# HG changeset patch
# User Timo Sirainen <tss@iki.fi>
# Date 1128111038 -10800
# Node ID e05a1af4bbc770908a9a62a87ce6db7c5f84ea05
# Parent  571336db01f46da5d37c06239b1982e80bf810c2
Added i_stream_seek_mark() and used it

diff -r 571336db01f4 -r e05a1af4bbc7 src/lib-mail/istream-header-filter.c
--- a/src/lib-mail/istream-header-filter.c	Fri Sep 30 21:55:00 2005 +0300
+++ b/src/lib-mail/istream-header-filter.c	Fri Sep 30 23:10:38 2005 +0300
@@ -234,7 +234,8 @@
 	return ret;
 }
 
-static void _seek(struct _istream *stream, uoff_t v_offset)
+static void _seek(struct _istream *stream, uoff_t v_offset,
+		  int mark __attr_unused__)
 {
 	struct header_filter_istream *mstream =
 		(struct header_filter_istream *)stream;
diff -r 571336db01f4 -r e05a1af4bbc7 src/lib-storage/index/mbox/istream-raw-mbox.c
--- a/src/lib-storage/index/mbox/istream-raw-mbox.c	Fri Sep 30 21:55:00 2005 +0300
+++ b/src/lib-storage/index/mbox/istream-raw-mbox.c	Fri Sep 30 23:10:38 2005 +0300
@@ -279,7 +279,8 @@
 	return ret;
 }
 
-static void _seek(struct _istream *stream, uoff_t v_offset)
+static void _seek(struct _istream *stream, uoff_t v_offset,
+		  int mark __attr_unused__)
 {
 	struct raw_mbox_istream *rstream = (struct raw_mbox_istream *)stream;
 
@@ -492,8 +493,8 @@
 	rstream->body_offset = (uoff_t)-1;
 
 	if (stream->v_offset != rstream->from_offset)
-		i_stream_seek(stream, rstream->from_offset);
-	i_stream_seek(rstream->input, rstream->from_offset);
+		i_stream_seek_mark(stream, rstream->from_offset);
+	i_stream_seek_mark(rstream->input, rstream->from_offset);
 
 	rstream->eof = FALSE;
 	rstream->istream.istream.eof = FALSE;
@@ -535,8 +536,8 @@
 		check = TRUE;
 	}
 
-	i_stream_seek(stream, offset);
-	i_stream_seek(rstream->input, offset);
+	i_stream_seek_mark(stream, offset);
+	i_stream_seek_mark(rstream->input, offset);
 
 	if (check)
 		(void)_read(&rstream->istream);
diff -r 571336db01f4 -r e05a1af4bbc7 src/lib/istream-data.c
--- a/src/lib/istream-data.c	Fri Sep 30 21:55:00 2005 +0300
+++ b/src/lib/istream-data.c	Fri Sep 30 23:10:38 2005 +0300
@@ -22,7 +22,8 @@
 	return -1;
 }
 
-static void _seek(struct _istream *stream, uoff_t v_offset)
+static void _seek(struct _istream *stream, uoff_t v_offset,
+		  int mark __attr_unused__)
 {
 	stream->skip = v_offset;
 	stream->istream.v_offset = v_offset;
diff -r 571336db01f4 -r e05a1af4bbc7 src/lib/istream-file.c
--- a/src/lib/istream-file.c	Fri Sep 30 21:55:00 2005 +0300
+++ b/src/lib/istream-file.c	Fri Sep 30 23:10:38 2005 +0300
@@ -159,7 +159,8 @@
 	return ret;
 }
 
-static void _seek(struct _istream *stream, uoff_t v_offset)
+static void _seek(struct _istream *stream, uoff_t v_offset,
+		  int mark __attr_unused__)
 {
 	struct file_istream *fstream = (struct file_istream *) stream;
 
diff -r 571336db01f4 -r e05a1af4bbc7 src/lib/istream-internal.h
--- a/src/lib/istream-internal.h	Fri Sep 30 21:55:00 2005 +0300
+++ b/src/lib/istream-internal.h	Fri Sep 30 23:10:38 2005 +0300
@@ -12,7 +12,7 @@
 
 /* methods: */
 	ssize_t (*read)(struct _istream *stream);
-	void (*seek)(struct _istream *stream, uoff_t v_offset);
+	void (*seek)(struct _istream *stream, uoff_t v_offset, int mark);
 	void (*sync)(struct _istream *stream);
 	const struct stat *(*stat)(struct _istream *stream);
 
diff -r 571336db01f4 -r e05a1af4bbc7 src/lib/istream-limit.c
--- a/src/lib/istream-limit.c	Fri Sep 30 21:55:00 2005 +0300
+++ b/src/lib/istream-limit.c	Fri Sep 30 23:10:38 2005 +0300
@@ -80,7 +80,8 @@
 	return ret;
 }
 
-static void _seek(struct _istream *stream, uoff_t v_offset)
+static void _seek(struct _istream *stream, uoff_t v_offset,
+		  int mark __attr_unused__)
 {
 	struct limit_istream *lstream = (struct limit_istream *) stream;
 
diff -r 571336db01f4 -r e05a1af4bbc7 src/lib/istream-mmap.c
--- a/src/lib/istream-mmap.c	Fri Sep 30 21:55:00 2005 +0300
+++ b/src/lib/istream-mmap.c	Fri Sep 30 23:10:38 2005 +0300
@@ -141,7 +141,8 @@
 	return stream->pos - stream->skip;
 }
 
-static void _seek(struct _istream *stream, uoff_t v_offset)
+static void _seek(struct _istream *stream, uoff_t v_offset,
+		  int mark __attr_unused__)
 {
 	struct mmap_istream *mstream = (struct mmap_istream *) stream;
 
diff -r 571336db01f4 -r e05a1af4bbc7 src/lib/istream-seekable.c
--- a/src/lib/istream-seekable.c	Fri Sep 30 21:55:00 2005 +0300
+++ b/src/lib/istream-seekable.c	Fri Sep 30 23:10:38 2005 +0300
@@ -255,7 +255,8 @@
 	return ret;
 }
 
-static void _seek(struct _istream *stream, uoff_t v_offset)
+static void _seek(struct _istream *stream, uoff_t v_offset,
+		  int mark __attr_unused__)
 {
 	stream->istream.stream_errno = 0;
 	stream->istream.v_offset = v_offset;
diff -r 571336db01f4 -r e05a1af4bbc7 src/lib/istream.c
--- a/src/lib/istream.c	Fri Sep 30 21:55:00 2005 +0300
+++ b/src/lib/istream.c	Fri Sep 30 23:10:38 2005 +0300
@@ -72,7 +72,7 @@
 	if (stream->closed)
 		return;
 
-	_stream->seek(_stream, stream->v_offset + count);
+	_stream->seek(_stream, stream->v_offset + count, FALSE);
 }
 
 void i_stream_seek(struct istream *stream, uoff_t v_offset)
@@ -88,7 +88,18 @@
 		return;
 
 	stream->eof = FALSE;
-	_stream->seek(_stream, v_offset);
+	_stream->seek(_stream, v_offset, FALSE);
+}
+
+void i_stream_seek_mark(struct istream *stream, uoff_t v_offset)
+{
+	struct _istream *_stream = stream->real_stream;
+
+	if (stream->closed)
+		return;
+
+	stream->eof = FALSE;
+	_stream->seek(_stream, v_offset, TRUE);
 }
 
 void i_stream_sync(struct istream *stream)
diff -r 571336db01f4 -r e05a1af4bbc7 src/lib/istream.h
--- a/src/lib/istream.h	Fri Sep 30 21:55:00 2005 +0300
+++ b/src/lib/istream.h	Fri Sep 30 23:10:38 2005 +0300
@@ -52,6 +52,11 @@
 /* Seek to specified position from beginning of file. Never fails, the next
    read tells if it was successful. This works only for files. */
 void i_stream_seek(struct istream *stream, uoff_t v_offset);
+/* Like i_stream_seek(), but also giving a hint that after reading some data
+   we could be seeking back to this mark or somewhere after it. If input
+   stream's implementation is slow in seeking backwards, it can use this hint
+   to cache some of the data in memory. */
+void i_stream_seek_mark(struct istream *stream, uoff_t v_offset);
 /* Returns struct stat, or NULL if error. As the underlying stream may not be
    a file, only some of the fields might be set, others would be zero.
    st_size is always set, and if it's not known, it's -1. */