first commit

2023-05-19 00:42:48 +08:00
commit 53de9c6c51
243 changed files with 39485 additions and 0 deletions
@@ -0,0 +1,166 @@
+'use strict';
+
+function ArrayBufferSer(type, data, options) {
+  if(type === undefined) {
+      throw "ArrayBufferSer should be created with a type";
+  }
+  this.options = options || {};
+  this._initFunctions();
+  this.headerSize = 8;
+  this.data = data;
+  this.type = type = Math.min(type, ArrayBufferSer.BUFFER);
+  var size = this._sizeFor(this.headerSize, data);
+  this.buffer = new Buffer(this.headerSize + size);
+  this.buffer.writeUInt32BE(type, 0); // this could be one byte but for byte padding is better to be 4 bytes
+  this.buffer.writeUInt32BE(size, 4);
+  this.offset = this.headerSize;
+
+  var w = this.writeFn[type];
+
+  var i;
+  if(!this.options.delta) {
+    for(i = 0; i < data.length; ++i) {
+      this[w](data[i]);
+    }
+  } else {
+    this[w](data[0]);
+    for(i = 1; i < data.length; ++i) {
+      this[w](data[i] - data[i - 1]);
+    }
+  }
+}
+
+//
+// constants
+//
+ArrayBufferSer.INT8 = 1;
+ArrayBufferSer.UINT8 = 2;
+ArrayBufferSer.UINT8_CLAMP = 3;
+ArrayBufferSer.INT16 = 4;
+ArrayBufferSer.UINT16 = 5;
+ArrayBufferSer.INT32 = 6;
+ArrayBufferSer.UINT32 = 7;
+ArrayBufferSer.FLOAT32 = 8;
+//ArrayBufferSer.FLOAT64 = 9; not supported
+ArrayBufferSer.STRING = 10;
+ArrayBufferSer.BUFFER = 11;
+
+ArrayBufferSer.MAX_PADDING = ArrayBufferSer.INT32;
+
+
+ArrayBufferSer.typeNames = {
+  'int8': ArrayBufferSer.INT8,
+  'uint8': ArrayBufferSer.UINT8,
+  'uintclamp': ArrayBufferSer.UINT8_CLAMP,
+  'int16': ArrayBufferSer.INT16,
+  'uint16': ArrayBufferSer.UINT16,
+  'int32': ArrayBufferSer.INT32,
+  'uint32': ArrayBufferSer.UINT32,
+  'float32': ArrayBufferSer.FLOAT32,
+  'string': ArrayBufferSer.STRING,
+  'buffer': ArrayBufferSer.BUFFER
+};
+
+ArrayBufferSer.prototype = {
+
+  // 0 not used
+  sizes: [NaN, 1, 1, 1, 2, 2, 4, 4, 4, 8],
+
+  _paddingFor: function(off, type) {
+    var s = this.sizes[type];
+    if(s) {
+      var r = off % s;
+      return r === 0 ? 0 : s - r;
+    }
+    return 0;
+  },
+
+  _sizeFor: function(offset, t) {
+    var self = this;
+    var s = this.sizes[this.type];
+    if(s) {
+      return s*t.length;
+    }
+    s = 0;
+    if(this.type === ArrayBufferSer.STRING) {
+      // calculate size with padding
+      t.forEach(function(arr) {
+        var pad = self._paddingFor(offset, ArrayBufferSer.MAX_PADDING);
+        s += pad;
+        offset += pad;
+        var len = (self.headerSize + arr.length*2);
+        s += len;
+        offset += len;
+      });
+    } else {
+      t.forEach(function(arr) {
+        var pad = self._paddingFor(offset, ArrayBufferSer.MAX_PADDING);
+        s += pad;
+        offset += pad;
+        s += arr.getSize();
+        offset += arr.getSize();
+      });
+    }
+    return s;
+  },
+
+  getDataSize: function() {
+    return this._sizeFor(0, this.data);
+  },
+
+  getSize: function() {
+    return this.headerSize + this._sizeFor(this.headerSize, this.data);
+  },
+
+  writeFn: [
+      '',
+      'writeInt8',
+      'writeUInt8',
+      'writeUInt8Clamp',
+      'writeInt16LE',
+      'writeUInt16LE',
+      'writeUInt32LE',
+      'writeUInt32LE',
+      'writeFloatLE',
+      'writeDoubleLE',
+      'writeString',
+      'writteBuffer'
+  ],
+
+  _initFunctions: function() {
+    var self = this;
+    this.writeFn.forEach(function(fn) {
+      if(self[fn] === undefined) {
+        self[fn] = function(d) {
+          self.buffer[fn](d, self.offset);
+          self.offset += self.sizes[self.type];
+        };
+      }
+    });
+  },
+
+  writeUInt8Clamp: function(c) {
+    this.buffer.writeUInt8(Math.min(255, c), this.offset);
+    this.offset += 1;
+  },
+
+  writeString: function(s) {
+    var arr = [];
+    for(var i = 0, len = s.length; i < len; ++i) {
+      arr.push(s.charCodeAt(i));
+    }
+    var str = new ArrayBufferSer(ArrayBufferSer.UINT16, arr);
+    this.writteBuffer(str);
+  },
+
+  writteBuffer: function(b) {
+    this.offset += this._paddingFor(this.offset, ArrayBufferSer.MAX_PADDING);
+    // copy header
+    b.buffer.copy(this.buffer, this.offset);
+    this.offset += b.buffer.length;
+  }
+
+};
+
+
+module.exports = ArrayBufferSer;