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reader.js
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reader.js
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/**
* @module BufferStreamReader
*/
var stream = require('stream');
/**
* Create a new stream reader
*
* @param data
* @param options
* @returns {StringReader}
*
* @constructor
*/
function BufferStreamReader (data, options) {
if (!(this instanceof BufferStreamReader)) {
return new BufferStreamReader(data);
}
if (!options) {
options = {};
}
stream.Readable.call(this, options);
this._data = null;
this._chunkSize = options.chunkSize || -1;
if (typeof data === 'string') {
this._data = new Buffer(data, options.encoding || 'utf8');
} else if (Buffer.isBuffer(data)) {
this._data = data;
}
}
/**
* Derive from stream.Readable prototype
*/
BufferStreamReader.prototype = Object.create(stream.Readable.prototype, {
constructor: { value: BufferStreamReader }
});
/**
* Implement _read
*
* @param size
* @private
*/
BufferStreamReader.prototype._read = function _read (size) {
if (!this._data) {
return this.push(null);
}
var canRead = true;
var data = this._data;
var bytesToRead = data.length;
var chunkSize = this._chunkSize > 0 ? this._chunkSize : size;
while (canRead) {
var read = Math.min(chunkSize, bytesToRead);
var buf = data.slice(0, read);
this.push(buf);
bytesToRead -= read;
if (bytesToRead <= 0) {
canRead = false;
delete data;
return this.push(null);
}
data = data.slice(read, data.length);
}
};
module.exports = BufferStreamReader;