main.resources.js.hashtable.js Maven / Gradle / Ivy
/**
* @license jahashtable, a JavaScript implementation of a hash table. It creates a single constructor function called
* Hashtable in the global scope.
*
* http://www.timdown.co.uk/jshashtable/
* Copyright %%build:year%% Tim Down.
* Version: %%build:version%%
* Build date: %%build:date%%
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
var Hashtable = (function(UNDEFINED) {
var FUNCTION = "function", STRING = "string", UNDEF = "undefined";
// Require Array.prototype.splice, Object.prototype.hasOwnProperty and encodeURIComponent. In environments not
// having these (e.g. IE <= 5), we bail out now and leave Hashtable null.
if (typeof encodeURIComponent == UNDEF ||
Array.prototype.splice === UNDEFINED ||
Object.prototype.hasOwnProperty === UNDEFINED) {
return null;
}
function toStr(obj) {
return (typeof obj == STRING) ? obj : "" + obj;
}
function hashObject(obj) {
var hashCode;
if (typeof obj == STRING) {
return obj;
} else if (typeof obj.hashCode == FUNCTION) {
// Check the hashCode method really has returned a string
hashCode = obj.hashCode();
return (typeof hashCode == STRING) ? hashCode : hashObject(hashCode);
} else {
return toStr(obj);
}
}
function merge(o1, o2) {
for (var i in o2) {
if (o2.hasOwnProperty(i)) {
o1[i] = o2[i];
}
}
}
function equals_fixedValueHasEquals(fixedValue, variableValue) {
return fixedValue.equals(variableValue);
}
function equals_fixedValueNoEquals(fixedValue, variableValue) {
return (typeof variableValue.equals == FUNCTION) ?
variableValue.equals(fixedValue) : (fixedValue === variableValue);
}
function createKeyValCheck(kvStr) {
return function(kv) {
if (kv === null) {
throw new Error("null is not a valid " + kvStr);
} else if (kv === UNDEFINED) {
throw new Error(kvStr + " must not be undefined");
}
};
}
var checkKey = createKeyValCheck("key"), checkValue = createKeyValCheck("value");
/*----------------------------------------------------------------------------------------------------------------*/
function Bucket(hash, firstKey, firstValue, equalityFunction) {
this[0] = hash;
this.entries = [];
this.addEntry(firstKey, firstValue);
if (equalityFunction !== null) {
this.getEqualityFunction = function() {
return equalityFunction;
};
}
}
var EXISTENCE = 0, ENTRY = 1, ENTRY_INDEX_AND_VALUE = 2;
function createBucketSearcher(mode) {
return function(key) {
var i = this.entries.length, entry, equals = this.getEqualityFunction(key);
while (i--) {
entry = this.entries[i];
if ( equals(key, entry[0]) ) {
switch (mode) {
case EXISTENCE:
return true;
case ENTRY:
return entry;
case ENTRY_INDEX_AND_VALUE:
return [ i, entry[1] ];
}
}
}
return false;
};
}
function createBucketLister(entryProperty) {
return function(aggregatedArr) {
var startIndex = aggregatedArr.length;
for (var i = 0, entries = this.entries, len = entries.length; i < len; ++i) {
aggregatedArr[startIndex + i] = entries[i][entryProperty];
}
};
}
Bucket.prototype = {
getEqualityFunction: function(searchValue) {
return (typeof searchValue.equals == FUNCTION) ? equals_fixedValueHasEquals : equals_fixedValueNoEquals;
},
getEntryForKey: createBucketSearcher(ENTRY),
getEntryAndIndexForKey: createBucketSearcher(ENTRY_INDEX_AND_VALUE),
removeEntryForKey: function(key) {
var result = this.getEntryAndIndexForKey(key);
if (result) {
this.entries.splice(result[0], 1);
return result[1];
}
return null;
},
addEntry: function(key, value) {
this.entries.push( [key, value] );
},
keys: createBucketLister(0),
values: createBucketLister(1),
getEntries: function(destEntries) {
var startIndex = destEntries.length;
for (var i = 0, entries = this.entries, len = entries.length; i < len; ++i) {
// Clone the entry stored in the bucket before adding to array
destEntries[startIndex + i] = entries[i].slice(0);
}
},
containsKey: createBucketSearcher(EXISTENCE),
containsValue: function(value) {
var entries = this.entries, i = entries.length;
while (i--) {
if ( value === entries[i][1] ) {
return true;
}
}
return false;
}
};
/*----------------------------------------------------------------------------------------------------------------*/
// Supporting functions for searching hashtable buckets
function searchBuckets(buckets, hash) {
var i = buckets.length, bucket;
while (i--) {
bucket = buckets[i];
if (hash === bucket[0]) {
return i;
}
}
return null;
}
function getBucketForHash(bucketsByHash, hash) {
var bucket = bucketsByHash[hash];
// Check that this is a genuine bucket and not something inherited from the bucketsByHash's prototype
return ( bucket && (bucket instanceof Bucket) ) ? bucket : null;
}
/*----------------------------------------------------------------------------------------------------------------*/
function Hashtable() {
var buckets = [];
var bucketsByHash = {};
var properties = {
replaceDuplicateKey: true,
hashCode: hashObject,
equals: null
};
var arg0 = arguments[0], arg1 = arguments[1];
if (arg1 !== UNDEFINED) {
properties.hashCode = arg0;
properties.equals = arg1;
} else if (arg0 !== UNDEFINED) {
merge(properties, arg0);
}
var hashCode = properties.hashCode, equals = properties.equals;
this.properties = properties;
this.put = function(key, value) {
checkKey(key);
// checkValue(value);
var hash = hashCode(key), bucket, bucketEntry, oldValue = null;
// Check if a bucket exists for the bucket key
bucket = getBucketForHash(bucketsByHash, hash);
if (bucket) {
// Check this bucket to see if it already contains this key
bucketEntry = bucket.getEntryForKey(key);
if (bucketEntry) {
// This bucket entry is the current mapping of key to value, so replace the old value.
// Also, we optionally replace the key so that the latest key is stored.
if (properties.replaceDuplicateKey) {
bucketEntry[0] = key;
}
oldValue = bucketEntry[1];
bucketEntry[1] = value;
} else {
// The bucket does not contain an entry for this key, so add one
bucket.addEntry(key, value);
}
} else {
// No bucket exists for the key, so create one and put our key/value mapping in
bucket = new Bucket(hash, key, value, equals);
buckets.push(bucket);
bucketsByHash[hash] = bucket;
}
return oldValue;
};
this.get = function(key) {
checkKey(key);
var hash = hashCode(key);
// Check if a bucket exists for the bucket key
var bucket = getBucketForHash(bucketsByHash, hash);
if (bucket) {
// Check this bucket to see if it contains this key
var bucketEntry = bucket.getEntryForKey(key);
if (bucketEntry) {
// This bucket entry is the current mapping of key to value, so return the value.
return bucketEntry[1];
}
}
return null;
};
this.containsKey = function(key) {
checkKey(key);
var bucketKey = hashCode(key);
// Check if a bucket exists for the bucket key
var bucket = getBucketForHash(bucketsByHash, bucketKey);
return bucket ? bucket.containsKey(key) : false;
};
this.containsValue = function(value) {
checkValue(value);
var i = buckets.length;
while (i--) {
if (buckets[i].containsValue(value)) {
return true;
}
}
return false;
};
this.clear = function() {
buckets.length = 0;
bucketsByHash = {};
};
this.isEmpty = function() {
return !buckets.length;
};
var createBucketAggregator = function(bucketFuncName) {
return function() {
var aggregated = [], i = buckets.length;
while (i--) {
buckets[i][bucketFuncName](aggregated);
}
return aggregated;
};
};
this.keys = createBucketAggregator("keys");
this.values = createBucketAggregator("values");
this.entries = createBucketAggregator("getEntries");
this.remove = function(key) {
checkKey(key);
var hash = hashCode(key), bucketIndex, oldValue = null;
// Check if a bucket exists for the bucket key
var bucket = getBucketForHash(bucketsByHash, hash);
if (bucket) {
// Remove entry from this bucket for this key
oldValue = bucket.removeEntryForKey(key);
if (oldValue !== null) {
// Entry was removed, so check if bucket is empty
if (bucket.entries.length == 0) {
// Bucket is empty, so remove it from the bucket collections
bucketIndex = searchBuckets(buckets, hash);
buckets.splice(bucketIndex, 1);
delete bucketsByHash[hash];
}
}
}
return oldValue;
};
this.size = function() {
var total = 0, i = buckets.length;
while (i--) {
total += buckets[i].entries.length;
}
return total;
};
}
Hashtable.prototype = {
each: function(callback) {
var entries = this.entries(), i = entries.length, entry;
while (i--) {
entry = entries[i];
callback(entry[0], entry[1]);
}
},
equals: function(hashtable) {
var keys, key, val, count = this.size();
if (count == hashtable.size()) {
keys = this.keys();
while (count--) {
key = keys[count];
val = hashtable.get(key);
if (val === null || val !== this.get(key)) {
return false;
}
}
return true;
}
return false;
},
putAll: function(hashtable, conflictCallback) {
var entries = hashtable.entries();
var entry, key, value, thisValue, i = entries.length;
var hasConflictCallback = (typeof conflictCallback == FUNCTION);
while (i--) {
entry = entries[i];
key = entry[0];
value = entry[1];
// Check for a conflict. The default behaviour is to overwrite the value for an existing key
if ( hasConflictCallback && (thisValue = this.get(key)) ) {
value = conflictCallback(key, thisValue, value);
}
this.put(key, value);
}
},
clone: function() {
var clone = new Hashtable(this.properties);
clone.putAll(this);
return clone;
}
};
Hashtable.prototype.toQueryString = function() {
var entries = this.entries(), i = entries.length, entry;
var parts = [];
while (i--) {
entry = entries[i];
parts[i] = encodeURIComponent( toStr(entry[0]) ) + "=" + encodeURIComponent( toStr(entry[1]) );
}
return parts.join("&");
};
return Hashtable;
})();© 2015 - 2025 Weber Informatics LLC | Privacy Policy