1 files changed, 51 insertions, 0 deletions
diff --git a/stream/filt_process.c b/stream/filt_process.c
new file mode 100644
index 00000000..afe4feed
--- /dev/null
+++ b/stream/filt_process.c
@@ -0,0 +1,51 @@
+#include <fitz.h>
+
+fz_error fz_kioneedin = { -1, "<ioneedin>", "<process>", "filter.c", 0 };
+fz_error fz_kioneedout = { -1, "<ioneedout>", "<process>", "filter.c", 0 };
+fz_error fz_kiodone = { -1, "<iodone>", "<process>", "filter.c", 0 };
+
+fz_error *
+fz_process(fz_filter *f, fz_buffer *in, fz_buffer *out)
+{
+	fz_error *reason;
+	unsigned char *oldrp;
+	unsigned char *oldwp;
+
+	assert(!out->eof);
+
+	oldrp = in->rp;
+	oldwp = out->wp;
+
+	reason = f->process(f, in, out);
+
+	assert(in->rp <= in->wp);
+	assert(out->wp <= out->ep);
+
+	f->consumed = in->rp > oldrp;
+	f->produced = out->wp > oldwp;
+	f->count += out->wp - oldwp;
+
+	if (reason != fz_ioneedin && reason != fz_ioneedout)
+		out->eof = 1;
+
+	return reason;
+}
+
+fz_filter *
+fz_keepfilter(fz_filter *f)
+{
+	f->refs ++;
+	return f;
+}
+
+void
+fz_dropfilter(fz_filter *f)
+{
+	if (--f->refs == 0)
+	{
+		if (f->drop)
+			f->drop(f);
+		fz_free(f);
+	}
+}
+