first commit

build/node_modules/pngjs/lib/sync-reader.js

@@ -0,0 +1,51 @@
+'use strict';
+
+var SyncReader = module.exports = function(buffer) {
+
+  this._buffer = buffer;
+  this._reads = [];
+};
+
+SyncReader.prototype.read = function(length, callback) {
+
+  this._reads.push({
+    length: Math.abs(length),  // if length < 0 then at most this length
+    allowLess: length < 0,
+    func: callback
+  });
+};
+
+SyncReader.prototype.process = function() {
+
+  // as long as there is any data and read requests
+  while (this._reads.length > 0 && this._buffer.length) {
+
+    var read = this._reads[0];
+
+    if (this._buffer.length && (this._buffer.length >= read.length || read.allowLess)) {
+
+      // ok there is any data so that we can satisfy this request
+      this._reads.shift(); // == read
+
+      var buf = this._buffer;
+
+      this._buffer = buf.slice(read.length);
+
+      read.func.call(this, buf.slice(0, read.length));
+
+    }
+    else {
+      break;
+    }
+
+  }
+
+  if (this._reads.length > 0) {
+    return new Error('There are some read requests waitng on finished stream');
+  }
+
+  if (this._buffer.length > 0) {
+    return new Error('unrecognised content at end of stream');
+  }
+
+};