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node_modules/smart-buffer/lib/smart-buffer.js
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var SmartBuffer = (function () { /** * Constructor for SmartBuffer. * @param arg1 {Buffer || Number || String} Buffer to read from, or expected size to write to, or encoding to use. * @param arg2 {String} Encoding to use for writing and reading strings. Defaults to utf8. If encoding is given in arg1, this is ignored. * @constructor * * There are a few ways to construct a SmartBuffer: * * SmartBuffer() - Defaults to utf8, 4096 pre-set internal Buffer length. * SmartBuffer(size) - Defaults to utf8, sets internal Buffer length to the size given. * SmartBuffer(encoding) - Sets the given encoding, defaults to 4096 pre-set internal Buffer length. * SmartBuffer(Buffer) - Defaults to utf8, sets the internal Buffer to the given buffer (same memory). * SmartBuffer(Buffer, encoding) - Sets the given encoding, sets the internal Buffer to the given buffer (same memory). * */ function SmartBuffer(arg1, arg2) { var type; switch (type = typeof arg1) { case 'number': if (isFinite(arg1) && arg1 > 0) { this.buff = new Buffer(Math.ceil(arg1)); this.length = 0; } else { throw new Error('When specifying a size, it must be a valid number above zero.'); } break; case 'string': if (Buffer.isEncoding(arg1)) { this.buff = new Buffer(4096); this.length = 0; this.encoding = arg1; } else { throw new Error('Invalid Encoding'); } break; case 'object': if (Buffer.isBuffer(arg1)) { this.buff = arg1; this.length = arg1.length; } else { throw new TypeError('First argument must be a Buffer, Number representing the size, or a String representing the encoding.'); } break; default: this.buff = new Buffer(4096); this.length = 0; break; } if (typeof this.encoding === 'undefined') { if (typeof arg2 === 'string') { if (Buffer.isEncoding(arg2)) { this.encoding = arg2; } else { throw new Error('Invalid Encoding'); } } } this._readOffset = 0; this._writeOffset = 0; } SmartBuffer.prototype._ensureWritable = function (len, offset) { this._ensureCapacity(this.length + len + (typeof offset === 'number' ? offset : 0)); if (typeof offset === 'number') { this.buff.copy(this.buff, offset + len, offset, this.buff.length); } this.length = Math.max(this.length + len, (typeof offset === 'number' ? offset : 0) + len); }; SmartBuffer.prototype._ensureCapacity = function (minlen) { var oldlen = this.buff.length; if (minlen > oldlen) { var data = this.buff; var newlen = (oldlen * 3) / 2 + 1; if (newlen < minlen) newlen = minlen; this.buff = new Buffer(newlen); data.copy(this.buff, 0, 0, oldlen); } }; var makeReader = function (func, size) { return function () { var ret = func.call(this.buff, this._readOffset); this._readOffset += size; return ret; } }; var makeWriter = function (func, size) { return function (value, offset) { this._ensureWritable(size, offset); func.call(this.buff, value, typeof offset === 'number' ? offset : this._writeOffset); this._writeOffset += size; return this; } }; /* Read Operations */ SmartBuffer.prototype.readInt8 = makeReader(Buffer.prototype.readInt8, 1); SmartBuffer.prototype.readInt16BE = makeReader(Buffer.prototype.readInt16BE, 2); SmartBuffer.prototype.readInt16LE = makeReader(Buffer.prototype.readInt16LE, 2); SmartBuffer.prototype.readInt32BE = makeReader(Buffer.prototype.readInt32BE, 4); SmartBuffer.prototype.readInt32LE = makeReader(Buffer.prototype.readInt32LE, 4); SmartBuffer.prototype.readUInt8 = makeReader(Buffer.prototype.readUInt8, 1); SmartBuffer.prototype.readUInt16BE = makeReader(Buffer.prototype.readUInt16BE, 2); SmartBuffer.prototype.readUInt16LE = makeReader(Buffer.prototype.readUInt16LE, 2); SmartBuffer.prototype.readUInt32BE = makeReader(Buffer.prototype.readUInt32BE, 4); SmartBuffer.prototype.readUInt32LE = makeReader(Buffer.prototype.readUInt32LE, 4); SmartBuffer.prototype.readFloatBE = makeReader(Buffer.prototype.readFloatBE, 4); SmartBuffer.prototype.readFloatLE = makeReader(Buffer.prototype.readFloatLE, 4); SmartBuffer.prototype.readDoubleBE = makeReader(Buffer.prototype.readDoubleBE, 8); SmartBuffer.prototype.readDoubleLE = makeReader(Buffer.prototype.readDoubleLE, 8); /** * Reads a string of the given length. * @param length {Number} The length of the string to read. (Defaults to the length of the remaining data) * @param encoding {String} The encoding to use. (Defaults to encoding set in constructor, or utf8) * @returns {string} The string. */ SmartBuffer.prototype.readString = function (length, encoding) { var len = Math.min(length, this.length - this._readOffset) || (this.length - this._readOffset); var ret = this.buff.slice(this._readOffset, this._readOffset + len).toString(encoding || this.encoding); this._readOffset += len; return ret; }; /** * Reads a null terminated string from the underlying buffer. * @param encoding {String} Encoding to use. Defaults to encoding set in constructor, or utf8. * @returns {string} */ SmartBuffer.prototype.readStringNT = function (encoding) { var nullpos = this.length; for (var i = this._readOffset; i < this.length; i++) { if (this.buff[i] == 0x00) { nullpos = i; break; } } var result = this.buff.slice(this._readOffset, nullpos); this._readOffset = nullpos + 1; return result.toString(encoding || this.encoding); }; /** * Reads a specified number of bytes. * @param len {Number} Numbers of bytes to read. (Defaults to the remaining data length) * @returns {Buffer} Buffer containing the read bytes. */ SmartBuffer.prototype.readBuffer = function (len) { var endpoint = Math.min(this.length, this._readOffset + (typeof len === 'number' ? len : this.length)); var ret = this.buff.slice(this._readOffset, endpoint); this._readOffset = endpoint; return ret; }; /** * Reads a null terminated sequence of bytes from the underlying buffer. * @returns {Buffer} Buffer containing the read bytes. */ SmartBuffer.prototype.readBufferNT = function () { var nullpos = this.length; for (var i = this._readOffset; i < this.length; i++) { if (this.buff[i] == 0x00) { nullpos = i; break; } } var ret = this.buff.slice(this._readOffset, nullpos); this._readOffset = nullpos + 1; return ret; }; /* Write Operations */ SmartBuffer.prototype.writeInt8 = makeWriter(Buffer.prototype.writeInt8, 1); SmartBuffer.prototype.writeInt16BE = makeWriter(Buffer.prototype.writeInt16BE, 2); SmartBuffer.prototype.writeInt16LE = makeWriter(Buffer.prototype.writeInt16LE, 2); SmartBuffer.prototype.writeInt32BE = makeWriter(Buffer.prototype.writeInt32BE, 4); SmartBuffer.prototype.writeInt32LE = makeWriter(Buffer.prototype.writeInt32LE, 4); SmartBuffer.prototype.writeUInt8 = makeWriter(Buffer.prototype.writeUInt8, 1); SmartBuffer.prototype.writeUInt16BE = makeWriter(Buffer.prototype.writeUInt16BE, 2); SmartBuffer.prototype.writeUInt16LE = makeWriter(Buffer.prototype.writeUInt16LE, 2); SmartBuffer.prototype.writeUInt32BE = makeWriter(Buffer.prototype.writeUInt32BE, 4); SmartBuffer.prototype.writeUInt32LE = makeWriter(Buffer.prototype.writeUInt32LE, 4); SmartBuffer.prototype.writeFloatBE = makeWriter(Buffer.prototype.writeFloatBE, 4); SmartBuffer.prototype.writeFloatLE = makeWriter(Buffer.prototype.writeFloatLE, 4); SmartBuffer.prototype.writeDoubleBE = makeWriter(Buffer.prototype.writeDoubleBE, 8); SmartBuffer.prototype.writeDoubleLE = makeWriter(Buffer.prototype.writeDoubleLE, 8); /** * Writes a string to the underlying buffer. * @param value {String} The string to write. * @param offset {Number} The offset to write the string to. (Encoding can also be set here in place of offset) * @param encoding {String} The encoding to use. (Defaults to encoding set in constructor, or to utf8) * @returns {*} */ SmartBuffer.prototype.writeString = function (value, offset, encoding) { var len, _offset, type = typeof offset; if (type === 'number') { _offset = offset; } else if (type === 'string') { encoding = offset; offset = this._writeOffset; } else { encoding = undefined; offset = this._writeOffset; } len = Buffer.byteLength(value, encoding || this.encoding); this._ensureWritable(len, _offset); this.buff.write(value, offset, len, encoding || this.encoding); this._writeOffset += len; return this; }; /** * Writes a null terminated string to the underlying buffer. * @param value {String} The string to write. * @param offset {Number} The offset to write the string to. (Encoding can also be set here in place of offset) * @param encoding {String} The encoding to use. (Defaults to encoding set in constructor, or to utf8) * @returns {*} */ SmartBuffer.prototype.writeStringNT = function (value, offset, encoding) { this.writeString(value, offset, encoding); this.writeUInt8(0x00, (typeof offset === 'number' ? offset + value.length : this._writeOffset)); return this; }; /** * Writes a Buffer to the underlying buffer. * @param value {Buffer} The buffer to write. * @param offset {Number} The offset to write the Buffer to. * @returns {*} */ SmartBuffer.prototype.writeBuffer = function (value, offset) { var len = value.length; this._ensureWritable(len, offset); value.copy(this.buff, typeof offset === 'number' ? offset : this._writeOffset); this._writeOffset += len; return this; }; /** * Writes a null terminated Buffer to the underlying buffer. * @param value {Buffer} The buffer to write. * @param offset {Number} The offset to write the Buffer to. * @returns {*} */ SmartBuffer.prototype.writeBufferNT = function (value, offset) { this.writeBuffer(value, offset); this.writeUInt8(0x00, (typeof offset === 'number' ? offset + value.length : this._writeOffset)); return this; }; /** * Resets the Endless Buffer. */ SmartBuffer.prototype.clear = function () { this._writeOffset = 0; this._readOffset = 0; this.length = 0; }; /** * Gets the remaining number of bytes to be read from the existing Buffer. * @returns {number} The number of bytes remaining. */ SmartBuffer.prototype.remaining = function () { return this.length - this._readOffset; }; /** * Skips the read position forward by the amount of given. * @param amount {Number} The amount of bytes to skip forward. */ SmartBuffer.prototype.skip = function (amount) { if (this._readOffset + amount > this.length) throw new Error('Target position is beyond the bounds of the data.'); this._readOffset += amount; }; /** * Rewinds the read position backward by the amount given. * @param amount {Number} The amount of bytes to reverse backward. */ SmartBuffer.prototype.rewind = function (amount) { if (this._readOffset - amount < 0) throw new Error('Target position is beyond the bounds of the data.'); this._readOffset -= amount; }; /** * Skips the read position to the given position. * @param position {Number} The position to skip to. */ SmartBuffer.prototype.skipTo = function (position) { if (position < 0 || position > this.length) throw new Error('Target position is beyond the bounds of the data.'); this._readOffset = position; }; /** * Gets the underlying Buffer. * @returns {*} */ SmartBuffer.prototype.toBuffer = function () { return this.buff.slice(0, this.length); }; /** * Gets a string representation of the underlying Buffer. * @param encoding {String} Encoding to use. (Defaults to encoding set in constructor, or utf8.) * @returns {*} */ SmartBuffer.prototype.toString = function (encoding) { return this.buff.toString(encoding || this.encoding, 0, this.length); }; /** * Destroys the underlying Buffer, and resets the SmartBuffer. */ SmartBuffer.prototype.destroy = function () { delete this.buff; this.clear(); }; return SmartBuffer; })(); module.exports = SmartBuffer; |