1 files changed, 127 insertions, 0 deletions
diff --git a/src/lib-mail/istream-qp-encoder.c b/src/lib-mail/istream-qp-encoder.c
new file mode 100644
index 0000000..25b7589
--- /dev/null
+++ b/src/lib-mail/istream-qp-encoder.c
@@ -0,0 +1,127 @@
+/* Copyright (c) 2017-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "buffer.h"
+#include "hex-binary.h"
+#include "qp-encoder.h"
+#include "istream-private.h"
+#include "istream-qp.h"
+
+struct qp_encoder_istream {
+	struct istream_private istream;
+	buffer_t *buf;
+	struct qp_encoder *qp;
+};
+
+static void i_stream_qp_encoder_close(struct iostream_private *stream,
+				      bool close_parent)
+{
+	struct qp_encoder_istream *bstream =
+		(struct qp_encoder_istream *)stream;
+
+	if (bstream->qp != NULL)
+		qp_encoder_deinit(&bstream->qp);
+	buffer_free(&bstream->buf);
+	if (close_parent)
+		i_stream_close(bstream->istream.parent);
+}
+
+static ssize_t i_stream_qp_encoder_read(struct istream_private *stream)
+{
+	struct qp_encoder_istream *bstream =
+		(struct qp_encoder_istream *)stream;
+	const unsigned char *data;
+	size_t size;
+	int ret;
+
+	for(;;) {
+		if (stream->skip > 0) {
+			i_assert(stream->skip <= bstream->buf->used);
+			buffer_delete(bstream->buf, 0, stream->skip);
+			stream->pos -= stream->skip;
+			stream->skip = 0;
+		}
+
+		stream->buffer = bstream->buf->data;
+		i_assert(stream->pos <= bstream->buf->used);
+
+		if (stream->pos >= bstream->istream.max_buffer_size) {
+			/* stream buffer still at maximum */
+			return -2;
+		}
+
+		/* if something is already interpolated, return as much of it as
+		   we can */
+		if (bstream->buf->used > 0) {
+			size_t new_pos, bytes;
+
+			/* only return up to max_buffer_size bytes, even when buffer
+			   actually has more, as not to confuse the caller */
+			if (bstream->buf->used <= bstream->istream.max_buffer_size) {
+				new_pos = bstream->buf->used;
+				if (stream->parent->eof)
+					stream->istream.eof = TRUE;
+			} else {
+				new_pos = bstream->istream.max_buffer_size;
+			}
+
+			bytes = new_pos - stream->pos;
+			stream->pos = new_pos;
+			return (ssize_t)bytes;
+		}
+
+		/* need to read more input */
+		ret = i_stream_read_more_memarea(stream->parent, &data, &size);
+		if (ret == 0)
+			return ret;
+		if (size == 0 && ret == -1) {
+			stream->istream.stream_errno =
+				stream->parent->stream_errno;
+			stream->istream.eof = stream->parent->eof;
+			return ret;
+		}
+		qp_encoder_more(bstream->qp, data, size);
+		i_stream_skip(stream->parent, size);
+	}
+}
+
+static void
+i_stream_qp_encoder_seek(struct istream_private *stream,
+			     uoff_t v_offset, bool mark)
+{
+	struct qp_encoder_istream *bstream =
+		(struct qp_encoder_istream *)stream;
+
+	if (v_offset < stream->istream.v_offset) {
+		/* seeking backwards - go back to beginning and seek
+		   forward from there. */
+		stream->parent_expected_offset = stream->parent_start_offset;
+		stream->skip = stream->pos = 0;
+		stream->istream.v_offset = 0;
+		i_stream_seek(stream->parent, 0);
+		qp_encoder_finish(bstream->qp);
+		buffer_set_used_size(bstream->buf, 0);
+	}
+	i_stream_default_seek_nonseekable(stream, v_offset, mark);
+}
+
+struct istream *i_stream_create_qp_encoder(struct istream *input,
+					   enum qp_encoder_flag flags)
+{
+	struct qp_encoder_istream *bstream;
+
+	bstream = i_new(struct qp_encoder_istream, 1);
+	bstream->istream.max_buffer_size = input->real_stream->max_buffer_size;
+	bstream->buf = buffer_create_dynamic(default_pool, 128);
+	bstream->qp = qp_encoder_init(bstream->buf, ISTREAM_QP_ENCODER_MAX_LINE_LENGTH, flags);
+
+	bstream->istream.iostream.close = i_stream_qp_encoder_close;
+	bstream->istream.read = i_stream_qp_encoder_read;
+	bstream->istream.seek = i_stream_qp_encoder_seek;
+
+	bstream->istream.istream.readable_fd = FALSE;
+	bstream->istream.istream.blocking = input->blocking;
+	bstream->istream.istream.seekable = input->seekable;
+	return i_stream_create(&bstream->istream, input,
+			       i_stream_get_fd(input), 0);
+}