changeset 174:dc12ba30d559

Fix further crashes when following dgamelaunch games. The crashes apparently resulted from reading a ttyrec header and then trying to read the data chunk before dgamelaunch produced it. When the data chunk did become available, it would be read by the header function. The simplest solution was to store the position for reading the ttyrec file in the DGLSession, and to leave it unchanged if anything unexpected occurs when reading.
author John "Elwin" Edwards
date Mon, 12 Jan 2015 17:10:35 +0000
parents 60605bacde36
children 4dd87508fc96
files rlgwebd.js
diffstat 1 files changed, 17 insertions(+), 4 deletions(-) [+]
line wrap: on
line diff
--- a/rlgwebd.js	Sun Jan 11 07:41:36 2015 -0500
+++ b/rlgwebd.js	Mon Jan 12 17:10:35 2015 +0000
@@ -258,6 +258,7 @@
   /* Flag to prevent multiple handlers from reading simultaneously and
    * getting into a race. */
   this.reading = false;
+  this.rpos = 0;
   this.framebuf = new Buffer(1024);
   this.frameoff = 0;
   this.framepush = function(chunk) {
@@ -286,24 +287,36 @@
       return;
     this.reading = true;
     var header = new Buffer(12);
-    fs.read(ss.fd, header, 0, 12, null, function (err, n, buf) {
+    fs.read(ss.fd, header, 0, 12, ss.rpos, function (err, n, buf) {
       /* Stop recursion if end of file has been reached. */
       if (err || n < 12) {
+        if (!err && n > 0) {
+          tslog("DGL %s: expected 12-byte header, got %d", ss.tag(), n);
+        }
         ss.reading = false;
         return;
       }
+      ss.rpos += 12;
       var datalen = buf.readUInt32LE(8);
       //tslog("Allocating %d bytes", datalen);
+      if (datalen > 16384) {
+        tslog("DGL %s: looking for %d bytes", ss.tag(), datalen);
+      }
       var databuf = new Buffer(datalen);
-      fs.read(ss.fd, databuf, 0, datalen, null, function (err, n, buf) {
-        ss.reading = false;
+      fs.read(ss.fd, databuf, 0, datalen, ss.rpos, function (err, n, buf) {
         if (err || n < datalen) {
+          /* Next time, read the header again. */
+          ss.rpos -= 12;
+          ss.reading = false;
+          tslog("DGL %s: expected %d bytes, got %d", ss.tag(), datalen, n);
           return;
         }
+        ss.rpos += n;
+        ss.reading = false;
         /* Process the data */
         ss.framepush(buf);
         ss.emit("data", buf);
-        tslog("DGL %s: %d bytes", ss.tag(), buf.length);
+        //tslog("DGL %s: %d bytes", ss.tag(), buf.length);
         /* Recurse. */
         ss.readchunk();
       });