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shrine-medco/shrine-webclient/src/main/html/node_modules/base64id/lib/base64id.js
23de2099ce18release/1.22.2.4

base64id.js
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			/*!
			* base64id v0.1.0
			*/

			/**
			* Module dependencies
			*/

			var crypto = require('crypto');

			/**
			* Constructor
			*/

			var Base64Id = function() { };

			/**
			* Get random bytes
			*
			* Uses a buffer if available, falls back to crypto.randomBytes
			*/

			Base64Id.prototype.getRandomBytes = function(bytes) {

			var BUFFER_SIZE = 4096
			var self = this;

			bytes = bytes \|\| 12;

			if (bytes > BUFFER_SIZE) {
			return crypto.randomBytes(bytes);
			}

			var bytesInBuffer = parseInt(BUFFER_SIZE/bytes);
			var threshold = parseInt(bytesInBuffer*0.85);

			if (!threshold) {
			return crypto.randomBytes(bytes);
			}

			if (this.bytesBufferIndex == null) {
			this.bytesBufferIndex = -1;
			}

			if (this.bytesBufferIndex == bytesInBuffer) {
			this.bytesBuffer = null;
			this.bytesBufferIndex = -1;
			}

			// No buffered bytes available or index above threshold
			if (this.bytesBufferIndex == -1 \|\| this.bytesBufferIndex > threshold) {

			if (!this.isGeneratingBytes) {
			this.isGeneratingBytes = true;
			crypto.randomBytes(BUFFER_SIZE, function(err, bytes) {
			self.bytesBuffer = bytes;
			self.bytesBufferIndex = 0;
			self.isGeneratingBytes = false;
			});
			}

			// Fall back to sync call when no buffered bytes are available
			if (this.bytesBufferIndex == -1) {
			return crypto.randomBytes(bytes);
			}
			}

			var result = this.bytesBuffer.slice(bytesthis.bytesBufferIndex, bytes(this.bytesBufferIndex+1));
			this.bytesBufferIndex++;

			return result;
			}

			/**
			* Generates a base64 id
			*
			* (Original version from socket.io <http://socket.io>)
			*/

			Base64Id.prototype.generateId = function () {
			var rand = new Buffer(15); // multiple of 3 for base64
			if (!rand.writeInt32BE) {
			return Math.abs(Math.random() * Math.random() * Date.now() \| 0).toString()
			+ Math.abs(Math.random() * Math.random() * Date.now() \| 0).toString();
			}
			this.sequenceNumber = (this.sequenceNumber + 1) \| 0;
			rand.writeInt32BE(this.sequenceNumber, 11);
			if (crypto.randomBytes) {
			this.getRandomBytes(12).copy(rand);
			} else {
			// not secure for node 0.4
			[0, 4, 8].forEach(function(i) {
			rand.writeInt32BE(Math.random() * Math.pow(2, 32) \| 0, i);
			});
			}
			return rand.toString('base64').replace(/\//g, '_').replace(/\+/g, '-');
			};

			/**
			* Export
			*/

			exports = module.exports = new Base64Id();