add plumbing for stream minimise

and ::finish becomes a vfunc

libvips/include/vips/basic.h

@@ -71,6 +71,11 @@ typedef enum {
 char *vips_path_filename7( const char *path );
 char *vips_path_mode7( const char *path );
 
+struct _VipsImage; 
+typedef struct _VipsImage VipsImage;
+struct _VipsRegion; 
+typedef struct _VipsRegion VipsRegion;
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus*/

libvips/include/vips/image.h

@@ -133,9 +133,6 @@ typedef enum {
 	VIPS_ACCESS_LAST
 } VipsAccess;
 
-struct _VipsImage; 
-struct _VipsRegion; 
-
 typedef void *(*VipsStartFn)( struct _VipsImage *out, void *a, void *b );
 typedef int (*VipsGenerateFn)( struct _VipsRegion *out, 
 	void *seq, void *a, void *b, gboolean *stop );

libvips/include/vips/stream.h

@@ -68,7 +68,7 @@ typedef struct _VipsStream {
 	 */
 	int tracked_descriptor;	
 
-	/* A descriptor we close close().
+	/* A descriptor we close with close().
 	 */
 	int close_descriptor;	
 
@@ -86,8 +86,6 @@ typedef struct _VipsStreamClass {
 
 GType vips_stream_get_type( void );
 
-void vips_stream_attach( VipsStream *stream );
-
 #define VIPS_TYPE_STREAM_INPUT (vips_stream_input_get_type())
 #define VIPS_STREAM_INPUT( obj ) \
 	(G_TYPE_CHECK_INSTANCE_CAST( (obj), \
@@ -162,6 +160,15 @@ typedef struct _VipsStreamInputClass {
 	ssize_t (*read)( VipsStreamInput *, unsigned char *, size_t );
 	int (*rewind)( VipsStreamInput * );
 
+	/* Shut down anything that can safely restarted. For example, if
+	 * there's a fd that supports lseek(), it can be closed, since later 
+	 * (if neccessary) it can be reopened and lseek()ed back to the 
+	 * correct point.
+	 *
+	 * Non-restartable shutdown shuld be in _finalize().
+	 */
+	void (*minimise)( VipsStreamInput * );
+
 } VipsStreamInputClass;
 
 GType vips_stream_input_get_type( void );
@@ -176,6 +183,8 @@ VipsStreamInput *vips_stream_input_new_from_options( const char *options );
 ssize_t vips_stream_input_read( VipsStreamInput *input, 
 	unsigned char *data, size_t length );
 int vips_stream_input_rewind( VipsStreamInput *input );
+void vips_stream_minimise( VipsStreamInput *input );
+void vips_stream_set_image( VipsStreamInput *input, VipsImage *image );
 void vips_stream_input_decode( VipsStreamInput *input );
 gboolean vips_stream_input_eof( VipsStreamInput *input );
 unsigned char *vips_stream_input_sniff( VipsStreamInput *input, size_t length );
@@ -219,6 +228,11 @@ typedef struct _VipsStreamOutputClass {
 	 */
 	ssize_t (*write)( VipsStreamOutput *, const unsigned char *, size_t );
 
+	/* A complete output image has been generated, so do any clearing up,
+	 * eg. copy the bytes we saved in memory to the output blob.
+	 */
+	void (*finish)( VipsStreamOutput * );
+
 } VipsStreamOutputClass;
 
 GType vips_stream_output_get_type( void );
@@ -226,7 +240,7 @@ GType vips_stream_output_get_type( void );
 VipsStreamOutput *vips_stream_output_new_from_descriptor( int descriptor );
 VipsStreamOutput *vips_stream_output_new_from_filename( const char *filename );
 VipsStreamOutput *vips_stream_output_new_memory( void );
-int vips_stream_output_write( VipsStreamOutput *stream,
+int vips_stream_output_write( VipsStreamOutput *output,
 	const unsigned char *data, size_t length );
 void vips_stream_output_finish( VipsStreamOutput *output );
 

libvips/iofuncs/stream.c

@@ -65,6 +65,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <unistd.h>
 
 #include <vips/vips.h>
 #include <vips/debug.h>
@@ -114,19 +115,10 @@
 
 G_DEFINE_ABSTRACT_TYPE( VipsStream, vips_stream, VIPS_TYPE_OBJECT );
 
-static void
+#define STREAM_NAME( STREAM ) \
-vips_stream_close( VipsStream *stream )
+	(VIPS_STREAM( STREAM )->filename ? \
-{
+		VIPS_STREAM( STREAM )->filename : \
-	if( stream->close_descriptor >= 0 ) {
+		VIPS_OBJECT( STREAM )->nickname)
-		close( stream->close_descriptor );
-		stream->close_descriptor = -1;
-	}
-
-	if( stream->tracked_descriptor >= 0 ) {
-		vips_tracked_close( stream->tracked_descriptor );
-		stream->tracked_descriptor = -1;
-	}
-}
 
 static void
 vips_stream_finalize( GObject *gobject )
@@ -139,7 +131,16 @@ vips_stream_finalize( GObject *gobject )
 	VIPS_DEBUG_MSG( "\n" );
 #endif /*VIPS_DEBUG*/
 
-	vips_stream_close( stream );
+	if( stream->close_descriptor >= 0 ) {
+		close( stream->close_descriptor );
+		stream->close_descriptor = -1;
+	}
+
+	if( stream->tracked_descriptor >= 0 ) {
+		vips_tracked_close( stream->tracked_descriptor );
+		stream->tracked_descriptor = -1;
+	}
+
 	VIPS_FREE( stream->filename ); 
 
 	G_OBJECT_CLASS( vips_stream_parent_class )->finalize( gobject );
@@ -178,11 +179,6 @@ vips_stream_init( VipsStream *stream )
 	stream->close_descriptor = -1;
 }
 
-#define STREAM_NAME( STREAM ) \
-	(VIPS_STREAM( STREAM )->filename ? \
-		VIPS_STREAM( STREAM )->filename : \
-		VIPS_OBJECT( STREAM )->nickname)
-
 G_DEFINE_TYPE( VipsStreamInput, vips_stream_input, VIPS_TYPE_STREAM );
 
 static void
@@ -313,6 +309,12 @@ vips_stream_input_rewind_real( VipsStreamInput *input )
 	return( 0 );
 }
 
+static void
+vips_stream_input_minimise_real( VipsStreamInput *input )
+{
+	VIPS_DEBUG_MSG( "vips_stream_minimise_real:\n" );
+}
+
 static void
 vips_stream_input_class_init( VipsStreamInputClass *class )
 {
@@ -330,6 +332,7 @@ vips_stream_input_class_init( VipsStreamInputClass *class )
 
 	class->read = vips_stream_input_read_real;
 	class->rewind = vips_stream_input_rewind_real;
+	class->minimise = vips_stream_input_minimise_real;
 
 	VIPS_ARG_BOXED( class, "blob", 3, 
 		_( "Blob" ),
@@ -572,6 +575,14 @@ vips_stream_input_rewind( VipsStreamInput *input )
 	return( class->rewind( input ) );
 }
 
+void
+vips_stream_input_minimise( VipsStreamInput *input )
+{
+	VipsStreamInputClass *class = VIPS_STREAM_INPUT_GET_CLASS( input );
+
+	class->minimise( input );
+}
+
 gboolean
 vips_stream_input_eof( VipsStreamInput *input )
 {
@@ -592,6 +603,19 @@ vips_stream_input_decode( VipsStreamInput *input )
 	}
 }
 
+static void
+vips_stream_input_minimise_cb( VipsImage *image, VipsStreamInput *input )
+{
+	vips_stream_input_minimise( input );
+}
+
+void 
+vips_stream_input_set_image( VipsStreamInput *input, VipsImage *image )
+{
+	g_signal_connect( image, "minimise", 
+		G_CALLBACK( vips_stream_input_minimise_cb ), input ); 
+}
+
 /**
  * vips_stream_input_sniff: 
  * @bytes: number of bytes to sniff
@@ -704,6 +728,25 @@ vips_stream_output_write_real( VipsStreamOutput *output,
 	return( len );
 }
 
+static void
+vips_stream_output_finish_real( VipsStreamOutput *output ) 
+{
+	VIPS_DEBUG_MSG( "vips_stream_output_finish_real:\n" );
+
+	/* Move the output buffer into the blob so it can be read out.
+	 */
+	if( output->memory ) {
+		unsigned char *data;
+		size_t length;
+
+		length = output->memory->len;
+		data = g_byte_array_free( output->memory, FALSE );
+		output->memory = NULL;
+		vips_blob_set( output->blob,
+			(VipsCallbackFn) g_free, data, length );
+	}
+}
+
 static void
 vips_stream_output_class_init( VipsStreamOutputClass *class )
 {
@@ -720,6 +763,7 @@ vips_stream_output_class_init( VipsStreamOutputClass *class )
 	object_class->build = vips_stream_output_build;
 
 	class->write = vips_stream_output_write_real;
+	class->finish = vips_stream_output_finish_real;
 
 	/* SET_ALWAYS means that blob is set by C and the obj system is not
 	 * involved in creation or destruction. It can be read at any time.
@@ -866,20 +910,11 @@ vips_stream_output_write( VipsStreamOutput *output,
 }
 
 void
-vips_stream_output_finish( VipsStreamOutput *output ) 
+vips_stream_output_finish( VipsStreamOutput *output )
 {
+	VipsStreamOutputClass *class = VIPS_STREAM_OUTPUT_GET_CLASS( output );
+
 	VIPS_DEBUG_MSG( "vips_stream_output_finish:\n" );
 
-	if( output->memory ) {
+	class->finish( output );
-		unsigned char *data;
-		size_t length;
-
-		length = output->memory->len;
-		data = g_byte_array_free( output->memory, FALSE );
-		output->memory = NULL;
-		vips_blob_set( output->blob,
-			(VipsCallbackFn) g_free, data, length );
-	}
-
-	vips_stream_close( VIPS_STREAM( output ) );
 }