[balsa] Reduce the compressed IMAP stream flushing frequency.

[Pawel Salek <pawels src gnome org>]

commit 3891da5ff013e3afa4ae52decd63b121b18401b6
Author: Pawel Salek <pawsa damage localdomain>
Date:   Fri Feb 5 18:32:14 2010 +0100

    Reduce the compressed IMAP stream flushing frequency.

 ChangeLog                     |    6 ++++++
 libbalsa/imap/imap_compress.c |    4 ++--
 libbalsa/imap/siobuf.c        |   36 +++++++++++++++++++++++++++++++-----
 3 files changed, 39 insertions(+), 7 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 6bc3f0b..3335e55 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-02-05  Pawel Salek
+
+	* libbalsa/imap/imap_compress.c: reduce the compressed stream
+	flushing frequency.
+	* libbalsa/imap/siobuf.c: matching change on the buffering side.
+
 2010-01-27  Pawel Salek
 
 	* configure.in, NEWS: release 2.4.6.
diff --git a/libbalsa/imap/imap_compress.c b/libbalsa/imap/imap_compress.c
index 54340be..50638a7 100644
--- a/libbalsa/imap/imap_compress.c
+++ b/libbalsa/imap/imap_compress.c
@@ -26,7 +26,7 @@
 #include "imap_private.h"
 
 /** Arbitrary. Current choice is as good as any other. */
-static const unsigned IMAP_COMPRESS_BUFFER_SIZE = 4096;
+static const unsigned IMAP_COMPRESS_BUFFER_SIZE = 8192;
 
 static int
 imap_compress_cb(char **dstbuf, int *dstlen,
@@ -46,7 +46,7 @@ imap_compress_cb(char **dstbuf, int *dstlen,
   icb->out_stream.next_out = (Byte*)*dstbuf;
   icb->out_stream.avail_out = IMAP_COMPRESS_BUFFER_SIZE;
 
-  err = deflate(&icb->out_stream, Z_SYNC_FLUSH);
+  err = deflate(&icb->out_stream, srclen ? Z_NO_FLUSH : Z_SYNC_FLUSH);
   if ( !(err == Z_OK || err == Z_STREAM_END || err == Z_BUF_ERROR) ) {
     fprintf(stderr, "deflate error1 %d\n", err);
     *dstlen = -1;
diff --git a/libbalsa/imap/siobuf.c b/libbalsa/imap/siobuf.c
index 225bc0d..b465483 100644
--- a/libbalsa/imap/siobuf.c
+++ b/libbalsa/imap/siobuf.c
@@ -85,6 +85,8 @@ struct siobuf
     void *user_data;
   };
 
+static void sio_flush_buffer (struct siobuf *sio);
+
 /* Attach bi-directional buffering to the socket descriptor.
  */
 struct siobuf *
@@ -375,7 +377,7 @@ sio_write (struct siobuf *sio, const void *bufp, int buflen)
 	  buf += sio->write_available;
 	  buflen -= sio->write_available;
 	}
-      sio_flush (sio);
+      sio_flush_buffer (sio);
       assert (sio->write_available > 0);
     }
   if (buflen > 0)
@@ -385,7 +387,7 @@ sio_write (struct siobuf *sio, const void *bufp, int buflen)
       sio->write_available -= buflen;
       /* If the buffer is exactly filled, flush it */
       if (sio->write_available == 0)
-	sio_flush (sio);
+	sio_flush_buffer (sio);
     }
 }
 
@@ -442,8 +444,8 @@ raw_write (struct siobuf *sio, const char *buf, int len)
       }
 }
 
-void
-sio_flush (struct siobuf *sio)
+static void
+sio_flush_buffer (struct siobuf *sio)
 {
   int length;
 
@@ -494,6 +496,30 @@ sio_flush (struct siobuf *sio)
 }
 
 void
+sio_flush (struct siobuf *sio)
+{
+  sio_flush_buffer (sio);
+  if (sio->encode_cb != NULL)
+    {
+      char *buf;
+      int len = 0;
+
+      /* Rules for the encode callback.
+
+         The output variables (here buf and len) may be set to the
+         write_buffer iff the encoding can be performed in place and
+         the result is shorter than the original data.  Otherwise the
+         callback must maintain its own buffer which must persist until
+         the next call in the same thread.  The secarg argument may be
+         used to maintain this buffer. */
+      while ((*sio->encode_cb) (&buf, &len, sio->write_buffer, 
+                                0, sio->secarg) >0) {
+        raw_write (sio, buf, len);
+      }
+    }
+}
+  
+void
 sio_mark (struct siobuf *sio)
 {
   assert (sio != NULL);
@@ -583,7 +609,7 @@ sio_fill (struct siobuf *sio)
                                sio->read_buffer, sio->read_unread,
                                sio->secarg) == 0) {
       sio->read_unread = raw_read (sio, sio->read_buffer, sio->buffer_size);
-      if (sio->read_unread < 0)
+      if (sio->read_unread <= 0)
         break;
     }
     sio->read_buffer_start = sio->read_position;