1 files changed, 88 insertions, 0 deletions
diff --git a/src/lib/ostream-buffer.c b/src/lib/ostream-buffer.c
new file mode 100644
index 0000000..af3dbef
--- /dev/null
+++ b/src/lib/ostream-buffer.c
@@ -0,0 +1,88 @@
+/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "buffer.h"
+#include "ostream-private.h"
+
+struct buffer_ostream {
+	struct ostream_private ostream;
+	buffer_t *buf;
+	bool seeked;
+};
+
+static int o_stream_buffer_seek(struct ostream_private *stream, uoff_t offset)
+{
+	struct buffer_ostream *bstream =
+		container_of(stream, struct buffer_ostream, ostream);
+
+	bstream->seeked = TRUE;
+	stream->ostream.offset = offset;
+	return 1;
+}
+
+static int
+o_stream_buffer_write_at(struct ostream_private *stream,
+			 const void *data, size_t size, uoff_t offset)
+{
+	struct buffer_ostream *bstream =
+		container_of(stream, struct buffer_ostream, ostream);
+
+	buffer_write(bstream->buf, offset, data, size);
+	return 0;
+}
+
+static ssize_t
+o_stream_buffer_sendv(struct ostream_private *stream,
+		      const struct const_iovec *iov, unsigned int iov_count)
+{
+	struct buffer_ostream *bstream =
+		container_of(stream, struct buffer_ostream, ostream);
+	size_t left, n, offset;
+	ssize_t ret = 0;
+	unsigned int i;
+
+	offset = bstream->seeked ? stream->ostream.offset : bstream->buf->used;
+
+	for (i = 0; i < iov_count; i++) {
+		left = bstream->ostream.max_buffer_size -
+			stream->ostream.offset;
+		n = I_MIN(left, iov[i].iov_len);
+		buffer_write(bstream->buf, offset, iov[i].iov_base, n);
+		stream->ostream.offset += n; offset += n;
+		ret += n;
+		if (n != iov[i].iov_len)
+			break;
+	}
+	return ret;
+}
+
+static size_t
+o_stream_buffer_get_buffer_used_size(const struct ostream_private *stream)
+{
+	const struct buffer_ostream *bstream =
+		container_of(stream, const struct buffer_ostream, ostream);
+
+	return bstream->buf->used;
+}
+
+struct ostream *o_stream_create_buffer(buffer_t *buf)
+{
+	struct buffer_ostream *bstream;
+	struct ostream *output;
+
+	bstream = i_new(struct buffer_ostream, 1);
+	/* we don't set buffer as blocking, because if max_buffer_size is
+	   changed it can get truncated. this is used in various places in
+	   unit tests. */
+	bstream->ostream.max_buffer_size = SIZE_MAX;
+	bstream->ostream.seek = o_stream_buffer_seek;
+	bstream->ostream.sendv = o_stream_buffer_sendv;
+	bstream->ostream.write_at = o_stream_buffer_write_at;
+	bstream->ostream.get_buffer_used_size =
+		o_stream_buffer_get_buffer_used_size;
+
+	bstream->buf = buf;
+	output = o_stream_create(&bstream->ostream, NULL, -1);
+	o_stream_set_name(output, "(buffer)");
+	return output;
+}