413 lines
No EOL
12 KiB
JavaScript
413 lines
No EOL
12 KiB
JavaScript
/*
|
||
* provider.js: Abstraction providing an interface into pluggable configuration storage.
|
||
*
|
||
* (C) 2011, Charlie Robbins
|
||
*
|
||
*/
|
||
|
||
var async = require('async'),
|
||
common = require('./common'),
|
||
stores = require('./stores');
|
||
|
||
|
||
|
||
//
|
||
// ### function Provider (options)
|
||
// #### @options {Object} Options for this instance.
|
||
// Constructor function for the Provider object responsible
|
||
// for exposing the pluggable storage features of `nconf`.
|
||
//
|
||
var Provider = exports.Provider = function (options) {
|
||
var self = this;
|
||
|
||
//
|
||
// Setup default options for working with `stores`,
|
||
// `overrides`, `process.env` and `process.argv`.
|
||
//
|
||
options = options || {};
|
||
this._overrides = options.overrides || null;
|
||
this._argv = options.argv || false;
|
||
this._env = options.env || false;
|
||
this._reserved = Object.keys(Provider.prototype);
|
||
this._stores = [];
|
||
|
||
//
|
||
// Add the default `system` store for working with
|
||
// `overrides`, `process.env`, `process.argv` and
|
||
// a simple in-memory objects.
|
||
//
|
||
this.add('system', options);
|
||
|
||
if (options.type) {
|
||
this.add(options.type, options);
|
||
}
|
||
else if (options.store) {
|
||
this.add(options.store.name || options.store.type, options.store);
|
||
}
|
||
else if (options.stores) {
|
||
Object.keys(options.stores).forEach(function (store) {
|
||
self.add(store.name || store.type, store);
|
||
});
|
||
}
|
||
};
|
||
|
||
//
|
||
// ### function use (name, options)
|
||
// #### @type {string} Type of the nconf store to use.
|
||
// #### @options {Object} Options for the store instance.
|
||
// Adds (or replaces) a new store with the specified `name`
|
||
// and `options`. If `options.type` is not set, then `name`
|
||
// will be used instead:
|
||
//
|
||
// provider.use('file');
|
||
// provider.use('file', { type: 'file', filename: '/path/to/userconf' })
|
||
//
|
||
Provider.prototype.use = function (name, options) {
|
||
if (name === 'system') {
|
||
return;
|
||
}
|
||
else if (this._reserved.indexOf(name) !== -1) {
|
||
throw new Error('Cannot use reserved name: ' + name);
|
||
}
|
||
|
||
options = options || {};
|
||
options.type = options.type || name;
|
||
|
||
function sameOptions (store) {
|
||
return Object.keys(options).every(function (key) {
|
||
return options[key] === store[key];
|
||
});
|
||
}
|
||
|
||
var store = this[name],
|
||
update = store && !sameOptions(store);
|
||
|
||
if (!store || update) {
|
||
if (update) {
|
||
this.remove(name);
|
||
}
|
||
|
||
this.add(name, options);
|
||
}
|
||
|
||
return this;
|
||
};
|
||
|
||
//
|
||
// ### function add (name, options)
|
||
// #### @name {string} Name of the store to add to this instance
|
||
// #### @options {Object} Options for the store to create
|
||
// Adds a new store with the specified `name` and `options`. If `options.type`
|
||
// is not set, then `name` will be used instead:
|
||
//
|
||
// provider.add('memory');
|
||
// provider.add('userconf', { type: 'file', filename: '/path/to/userconf' })
|
||
//
|
||
Provider.prototype.add = function (name, options) {
|
||
if (this._reserved.indexOf(name) !== -1) {
|
||
throw new Error('Cannot use reserved name: ' + name);
|
||
}
|
||
|
||
options = options || {};
|
||
options.type = options.type || name;
|
||
|
||
if (Object.keys(stores).indexOf(common.capitalize(options.type)) === -1) {
|
||
throw new Error('Cannot add store with unknown type: ' + options.type);
|
||
}
|
||
|
||
this[name] = this.create(options.type, options);
|
||
this._stores.push(name);
|
||
};
|
||
|
||
//
|
||
// ### function remove (name)
|
||
// #### @name {string} Name of the store to remove from this instance
|
||
// Removes a store with the specified `name` from this instance. Users
|
||
// are allowed to pass in a type argument (e.g. `memory`) as name if
|
||
// this was used in the call to `.add()`.
|
||
//
|
||
Provider.prototype.remove = function (name) {
|
||
if (this._reserved.indexOf(name) !== -1) {
|
||
throw new Error('Cannot use reserved name: ' + name);
|
||
}
|
||
else if (!this[name]) {
|
||
throw new Error('Cannot remove store that does not exist: ' + name);
|
||
}
|
||
|
||
delete this[name];
|
||
this._stores.splice(this._stores.indexOf(name), 1);
|
||
};
|
||
|
||
//
|
||
// ### function create (type, options)
|
||
// #### @type {string} Type of the nconf store to use.
|
||
// #### @options {Object} Options for the store instance.
|
||
// Creates a store of the specified `type` using the
|
||
// specified `options`.
|
||
//
|
||
Provider.prototype.create = function (type, options) {
|
||
return new stores[common.capitalize(type.toLowerCase())](options);
|
||
};
|
||
|
||
//
|
||
// ### function get (key, callback)
|
||
// #### @key {string} Key to retrieve for this instance.
|
||
// #### @callback {function} **Optional** Continuation to respond to when complete.
|
||
// Retrieves the value for the specified key (if any).
|
||
//
|
||
Provider.prototype.get = function (key, callback) {
|
||
return this._execute('get', 1, key, callback);
|
||
};
|
||
|
||
//
|
||
// ### function set (key, value, callback)
|
||
// #### @key {string} Key to set in this instance
|
||
// #### @value {literal|Object} Value for the specified key
|
||
// #### @callback {function} **Optional** Continuation to respond to when complete.
|
||
// Sets the `value` for the specified `key` in this instance.
|
||
//
|
||
Provider.prototype.set = function (key, value, callback) {
|
||
return this._execute('set', 2, key, value, callback);
|
||
};
|
||
|
||
//
|
||
// ### function reset (callback)
|
||
// #### @callback {function} **Optional** Continuation to respond to when complete.
|
||
// Clears all keys associated with this instance.
|
||
//
|
||
Provider.prototype.reset = function (callback) {
|
||
return this._execute('reset', 0, callback);
|
||
};
|
||
|
||
//
|
||
// ### function clear (key, callback)
|
||
// #### @key {string} Key to remove from this instance
|
||
// #### @callback {function} **Optional** Continuation to respond to when complete.
|
||
// Removes the value for the specified `key` from this instance.
|
||
//
|
||
Provider.prototype.clear = function (key, callback) {
|
||
return this._execute('clear', 1, key, callback);
|
||
};
|
||
|
||
//
|
||
// ### function merge ([key,] value [, callback])
|
||
// #### @key {string} Key to merge the value into
|
||
// #### @value {literal|Object} Value to merge into the key
|
||
// #### @callback {function} **Optional** Continuation to respond to when complete.
|
||
// Merges the properties in `value` into the existing object value at `key`.
|
||
//
|
||
// 1. If the existing value `key` is not an Object, it will be completely overwritten.
|
||
// 2. If `key` is not supplied, then the `value` will be merged into the root.
|
||
//
|
||
Provider.prototype.merge = function () {
|
||
var self = this,
|
||
args = Array.prototype.slice.call(arguments),
|
||
callback = typeof args[args.length - 1] === 'function' && args.pop(),
|
||
value = args.pop(),
|
||
key = args.pop();
|
||
|
||
function mergeProperty (prop, next) {
|
||
return self._execute('merge', 2, prop, value[prop], next);
|
||
}
|
||
|
||
if (!key) {
|
||
if (Array.isArray(value) || typeof value !== 'object') {
|
||
return onError(new Error('Cannot merge non-Object into top-level.'), callback);
|
||
}
|
||
|
||
return async.forEach(Object.keys(value), mergeProperty, callback || function () { })
|
||
}
|
||
|
||
return this._execute('merge', 2, key, value, callback);
|
||
};
|
||
|
||
//
|
||
// ### function load (callback)
|
||
// #### @callback {function} Continuation to respond to when complete.
|
||
// Responds with an Object representing all keys associated in this instance.
|
||
//
|
||
Provider.prototype.load = function (callback) {
|
||
var self = this;
|
||
|
||
function loadStoreSync(name) {
|
||
var store = self[name];
|
||
|
||
if (!store.loadSync) {
|
||
throw new Error('nconf store ' + store.type + ' has no loadSync() method');
|
||
}
|
||
|
||
return store.loadSync();
|
||
}
|
||
|
||
function loadStore(name, next) {
|
||
var store = self[name];
|
||
|
||
if (!store.load && !store.loadSync) {
|
||
return next(new Error('nconf store ' + store.type + ' has no load() method'));
|
||
}
|
||
|
||
return store.loadSync
|
||
? next(null, store.loadSync())
|
||
: store.load(next);
|
||
}
|
||
|
||
//
|
||
// If we don't have a callback and the current
|
||
// store is capable of loading synchronously
|
||
// then do so.
|
||
//
|
||
if (!callback) {
|
||
return common.merge(this._stores.map(loadStoreSync));
|
||
}
|
||
|
||
async.map(this._stores, loadStore, function (err, objs) {
|
||
return err ? callback(err) : callback(null, common.merge(objs));
|
||
});
|
||
};
|
||
|
||
//
|
||
// ### function save (value, callback)
|
||
// #### @value {Object} **Optional** Config object to set for this instance
|
||
// #### @callback {function} Continuation to respond to when complete.
|
||
// Removes any existing configuration settings that may exist in this
|
||
// instance and then adds all key-value pairs in `value`.
|
||
//
|
||
Provider.prototype.save = function (value, callback) {
|
||
if (!callback && typeof value === 'function') {
|
||
callback = value;
|
||
value = null;
|
||
}
|
||
|
||
var self = this;
|
||
|
||
function saveStoreSync(name) {
|
||
var store = self[name];
|
||
|
||
if (!store.saveSync) {
|
||
throw new Error('nconf store ' + store.type + ' has no saveSync() method');
|
||
}
|
||
|
||
return store.saveSync();
|
||
}
|
||
|
||
function saveStore(name, next) {
|
||
var store = self[name];
|
||
|
||
if (!store.load && !store.saveSync) {
|
||
return next(new Error('nconf store ' + store.type + ' has no save() method'));
|
||
}
|
||
|
||
return store.saveSync
|
||
? next(null, store.saveSync())
|
||
: store.save(next);
|
||
}
|
||
|
||
//
|
||
// If we don't have a callback and the current
|
||
// store is capable of saving synchronously
|
||
// then do so.
|
||
//
|
||
if (!callback) {
|
||
return common.merge(this._stores.map(saveStoreSync));
|
||
}
|
||
|
||
async.map(this._stores, saveStore, function (err, objs) {
|
||
return err ? callback(err) : callback();
|
||
});
|
||
};
|
||
|
||
//
|
||
// ### @private function _execute (action, syncLength, [arguments])
|
||
// #### @action {string} Action to execute on `this.store`.
|
||
// #### @syncLength {number} Function length of the sync version.
|
||
// #### @arguments {Array} Arguments array to apply to the action
|
||
// Executes the specified `action` on all stores for this instance, ensuring a callback supplied
|
||
// to a synchronous store function is still invoked.
|
||
//
|
||
Provider.prototype._execute = function (action, syncLength /* [arguments] */) {
|
||
var args = Array.prototype.slice.call(arguments, 2),
|
||
callback = typeof args[args.length - 1] === 'function' && args.pop(),
|
||
self = this,
|
||
response;
|
||
|
||
function runAction (name, next) {
|
||
var store = self[name]
|
||
|
||
return store[action].length > syncLength
|
||
? store[action].apply(store, args.concat(next))
|
||
: next(null, store[action].apply(store, args));
|
||
}
|
||
|
||
if (callback) {
|
||
return async.forEach(self._stores, runAction, function (err) {
|
||
return err ? callback(err) : callback();
|
||
});
|
||
}
|
||
|
||
this._stores.forEach(function (name) {
|
||
var store = self[name];
|
||
response = store[action].apply(store, args);
|
||
});
|
||
|
||
return response;
|
||
}
|
||
|
||
//
|
||
// ### @argv {boolean}
|
||
// Gets or sets a property representing overrides which supercede all
|
||
// other values for this instance.
|
||
//
|
||
Provider.prototype.__defineSetter__('overrides', updateSystem.bind(this, 'overrides'));
|
||
Provider.prototype.__defineGetter__('overrides', function () {
|
||
return this._argv;
|
||
});
|
||
|
||
//
|
||
// ### @argv {boolean}
|
||
// Gets or sets a property indicating if we should wrap calls to `.get`
|
||
// by checking `optimist.argv`. Can be a boolean or the pass-thru
|
||
// options for `optimist`.
|
||
//
|
||
Provider.prototype.__defineSetter__('argv', updateSystem.bind(this, 'argv'));
|
||
Provider.prototype.__defineGetter__('argv', function () {
|
||
return this._argv;
|
||
});
|
||
|
||
//
|
||
// ### @env {boolean}
|
||
// Gets or sets a property indicating if we should wrap calls to `.get`
|
||
// by checking `process.env`. Can be a boolean or an Array of
|
||
// environment variables to extract.
|
||
//
|
||
Provider.prototype.__defineSetter__('env', updateSystem.bind(this, 'env'));
|
||
Provider.prototype.__defineGetter__('env', function () {
|
||
return this._env;
|
||
});
|
||
|
||
//
|
||
// Throw the `err` if a callback is not supplied
|
||
//
|
||
function onError(err, callback) {
|
||
if (callback) {
|
||
return callback(err);
|
||
}
|
||
|
||
throw err;
|
||
}
|
||
|
||
//
|
||
// Helper function for working with the
|
||
// default `system` store for providers.
|
||
//
|
||
function updateSystem(prop, value) {
|
||
var system = this['system'];
|
||
|
||
if (system[prop] === value) {
|
||
return;
|
||
}
|
||
|
||
value = value || false;
|
||
this['_' + prop] = value;
|
||
system[prop] = value;
|
||
system.loadSync();
|
||
} |