[vte] [ring/stream] Handle stream failure (out of space)

[Behdad Esfahbod <behdad src gnome org>]

commit 5254710eb86008ab218f2ad0a61e631f3f6d6b39
Author: Behdad Esfahbod <behdad behdad org>
Date:   Tue Sep 15 21:17:51 2009 -0400

    [ring/stream] Handle stream failure (out of space)

 src/ring.c           |   19 ++++++++++++++-----
 src/vtestream-base.h |    6 +++---
 src/vtestream-file.h |   15 ++++++---------
 src/vtestream.h      |    3 +--
 4 files changed, 24 insertions(+), 19 deletions(-)
---
diff --git a/src/ring.c b/src/ring.c
index 6f73572..c4a2376 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -179,12 +179,17 @@ _vte_ring_thaw_row (VteRing *ring, guint position, VteRowData *row, gboolean tru
 
 	attr_change.text_offset = 0;
 
-	_vte_stream_read (ring->row_stream, position * sizeof (record), (char *) records, sizeof (records));
-	if (records[1].text_offset < records[0].text_offset)
+	if (!_vte_stream_read (ring->row_stream, position * sizeof (records[0]), (char *) &records[0], sizeof (records[0])))
+		return;
+	if ((position + 1) * sizeof (VteRowRecord) < _vte_stream_head (ring->row_stream)) {
+		if (!_vte_stream_read (ring->row_stream, (position + 1) * sizeof (records[1]), (char *) &records[1], sizeof (records[1])))
+			return;
+	} else
 		records[1].text_offset = _vte_stream_head (ring->text_stream);
 
 	g_string_set_size (buffer, records[1].text_offset - records[0].text_offset);
-	_vte_stream_read (ring->text_stream, records[0].text_offset, buffer->str, buffer->len);
+	if (!_vte_stream_read (ring->text_stream, records[0].text_offset, buffer->str, buffer->len))
+		return;
 
 	record = records[0];
 
@@ -201,7 +206,8 @@ _vte_ring_thaw_row (VteRing *ring, guint position, VteRowData *row, gboolean tru
 			attr = ring->last_attr.attr;
 		} else {
 			if (record.text_offset >= attr_change.text_offset) {
-				_vte_stream_read (ring->attr_stream, record.attr_offset, (char *) &attr_change, sizeof (attr_change));
+				if (!_vte_stream_read (ring->attr_stream, record.attr_offset, (char *) &attr_change, sizeof (attr_change)))
+					return;
 				record.attr_offset += sizeof (attr_change);
 			}
 			attr = attr_change.attr;
@@ -233,7 +239,10 @@ _vte_ring_thaw_row (VteRing *ring, guint position, VteRowData *row, gboolean tru
 
 	if (truncate) {
 		if (records[0].text_offset < ring->last_attr.text_offset)
-			_vte_stream_read (ring->attr_stream, records[0].attr_offset, (char *) &ring->last_attr, sizeof (ring->last_attr));
+			if (!_vte_stream_read (ring->attr_stream, records[0].attr_offset, (char *) &ring->last_attr, sizeof (ring->last_attr))) {
+				ring->last_attr.text_offset = 0;
+				ring->last_attr.attr.i = 0;
+			}
 		_vte_stream_truncate (ring->row_stream, position * sizeof (record));
 		_vte_stream_truncate (ring->attr_stream, records[0].attr_offset);
 		_vte_stream_truncate (ring->text_stream, records[0].text_offset);
diff --git a/src/vtestream-base.h b/src/vtestream-base.h
index b79179a..80c6c3e 100644
--- a/src/vtestream-base.h
+++ b/src/vtestream-base.h
@@ -33,7 +33,7 @@ typedef struct _VteStreamClass {
 
 	void (*reset) (VteStream *stream, gsize offset);
 	gsize (*append) (VteStream *stream, const char *data, gsize len);
-	void (*read) (VteStream *stream, gsize offset, char *data, gsize len);
+	gboolean (*read) (VteStream *stream, gsize offset, char *data, gsize len);
 	void (*truncate) (VteStream *stream, gsize offset);
 	void (*new_page) (VteStream *stream);
 	gsize (*head) (VteStream *stream);
@@ -67,10 +67,10 @@ _vte_stream_append (VteStream *stream, const char *data, gsize len)
 	return VTE_STREAM_GET_CLASS (stream)->append (stream, data, len);
 }
 
-void
+gboolean
 _vte_stream_read (VteStream *stream, gsize offset, char *data, gsize len)
 {
-	VTE_STREAM_GET_CLASS (stream)->read (stream, offset, data, len);
+	return VTE_STREAM_GET_CLASS (stream)->read (stream, offset, data, len);
 }
 
 void
diff --git a/src/vtestream-file.h b/src/vtestream-file.h
index 36a9fc1..7693154 100644
--- a/src/vtestream-file.h
+++ b/src/vtestream-file.h
@@ -166,29 +166,26 @@ _vte_file_stream_append (VteStream *astream, const char *data, gsize len)
 	return stream->offset[0] + ret;
 }
 
-static void
+static gboolean
 _vte_file_stream_read (VteStream *astream, gsize offset, char *data, gsize len)
 {
 	VteFileStream *stream = (VteFileStream *) astream;
 	gsize l;
 
-	if (G_UNLIKELY (offset < stream->offset[1])) {
-		l = MIN (len, stream->offset[1] - offset);
-		memset (data, 0, l);
-		offset += l; data += l; len -= l; if (!len) return;
-	}
+	if (G_UNLIKELY (offset < stream->offset[1]))
+		return FALSE;
 
 	if (offset < stream->offset[0]) {
 		lseek (stream->fd[1], offset - stream->offset[1], SEEK_SET);
 		l = _xread (stream->fd[1], data, len);
-		offset += l; data += l; len -= l; if (!len) return;
+		offset += l; data += l; len -= l; if (!len) return TRUE;
 	}
 
 	lseek (stream->fd[0], offset - stream->offset[0], SEEK_SET);
 	l = _xread (stream->fd[0], data, len);
-	offset += l; data += l; len -= l; if (!len) return;
+	offset += l; data += l; len -= l; if (!len) return TRUE;
 
-	memset (data, 0, len);
+	return FALSE;
 }
 
 static void
diff --git a/src/vtestream.h b/src/vtestream.h
index ec45fcc..56df5a0 100644
--- a/src/vtestream.h
+++ b/src/vtestream.h
@@ -29,7 +29,7 @@ typedef struct _VteStream VteStream;
 
 void _vte_stream_reset (VteStream *stream, gsize offset);
 gsize _vte_stream_append (VteStream *stream, const char *data, gsize len);
-void _vte_stream_read (VteStream *stream, gsize offset, char *data, gsize len);
+gboolean _vte_stream_read (VteStream *stream, gsize offset, char *data, gsize len);
 void _vte_stream_truncate (VteStream *stream, gsize offset);
 void _vte_stream_new_page (VteStream *stream);
 gsize _vte_stream_head (VteStream *stream);
@@ -43,4 +43,3 @@ _vte_file_stream_new (void);
 G_END_DECLS
 
 #endif
-