sergiotarxz/libvips
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start reworking again

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This commit is contained in:
John Cupitt 2019-10-24 10:57:52 +01:00
parent af8a3bfee7
commit 0e29e1c41e
4 changed files with 96 additions and 115 deletions
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24
libvips/include/vips/stream.h
View File

@ -173,24 +173,15 @@ typedef struct _VipsStreamiClass {
/* Subclasses can define these to implement other streami methods.
*/
/* Read up to N bytes from the stream into the supplied buffer,
* returning the number of bytes actually read.
*
* -1 on error, 0 on EOF.
/* Read from the stream into the supplied buffer, args exactly as
* read(2).
*/
ssize_t (*read)( VipsStreami *, void *, size_t );
/* Map the entire stream into memory, for example with mmap(). Return
* the base and size of the mapped area.
/* Seek to a certain position, args exactly as lseek(2).
*
* If this is not defined, the file will be read in with repeated
* calls to ->read().
*
* NULL on error.
*/
const void *(*map)( VipsStreami *, size_t * );
/* Seek to a certain position, args exactly as lseek(2).
* Unseekable streams should just return -1. VipsStreami will then
* seek by _read()ing bytes into memory as required.
*/
gint64 (*seek)( VipsStreami *, gint64 offset, int );
@ -207,11 +198,6 @@ typedef struct _VipsStreamiClass {
*/
int (*unminimise)( VipsStreami * );
/* Length of object in bytes. If this is a pipe, it will force the
* whole object to be read into memory, so use cautiously.
*/
gint64 (*size)( VipsStreami * );
} VipsStreamiClass;
GType vips_streami_get_type( void );

1
libvips/include/vips/util.h
View File

@ -277,7 +277,6 @@ GSList *vips__gslist_gvalue_merge( GSList *a, const GSList *b );
char *vips__gslist_gvalue_get( const GSList *list );
gint64 vips__seek( int fd, gint64 pos, int whence );
gboolean vips__can_seek( int fd );
int vips__ftruncate( int fd, gint64 pos );
int vips_existsf( const char *name, ... )
__attribute__((format(printf, 1, 2)));

172
libvips/iofuncs/streami.c
View File

@ -34,6 +34,8 @@
/* TODO
*
* - filename encoding
* - gaussblur is missing the vector path again argh
* - can we map and then close the fd?
* - are we detecting EOF correctly? what about interrupted reads? perhaps
* we should check errno as well
* - need to be able to set is_pipe via constructor
@ -203,6 +205,7 @@ vips_streami_build( VipsObject *object )
{
VipsStream *stream = VIPS_STREAM( object );
VipsStreami *streami = VIPS_STREAMI( object );
VipsStreamiClass *class = VIPS_STREAMI_GET_CLASS( streami );
VIPS_DEBUG_MSG( "vips_streami_build: %p\n", streami );
@ -234,28 +237,28 @@ vips_streami_build( VipsObject *object )
*/
if( stream->descriptor != -1 ) {
/* Can we seek? If not, this is some kind of pipe.
*
* We must call the class method directly: if we go via
* vips_streami_seek() we'll trigger seek emulation on pipes.
*/
if( !vips__can_seek( stream->descriptor ) ) {
vips_error_freeze();
if( class->seek( stream->descriptor, 0, SEEK_CUR ) == -1 ) {
VIPS_DEBUG_MSG( " not seekable\n" );
streami->is_pipe = TRUE;
}
vips_error_thaw();
/* Try and get the length. Don't bother for pipes.
/* Try and get the length, as long as we're seekable.
*/
if( !streami->is_pipe &&
(streami->length =
vips_file_length( stream->descriptor )) == -1 )
(streami->length = vips_streami_size( streami )) == -1 )
return( -1 );
}
/* Need to save the header for pipe-style sources.
/* If we can seek, we won't need to save header bytes.
*/
if( streami->is_pipe )
streami->header_bytes = g_byte_array_new();
/* We always want a sniff buffer.
*/
streami->sniff = g_byte_array_new();
if( !streami->is_pipe )
VIPS_FREEF( g_byte_array_unref, streami->header_bytes );
return( 0 );
}
@ -267,44 +270,7 @@ vips_streami_read_real( VipsStreami *streami, void *data, size_t length )
VIPS_DEBUG_MSG( "vips_streami_read_real:\n" );
if( streami->blob ) {
VipsArea *area = VIPS_AREA( streami->blob );
ssize_t available = VIPS_MIN( length,
area->length - streami->read_position );
if( available <= 0 )
return( 0 );
memcpy( data, area->data + streami->read_position, available );
return( available );
}
else if( stream->descriptor != -1 ) {
return( read( stream->descriptor, data, length ) );
}
else {
g_assert( 0 );
return( -1 );
}
}
static const void *
vips_streami_map_real( VipsStreami *streami, size_t *length )
{
VipsStream *stream = VIPS_STREAM( streami );
const void *file_baseaddr;
g_assert( streami->length > 0 );
if( !(file_baseaddr = vips__mmap( stream->descriptor,
FALSE, streami->length, 0 )) )
return( NULL );
if( length )
*length = streami->length;
return( file_baseaddr );
return( read( stream->descriptor, data, length ) );
}
static gint64
@ -312,39 +278,9 @@ vips_streami_seek_real( VipsStreami *streami, gint64 offset, int whence )
{
VipsStream *stream = VIPS_STREAM( streami );
gint64 new_pos;
VIPS_DEBUG_MSG( "vips_streami_seek_real:\n" );
if( streami->blob ) {
switch( whence ) {
case SEEK_SET:
new_pos = offset;
break;
case SEEK_CUR:
new_pos = streami->read_position + offset;
break;
case SEEK_END:
new_pos = streami->length + offset;
break;
default:
g_assert_not_reached();
break;
}
}
else if( stream->descriptor != -1 ) {
new_pos = vips__seek( stream->descriptor, offset, whence );
}
else {
vips_error( vips_stream_name( stream ),
"%s", _( "not seekable" ) );
return( -1 );
}
return( new_pos );
return( vips__seek( stream->descriptor, offset, whence ) );
}
static void
@ -444,6 +380,8 @@ vips_streami_pipe_to_memory( VipsStreami *streami )
VIPS_DEBUG_MSG( "vips_streami_pipe_to_memory:\n" );
g_assert( streami->is_pipe );
vips_streami_sanity( streami );
if( vips_streami_pipe_read_to_position( streami, -1 ) )
@ -511,6 +449,8 @@ static void
vips_streami_init( VipsStreami *streami )
{
streami->length = -1;
streami->sniff = g_byte_array_new();
streami->header_bytes = g_byte_array_new();
}
/**
@ -700,6 +640,20 @@ vips_streami_read( VipsStreami *streami, void *buffer, size_t length )
VIPS_DEBUG_MSG( " %zd bytes from cache\n", available );
}
revise this:
if( streami->blob ) {
VipsArea *area = VIPS_AREA( streami->blob );
ssize_t available = VIPS_MIN( length,
area->length - streami->read_position );
if( available <= 0 )
return( 0 );
memcpy( data, area->data + streami->read_position, available );
return( available );
}
/* Any more bytes requested? Call the read() vfunc.
*/
if( length > 0 ) {
@ -735,6 +689,32 @@ vips_streami_read( VipsStreami *streami, void *buffer, size_t length )
return( bytes_read );
}
static const void *
vips_streami_map_real( VipsStreami *streami, size_t *length )
{
VipsStream *stream = VIPS_STREAM( streami );
const void *file_baseaddr;
g_assert( streami->length > 0 );
if( !(file_baseaddr = vips__mmap( stream->descriptor,
FALSE, streami->length, 0 )) )
return( NULL );
if( length )
*length = streami->length;
return( file_baseaddr );
}
static void
vips_streami_unmap_real( VipsStreami *streami, size_t *length )
{
VipsStream *stream = VIPS_STREAM( streami );
}
const void *
vips_streami_map( VipsStreami *streami, size_t *length_out )
{
@ -800,6 +780,12 @@ vips_streami_seek( VipsStreami *streami, gint64 offset, int whence )
vips_streami_sanity( streami );
/* Not tagged as a pipe? Attempt to use the seek method.
*/
if( !streami->is_pipe ) {
if( (new_pos = class->seek( streami, offset, whence )) == -1 )
return( -1 );
switch( whence ) {
case SEEK_SET:
new_pos = offset;
@ -834,6 +820,27 @@ vips_streami_seek( VipsStreami *streami, gint64 offset, int whence )
return( -1 );
}
revise this:
if( streami->blob ) {
switch( whence ) {
case SEEK_SET:
new_pos = offset;
break;
case SEEK_CUR:
new_pos = streami->read_position + offset;
break;
case SEEK_END:
new_pos = streami->length + offset;
break;
default:
g_assert_not_reached();
break;
}
}
if( streami->is_pipe ) {
if( vips_streami_pipe_read_to_position( streami, new_pos ) )
return( -1 );
@ -907,12 +914,15 @@ vips_streami_size( VipsStreami *streami )
VipsStreamiClass *class = VIPS_STREAMI_GET_CLASS( streami );
gint64 size;
gint64 read_position;
VIPS_DEBUG_MSG( "vips_streami_size:\n" );
vips_streami_sanity( streami );
size = class->size( streami );
read_position = vips_streami_seek( streami, 0, SEEK_CUR );
size = vips_streami_seek( streami, 0, SEEK_END );
vips_streami_seek( streami, read_position, SEEK_SET );
vips_streami_sanity( streami );

14
libvips/iofuncs/util.c
View File

@ -1062,20 +1062,6 @@ vips__seek( int fd, gint64 pos, int whence )
return( new_pos );
}
/* Does an fd support seek? Pipes do not, for example.
*/
gboolean
vips__can_seek( int fd )
{
gboolean result;
vips_error_freeze();
result = vips__seek( fd, 0, SEEK_CUR ) != -1;
vips_error_thaw();
return( result );
}
/* Need our own ftruncate(), since ftruncate() on win32 can't do long files.
DANGER ... this moves the file pointer to the end of file on win32,