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var baseSetData = require('./baseSetData'),
now = require('../date/now');
/** Used to detect when a function becomes hot. */
var HOT_COUNT = 150,
HOT_SPAN = 16;
/**
* Sets metadata for `func`.
*
* **Note:** If this function becomes hot, i.e. is invoked a lot in a short
* period of time, it will trip its breaker and transition to an identity function
* to avoid garbage collection pauses in V8. See [V8 issue 2070](https://code.google.com/p/v8/issues/detail?id=2070)
* for more details.
*
* @private
* @param {Function} func The function to associate metadata with.
* @param {*} data The metadata.
* @returns {Function} Returns `func`.
*/
var setData = (function() {
var count = 0,
lastCalled = 0;
return function(key, value) {
var stamp = now(),
remaining = HOT_SPAN - (stamp - lastCalled);
lastCalled = stamp;
if (remaining > 0) {
if (++count >= HOT_COUNT) {
return key;
}
} else {
count = 0;
}
return baseSetData(key, value);
};
}());
module.exports = setData;
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