sergiotarxz/libvips
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polish png read

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This commit is contained in:
John Cupitt 2019-10-15 08:33:48 +01:00
parent c3e1dd47bf
commit 88aa1bca86
2 changed files with 28 additions and 38 deletions
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61
libvips/foreign/vipspng.c
View File

@ -189,6 +189,10 @@ typedef struct {
static void
read_destroy( Read *read )
{
/* We never call png_read_end(), perhaps we should. It can fail on
* truncated files, so we'd need a setjmp().
*/
if( read->pPng )
png_destroy_read_struct( &read->pPng, &read->pInfo, NULL );
VIPS_UNREF( read->input );
@ -221,19 +225,9 @@ vips_png_read_stream( png_structp pPng, png_bytep data, png_size_t length )
* syscall for each one. Read via our own buffer.
*/
while( length > 0 ) {
ssize_t bytes_available =
VIPS_MIN( read->bytes_in_buffer, length );
ssize_t bytes_available;
if( bytes_available > 0 ) {
memcpy( data, read->next_byte, bytes_available );
data += bytes_available;
length -= bytes_available;
read->next_byte += bytes_available;
read->bytes_in_buffer -= bytes_available;
}
else {
if( read->bytes_in_buffer <= 0 ) {
ssize_t bytes_read;
bytes_read = vips_stream_input_read( read->input,
@ -244,6 +238,13 @@ vips_png_read_stream( png_structp pPng, png_bytep data, png_size_t length )
read->next_byte = read->input_buffer;
read->bytes_in_buffer = bytes_read;
}
bytes_available = VIPS_MIN( read->bytes_in_buffer, length );
memcpy( data, read->next_byte, bytes_available );
data += bytes_available;
length -= bytes_available;
read->next_byte += bytes_available;
read->bytes_in_buffer -= bytes_available;
}
}
@ -252,9 +253,6 @@ read_new( VipsStreamInput *input, VipsImage *out, gboolean fail )
{
Read *read;
if( vips_stream_input_rewind( input ) )
return( NULL );
if( !(read = VIPS_NEW( out, Read )) )
return( NULL );
@ -292,14 +290,14 @@ read_new( VipsStreamInput *input, VipsImage *out, gboolean fail )
PNG_CRC_QUIET_USE, PNG_CRC_QUIET_USE );
#endif /*FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION*/
if( vips_stream_input_rewind( input ) )
return( NULL );
png_set_read_fn( read->pPng, read, vips_png_read_stream );
/* Catch PNG errors from png_read_info() etc.
*/
if( setjmp( png_jmpbuf( read->pPng ) ) ) {
read_destroy( read );
if( setjmp( png_jmpbuf( read->pPng ) ) )
return( NULL );
}
if( !(read->pInfo = png_create_info_struct( read->pPng )) )
return( NULL );
@ -310,6 +308,7 @@ read_new( VipsStreamInput *input, VipsImage *out, gboolean fail )
#ifdef HAVE_PNG_SET_CHUNK_MALLOC_MAX
png_set_chunk_malloc_max( read->pPng, 50 * 1024 * 1024 );
#endif /*HAVE_PNG_SET_CHUNK_MALLOC_MAX*/
png_read_info( read->pPng, read->pInfo );
return( read );
@ -582,8 +581,6 @@ png2vips_interlace( Read *read, VipsImage *out )
png_read_image( read->pPng, read->row_pointer );
png_read_end( read->pPng, NULL );
read_destroy( read );
return( 0 );
@ -616,10 +613,6 @@ png2vips_generate( VipsRegion *or,
g_assert( r->height == VIPS_MIN( VIPS__FATSTRIP_HEIGHT,
or->im->Ysize - r->top ) );
/* In pixel decode mode.
*/
vips_stream_input_decode( read->input );
/* And check that y_pos is correct. It should be, since we are inside
* a vips_sequential().
*/
@ -629,6 +622,10 @@ png2vips_generate( VipsRegion *or,
return( -1 );
}
/* In pixel decode mode.
*/
vips_stream_input_decode( read->input );
for( y = 0; y < r->height; y++ ) {
png_bytep q = (png_bytep) VIPS_REGION_ADDR( or, 0, r->top + y );
@ -664,18 +661,6 @@ png2vips_generate( VipsRegion *or,
read->y_pos += 1;
}
/* Catch errors from png_read_end(). This can fail on a truncated
* file.
*/
if( setjmp( png_jmpbuf( read->pPng ) ) ) {
if( read->fail ) {
vips_error( "vipspng", "%s", _( "libpng read error" ) );
return( -1 );
}
return( 0 );
}
return( 0 );
}
@ -791,7 +776,7 @@ static void
write_finish( Write *write )
{
VIPS_UNREF( write->memory );
if( write->output )
if( write->output )
vips_stream_output_finish( write->output );
VIPS_UNREF( write->output );
if( write->pPng )
@ -868,7 +853,7 @@ write_png_block( VipsRegion *region, VipsRect *area, void *a )
g_assert( area->width == region->im->Xsize );
g_assert( area->top + area->height <= region->im->Ysize );
/* Catch PNG errors. Yuk.
/* Catch PNG errors.
*/
if( setjmp( png_jmpbuf( write->pPng ) ) )
return( -1 );

5
libvips/iofuncs/stream.c
View File

@ -606,6 +606,11 @@ vips_stream_input_read( VipsStreamInput *input,
return( bytes_read );
}
unsigned char *
vips_stream_input_map( VipsStreamInput *input, size_t *length )
{
}
int
vips_stream_input_rewind( VipsStreamInput *input )
{