20.arc and pub/msdos/info/limems41.zip. - */ - - -/* - * Access methods for a DOS file. - */ - - -METHODDEF(void) -read_file_store (j_common_ptr cinfo, backing_store_ptr info, - void FAR * buffer_address, - long file_offset, long byte_count) -{ - if (jdos_seek(info->handle.file_handle, file_offset)) - ERREXIT(cinfo, JERR_TFILE_SEEK); - /* Since MAX_ALLOC_CHUNK is less than 64K, byte_count will be too. */ - if (byte_count > 65535L) /* safety check */ - ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK); - if (jdos_read(info->handle.file_handle, buffer_address, - (unsigned short) byte_count)) - ERREXIT(cinfo, JERR_TFILE_READ); -} - - -METHODDEF(void) -write_file_store (j_common_ptr cinfo, backing_store_ptr info, - void FAR * buffer_address, - long file_offset, long byte_count) -{ - if (jdos_seek(info->handle.file_handle, file_offset)) - ERREXIT(cinfo, JERR_TFILE_SEEK); - /* Since MAX_ALLOC_CHUNK is less than 64K, byte_count will be too. */ - if (byte_count > 65535L) /* safety check */ - ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK); - if (jdos_write(info->handle.file_handle, buffer_address, - (unsigned short) byte_count)) - ERREXIT(cinfo, JERR_TFILE_WRITE); -} - - -METHODDEF(void) -close_file_store (j_common_ptr cinfo, backing_store_ptr info) -{ - jdos_close(info->handle.file_handle); /* close the file */ - remove(info->temp_name); /* delete the file */ -/* If your system doesn't have remove(), try unlink() instead. - * remove() is the ANSI-standard name for this function, but - * unlink() was more common in pre-ANSI systems. - */ - TRACEMSS(cinfo, 1, JTRC_TFILE_CLOSE, info->temp_name); -} - - -LOCAL(boolean) -open_file_store (j_common_ptr cinfo, backing_store_ptr info, - long total_bytes_needed) -{ - short handle; - - select_file_name(info->temp_name); - if (jdos_open((short far *) & handle, (char far *) info->temp_name)) { - /* might as well exit since jpeg_open_backing_store will fail anyway */ - ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name); - return FALSE; - } - info->handle.file_handle = handle; - info->read_backing_store = read_file_store; - info->write_backing_store = write_file_store; - info->close_backing_store = close_file_store; - TRACEMSS(cinfo, 1, JTRC_TFILE_OPEN, info->temp_name); - return TRUE; /* succeeded */ -} - - -/* - * Access methods for extended memory. - */ - -#if XMS_SUPPORTED - -static XMSDRIVER xms_driver; /* saved address of XMS driver */ - -typedef union { /* either long offset or real-mode pointer */ - long offset; - void far * ptr; - } XMSPTR; - -typedef struct { /* XMS move specification structure */ - long length; - XMSH src_handle; - XMSPTR src; - XMSH dst_handle; - XMSPTR dst; - } XMSspec; - -#define ODD(X) (((X) & 1L) != 0) - - -METHODDEF(void) -read_xms_store (j_common_ptr cinfo, backing_store_ptr info, - void FAR * buffer_address, - long file_offset, long byte_count) -{ - XMScontext ctx; - XMSspec spec; - char endbuffer[2]; - - /* The XMS driver can't cope with an odd length, so handle the last byte - * specially if byte_count is odd. We don't expect this to be common. - */ - - spec.length = byte_count & (~ 1L); - spec.src_handle = info->handle.xms_handle; - spec.src.offset = file_offset; - spec.dst_handle = 0; - spec.dst.ptr = buffer_address; - - ctx.ds_si = (void far *) & spec; - ctx.ax = 0x0b00; /* EMB move */ - jxms_calldriver(xms_driver, (XMScontext far *) & ctx); - if (ctx.ax != 1) - ERREXIT(cinfo, JERR_XMS_READ); - - if (ODD(byte_count)) { - read_xms_store(cinfo, info, (void FAR *) endbuffer, - file_offset + byte_count - 1L, 2L); - ((char FAR *) buffer_address)[byte_count - 1L] = endbuffer[0]; - } -} - - -METHODDEF(void) -write_xms_store (j_common_ptr cinfo, backing_store_ptr info, - void FAR * buffer_address, - long file_offset, long byte_count) -{ - XMScontext ctx; - XMSspec spec; - char endbuffer[2]; - - /* The XMS driver can't cope with an odd length, so handle the last byte - * specially if byte_count is odd. We don't expect this to be common. - */ - - spec.length = byte_count & (~ 1L); - spec.src_handle = 0; - spec.src.ptr = buffer_address; - spec.dst_handle = info->handle.xms_handle; - spec.dst.offset = file_offset; - - ctx.ds_si = (void far *) & spec; - ctx.ax = 0x0b00; /* EMB move */ - jxms_calldriver(xms_driver, (XMScontext far *) & ctx); - if (ctx.ax != 1) - ERREXIT(cinfo, JERR_XMS_WRITE); - - if (ODD(byte_count)) { - read_xms_store(cinfo, info, (void FAR *) endbuffer, - file_offset + byte_count - 1L, 2L); - endbuffer[0] = ((char FAR *) buffer_address)[byte_count - 1L]; - write_xms_store(cinfo, info, (void FAR *) endbuffer, - file_offset + byte_count - 1L, 2L); - } -} - - -METHODDEF(void) -close_xms_store (j_common_ptr cinfo, backing_store_ptr info) -{ - XMScontext ctx; - - ctx.dx = info->handle.xms_handle; - ctx.ax = 0x0a00; - jxms_calldriver(xms_driver, (XMScontext far *) & ctx); - TRACEMS1(cinfo, 1, JTRC_XMS_CLOSE, info->handle.xms_handle); - /* we ignore any error return from the driver */ -} - - -LOCAL(boolean) -open_xms_store (j_common_ptr cinfo, backing_store_ptr info, - long total_bytes_needed) -{ - XMScontext ctx; - - /* Get address of XMS driver */ - jxms_getdriver((XMSDRIVER far *) & xms_driver); - if (xms_driver == NULL) - return FALSE; /* no driver to be had */ - - /* Get version number, must be >= 2.00 */ - ctx.ax = 0x0000; - jxms_calldriver(xms_driver, (XMScontext far *) & ctx); - if (ctx.ax < (unsigned short) 0x0200) - return FALSE; - - /* Try to get space (expressed in kilobytes) */ - ctx.dx = (unsigned short) ((total_bytes_needed + 1023L) >> 10); - ctx.ax = 0x0900; - jxms_calldriver(xms_driver, (XMScontext far *) & ctx); - if (ctx.ax != 1) - return FALSE; - - /* Succeeded, save the handle and away we go */ - info->handle.xms_handle = ctx.dx; - info->read_backing_store = read_xms_store; - info->write_backing_store = write_xms_store; - info->close_backing_store = close_xms_store; - TRACEMS1(cinfo, 1, JTRC_XMS_OPEN, ctx.dx); - return TRUE; /* succeeded */ -} - -#endif /* XMS_SUPPORTED */ - - -/* - * Access methods for expanded memory. - */ - -#if EMS_SUPPORTED - -/* The EMS move specification structure requires word and long fields aligned - * at odd byte boundaries. Some compilers will align struct fields at even - * byte boundaries. While it's usually possible to force byte alignment, - * that causes an overall performance penalty and may pose problems in merging - * JPEG into a larger application. Instead we accept some rather dirty code - * here. Note this code would fail if the hardware did not allow odd-byte - * word & long accesses, but all 80x86 CPUs do. - */ - -typedef void far * EMSPTR; - -typedef union { /* EMS move specification structure */ - long length; /* It's easy to access first 4 bytes */ - char bytes[18]; /* Misaligned fields in here! */ - } EMSspec; - -/* Macros for accessing misaligned fields */ -#define FIELD_AT(spec,offset,type) (*((type *) &(spec.bytes[offset]))) -#define SRC_TYPE(spec) FIELD_AT(spec,4,char) -#define SRC_HANDLE(spec) FIELD_AT(spec,5,EMSH) -#define SRC_OFFSET(spec) FIELD_AT(spec,7,unsigned short) -#define SRC_PAGE(spec) FIELD_AT(spec,9,unsigned short) -#define SRC_PTR(spec) FIELD_AT(spec,7,EMSPTR) -#define DST_TYPE(spec) FIELD_AT(spec,11,char) -#define DST_HANDLE(spec) FIELD_AT(spec,12,EMSH) -#define DST_OFFSET(spec) FIELD_AT(spec,14,unsigned short) -#define DST_PAGE(spec) FIELD_AT(spec,16,unsigned short) -#define DST_PTR(spec) FIELD_AT(spec,14,EMSPTR) - -#define EMSPAGESIZE 16384L /* gospel, see the EMS specs */ - -#define HIBYTE(W) (((W) >> 8) & 0xFF) -#define LOBYTE(W) ((W) & 0xFF) - - -METHODDEF(void) -read_ems_store (j_common_ptr cinfo, backing_store_ptr info, - void FAR * buffer_address, - long file_offset, long byte_count) -{ - EMScontext ctx; - EMSspec spec; - - spec.length = byte_count; - SRC_TYPE(spec) = 1; - SRC_HANDLE(spec) = info->handle.ems_handle; - SRC_PAGE(spec) = (unsigned short) (file_offset / EMSPAGESIZE); - SRC_OFFSET(spec) = (unsigned short) (file_offset % EMSPAGESIZE); - DST_TYPE(spec) = 0; - DST_HANDLE(spec) = 0; - DST_PTR(spec) = buffer_address; - - ctx.ds_si = (void far *) & spec; - ctx.ax = 0x5700; /* move memory region */ - jems_calldriver((EMScontext far *) & ctx); - if (HIBYTE(ctx.ax) != 0) - ERREXIT(cinfo, JERR_EMS_READ); -} - - -METHODDEF(void) -write_ems_store (j_common_ptr cinfo, backing_store_ptr info, - void FAR * buffer_address, - long file_offset, long byte_count) -{ - EMScontext ctx; - EMSspec spec; - - spec.length = byte_count; - SRC_TYPE(spec) = 0; - SRC_HANDLE(spec) = 0; - SRC_PTR(spec) = buffer_address; - DST_TYPE(spec) = 1; - DST_HANDLE(spec) = info->handle.ems_handle; - DST_PAGE(spec) = (unsigned short) (file_offset / EMSPAGESIZE); - DST_OFFSET(spec) = (unsigned short) (file_offset % EMSPAGESIZE); - - ctx.ds_si = (void far *) & spec; - ctx.ax = 0x5700; /* move memory region */ - jems_calldriver((EMScontext far *) & ctx); - if (HIBYTE(ctx.ax) != 0) - ERREXIT(cinfo, JERR_EMS_WRITE); -} - - -METHODDEF(void) -close_ems_store (j_common_ptr cinfo, backing_store_ptr info) -{ - EMScontext ctx; - - ctx.ax = 0x4500; - ctx.dx = info->handle.ems_handle; - jems_calldriver((EMScontext far *) & ctx); - TRACEMS1(cinfo, 1, JTRC_EMS_CLOSE, info->handle.ems_handle); - /* we ignore any error return from the driver */ -} - - -LOCAL(boolean) -open_ems_store (j_common_ptr cinfo, backing_store_ptr info, - long total_bytes_needed) -{ - EMScontext ctx; - - /* Is EMS driver there? */ - if (! jems_available()) - return FALSE; - - /* Get status, make sure EMS is OK */ - ctx.ax = 0x4000; - jems_calldriver((EMScontext far *) & ctx); - if (HIBYTE(ctx.ax) != 0) - return FALSE; - - /* Get version, must be >= 4.0 */ - ctx.ax = 0x4600; - jems_calldriver((EMScontext far *) & ctx); - if (HIBYTE(ctx.ax) != 0 || LOBYTE(ctx.ax) < 0x40) - return FALSE; - - /* Try to allocate requested space */ - ctx.ax = 0x4300; - ctx.bx = (unsigned short) ((total_bytes_needed + EMSPAGESIZE-1L) / EMSPAGESIZE); - jems_calldriver((EMScontext far *) & ctx); - if (HIBYTE(ctx.ax) != 0) - return FALSE; - - /* Succeeded, save the handle and away we go */ - info->handle.ems_handle = ctx.dx; - info->read_backing_store = read_ems_store; - info->write_backing_store = write_ems_store; - info->close_backing_store = close_ems_store; - TRACEMS1(cinfo, 1, JTRC_EMS_OPEN, ctx.dx); - return TRUE; /* succeeded */ -} - -#endif /* EMS_SUPPORTED */ - - -/* - * Initial opening of a backing-store object. - */ - -GLOBAL(void) -jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info, - long total_bytes_needed) -{ - /* Try extended memory, then expanded memory, then regular file. */ -#if XMS_SUPPORTED - if (open_xms_store(cinfo, info, total_bytes_needed)) - return; -#endif -#if EMS_SUPPORTED - if (open_ems_store(cinfo, info, total_bytes_needed)) - return; -#endif - if (open_file_store(cinfo, info, total_bytes_needed)) - return; - ERREXITS(cinfo, JERR_TFILE_CREATE, ""); -} - - -/* - * These routines take care of any system-dependent initialization and - * cleanup required. - */ - -GLOBAL(long) -jpeg_mem_init (j_common_ptr cinfo) -{ - next_file_num = 0; /* initialize temp file name generator */ - return DEFAULT_MAX_MEM; /* default for max_memory_to_use */ -} - -GLOBAL(void) -jpeg_mem_term (j_common_ptr cinfo) -{ - /* Microsoft C, at least in v6.00A, will not successfully reclaim freed - * blocks of size > 32Kbytes unless we give it a kick in the rear, like so: - */ -#ifdef NEED_FHEAPMIN - _fheapmin(); -#endif -} |