Merge pull request #86 from colinmutter/fix/range-error

Fix for range error when attempting to read from buffer
nlf · Oct 28, 2014 · e1892b7 · e1892b7
2 parents 72c6e44 + d3a577f
commit e1892b7
Showing 1 changed file with 30 additions and 9 deletions.
diff --git a/lib/connection.js b/lib/connection.js
@@ -121,23 +121,44 @@ ConnectionManager.prototype._receive = function (data) {
 
     var length;
 
-    if (this.readBufPos) {
-        // Manually disable coverage here. This is known to cause an issue
-        // in some cases, but has been unreproducable with a test.
-        /* $lab:coverage:off$ */
-        if (this.readBuf.length < this.readBufPos + data.length) {
-            this._growReadBuffer(this.readBufPos + data.length);   
-        }
-        /* $lab:coverage:on$ */
+    // Make sure we can accomodate the incoming data
+    // Manually disable coverage here. This is known to cause an issue
+    // in some cases, but has been unreproducable with a test.
+    /* $lab:coverage:off$ */
+    if (this.readBuf.length < this.readBufPos + data.length) {
+        this._growReadBuffer(this.readBufPos + data.length);
+    }
+    /* $lab:coverage:on$ */
 
+    // If we have data in the read buffer already, append and
+    // replace this `data` with the entirety of the buffer
+    if (this.readBufPos) {
         data.copy(this.readBuf, this.readBufPos);
         this.readBufPos += data.length;
         data = this.readBuf.slice(0, this.readBufPos);
     }
 
+    // If we don't have enough data to even constitute the `length` bit from the
+    // protocol, we're going to have to wait for more data
+    /* $lab:coverage:off$ */
+    if (data.length < 4) {
+        // Accomodate in read buffer
+        this._growReadBuffer(this.readBufPos + data.length);
+        data.copy(this.readBuf, this.readBufPos);
+        this.readBufPos += data.length;
+        // Wait for the rest of the message...
+        return;
+    }
+    /* $lab:coverage:on$ */
+
+    // Read the protocol `message length`
     length = data.readInt32BE(0);
 
+    // If the current read buffer has less data
+    // than the protocol message *should* have, copy and wait for more
     if (data.length < 4 + length) {
+        // If the buffer read position is > 0,
+        // then we have already appended it above.
         if (this.readBufPos === 0) {
             this._growReadBuffer(4 + length);
             data.copy(this.readBuf);
@@ -249,4 +270,4 @@ ConnectionManager.prototype.makeRequest = function (options, callback) {
     this._processNext(callback);
 };
 
-module.exports = ConnectionManager;
+module.exports = ConnectionManager;