Fix issue 420: accept truncated log files.

http://code.google.com/p/v8/issues/detail?id=420

Review URL: http://codereview.chromium.org/171038

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2695 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/mjsunit/mjsunit.js

@@ -179,9 +179,13 @@ function assertInstanceof(obj, type) {
 
 function assertDoesNotThrow(code) {
   try {
-    eval(code);
+    if (typeof code == 'function') {
+      code();
+    } else {
+      eval(code);
+    }
   } catch (e) {
-    assertTrue(false, "threw an exception");
+    assertTrue(false, "threw an exception: " + (e.message || e));
   }
 }
 

test/mjsunit/tools/logreader.js

@@ -80,3 +80,19 @@
   assertEquals('bbbbaaaa', reader.expandBackRef_('bbbb#2:4'));
   assertEquals('"#1:1"', reader.expandBackRef_('"#1:1"'));
 })();
+
+
+// See http://code.google.com/p/v8/issues/detail?id=420
+(function testReadingTruncatedLog() {
+  // Having an incorrect event in the middle of a log should throw an exception.
+  var reader1 = new devtools.profiler.LogReader({});
+  assertThrows(function() {
+    reader1.processLogChunk('alias,a,b\nxxxx\nalias,c,d\n');
+  });
+
+  // But having it as the last record should not.
+  var reader2 = new devtools.profiler.LogReader({});
+  assertDoesNotThrow(function() {
+    reader2.processLogChunk('alias,a,b\nalias,c,d\nxxxx');
+  });
+})();

tools/logreader.js

@@ -294,8 +294,11 @@ devtools.profiler.LogReader.prototype.processLog_ = function(lines) {
       this.dispatchLogRow_(fields);
     }
   } catch (e) {
-    this.printError('line ' + (i + 1) + ': ' + (e.message || e));
-    throw e;
+    // An error on the last line is acceptable since log file can be truncated.
+    if (i < n - 1) {
+      this.printError('line ' + (i + 1) + ': ' + (e.message || e));
+      throw e;
+    }
   }
 };