nconf-lite/lib/nconf/stores/file.js
2011-12-25 15:30:48 +01:00

226 lines
5.3 KiB
JavaScript

/*
* file.js: Simple file storage engine for nconf files
*
* (C) 2011, Nodejitsu Inc.
*
*/
var fs = require('fs'),
path = require('path'),
util = require('util'),
formats = require('../formats'),
Memory = require('./memory').Memory;
//
// ### function File (options)
// #### @options {Object} Options for this instance
// Constructor function for the File nconf store, a simple abstraction
// around the Memory store that can persist configuration to disk.
//
var File = exports.File = function (options) {
if (!options || !options.file) {
throw new Error ('Missing required option `files`');
}
Memory.call(this, options);
this.type = 'file';
this.file = options.file;
this.dir = options.dir || process.cwd();
this.format = options.format || formats.json;
if (options.search) {
this.search(this.dir);
}
};
// Inherit from the Memory store
util.inherits(File, Memory);
//
// ### function save (value, callback)
// #### @value {Object} _Ignored_ Left here for consistency
// #### @callback {function} Continuation to respond to when complete.
// Saves the current configuration object to disk at `this.file`
// using the format specified by `this.format`.
//
File.prototype.save = function (value, callback) {
if (!callback) {
callback = value;
value = null;
}
fs.writeFile(this.file, this.format.stringify(this.store), function (err) {
return err ? callback(err) : callback();
});
};
//
// ### function saveSync (value, callback)
// #### @value {Object} _Ignored_ Left here for consistency
// #### @callback {function} **Optional** Continuation to respond to when complete.
// Saves the current configuration object to disk at `this.file`
// using the format specified by `this.format` synchronously.
//
File.prototype.saveSync = function (value) {
try {
fs.writeFileSync(this.file, this.format.stringify(this.store));
}
catch (ex) {
throw(ex);
}
return this.store;
};
//
// ### function load (callback)
// #### @callback {function} Continuation to respond to when complete.
// Responds with an Object representing all keys associated in this instance.
//
File.prototype.load = function (callback) {
var self = this;
path.exists(self.file, function (exists) {
if (!exists) {
return callback(null, {});
}
//
// Else, the path exists, read it from disk
//
fs.readFile(self.file, function (err, data) {
if (err) {
return callback(err);
}
try {
self.store = self.format.parse(data.toString());
}
catch (ex) {
return callback(new Error("Error parsing your JSON configuration file."));
}
callback(null, self.store);
});
});
};
//
// ### function loadSync (callback)
// Attempts to load the data stored in `this.file` synchronously
// and responds appropriately.
//
File.prototype.loadSync = function () {
var data, self = this;
if (!path.existsSync(self.file)) {
self.store = {};
data = {};
}
else {
//
// Else, the path exists, read it from disk
//
try {
data = this.format.parse(fs.readFileSync(this.file, 'utf8'));
this.store = data;
}
catch (ex) {
throw new Error("Error parsing your JSON configuration file.")
}
}
return data;
};
//
// ### function search (base)
// #### @base {string} Base directory (or file) to begin searching for the target file.
// Attempts to find `this.file` by iteratively searching up the
// directory structure
//
File.prototype.search = function (base) {
var looking = true,
fullpath,
previous,
stats;
base = base || process.cwd();
if (this.file[0] === '/') {
//
// If filename for this instance is a fully qualified path
// (i.e. it starts with a `'/'`) then check if it exists
//
try {
stats = fs.statSync(fs.realpathSync(this.file));
if (stats.isFile()) {
fullpath = this.file;
looking = false;
}
}
catch (ex) {
//
// Ignore errors
//
}
}
if (looking && base) {
//
// Attempt to stat the realpath located at `base`
// if the directory does not exist then return false.
//
try {
var stat = fs.statSync(fs.realpathSync(base));
looking = stat.isDirectory();
}
catch (ex) {
return false;
}
}
while (looking) {
//
// Iteratively look up the directory structure from `base`
//
try {
stats = fs.statSync(fs.realpathSync(fullpath = path.join(base, this.file)));
looking = stats.isDirectory();
}
catch (ex) {
previous = base;
base = path.dirname(base);
if (previous === base) {
//
// If we've reached the top of the directory structure then simply use
// the default file path.
//
try {
stats = fs.statSync(fs.realpathSync(fullpath = path.join(this.dir, this.file)));
if (stats.isDirectory()) {
fullpath = undefined;
}
}
catch (ex) {
//
// Ignore errors
//
}
looking = false;
}
}
}
//
// Set the file for this instance to the fullpath
// that we have found during the search. In the event that
// the search was unsuccessful use the original value for `this.file`.
//
this.file = fullpath || this.file;
return fullpath;
};