SHA1 Hash:	bd3c1d0023c2e573dbf92d19de29952603d24a92
Date:	2007-08-09 19:07:28
User:	drh
Comment:	Additional work on the xfer mechanism, trying to increase the use of delta compression.
Timelines:	ancestors | descendants | both | trunk
Other Links:	files | ZIP archive | manifest

• branch=trunk inherited from [a28c83647d]
• sym-trunk inherited from [a28c83647d]

Modified src/xfer.c from [78443669a5] to [0239f4e4fe].

@@ -236,23 +236,47 @@
 
 /*
 ** Send all pending files.
 */
 static int send_all_pending(Blob *pOut){
-  int iRidSent = 0;
+  int rid, xid, i;
+  int nIgot = 0;
   int sent = 0;
   int nSent = 0;
   int maxSize = db_get_int("http-msg-size", 500000);
-  Stmt q;
-
-  db_prepare(&q, "SELECT rid FROM pending ORDER BY rid");
-  while( db_step(&q)==SQLITE_ROW ){
-    int rid = db_column_int(&q, 0);
+  static const char *azQuery[] = {
+      "SELECT srcid FROM delta JOIN pending ON pending.rid=delta.srcid"
+      " WHERE delta.rid=%d"
+      "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=srcid)",
+
+      "SELECT delta.rid FROM delta JOIN pending ON pending.rid=delta.rid"
+      " WHERE srcid=%d"
+      "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=delta.rid)",
+
+      "SELECT pid FROM plink JOIN pending ON rid=pid"
+      " WHERE cid=%d"
+      "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=pid)",
+
+      "SELECT cid FROM plink JOIN pending ON rid=cid"
+      " WHERE pid=%d"
+      "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=cid)",
+
+      "SELECT pid FROM mlink JOIN pending ON rid=pid"
+      " WHERE fid=%d"
+      "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=pid)",
+
+      "SELECT fid FROM mlink JOIN pending ON rid=fid"
+      " WHERE pid=%d"
+      "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=fid)",
+  };
+
+  rid = db_int(0, "SELECT rid FROM pending");
+  while( rid && nIgot<200 ){
+    db_multi_exec("DELETE FROM pending WHERE rid=%d", rid);
     if( sent<maxSize ){
       sent += send_file(rid, pOut);
       nSent++;
-      iRidSent = rid;
     }else{
       char *zUuid = db_text(0,
                       "SELECT uuid FROM blob WHERE rid=%d AND size>=0", rid);
       if( zUuid ){
         if( pOut ){
@@ -259,22 +283,22 @@
           blob_appendf(pOut, "igot %s\n", zUuid);
         }else{
           cgi_printf("igot %s\n", zUuid);
         }
         free(zUuid);
-      }
+        nIgot++;
+      }
+    }
+    xid = 0;
+    for(i=0; xid==0 && i<sizeof(azQuery)/sizeof(azQuery[0]); i++){
+      xid = db_int(0, azQuery[i], rid);
+    }
+    rid = xid;
+    if( rid==0 ){
+      rid = db_int(0, "SELECT rid FROM pending");
     }
   }
-  db_finalize(&q);
-
-  /* Delete the 'pending' records for all files just sent. Otherwise,
-  ** we can wind up sending some files more than once.
-  */
-  if( nSent>0 ){
-    db_multi_exec("DELETE FROM pending WHERE rid <= %d", iRidSent);
-  }
-
   return nSent;
 }
 
 
 /*