1 files changed, 128 insertions, 0 deletions
diff --git a/filter/pipeline.c b/filter/pipeline.c
new file mode 100644
index 00000000..ef0412c0
--- /dev/null
+++ b/filter/pipeline.c
@@ -0,0 +1,128 @@
+#include <fitz.h>
+
+#define noDEBUG 1
+
+typedef struct fz_pipeline_s fz_pipeline;
+
+fz_error * fz_processpipeline(fz_filter *filter, fz_buffer *in, fz_buffer *out);
+
+struct fz_pipeline_s
+{
+	fz_filter super;
+	fz_filter *head;
+	fz_buffer *buffer;
+	fz_filter *tail;
+	int tailneedsin;
+};
+
+fz_error *
+fz_chainpipeline(fz_filter **fp, fz_filter *head, fz_filter *tail, fz_buffer *buf)
+{
+	FZ_NEWFILTER(fz_pipeline, p, pipeline);
+	p->head = head;
+	p->tail = tail;
+	p->tailneedsin = 1;
+	p->buffer = buf;
+	return nil;
+}
+
+void
+fz_unchainpipeline(fz_filter *filter, fz_filter **oldfp, fz_buffer **oldbp)
+{
+	fz_pipeline *p = (fz_pipeline*)filter;
+	*oldfp = p->head;
+	*oldbp = p->buffer;
+	fz_freefilter(p->tail);
+	fz_free(p);
+}
+
+fz_error *
+fz_newpipeline(fz_filter **fp, fz_filter *head, fz_filter *tail)
+{
+	fz_error *err;
+
+	FZ_NEWFILTER(fz_pipeline, p, pipeline);
+	p->head = head;
+	p->tail = tail;
+	p->tailneedsin = 1;
+
+	err = fz_newbuffer(&p->buffer, FZ_BUFSIZE);
+	if (err) { fz_free(p); return err; }
+
+	return nil;
+}
+
+void
+fz_freepipeline(fz_filter *filter)
+{
+	fz_pipeline *p = (fz_pipeline*)filter;
+	fz_freefilter(p->head);
+	fz_freefilter(p->tail);
+	fz_freebuffer(p->buffer);
+	fz_free(p);
+}
+
+fz_error *
+fz_processpipeline(fz_filter *filter, fz_buffer *in, fz_buffer *out)
+{
+	fz_pipeline *p = (fz_pipeline*)filter;
+	fz_error *e;
+
+	if (p->buffer->eof)
+		goto tail;
+
+	if (p->tailneedsin && p->head->produced)
+		goto tail;
+
+head:
+	e = fz_process(p->head, in, p->buffer);
+
+	if (e == fz_ioneedin)
+		return fz_ioneedin;
+
+	else if (e == fz_ioneedout)
+	{
+		if (p->tailneedsin && !p->head->produced)
+		{
+			fz_error *be = nil;
+			if (p->buffer->rp > p->buffer->bp)
+				be = fz_rewindbuffer(p->buffer);
+			else
+				be = fz_growbuffer(p->buffer);
+			if (be)
+				return be;
+			goto head;
+		}
+		goto tail;
+	}
+
+	else if (e == fz_iodone)
+		goto tail;
+
+	else
+		return e;
+
+tail:
+	e = fz_process(p->tail, p->buffer, out);
+
+	if (e == fz_ioneedin)
+	{
+		if (p->buffer->eof)
+			return fz_throw("ioerror: premature eof in pipeline");
+		p->tailneedsin = 1;
+		goto head;
+	}
+
+	else if (e == fz_ioneedout)
+	{
+		p->tailneedsin = 0;
+		return fz_ioneedout;
+	}
+
+	else if (e == fz_iodone)
+		return fz_iodone;
+
+	else
+		return e;
+}
+