135 lines
3.1 KiB
JavaScript
135 lines
3.1 KiB
JavaScript
/*
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* file.js: Simple file storage engine for nconf files
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*
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* (C) 2011, Charlie Robbins
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*
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*/
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var fs = require('fs'),
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util = require('util'),
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Memory = require('./memory').Memory;
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//
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// ### function File (options)
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// #### @options {Object} Options for this instance
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// Constructor function for the File nconf store, a simple abstraction
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// around the Memory store that can persist configuration to disk.
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//
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var File = exports.File = function (options) {
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if (!options.file) {
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throw new Error ('Missing required option `files`');
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}
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Memory.call(this, options);
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this.type = 'file';
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this.file = options.file;
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this.format = options.format || {
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stringify: function (obj) {
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return JSON.stringify(obj, null, 2)
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},
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parse: JSON.parse
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};
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};
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// Inherit from the Memory store
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util.inherits(File, Memory);
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//
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// ### function save (value, callback)
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// #### @value {Object} _Ignored_ Left here for consistency
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// #### @callback {function} Continuation to respond to when complete.
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// Saves the current configuration object to disk at `this.file`
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// using the format specified by `this.format`.
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//
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File.prototype.save = function (value, callback) {
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if (!callback) {
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callback = value;
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value = null;
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}
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fs.writeFile(this.file, this.format.stringify(this.store), function (err) {
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return err ? callback(err) : callback();
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});
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};
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//
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// ### function saveSync (value, callback)
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// #### @value {Object} _Ignored_ Left here for consistency
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// #### @callback {function} **Optional** Continuation to respond to when complete.
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// Saves the current configuration object to disk at `this.file`
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// using the format specified by `this.format` synchronously.
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//
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File.prototype.saveSync = function (value, callback) {
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if (!callback) {
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callback = value;
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value = null;
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}
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var err;
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try {
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fs.writeFileSync(this.file, this.format.stringify(this.store));
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}
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catch (ex) {
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err = ex;
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}
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if (callback) {
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return callback(err);
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}
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if (err) {
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throw err;
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}
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};
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//
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// ### function load (callback)
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// #### @callback {function} Continuation to respond to when complete.
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// Responds with an Object representing all keys associated in this instance.
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//
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File.prototype.load = function (callback) {
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var self = this;
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fs.readFile(this.file, function (err, data) {
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if (err) {
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return callback(err);
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}
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try {
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self.store = self.format.parse(data.toString());
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callback(null, self.store);
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}
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catch (ex) {
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self.store = {};
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callback(ex);
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}
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});
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};
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//
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// ### function load (callback)
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// #### @callback {function} **Optional** Continuation to respond to when complete.
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// Attempts to load the data stored in `this.file` synchronously and responds appropriately.
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//
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File.prototype.loadSync = function (callback) {
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var err, data;
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try {
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data = fs.readFileSync(this.file, 'utf8');
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this.store = this.format.parse(data);
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}
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catch (ex) {
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err = ex;
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}
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if (callback) {
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return callback(err, data);
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}
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if (err) {
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err.message = "Error parsing your JSON configuration file."
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throw err;
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}
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return data;
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}; |