LCOV - code coverage report
Current view: directory - media/libpng - pngwio.c (source / functions) Found Hit Coverage
Test: app.info Lines: 32 13 40.6 %
Date: 2012-06-02 Functions: 5 2 40.0 %

       1                 : 
       2                 : /* pngwio.c - functions for data output
       3                 :  *
       4                 :  * Last changed in libpng 1.5.0 [January 6, 2011]
       5                 :  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
       6                 :  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
       7                 :  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
       8                 :  *
       9                 :  * This code is released under the libpng license.
      10                 :  * For conditions of distribution and use, see the disclaimer
      11                 :  * and license in png.h
      12                 :  *
      13                 :  * This file provides a location for all output.  Users who need
      14                 :  * special handling are expected to write functions that have the same
      15                 :  * arguments as these and perform similar functions, but that possibly
      16                 :  * use different output methods.  Note that you shouldn't change these
      17                 :  * functions, but rather write replacement functions and then change
      18                 :  * them at run time with png_set_write_fn(...).
      19                 :  */
      20                 : 
      21                 : #include "pngpriv.h"
      22                 : 
      23                 : #ifdef PNG_WRITE_SUPPORTED
      24                 : 
      25                 : /* Write the data to whatever output you are using.  The default routine
      26                 :  * writes to a file pointer.  Note that this routine sometimes gets called
      27                 :  * with very small lengths, so you should implement some kind of simple
      28                 :  * buffering if you are using unbuffered writes.  This should never be asked
      29                 :  * to write more than 64K on a 16 bit machine.
      30                 :  */
      31                 : 
      32                 : void /* PRIVATE */
      33             358 : png_write_data(png_structp png_ptr, png_const_bytep data, png_size_t length)
      34                 : {
      35                 :    /* NOTE: write_data_fn must not change the buffer! */
      36             358 :    if (png_ptr->write_data_fn != NULL )
      37             358 :       (*(png_ptr->write_data_fn))(png_ptr, (png_bytep)data, length);
      38                 : 
      39                 :    else
      40               0 :       png_error(png_ptr, "Call to NULL write function");
      41             358 : }
      42                 : 
      43                 : #ifdef PNG_STDIO_SUPPORTED
      44                 : /* This is the function that does the actual writing of data.  If you are
      45                 :  * not writing to a standard C stream, you should create a replacement
      46                 :  * write_data function and use it at run time with png_set_write_fn(), rather
      47                 :  * than changing the library.
      48                 :  */
      49                 : #ifndef USE_FAR_KEYWORD
      50                 : void PNGCBAPI
      51               0 : png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
      52                 : {
      53                 :    png_size_t check;
      54                 : 
      55               0 :    if (png_ptr == NULL)
      56               0 :       return;
      57                 : 
      58               0 :    check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
      59                 : 
      60               0 :    if (check != length)
      61               0 :       png_error(png_ptr, "Write Error");
      62                 : }
      63                 : #else
      64                 : /* This is the model-independent version. Since the standard I/O library
      65                 :  * can't handle far buffers in the medium and small models, we have to copy
      66                 :  * the data.
      67                 :  */
      68                 : 
      69                 : #define NEAR_BUF_SIZE 1024
      70                 : #define MIN(a,b) (a <= b ? a : b)
      71                 : 
      72                 : void PNGCBAPI
      73                 : png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
      74                 : {
      75                 :    png_uint_32 check;
      76                 :    png_byte *near_data;  /* Needs to be "png_byte *" instead of "png_bytep" */
      77                 :    png_FILE_p io_ptr;
      78                 : 
      79                 :    if (png_ptr == NULL)
      80                 :       return;
      81                 : 
      82                 :    /* Check if data really is near. If so, use usual code. */
      83                 :    near_data = (png_byte *)CVT_PTR_NOCHECK(data);
      84                 :    io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
      85                 : 
      86                 :    if ((png_bytep)near_data == data)
      87                 :    {
      88                 :       check = fwrite(near_data, 1, length, io_ptr);
      89                 :    }
      90                 : 
      91                 :    else
      92                 :    {
      93                 :       png_byte buf[NEAR_BUF_SIZE];
      94                 :       png_size_t written, remaining, err;
      95                 :       check = 0;
      96                 :       remaining = length;
      97                 : 
      98                 :       do
      99                 :       {
     100                 :          written = MIN(NEAR_BUF_SIZE, remaining);
     101                 :          png_memcpy(buf, data, written); /* Copy far buffer to near buffer */
     102                 :          err = fwrite(buf, 1, written, io_ptr);
     103                 : 
     104                 :          if (err != written)
     105                 :             break;
     106                 : 
     107                 :          else
     108                 :             check += err;
     109                 : 
     110                 :          data += written;
     111                 :          remaining -= written;
     112                 :       }
     113                 :       while (remaining != 0);
     114                 :    }
     115                 : 
     116                 :    if (check != length)
     117                 :       png_error(png_ptr, "Write Error");
     118                 : }
     119                 : 
     120                 : #endif
     121                 : #endif
     122                 : 
     123                 : /* This function is called to output any data pending writing (normally
     124                 :  * to disk).  After png_flush is called, there should be no data pending
     125                 :  * writing in any buffers.
     126                 :  */
     127                 : #ifdef PNG_WRITE_FLUSH_SUPPORTED
     128                 : void /* PRIVATE */
     129               0 : png_flush(png_structp png_ptr)
     130                 : {
     131               0 :    if (png_ptr->output_flush_fn != NULL)
     132               0 :       (*(png_ptr->output_flush_fn))(png_ptr);
     133               0 : }
     134                 : 
     135                 : #  ifdef PNG_STDIO_SUPPORTED
     136                 : void PNGCBAPI
     137               0 : png_default_flush(png_structp png_ptr)
     138                 : {
     139                 :    png_FILE_p io_ptr;
     140                 : 
     141               0 :    if (png_ptr == NULL)
     142               0 :       return;
     143                 : 
     144               0 :    io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr));
     145               0 :    fflush(io_ptr);
     146                 : }
     147                 : #  endif
     148                 : #endif
     149                 : 
     150                 : /* This function allows the application to supply new output functions for
     151                 :  * libpng if standard C streams aren't being used.
     152                 :  *
     153                 :  * This function takes as its arguments:
     154                 :  * png_ptr       - pointer to a png output data structure
     155                 :  * io_ptr        - pointer to user supplied structure containing info about
     156                 :  *                 the output functions.  May be NULL.
     157                 :  * write_data_fn - pointer to a new output function that takes as its
     158                 :  *                 arguments a pointer to a png_struct, a pointer to
     159                 :  *                 data to be written, and a 32-bit unsigned int that is
     160                 :  *                 the number of bytes to be written.  The new write
     161                 :  *                 function should call png_error(png_ptr, "Error msg")
     162                 :  *                 to exit and output any fatal error messages.  May be
     163                 :  *                 NULL, in which case libpng's default function will
     164                 :  *                 be used.
     165                 :  * flush_data_fn - pointer to a new flush function that takes as its
     166                 :  *                 arguments a pointer to a png_struct.  After a call to
     167                 :  *                 the flush function, there should be no data in any buffers
     168                 :  *                 or pending transmission.  If the output method doesn't do
     169                 :  *                 any buffering of output, a function prototype must still be
     170                 :  *                 supplied although it doesn't have to do anything.  If
     171                 :  *                 PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
     172                 :  *                 time, output_flush_fn will be ignored, although it must be
     173                 :  *                 supplied for compatibility.  May be NULL, in which case
     174                 :  *                 libpng's default function will be used, if
     175                 :  *                 PNG_WRITE_FLUSH_SUPPORTED is defined.  This is not
     176                 :  *                 a good idea if io_ptr does not point to a standard
     177                 :  *                 *FILE structure.
     178                 :  */
     179                 : void PNGAPI
     180              52 : png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
     181                 :     png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
     182                 : {
     183              52 :    if (png_ptr == NULL)
     184               0 :       return;
     185                 : 
     186              52 :    png_ptr->io_ptr = io_ptr;
     187                 : 
     188                 : #ifdef PNG_STDIO_SUPPORTED
     189              52 :    if (write_data_fn != NULL)
     190              26 :       png_ptr->write_data_fn = write_data_fn;
     191                 : 
     192                 :    else
     193              26 :       png_ptr->write_data_fn = png_default_write_data;
     194                 : #else
     195                 :    png_ptr->write_data_fn = write_data_fn;
     196                 : #endif
     197                 : 
     198                 : #ifdef PNG_WRITE_FLUSH_SUPPORTED
     199                 : #  ifdef PNG_STDIO_SUPPORTED
     200                 : 
     201              52 :    if (output_flush_fn != NULL)
     202               0 :       png_ptr->output_flush_fn = output_flush_fn;
     203                 : 
     204                 :    else
     205              52 :       png_ptr->output_flush_fn = png_default_flush;
     206                 : 
     207                 : #  else
     208                 :    png_ptr->output_flush_fn = output_flush_fn;
     209                 : #  endif
     210                 : #endif /* PNG_WRITE_FLUSH_SUPPORTED */
     211                 : 
     212                 :    /* It is an error to read while writing a png file */
     213              52 :    if (png_ptr->read_data_fn != NULL)
     214                 :    {
     215               0 :       png_ptr->read_data_fn = NULL;
     216                 : 
     217                 :       png_warning(png_ptr,
     218                 :           "Can't set both read_data_fn and write_data_fn in the"
     219                 :           " same structure");
     220                 :    }
     221                 : }
     222                 : 
     223                 : #ifdef USE_FAR_KEYWORD
     224                 : #  ifdef _MSC_VER
     225                 : void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
     226                 : {
     227                 :    void *near_ptr;
     228                 :    void FAR *far_ptr;
     229                 :    FP_OFF(near_ptr) = FP_OFF(ptr);
     230                 :    far_ptr = (void FAR *)near_ptr;
     231                 : 
     232                 :    if (check != 0)
     233                 :       if (FP_SEG(ptr) != FP_SEG(far_ptr))
     234                 :          png_error(png_ptr, "segment lost in conversion");
     235                 : 
     236                 :    return(near_ptr);
     237                 : }
     238                 : #  else
     239                 : void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
     240                 : {
     241                 :    void *near_ptr;
     242                 :    void FAR *far_ptr;
     243                 :    near_ptr = (void FAR *)ptr;
     244                 :    far_ptr = (void FAR *)near_ptr;
     245                 : 
     246                 :    if (check != 0)
     247                 :       if (far_ptr != ptr)
     248                 :          png_error(png_ptr, "segment lost in conversion");
     249                 : 
     250                 :    return(near_ptr);
     251                 : }
     252                 : #  endif
     253                 : #endif
     254                 : #endif /* PNG_WRITE_SUPPORTED */

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