Merge pull request #7 from oskarhane/decode-combined-buffer

jakewins · jakewins · commit fd853a7df52a · 2015-10-27T09:28:39.000-05:00
Decode combined buffer
diff --git a/gulpfile.js b/gulpfile.js
@@ -79,8 +79,6 @@ gulp.task('build-browser-test', function(){
         })
         .on('error', gutil.log)
         .pipe(source('neo4j-web.test.js'))
-        .pipe(buffer())
-        .pipe(uglify())
         .pipe(gulp.dest(browserOutput))
     },
     function(cb) {
diff --git a/lib/internal/utf8.js b/lib/internal/utf8.js
@@ -21,12 +21,14 @@
 // with the Buffer API defined in buf.js
 
 import buf from "./buf";
+import {StringDecoder} from 'string_decoder';
 let platformObj = {};
 
+
 try {
   // This will throw an exception is 'buffer' is not available
   require.resolve("buffer");
-
+  let decoder = new StringDecoder('utf8');
   let node = require("buffer");
 
   platformObj = {
@@ -39,7 +41,17 @@ try {
             end = start + length;
         buffer.position = end;
         return buffer._buffer.toString( 'utf8', start, end );
-      } else {
+      } 
+      else if( buffer instanceof buf.CombinedBuffer ) {
+        let out = streamDecodeCombinedBuffer(buffer._buffers, length,
+          (partBuffer) => {
+            return decoder.write(partBuffer._buffer);
+          },
+          () => { return decoder.end(); }
+        );
+        return out;
+      } 
+      else {
         throw new Error( "Don't know how to decode strings from `" + buffer + "`.");
       }
     }
@@ -59,11 +71,40 @@ try {
     "decode" : function( buffer, length ) {
       if( buffer instanceof buf.HeapBuffer ) {
         return decoder.decode( buffer.readView( length ) );
-      } else {
+      }
+      else if( buffer instanceof buf.CombinedBuffer ) {
+        let out = streamDecodeCombinedBuffer(buffer._buffers, length,
+          (partBuffer) => {
+            return decoder.decode(partBuffer.readView(partBuffer.length), {stream:true});
+          },
+          () => { return decoder.decode(); }
+        );
+        return out;
+      } 
+      else {
         throw new Error( "Don't know how to decode strings from `" + buffer + "`.");
       }
     }
   }
 }
 
+let streamDecodeCombinedBuffer = (combinedBuffers, length, decodeFn, endFn) => {
+  let remainingBytesToRead = length;
+  // Reduce CombinedBuffers to a decoded string
+  let out = combinedBuffers.reduce(function(last, partBuffer){
+    if(remainingBytesToRead <= 0) {
+      return last;
+    }
+    if(partBuffer.length > remainingBytesToRead) { // When we don't want the whole buffer
+      let lastSlice = partBuffer.readSlice(remainingBytesToRead);
+      partBuffer._updatePos(remainingBytesToRead);
+      remainingBytesToRead = 0;
+      return last + decodeFn(lastSlice);
+    }
+    remainingBytesToRead -= partBuffer.length;
+    return last + decodeFn(partBuffer);
+  }, '');
+  return out + endFn();
+}
+
 export default platformObj;
diff --git a/test/browser/testrunner-phantomjs.html b/test/browser/testrunner-phantomjs.html
@@ -1,6 +1,7 @@
 <!DOCTYPE html>
 <html>
 <head>
+  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
   <title>Jasmine Test Runner</title>
 
   <link rel="shortcut icon" type="image/png" href="jasmine/lib/jasmine-2.0.3/jasmine_favicon.png">
diff --git a/test/internal/utf8.test.js b/test/internal/utf8.test.js
@@ -1,5 +1,6 @@
 
 var utf8 = require('../../build/node/internal/utf8');
+var buffers = require('../../build/node/internal/buf');
 
 describe('utf8', function() {
   it('should have a nice clean buffer position after serializing', function() {
@@ -14,6 +15,40 @@ describe('utf8', function() {
     expect( packAndUnpack( "" ) ).toBe( "" );
     expect( packAndUnpack( "åäö123" ) ).toBe( "åäö123"  );
   });
+
+  it('should decode utf8 from a complete combined buffer', function() {
+    // Given
+    var msg = "asåfqwer";
+    var buf = utf8.encode(msg);
+    var bufa = buf.readSlice(3);
+    var bufb = buf.readSlice(3);
+    var bufc = buf.readSlice(3);
+    var combined = new buffers.CombinedBuffer( [bufa, bufb, bufc] );
+
+    // When
+    var decoded = utf8.decode(combined, combined.length);
+
+    // Then
+    expect(decoded).toBe(msg);
+  });
+
+  it('should decode utf8 from part of a combined buffer', function() {
+    // Given
+    var msg = "asåfq";
+    var expectMsg = msg.substring(0, msg.length-1);
+    var buf = utf8.encode(msg);
+    var bufa = buf.readSlice(3);
+    var bufb = buf.readSlice(3);
+    var unrelatedData = buffers.alloc(3);
+    var combined = new buffers.CombinedBuffer( [bufa, bufb, unrelatedData] );
+
+    // When 
+    // We read all but the unrelatedData and the last character of bufb
+    var decoded = utf8.decode(combined, combined.length - 1 - unrelatedData.length );
+
+    // Then
+    expect(decoded).toBe(expectMsg);
+  });
 });
 
 function packAndUnpack( str ) {
