Coverage Report

Created: 2024-07-27 06:27

/src/libjpeg-turbo/jdatadst.c
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Source (jump to first uncovered line)
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/*
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 * jdatadst.c
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 *
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 * This file was part of the Independent JPEG Group's software:
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 * Copyright (C) 1994-1996, Thomas G. Lane.
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 * Modified 2009-2012 by Guido Vollbeding.
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 * libjpeg-turbo Modifications:
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 * Copyright (C) 2013, 2016, 2022, D. R. Commander.
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 * For conditions of distribution and use, see the accompanying README.ijg
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 * file.
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 *
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 * This file contains compression data destination routines for the case of
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 * emitting JPEG data to memory or to a file (or any stdio stream).
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 * While these routines are sufficient for most applications,
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 * some will want to use a different destination manager.
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 * IMPORTANT: we assume that fwrite() will correctly transcribe an array of
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 * JOCTETs into 8-bit-wide elements on external storage.  If char is wider
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 * than 8 bits on your machine, you may need to do some tweaking.
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 */
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/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
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#include "jinclude.h"
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#include "jpeglib.h"
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#include "jerror.h"
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/* Expanded data destination object for stdio output */
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typedef struct {
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  struct jpeg_destination_mgr pub; /* public fields */
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  FILE *outfile;                /* target stream */
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  JOCTET *buffer;               /* start of buffer */
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} my_destination_mgr;
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typedef my_destination_mgr *my_dest_ptr;
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0
#define OUTPUT_BUF_SIZE  4096   /* choose an efficiently fwrite'able size */
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/* Expanded data destination object for memory output */
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typedef struct {
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  struct jpeg_destination_mgr pub; /* public fields */
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  unsigned char **outbuffer;    /* target buffer */
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  unsigned long *outsize;
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  unsigned char *newbuffer;     /* newly allocated buffer */
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  JOCTET *buffer;               /* start of buffer */
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  size_t bufsize;
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} my_mem_destination_mgr;
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typedef my_mem_destination_mgr *my_mem_dest_ptr;
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/*
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 * Initialize destination --- called by jpeg_start_compress
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 * before any data is actually written.
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 */
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METHODDEF(void)
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init_destination(j_compress_ptr cinfo)
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0
{
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  my_dest_ptr dest = (my_dest_ptr)cinfo->dest;
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  /* Allocate the output buffer --- it will be released when done with image */
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  dest->buffer = (JOCTET *)
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    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
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                                OUTPUT_BUF_SIZE * sizeof(JOCTET));
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  dest->pub.next_output_byte = dest->buffer;
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  dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
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}
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METHODDEF(void)
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init_mem_destination(j_compress_ptr cinfo)
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{
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  /* no work necessary here */
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0
}
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/*
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 * Empty the output buffer --- called whenever buffer fills up.
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 *
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 * In typical applications, this should write the entire output buffer
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 * (ignoring the current state of next_output_byte & free_in_buffer),
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 * reset the pointer & count to the start of the buffer, and return TRUE
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 * indicating that the buffer has been dumped.
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 *
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 * In applications that need to be able to suspend compression due to output
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 * overrun, a FALSE return indicates that the buffer cannot be emptied now.
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 * In this situation, the compressor will return to its caller (possibly with
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 * an indication that it has not accepted all the supplied scanlines).  The
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 * application should resume compression after it has made more room in the
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 * output buffer.  Note that there are substantial restrictions on the use of
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 * suspension --- see the documentation.
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 *
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 * When suspending, the compressor will back up to a convenient restart point
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 * (typically the start of the current MCU). next_output_byte & free_in_buffer
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 * indicate where the restart point will be if the current call returns FALSE.
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 * Data beyond this point will be regenerated after resumption, so do not
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 * write it out when emptying the buffer externally.
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 */
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METHODDEF(boolean)
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empty_output_buffer(j_compress_ptr cinfo)
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{
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  my_dest_ptr dest = (my_dest_ptr)cinfo->dest;
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  if (fwrite(dest->buffer, 1, OUTPUT_BUF_SIZE, dest->outfile) !=
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      (size_t)OUTPUT_BUF_SIZE)
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    ERREXIT(cinfo, JERR_FILE_WRITE);
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  dest->pub.next_output_byte = dest->buffer;
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  dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
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  return TRUE;
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}
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METHODDEF(boolean)
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empty_mem_output_buffer(j_compress_ptr cinfo)
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{
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  size_t nextsize;
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  JOCTET *nextbuffer;
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  my_mem_dest_ptr dest = (my_mem_dest_ptr)cinfo->dest;
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  /* Try to allocate new buffer with double size */
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  nextsize = dest->bufsize * 2;
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  nextbuffer = (JOCTET *)malloc(nextsize);
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  if (nextbuffer == NULL)
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    ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10);
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  memcpy(nextbuffer, dest->buffer, dest->bufsize);
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  free(dest->newbuffer);
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  dest->newbuffer = nextbuffer;
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  dest->pub.next_output_byte = nextbuffer + dest->bufsize;
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  dest->pub.free_in_buffer = dest->bufsize;
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  dest->buffer = nextbuffer;
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  dest->bufsize = nextsize;
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  return TRUE;
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0
}
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/*
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 * Terminate destination --- called by jpeg_finish_compress
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 * after all data has been written.  Usually needs to flush buffer.
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 *
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 * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
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 * application must deal with any cleanup that should happen even
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 * for error exit.
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 */
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METHODDEF(void)
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term_destination(j_compress_ptr cinfo)
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{
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  my_dest_ptr dest = (my_dest_ptr)cinfo->dest;
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  size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
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  /* Write any data remaining in the buffer */
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  if (datacount > 0) {
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    if (fwrite(dest->buffer, 1, datacount, dest->outfile) != datacount)
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      ERREXIT(cinfo, JERR_FILE_WRITE);
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  }
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  fflush(dest->outfile);
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  /* Make sure we wrote the output file OK */
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  if (ferror(dest->outfile))
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    ERREXIT(cinfo, JERR_FILE_WRITE);
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}
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METHODDEF(void)
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term_mem_destination(j_compress_ptr cinfo)
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{
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  my_mem_dest_ptr dest = (my_mem_dest_ptr)cinfo->dest;
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  *dest->outbuffer = dest->buffer;
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  *dest->outsize = (unsigned long)(dest->bufsize - dest->pub.free_in_buffer);
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}
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/*
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 * Prepare for output to a stdio stream.
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 * The caller must have already opened the stream, and is responsible
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 * for closing it after finishing compression.
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 */
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GLOBAL(void)
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jpeg_stdio_dest(j_compress_ptr cinfo, FILE *outfile)
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{
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  my_dest_ptr dest;
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  /* The destination object is made permanent so that multiple JPEG images
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   * can be written to the same file without re-executing jpeg_stdio_dest.
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   */
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  if (cinfo->dest == NULL) {    /* first time for this JPEG object? */
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    cinfo->dest = (struct jpeg_destination_mgr *)
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      (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_PERMANENT,
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                                  sizeof(my_destination_mgr));
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  } else if (cinfo->dest->init_destination != init_destination) {
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    /* It is unsafe to reuse the existing destination manager unless it was
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     * created by this function.  Otherwise, there is no guarantee that the
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     * opaque structure is the right size.  Note that we could just create a
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     * new structure, but the old structure would not be freed until
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     * jpeg_destroy_compress() was called.
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     */
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    ERREXIT(cinfo, JERR_BUFFER_SIZE);
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  }
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  dest = (my_dest_ptr)cinfo->dest;
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  dest->pub.init_destination = init_destination;
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  dest->pub.empty_output_buffer = empty_output_buffer;
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  dest->pub.term_destination = term_destination;
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  dest->outfile = outfile;
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0
}
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/*
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 * Prepare for output to a memory buffer.
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 * The caller may supply an own initial buffer with appropriate size.
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 * Otherwise, or when the actual data output exceeds the given size,
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 * the library adapts the buffer size as necessary.
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 * The standard library functions malloc/free are used for allocating
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 * larger memory, so the buffer is available to the application after
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 * finishing compression, and then the application is responsible for
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 * freeing the requested memory.
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 * Note:  An initial buffer supplied by the caller is expected to be
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 * managed by the application.  The library does not free such buffer
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 * when allocating a larger buffer.
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 */
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GLOBAL(void)
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jpeg_mem_dest(j_compress_ptr cinfo, unsigned char **outbuffer,
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              unsigned long *outsize)
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{
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  my_mem_dest_ptr dest;
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  if (outbuffer == NULL || outsize == NULL)     /* sanity check */
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    ERREXIT(cinfo, JERR_BUFFER_SIZE);
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  /* The destination object is made permanent so that multiple JPEG images
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   * can be written to the same buffer without re-executing jpeg_mem_dest.
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   */
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  if (cinfo->dest == NULL) {    /* first time for this JPEG object? */
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    cinfo->dest = (struct jpeg_destination_mgr *)
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      (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_PERMANENT,
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                                  sizeof(my_mem_destination_mgr));
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  } else if (cinfo->dest->init_destination != init_mem_destination) {
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    /* It is unsafe to reuse the existing destination manager unless it was
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     * created by this function.
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     */
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    ERREXIT(cinfo, JERR_BUFFER_SIZE);
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  }
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  dest = (my_mem_dest_ptr)cinfo->dest;
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  dest->pub.init_destination = init_mem_destination;
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  dest->pub.empty_output_buffer = empty_mem_output_buffer;
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  dest->pub.term_destination = term_mem_destination;
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  dest->outbuffer = outbuffer;
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  dest->outsize = outsize;
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  dest->newbuffer = NULL;
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  if (*outbuffer == NULL || *outsize == 0) {
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    /* Allocate initial buffer */
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    dest->newbuffer = *outbuffer = (unsigned char *)malloc(OUTPUT_BUF_SIZE);
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    if (dest->newbuffer == NULL)
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      ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10);
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    *outsize = OUTPUT_BUF_SIZE;
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  }
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  dest->pub.next_output_byte = dest->buffer = *outbuffer;
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  dest->pub.free_in_buffer = dest->bufsize = *outsize;
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0
}