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<pre class="prettyprint lang-js"><span id='Ext-data-UuidGenerator'>/**
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</span> * @extend Ext.data.IdGenerator
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* @author Don Griffin
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*
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* This class generates UUID's according to RFC 4122. This class has a default id property.
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* This means that a single instance is shared unless the id property is overridden. Thus,
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* two {@link Ext.data.Model} instances configured like the following share one generator:
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*
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* Ext.define('MyApp.data.MyModelX', {
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* extend: 'Ext.data.Model',
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* idgen: 'uuid'
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* });
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*
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* Ext.define('MyApp.data.MyModelY', {
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* extend: 'Ext.data.Model',
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* idgen: 'uuid'
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* });
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*
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* This allows all models using this class to share a commonly configured instance.
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*
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* # Using Version 1 ("Sequential") UUID's
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*
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* If a server can provide a proper timestamp and a "cryptographic quality random number"
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* (as described in RFC 4122), the shared instance can be configured as follows:
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*
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* Ext.data.IdGenerator.get('uuid').reconfigure({
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* version: 1,
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* clockSeq: clock, // 14 random bits
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* salt: salt, // 48 secure random bits (the Node field)
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* timestamp: ts // timestamp per Section 4.1.4
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* });
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*
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* // or these values can be split into 32-bit chunks:
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*
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* Ext.data.IdGenerator.get('uuid').reconfigure({
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* version: 1,
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* clockSeq: clock,
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* salt: { lo: saltLow32, hi: saltHigh32 },
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* timestamp: { lo: timestampLow32, hi: timestamptHigh32 }
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* });
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*
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* This approach improves the generator's uniqueness by providing a valid timestamp and
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* higher quality random data. Version 1 UUID's should not be used unless this information
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* can be provided by a server and care should be taken to avoid caching of this data.
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*
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* See http://www.ietf.org/rfc/rfc4122.txt for details.
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*/
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Ext.define('Ext.data.UuidGenerator', (function () {
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var twoPow14 = Math.pow(2, 14),
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twoPow16 = Math.pow(2, 16),
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twoPow28 = Math.pow(2, 28),
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twoPow32 = Math.pow(2, 32);
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function toHex (value, length) {
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var ret = value.toString(16);
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if (ret.length > length) {
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ret = ret.substring(ret.length - length); // right-most digits
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} else if (ret.length < length) {
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ret = Ext.String.leftPad(ret, length, '0');
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}
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return ret;
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}
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function rand (lo, hi) {
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var v = Math.random() * (hi - lo + 1);
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return Math.floor(v) + lo;
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}
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function split (bignum) {
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if (typeof(bignum) == 'number') {
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var hi = Math.floor(bignum / twoPow32);
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return {
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lo: Math.floor(bignum - hi * twoPow32),
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hi: hi
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};
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}
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return bignum;
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}
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return {
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extend: 'Ext.data.IdGenerator',
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alias: 'idgen.uuid',
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id: 'uuid', // shared by default
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<span id='Ext-data-UuidGenerator-property-salt'> /**
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</span> * @property {Number/Object} salt
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* When created, this value is a 48-bit number. For computation, this value is split
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* into 32-bit parts and stored in an object with `hi` and `lo` properties.
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*/
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<span id='Ext-data-UuidGenerator-property-timestamp'> /**
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</span> * @property {Number/Object} timestamp
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* When created, this value is a 60-bit number. For computation, this value is split
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* into 32-bit parts and stored in an object with `hi` and `lo` properties.
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*/
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<span id='Ext-data-UuidGenerator-cfg-version'> /**
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</span> * @cfg {Number} version
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* The Version of UUID. Supported values are:
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*
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* * 1 : Time-based, "sequential" UUID.
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* * 4 : Pseudo-random UUID.
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*
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* The default is 4.
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*/
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version: 4,
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constructor: function() {
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var me = this;
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me.callParent(arguments);
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me.parts = [];
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me.init();
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},
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generate: function () {
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var me = this,
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parts = me.parts,
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ts = me.timestamp;
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/*
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The magic decoder ring (derived from RFC 4122 Section 4.2.2):
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| time_low |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| time_mid | ver | time_hi |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|res| clock_hi | clock_low | salt 0 |M| salt 1 |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| salt (2-5) |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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time_mid clock_hi (low 6 bits)
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time_low | time_hi |clock_lo
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| | | || salt[0]
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| | | || | salt[1..5]
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v v v vv v v
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0badf00d-aced-1def-b123-dfad0badbeef
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^ ^ ^
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version | multicast (low bit)
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reserved (upper 2 bits)
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*/
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parts[0] = toHex(ts.lo, 8);
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parts[1] = toHex(ts.hi & 0xFFFF, 4);
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parts[2] = toHex(((ts.hi >>> 16) & 0xFFF) | (me.version << 12), 4);
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parts[3] = toHex(0x80 | ((me.clockSeq >>> 8) & 0x3F), 2) +
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toHex(me.clockSeq & 0xFF, 2);
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parts[4] = toHex(me.salt.hi, 4) + toHex(me.salt.lo, 8);
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if (me.version == 4) {
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me.init(); // just regenerate all the random values...
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} else {
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// sequentially increment the timestamp...
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++ts.lo;
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if (ts.lo >= twoPow32) { // if (overflow)
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ts.lo = 0;
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++ts.hi;
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}
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}
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return parts.join('-').toLowerCase();
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},
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getRecId: function (rec) {
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return rec.getId();
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},
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<span id='Ext-data-UuidGenerator-method-init'> /**
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</span> * @private
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*/
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init: function () {
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var me = this,
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salt, time;
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if (me.version == 4) {
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// See RFC 4122 (Secion 4.4)
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// o If the state was unavailable (e.g., non-existent or corrupted),
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// or the saved node ID is different than the current node ID,
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// generate a random clock sequence value.
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me.clockSeq = rand(0, twoPow14-1);
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// we run this on every id generation...
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salt = me.salt || (me.salt = {});
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time = me.timestamp || (me.timestamp = {});
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// See RFC 4122 (Secion 4.4)
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salt.lo = rand(0, twoPow32-1);
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salt.hi = rand(0, twoPow16-1);
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time.lo = rand(0, twoPow32-1);
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time.hi = rand(0, twoPow28-1);
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} else {
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// this is run only once per-instance
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me.salt = split(me.salt);
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me.timestamp = split(me.timestamp);
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// Set multicast bit: "the least significant bit of the first octet of the
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// node ID" (nodeId = salt for this implementation):
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me.salt.hi |= 0x100;
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}
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},
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<span id='Ext-data-UuidGenerator-method-reconfigure'> /**
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</span> * Reconfigures this generator given new config properties.
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*/
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reconfigure: function (config) {
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Ext.apply(this, config);
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this.init();
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}
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};
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}()));
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</pre>
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