Current File : //var/www/html/node_modules/flat-cache/src/cache.js
var path = require('path');
var fs = require('fs');
var utils = require('./utils');
var del = require('./del');
var writeJSON = utils.writeJSON;
var cache = {
/**
* Load a cache identified by the given Id. If the element does not exists, then initialize an empty
* cache storage. If specified `cacheDir` will be used as the directory to persist the data to. If omitted
* then the cache module directory `./cache` will be used instead
*
* @method load
* @param docId {String} the id of the cache, would also be used as the name of the file cache
* @param [cacheDir] {String} directory for the cache entry
*/
load: function (docId, cacheDir) {
var me = this;
me._visited = {};
me._persisted = {};
me._pathToFile = cacheDir ? path.resolve(cacheDir, docId) : path.resolve(__dirname, '../.cache/', docId);
if (fs.existsSync(me._pathToFile)) {
me._persisted = utils.tryParse(me._pathToFile, {});
}
},
/**
* Load the cache from the provided file
* @method loadFile
* @param {String} pathToFile the path to the file containing the info for the cache
*/
loadFile: function (pathToFile) {
var me = this;
var dir = path.dirname(pathToFile);
var fName = path.basename(pathToFile);
me.load(fName, dir);
},
/**
* Returns the entire persisted object
* @method all
* @returns {*}
*/
all: function () {
return this._persisted;
},
keys: function () {
return Object.keys(this._persisted);
},
/**
* sets a key to a given value
* @method setKey
* @param key {string} the key to set
* @param value {object} the value of the key. Could be any object that can be serialized with JSON.stringify
*/
setKey: function (key, value) {
this._visited[key] = true;
this._persisted[key] = value;
},
/**
* remove a given key from the cache
* @method removeKey
* @param key {String} the key to remove from the object
*/
removeKey: function (key) {
delete this._visited[key]; // esfmt-ignore-line
delete this._persisted[key]; // esfmt-ignore-line
},
/**
* Return the value of the provided key
* @method getKey
* @param key {String} the name of the key to retrieve
* @returns {*} the value from the key
*/
getKey: function (key) {
this._visited[key] = true;
return this._persisted[key];
},
/**
* Remove keys that were not accessed/set since the
* last time the `prune` method was called.
* @method _prune
* @private
*/
_prune: function () {
var me = this;
var obj = {};
var keys = Object.keys(me._visited);
// no keys visited for either get or set value
if (keys.length === 0) {
return;
}
keys.forEach(function (key) {
obj[key] = me._persisted[key];
});
me._visited = {};
me._persisted = obj;
},
/**
* Save the state of the cache identified by the docId to disk
* as a JSON structure
* @param [noPrune=false] {Boolean} whether to remove from cache the non visited files
* @method save
*/
save: function (noPrune) {
var me = this;
!noPrune && me._prune();
writeJSON(me._pathToFile, me._persisted);
},
/**
* remove the file where the cache is persisted
* @method removeCacheFile
* @return {Boolean} true or false if the file was successfully deleted
*/
removeCacheFile: function () {
return del(this._pathToFile);
},
/**
* Destroy the file cache and cache content.
* @method destroy
*/
destroy: function () {
var me = this;
me._visited = {};
me._persisted = {};
me.removeCacheFile();
},
};
module.exports = {
/**
* Alias for create. Should be considered depreacted. Will be removed in next releases
*
* @method load
* @param docId {String} the id of the cache, would also be used as the name of the file cache
* @param [cacheDir] {String} directory for the cache entry
* @returns {cache} cache instance
*/
load: function (docId, cacheDir) {
return this.create(docId, cacheDir);
},
/**
* Load a cache identified by the given Id. If the element does not exists, then initialize an empty
* cache storage.
*
* @method create
* @param docId {String} the id of the cache, would also be used as the name of the file cache
* @param [cacheDir] {String} directory for the cache entry
* @returns {cache} cache instance
*/
create: function (docId, cacheDir) {
var obj = Object.create(cache);
obj.load(docId, cacheDir);
return obj;
},
createFromFile: function (filePath) {
var obj = Object.create(cache);
obj.loadFile(filePath);
return obj;
},
/**
* Clear the cache identified by the given id. Caches stored in a different cache directory can be deleted directly
*
* @method clearCache
* @param docId {String} the id of the cache, would also be used as the name of the file cache
* @param cacheDir {String} the directory where the cache file was written
* @returns {Boolean} true if the cache folder was deleted. False otherwise
*/
clearCacheById: function (docId, cacheDir) {
var filePath = cacheDir ? path.resolve(cacheDir, docId) : path.resolve(__dirname, '../.cache/', docId);
return del(filePath);
},
/**
* Remove all cache stored in the cache directory
* @method clearAll
* @returns {Boolean} true if the cache folder was deleted. False otherwise
*/
clearAll: function (cacheDir) {
var filePath = cacheDir ? path.resolve(cacheDir) : path.resolve(__dirname, '../.cache/');
return del(filePath);
},
};
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