revise streamo, ppm save uses it

streamo is simpler, and has a fast putc.

libvips/foreign/pforeign.h

@@ -149,7 +149,7 @@ int vips__ppm_isppm( const char *filename );
 VipsForeignFlags vips__ppm_flags( const char *filename );
 extern const char *vips__ppm_suffs[];
 
-int vips__ppm_save( VipsImage *in, const char *filename, 
+int vips__ppm_save_stream( VipsImage *in, VipsStreamo *streamo,
 	gboolean ascii, gboolean squash );
 
 int vips__rad_israd( VipsStreami *streami );

libvips/foreign/ppm.c

@@ -36,6 +36,8 @@
  * 	  linebreaks
  * 29/7/19 Kyle-Kyle
  * 	- fix a loop with malformed ppm
+ * 13/11/19
+ * 	- ppm save redone with streams
  */
 
 /*
@@ -555,22 +557,22 @@ typedef int (*write_fn)( struct _Write *write, VipsPel *p );
  */
 typedef struct _Write {
 	VipsImage *in;
-	FILE *fp;
+	VipsStreamo *streamo;
-	char *name;
 	write_fn fn;
 } Write;
 
 static void
 write_destroy( Write *write )
 {
-	VIPS_FREEF( fclose, write->fp );
+	if( write->streamo ) 
-	VIPS_FREE( write->name );
+		vips_streamo_finish( write->streamo );
+	VIPS_UNREF( write->streamo );
 
 	vips_free( write );
 }
 
 static Write *
-write_new( VipsImage *in, const char *name )
+write_new( VipsImage *in, VipsStreamo *streamo )
 {
 	Write *write;
 
@@ -578,13 +580,9 @@ write_new( VipsImage *in, const char *name )
 		return( NULL );
 
 	write->in = in;
-	write->name = vips_strdup( NULL, name );
+        write->streamo = streamo;
-        write->fp = vips__file_open_write( name, FALSE );
+	g_object_ref( streamo );
-
+        write->fn = NULL;
-	if( !write->name || !write->fp ) {
-		write_destroy( write );
-		return( NULL );
-	}
 
         return( write );
 }
@@ -599,17 +597,17 @@ write_ppm_line_ascii( Write *write, VipsPel *p )
 		for( k = 0; k < write->in->Bands; k++ ) {
 			switch( write->in->BandFmt ) {
 			case VIPS_FORMAT_UCHAR:
-				fprintf( write->fp, 
+				vips_streamo_writef( write->streamo, 
 					"%d ", p[k] );
 				break;
 
 			case VIPS_FORMAT_USHORT:
-				fprintf( write->fp, 
+				vips_streamo_writef( write->streamo, 
 					"%d ", ((unsigned short *) p)[k] );
 				break;
 
 			case VIPS_FORMAT_UINT:
-				fprintf( write->fp, 
+				vips_streamo_writef( write->streamo, 
 					"%d ", ((unsigned int *) p)[k] );
 				break;
 
@@ -621,11 +619,8 @@ write_ppm_line_ascii( Write *write, VipsPel *p )
 		p += sk;
 	}
 
-	if( !fprintf( write->fp, "\n" ) ) {
+	if( vips_streamo_writef( write->streamo, "\n" ) ) 
-		vips_error_system( errno, "vips2ppm", 
-			"%s", _( "write error" ) );
 		return( -1 );
-	}
 
 	return( 0 );
 }
@@ -636,13 +631,10 @@ write_ppm_line_ascii_squash( Write *write, VipsPel *p )
 	int x;
 
 	for( x = 0; x < write->in->Xsize; x++ ) 
-		fprintf( write->fp, "%d ", p[x] ? 0 : 1 );
+		vips_streamo_writef( write->streamo, "%d ", p[x] ? 0 : 1 );
 
-	if( !fprintf( write->fp, "\n" ) ) {
+	if( vips_streamo_writef( write->streamo, "\n" ) ) 
-		vips_error_system( errno, "vips2ppm", 
-			"%s", _( "write error" ) );
 		return( -1 );
-	}
 
 	return( 0 );
 }
@@ -650,8 +642,8 @@ write_ppm_line_ascii_squash( Write *write, VipsPel *p )
 static int
 write_ppm_line_binary( Write *write, VipsPel *p )
 {
-	if( vips__file_write( p, VIPS_IMAGE_SIZEOF_LINE( write->in ), 1, 
+	if( vips_streamo_write( write->streamo, 
-		write->fp ) ) 
+		p, VIPS_IMAGE_SIZEOF_LINE( write->in ) ) ) 
 		return( -1 );
 
 	return( 0 );
@@ -672,11 +664,8 @@ write_ppm_line_binary_squash( Write *write, VipsPel *p )
 		bits |= p[x] ? 0 : 1;
 
 		if( n_bits == 8 ) {
-			if( fputc( bits, write->fp ) == EOF ) {
+			if( VIPS_STREAMO_PUTC( write->streamo, bits ) ) 
-				vips_error_system( errno, "vips2ppm", 
-					"%s", _( "write error" ) );
 				return( -1 );
-			}
 
 			bits = 0;
 			n_bits = 0;
@@ -685,13 +674,9 @@ write_ppm_line_binary_squash( Write *write, VipsPel *p )
 
 	/* Flush any remaining bits in this line.
 	 */
-	if( n_bits ) {
+	if( n_bits &&
-		if( fputc( bits, write->fp ) == EOF ) {
+		VIPS_STREAMO_PUTC( write->streamo, bits ) ) 
-			vips_error_system( errno, "vips2ppm", 
+		return( -1 );
-				"%s", _( "write error" ) );
-			return( -1 );
-		}
-	}
 
 	return( 0 );
 }
@@ -740,23 +725,27 @@ write_ppm( Write *write, gboolean ascii, gboolean squash )
 	else
 		g_assert_not_reached();
 
-	fprintf( write->fp, "%s\n", magic );
+	vips_streamo_writef( write->streamo, "%s\n", magic );
 	time( &timebuf );
-	fprintf( write->fp, "#vips2ppm - %s\n", ctime( &timebuf ) );
+	vips_streamo_writef( write->streamo, 
-	fprintf( write->fp, "%d %d\n", in->Xsize, in->Ysize );
+		"#vips2ppm - %s\n", ctime( &timebuf ) );
+	vips_streamo_writef( write->streamo, "%d %d\n", in->Xsize, in->Ysize );
 
 	if( !squash ) 
 		switch( in->BandFmt ) {
 		case VIPS_FORMAT_UCHAR:
-			fprintf( write->fp, "%d\n", UCHAR_MAX );
+			vips_streamo_writef( write->streamo, 
+				"%d\n", UCHAR_MAX );
 			break;
 
 		case VIPS_FORMAT_USHORT:
-			fprintf( write->fp, "%d\n", USHRT_MAX );
+			vips_streamo_writef( write->streamo, 
+				"%d\n", USHRT_MAX );
 			break;
 
 		case VIPS_FORMAT_UINT:
-			fprintf( write->fp, "%d\n", UINT_MAX );
+			vips_streamo_writef( write->streamo, 
+				"%d\n", UINT_MAX );
 			break;
 
 		case VIPS_FORMAT_FLOAT:
@@ -767,7 +756,8 @@ write_ppm( Write *write, gboolean ascii, gboolean squash )
 				scale = 1;
 			if( !vips_amiMSBfirst() )
 				scale *= -1;
-			fprintf( write->fp, "%g\n", scale );
+			vips_streamo_writef( write->streamo, 
+				"%g\n", scale );
 }
 			break;
 
@@ -791,7 +781,7 @@ write_ppm( Write *write, gboolean ascii, gboolean squash )
 }
 
 int
-vips__ppm_save( VipsImage *in, const char *filename, 
+vips__ppm_save_stream( VipsImage *in, VipsStreamo *streamo,
 	gboolean ascii, gboolean squash )
 {
 	Write *write;
@@ -820,7 +810,7 @@ vips__ppm_save( VipsImage *in, const char *filename,
 		squash = FALSE; 
 	}
 
-	if( !(write = write_new( in, filename )) )
+	if( !(write = write_new( in, streamo )) )
 		return( -1 );
 
 	if( write_ppm( write, ascii, squash ) ) {

libvips/foreign/ppmsave.c

@@ -70,13 +70,20 @@ vips_foreign_save_ppm_build( VipsObject *object )
 	VipsForeignSave *save = (VipsForeignSave *) object;
 	VipsForeignSavePpm *ppm = (VipsForeignSavePpm *) object;
 
+	VipsStreamo *streamo;
+
 	if( VIPS_OBJECT_CLASS( vips_foreign_save_ppm_parent_class )->
 		build( object ) )
 		return( -1 );
 
-	if( vips__ppm_save( save->ready, ppm->filename, 
+	if( !(streamo = vips_streamo_new_to_filename( ppm->filename )) )
-		ppm->ascii, ppm->squash ) )
 		return( -1 );
+	if( vips__ppm_save_stream( save->ready, streamo, 
+		ppm->ascii, ppm->squash ) ) {
+		VIPS_UNREF( streamo );
+		return( -1 );
+	}
+	VIPS_UNREF( streamo );
 
 	return( 0 );
 }

libvips/include/vips/stream.h

@@ -365,11 +365,11 @@ typedef struct _VipsStreamo {
 	 */
 	VipsBlob *blob;
 
-	/* Buffer small writes here. 
+	/* Buffer small writes here. write_point is the index of the next
+	 * character to write.
 	 */
 	unsigned char output_buffer[VIPS_STREAMO_BUFFER_SIZE];
-	unsigned char *write_point;
+	int write_point;
-	int bytes_remaining;
 
 } VipsStreamo;
 
@@ -395,6 +395,14 @@ VipsStreamo *vips_streamo_new_to_memory( void );
 int vips_streamo_write( VipsStreamo *streamo, const void *data, size_t length );
 void vips_streamo_finish( VipsStreamo *streamo );
 
+int vips_streamo_putc( VipsStreamo *streamo, int ch );
+
+#define VIPS_STREAMO_PUTC( S, C ) ( \
+	(S)->write_point <= VIPS_STREAMO_BUFFER_SIZE ? \
+	((S)->output_buffer[(S)->write_point++] = (C), 0) : \
+	vips_streamo_putc( (S), (C) ) \
+)
+
 int vips_streamo_writef( VipsStreamo *streamo, const char *fmt, ... )
 	__attribute__((format(printf, 2, 3)));
 

libvips/iofuncs/streamo.c

@@ -198,8 +198,7 @@ static void
 vips_streamo_init( VipsStreamo *streamo )
 {
 	streamo->blob = vips_blob_new( NULL, NULL, 0 );
-	streamo->bytes_remaining = VIPS_STREAMO_BUFFER_SIZE;
+	streamo->write_point = 0;
-	streamo->write_point = streamo->output_buffer;
 }
 
 /**
@@ -323,18 +322,14 @@ vips_streamo_write_unbuffered( VipsStreamo *streamo,
 static int
 vips_streamo_flush( VipsStreamo *streamo )
 {
-	int bytes_in_buffer = 
+	g_assert( streamo->write_point >= 0 );
-		VIPS_STREAMO_BUFFER_SIZE - streamo->bytes_remaining;
+	g_assert( streamo->write_point <= VIPS_STREAMO_BUFFER_SIZE );
 
-	g_assert( bytes_in_buffer >= 0 );
+	if( streamo->write_point > 0 ) {
-	g_assert( bytes_in_buffer <= VIPS_STREAMO_BUFFER_SIZE );
-
-	if( bytes_in_buffer > 0 ) {
 		if( vips_streamo_write_unbuffered( streamo, 
-			streamo->output_buffer, bytes_in_buffer ) )
+			streamo->output_buffer, streamo->write_point ) )
 			return( -1 );
-		streamo->bytes_remaining = VIPS_STREAMO_BUFFER_SIZE;
+		streamo->write_point = 0;
-		streamo->write_point = streamo->output_buffer;
 	}
 
 	return( 0 );
@@ -355,27 +350,20 @@ vips_streamo_write( VipsStreamo *streamo, const void *buffer, size_t length )
 {
 	VIPS_DEBUG_MSG( "vips_streamo_write: %zd bytes\n", length );
 
-	if( streamo->bytes_remaining >= length ) {
+	if( length > VIPS_STREAMO_BUFFER_SIZE - streamo->write_point &&
-		memcpy( streamo->write_point, buffer, length );
+		vips_streamo_flush( streamo ) )
-		streamo->bytes_remaining -= length;
+		return( -1 );
-		streamo->write_point += length;
+
+	if( length > VIPS_STREAMO_BUFFER_SIZE - streamo->write_point ) {
+		/* Still too large? Do an unbuffered write.
+		 */
+		if( vips_streamo_write_unbuffered( streamo, buffer, length ) )
+			return( -1 );
 	}
 	else {
-		if( vips_streamo_flush( streamo ) )
+		memcpy( streamo->output_buffer + streamo->write_point, 
-			return( -1 );
+			buffer, length );
-
+		streamo->write_point += length;
-		if( streamo->bytes_remaining >= length ) {
-			memcpy( streamo->write_point, buffer, length );
-			streamo->bytes_remaining -= length;
-			streamo->write_point += length;
-		}
-		else 
-			/* The buffer is empty and we still have too much
-			 * data. Write directly.
-			 */
-			if( vips_streamo_write_unbuffered( streamo, 
-				buffer, length ) )
-				return( -1 );
 	}
 
 	return( 0 );
@@ -443,6 +431,30 @@ vips_streamo_writef( VipsStreamo *streamo, const char *fmt, ... )
 	return( result ); 
 }
 
+/**
+ * vips_streamo_putc:
+ * @streamo: output stream to operate on
+ * @ch: character to write
+ *
+ * Write a single character @ch to @streamo. See the macro VIPS_STREAMO_PUTC()
+ * for a faster way to do this.
+ *
+ * Returns: 0 on success, -1 on error.
+ */
+int
+vips_streamo_putc( VipsStreamo *streamo, int ch )
+{
+	VIPS_DEBUG_MSG( "vips_streamo_putc: %d\n", ch );
+
+	if( streamo->write_point > VIPS_STREAMO_BUFFER_SIZE && 
+		vips_streamo_flush( streamo ) )
+		return( -1 );
+
+	streamo->output_buffer[streamo->write_point++] = ch;
+
+	return( 0 );
+}
+
 /**
  * vips_streamo_write_amp: 
  * @streamo: output stream to operate on
@@ -497,8 +509,7 @@ vips_streamo_write_amp( VipsStreamo *streamo, const char *str )
 				return( -1 );
 		}
 		else  {
-			if( !vips_streamo_write( streamo, 
+			if( !vips_streamo_putc( streamo, *p ) )
-				(guchar *) p, 1 ) )
 				return( -1 );
 		}