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Optimize _.assign, _.assignIn, & _.keys.

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John-David Dalton
2016-02-22 21:31:14 -08:00
parent a326a6badf
commit f9a2f74716
1 changed files with 65 additions and 18 deletions
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83
lodash.js
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@@ -14,6 +14,21 @@
/** Used as the semantic version number. */
var VERSION = '4.5.1';
/** Used as the size to enable large array optimizations. */
var LARGE_ARRAY_SIZE = 200;
/** Used as the `TypeError` message for "Functions" methods. */
var FUNC_ERROR_TEXT = 'Expected a function';
/** Used to stand-in for `undefined` hash values. */
var HASH_UNDEFINED = '__lodash_hash_undefined__';
/** Used as the internal argument placeholder. */
var PLACEHOLDER = '__lodash_placeholder__';
/** Used as the size to enable small object optimizations. */
var SMALL_OBJECT_SIZE = 10;
/** Used to compose bitmasks for wrapper metadata. */
var BIND_FLAG = 1,
BIND_KEY_FLAG = 2,
@@ -38,20 +53,11 @@
var HOT_COUNT = 150,
HOT_SPAN = 16;
/** Used as the size to enable large array optimizations. */
var LARGE_ARRAY_SIZE = 200;
/** Used to indicate the type of lazy iteratees. */
var LAZY_FILTER_FLAG = 1,
LAZY_MAP_FLAG = 2,
LAZY_WHILE_FLAG = 3;
/** Used as the `TypeError` message for "Functions" methods. */
var FUNC_ERROR_TEXT = 'Expected a function';
/** Used to stand-in for `undefined` hash values. */
var HASH_UNDEFINED = '__lodash_hash_undefined__';
/** Used as references for various `Number` constants. */
var INFINITY = 1 / 0,
MAX_SAFE_INTEGER = 9007199254740991,
@@ -63,9 +69,6 @@
MAX_ARRAY_INDEX = MAX_ARRAY_LENGTH - 1,
HALF_MAX_ARRAY_LENGTH = MAX_ARRAY_LENGTH >>> 1;
/** Used as the internal argument placeholder. */
var PLACEHOLDER = '__lodash_placeholder__';
/** `Object#toString` result references. */
var argsTag = '[object Arguments]',
arrayTag = '[object Array]',
@@ -1370,6 +1373,12 @@
/** Used to store function metadata. */
var metaMap = WeakMap && new WeakMap;
/** Detect if properties shadowing those on `Object.prototype` are non-enumerable. */
var nonEnumShadows = !({ 'valueOf': 1 }).propertyIsEnumerable('valueOf');
/** Used to lookup unminified function names. */
var realNames = {};
/** Used to detect maps, sets, and weakmaps. */
var mapCtorString = Map ? funcToString.call(Map) : '',
setCtorString = Set ? funcToString.call(Set) : '',
@@ -1380,9 +1389,6 @@
symbolValueOf = Symbol ? symbolProto.valueOf : undefined,
symbolToString = Symbol ? symbolProto.toString : undefined;
/** Used to lookup unminified function names. */
var realNames = {};
/*------------------------------------------------------------------------*/
/**
@@ -2993,7 +2999,28 @@
* @returns {Array} Returns the array of property names.
*/
function baseKeys(object) {
return nativeKeys(Object(object));
object = Object(object);
var count = 0,
resIndex = 0,
result = [];
for (var key in object) {
if (++count > SMALL_OBJECT_SIZE) {
return nativeKeys(object);
}
if (hasOwnProperty.call(object, key)) {
result[resIndex++] = key;
}
}
return result;
}
// Slow path for IE < 9.
if (nonEnumShadows) {
baseKeys = function(object) {
return nativeKeys(Object(object));
};
}
/**
@@ -10836,9 +10863,20 @@
* // => { 'a': 1, 'c': 3, 'e': 5 }
*/
var assign = createAssigner(function(object, source) {
copyObject(source, keys(source), object);
for (var key in source) {
if (hasOwnProperty.call(source, key)) {
assignValue(object, key, source[key]);
}
}
});
// Slow path for IE < 9.
if (nonEnumShadows) {
assign = createAssigner(function(object, source) {
copyObject(source, keys(source), object);
});
}
/**
* This method is like `_.assign` except that it iterates over own and
* inherited source properties.
@@ -10869,9 +10907,18 @@
* // => { 'a': 1, 'b': 2, 'c': 3, 'd': 4, 'e': 5 }
*/
var assignIn = createAssigner(function(object, source) {
copyObject(source, keysIn(source), object);
for (var key in source) {
assignValue(object, key, source[key]);
}
});
// Slow path for IE < 9.
if (nonEnumShadows) {
assignIn = createAssigner(function(object, source) {
copyObject(source, keysIn(source), object);
});
}
/**
* This method is like `_.assignIn` except that it accepts `customizer` which
* is invoked to produce the assigned values. If `customizer` returns `undefined`