The Tor Browser: media/libjpeg/jdatadst.c@b8a032363ba2 (annotated)

media/libjpeg/jdatadst.c@b8a032363ba2 (annotated)

media/libjpeg/jdatadst.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /*
  * jdatadst.c
  *
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1994-1996, Thomas G. Lane.
  * Modified 2009-2012 by Guido Vollbeding.
  * libjpeg-turbo Modifications:
  * Copyright (C) 2013, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README file.
  *
  * This file contains compression data destination routines for the case of
  * emitting JPEG data to memory or to a file (or any stdio stream).
  * While these routines are sufficient for most applications,
  * some will want to use a different destination manager.
  * IMPORTANT: we assume that fwrite() will correctly transcribe an array of
  * JOCTETs into 8-bit-wide elements on external storage.  If char is wider
  * than 8 bits on your machine, you may need to do some tweaking.
  */
 /* this is not a core library module, so it doesn't define JPEG_INTERNALS */
 #include "jinclude.h"
 #include "jpeglib.h"
 #include "jerror.h"
 #ifndef HAVE_STDLIB_H		/* <stdlib.h> should declare malloc(),free() */
 extern void * malloc JPP((size_t size));
 extern void free JPP((void *ptr));
 #endif
 /* Expanded data destination object for stdio output */
 typedef struct {
   struct jpeg_destination_mgr pub; /* public fields */
   FILE * outfile;		/* target stream */
   JOCTET * buffer;		/* start of buffer */
 } my_destination_mgr;
 typedef my_destination_mgr * my_dest_ptr;
 #define OUTPUT_BUF_SIZE  4096	/* choose an efficiently fwrite'able size */
 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
 /* Expanded data destination object for memory output */
 typedef struct {
   struct jpeg_destination_mgr pub; /* public fields */
   unsigned char ** outbuffer;	/* target buffer */
   unsigned long * outsize;
   unsigned char * newbuffer;	/* newly allocated buffer */
   JOCTET * buffer;		/* start of buffer */
   size_t bufsize;
 } my_mem_destination_mgr;
 typedef my_mem_destination_mgr * my_mem_dest_ptr;
 #endif
 /*
  * Initialize destination --- called by jpeg_start_compress
  * before any data is actually written.
  */
 METHODDEF(void)
 init_destination (j_compress_ptr cinfo)
 {
   my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
   /* Allocate the output buffer --- it will be released when done with image */
   dest->buffer = (JOCTET *)
       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
 				  OUTPUT_BUF_SIZE * SIZEOF(JOCTET));
   dest->pub.next_output_byte = dest->buffer;
   dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
 }
 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
 METHODDEF(void)
 init_mem_destination (j_compress_ptr cinfo)
 {
   /* no work necessary here */
 }
 #endif
 /*
  * Empty the output buffer --- called whenever buffer fills up.
  *
  * In typical applications, this should write the entire output buffer
  * (ignoring the current state of next_output_byte & free_in_buffer),
  * reset the pointer & count to the start of the buffer, and return TRUE
  * indicating that the buffer has been dumped.
  *
  * In applications that need to be able to suspend compression due to output
  * overrun, a FALSE return indicates that the buffer cannot be emptied now.
  * In this situation, the compressor will return to its caller (possibly with
  * an indication that it has not accepted all the supplied scanlines).  The
  * application should resume compression after it has made more room in the
  * output buffer.  Note that there are substantial restrictions on the use of
  * suspension --- see the documentation.
  *
  * When suspending, the compressor will back up to a convenient restart point
  * (typically the start of the current MCU). next_output_byte & free_in_buffer
  * indicate where the restart point will be if the current call returns FALSE.
  * Data beyond this point will be regenerated after resumption, so do not
  * write it out when emptying the buffer externally.
  */
 METHODDEF(boolean)
 empty_output_buffer (j_compress_ptr cinfo)
 {
   my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
   if (JFWRITE(dest->outfile, dest->buffer, OUTPUT_BUF_SIZE) !=
       (size_t) OUTPUT_BUF_SIZE)
     ERREXIT(cinfo, JERR_FILE_WRITE);
   dest->pub.next_output_byte = dest->buffer;
   dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
   return TRUE;
 }
 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
 METHODDEF(boolean)
 empty_mem_output_buffer (j_compress_ptr cinfo)
 {
   size_t nextsize;
   JOCTET * nextbuffer;
   my_mem_dest_ptr dest = (my_mem_dest_ptr) cinfo->dest;
   /* Try to allocate new buffer with double size */
   nextsize = dest->bufsize * 2;
   nextbuffer = (JOCTET *) malloc(nextsize);
   if (nextbuffer == NULL)
     ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10);
   MEMCOPY(nextbuffer, dest->buffer, dest->bufsize);
   if (dest->newbuffer != NULL)
     free(dest->newbuffer);
   dest->newbuffer = nextbuffer;
   dest->pub.next_output_byte = nextbuffer + dest->bufsize;
   dest->pub.free_in_buffer = dest->bufsize;
   dest->buffer = nextbuffer;
   dest->bufsize = nextsize;
   return TRUE;
 }
 #endif
 /*
  * Terminate destination --- called by jpeg_finish_compress
  * after all data has been written.  Usually needs to flush buffer.
  *
  * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
  * application must deal with any cleanup that should happen even
  * for error exit.
  */
 METHODDEF(void)
 term_destination (j_compress_ptr cinfo)
 {
   my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
   size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
   /* Write any data remaining in the buffer */
   if (datacount > 0) {
     if (JFWRITE(dest->outfile, dest->buffer, datacount) != datacount)
       ERREXIT(cinfo, JERR_FILE_WRITE);
   }
   fflush(dest->outfile);
   /* Make sure we wrote the output file OK */
   if (ferror(dest->outfile))
     ERREXIT(cinfo, JERR_FILE_WRITE);
 }
 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
 METHODDEF(void)
 term_mem_destination (j_compress_ptr cinfo)
 {
   my_mem_dest_ptr dest = (my_mem_dest_ptr) cinfo->dest;
   *dest->outbuffer = dest->buffer;
   *dest->outsize = (unsigned long)(dest->bufsize - dest->pub.free_in_buffer);
 }
 #endif
 /*
  * Prepare for output to a stdio stream.
  * The caller must have already opened the stream, and is responsible
  * for closing it after finishing compression.
  */
 GLOBAL(void)
 jpeg_stdio_dest (j_compress_ptr cinfo, FILE * outfile)
 {
   my_dest_ptr dest;
   /* The destination object is made permanent so that multiple JPEG images
    * can be written to the same file without re-executing jpeg_stdio_dest.
    * This makes it dangerous to use this manager and a different destination
    * manager serially with the same JPEG object, because their private object
    * sizes may be different.  Caveat programmer.
    */
   if (cinfo->dest == NULL) {	/* first time for this JPEG object? */
     cinfo->dest = (struct jpeg_destination_mgr *)
       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
 				  SIZEOF(my_destination_mgr));
   }
   dest = (my_dest_ptr) cinfo->dest;
   dest->pub.init_destination = init_destination;
   dest->pub.empty_output_buffer = empty_output_buffer;
   dest->pub.term_destination = term_destination;
   dest->outfile = outfile;
 }
 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
 /*
  * Prepare for output to a memory buffer.
  * The caller may supply an own initial buffer with appropriate size.
  * Otherwise, or when the actual data output exceeds the given size,
  * the library adapts the buffer size as necessary.
  * The standard library functions malloc/free are used for allocating
  * larger memory, so the buffer is available to the application after
  * finishing compression, and then the application is responsible for
  * freeing the requested memory.
  */
 GLOBAL(void)
 jpeg_mem_dest (j_compress_ptr cinfo,
 	       unsigned char ** outbuffer, unsigned long * outsize)
 {
   my_mem_dest_ptr dest;
   if (outbuffer == NULL || outsize == NULL)	/* sanity check */
     ERREXIT(cinfo, JERR_BUFFER_SIZE);
   /* The destination object is made permanent so that multiple JPEG images
    * can be written to the same buffer without re-executing jpeg_mem_dest.
    */
   if (cinfo->dest == NULL) {	/* first time for this JPEG object? */
     cinfo->dest = (struct jpeg_destination_mgr *)
       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
 				  SIZEOF(my_mem_destination_mgr));
   }
   dest = (my_mem_dest_ptr) cinfo->dest;
   dest->pub.init_destination = init_mem_destination;
   dest->pub.empty_output_buffer = empty_mem_output_buffer;
   dest->pub.term_destination = term_mem_destination;
   dest->outbuffer = outbuffer;
   dest->outsize = outsize;
   dest->newbuffer = NULL;
   if (*outbuffer == NULL || *outsize == 0) {
     /* Allocate initial buffer */
     dest->newbuffer = *outbuffer = (unsigned char *) malloc(OUTPUT_BUF_SIZE);
     if (dest->newbuffer == NULL)
       ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10);
     *outsize = OUTPUT_BUF_SIZE;
   }
   dest->pub.next_output_byte = dest->buffer = *outbuffer;
   dest->pub.free_in_buffer = dest->bufsize = *outsize;
 }
 #endif

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media/libjpeg/jdatadst.c@b8a032363ba2 (annotated)

media/libjpeg/jdatadst.c