90 lines
1.9 KiB
JavaScript
90 lines
1.9 KiB
JavaScript
var Writer = function(size) {
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this.size = size || 1024;
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this.buffer = new Buffer(this.size);
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this.offset = 0;
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};
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var p = Writer.prototype;
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p._remaining = function() {
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return this.buffer.length - this.offset;
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}
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//resizes internal buffer if not enough size left
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p._ensure = function(size) {
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if(this._remaining() < size) {
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var oldBuffer = this.buffer;
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this.buffer = Buffer(oldBuffer.length + size);
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oldBuffer.copy(this.buffer);
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}
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}
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p.addInt32 = function(num) {
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this._ensure(4)
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this.buffer[this.offset++] = (num >>> 24 & 0xFF)
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this.buffer[this.offset++] = (num >>> 16 & 0xFF)
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this.buffer[this.offset++] = (num >>> 8 & 0xFF)
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this.buffer[this.offset++] = (num >>> 0 & 0xFF)
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return this;
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}
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p.addInt16 = function(num) {
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this._ensure(2)
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this.buffer[this.offset++] = (num >>> 8 & 0xFF)
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this.buffer[this.offset++] = (num >>> 0 & 0xFF)
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return this;
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}
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p.addCString = function(string) {
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var string = string || "";
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var len = Buffer.byteLength(string) + 1;
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this._ensure(len);
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this.buffer.write(string, this.offset);
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this.offset += len;
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this.buffer[this.offset] = 0; //add null terminator
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return this;
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}
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p.addChar = function(char) {
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this._ensure(1);
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this.buffer.write(char, this.offset);
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this.offset++;
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return this;
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}
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p.join = function() {
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return this.buffer.slice(0, this.offset);
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}
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p.addString = function(string) {
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var string = string || "";
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var len = Buffer.byteLength(string);
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this._ensure(len);
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this.buffer.write(string, this.offset);
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this.offset += len;
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return this;
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}
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p.getByteLength = function() {
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return this.offset;
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}
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p.add = function(otherBuffer) {
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this._ensure(otherBuffer.length);
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otherBuffer.copy(this.buffer, this.offset);
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this.offset += otherBuffer.length;
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return this;
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}
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p.clear = function() {
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this.offset=0;
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}
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p.flush = function() {
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var result = this.join();
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this.clear();
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return result;
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}
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module.exports = Writer;
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