protobufjs#66 - BitSet support

src/types/bytes/bitset.js

@@ -0,0 +1,89 @@
+/**
+ * Writes the array as a bitset.
+ * @param {Array<boolean>} value Array of booleans to write
+ * @param {number=} offset Offset to read from. Will use and increase {@link ByteBuffer#offset} by `length` if omitted.
+ * @returns {!ByteBuffer}
+ * @expose
+ */
+ByteBufferPrototype.writeBitSet = function(value, offset) {
+  //? RELATIVE()  
+  if (!this.noAssert) {
+    if (!(value instanceof Array))
+      throw TypeError("Illegal BitSet: Not an array");
+    //? ASSERT_OFFSET();
+  }
+
+  var start = offset,
+      bits = value.length,
+      bytes = (bits >> 3),
+      bit = 0,
+      k;
+
+  offset += this.writeVarint32(bits,offset);
+
+  while(bytes--) {
+    k = (!!value[bit++] & 1) |
+        ((!!value[bit++] & 1) << 1) |
+        ((!!value[bit++] & 1) << 2) |
+        ((!!value[bit++] & 1) << 3) |
+        ((!!value[bit++] & 1) << 4) |
+        ((!!value[bit++] & 1) << 5) |
+        ((!!value[bit++] & 1) << 6) |
+        ((!!value[bit++] & 1) << 7);
+    this.writeByte(k,offset++);
+  }
+
+  if(bit < bits) {
+    var m = 0; k = 0;
+    while(bit < bits) k = k | ((!!value[bit++] & 1) << (m++));
+    this.writeByte(k,offset++);
+  }
+
+  if (relative) {
+    this.offset = offset;
+    return this;
+  }
+  return offset - start;
+}
+
+/**
+ * Reads a BitSet as an array of booleans.
+ * @param {number=} offset Offset to read from. Will use and increase {@link ByteBuffer#offset} by `length` if omitted.
+ * @returns {Array<boolean>
+ * @expose
+ */
+ByteBufferPrototype.readBitSet = function(offset) {
+  //? RELATIVE()  
+
+  var ret = this.readVarint32(offset),
+      bits = ret.value,
+      bytes = (bits >> 3),
+      bit = 0,
+      value = [],
+      k;
+
+  offset += ret.length;
+
+  while(bytes--) {
+    k = this.readByte(offset++);
+    value[bit++] = !!(k & 0x01);
+    value[bit++] = !!(k & 0x02);
+    value[bit++] = !!(k & 0x04);
+    value[bit++] = !!(k & 0x08);
+    value[bit++] = !!(k & 0x10);
+    value[bit++] = !!(k & 0x20);
+    value[bit++] = !!(k & 0x40);
+    value[bit++] = !!(k & 0x80);
+  }
+
+  if(bit < bits) {
+    var m = 0;
+    k = this.readByte(offset++);
+    while(bit < bits) value[bit++] = !!((k >> (m++)) & 1);
+  }
+
+  if (relative) {
+    this.offset = offset;
+  }
+  return value;
+}

tests/suite.js

@@ -633,6 +633,35 @@ function makeSuite(ByteBuffer) {
         };
     });
 
+    suite.types.bitset = function(test) {
+      var bb = new ByteBuffer(2),
+          arr;
+
+      function run(data) {
+        bb.reset();
+        bb.writeBitSet(data);
+        bb.reset();
+        test.deepEqual(bb.readBitSet(),data);
+      };
+
+      run([]);
+      run([true]);
+      run([false]);
+      run([false,true]);
+      run([false,false,false,false,false,false,false,false]);
+      run([true,false,true,false,true,false,true,false]);
+      run([true,true,true,true,true,true,true,true]);
+      run([true,false,true,false,true,false,true,false]);
+      run([true,false,true,false,true,false,true,false,true]);
+
+      bb.reset();
+      bb.writeBitSet([,null,"",0,42,"hello world",new Date(0),{},[]]);
+      bb.reset();
+      test.deepEqual(bb.readBitSet(),[false,false,false,false,true,true,true,true,true]);
+
+      test.done();
+    };
+
     suite.types.calculateVarint = function(test) {
         test.equal(ByteBuffer.MAX_VARINT32_BYTES, 5);
         test.equal(ByteBuffer.MAX_VARINT64_BYTES, 10);
@@ -973,4 +1002,4 @@ module.exports = {
     "node": makeSuite(ByteBufferNode),
     "browser": makeSuite(ByteBufferBrowser),
     "dataview": makeSuite(ByteBufferBrowser_DataView)
-};
+};