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node-red/red/runtime/nodes/context/index.js
2018-06-29 09:48:38 +01:00

262 lines
9.0 KiB
JavaScript

/**
* Copyright JS Foundation and other contributors, http://js.foundation
*
* 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 clone = require("clone");
var log = require("../../log");
var memory = require("./memory");
var settings;
var contexts = {};
var globalContext = null;
var externalContexts = {};
var hasExternalContext = false;
function init(_settings) {
settings = _settings;
externalContexts = {};
// init memory plugin
var seed = settings.functionGlobalContext || {};
externalContexts["_"] = memory();
externalContexts["_"].setGlobalContext(seed);
globalContext = createContext("global",seed);
contexts['global'] = globalContext;
}
function load() {
return new Promise(function(resolve,reject) {
// load & init plugins in settings.contextStorage
var plugins = settings.contextStorage;
var defaultIsAlias = false;
var promises = [];
if (plugins) {
for (var pluginName in plugins) {
if (plugins.hasOwnProperty(pluginName)) {
// "_" is a reserved name - do not allow it to be overridden
if (pluginName === "_") {
continue;
}
// Check if this is setting the 'default' context to be a named plugin
if (pluginName === "default" && typeof plugins[pluginName] === "string") {
// Check the 'default' alias exists before initialising anything
if (!plugins.hasOwnProperty(plugins[pluginName])) {
return reject(new Error(log._("context.error-invalid-default-module", {storage:plugins["default"]})));
}
defaultIsAlias = true;
continue;
}
var plugin;
if (plugins[pluginName].hasOwnProperty("module")) {
// Get the provided config and copy in the 'approved' top-level settings (eg userDir)
var config = plugins[pluginName].config || {};
copySettings(config, settings);
if (typeof plugins[pluginName].module === "string") {
// This config identifies the module by name - assume it is a built-in one
// TODO: check it exists locally, if not, try to require it as-is
try {
plugin = require("./"+plugins[pluginName].module);
} catch(err) {
return reject(new Error(log._("context.error-module-not-loaded", {module:plugins[pluginName].module})));
}
} else {
// Assume `module` is an already-required module we can use
plugin = plugins[pluginName].module;
}
try {
// Create a new instance of the plugin by calling its module function
externalContexts[pluginName] = plugin(config);
} catch(err) {
return reject(new Error(log._("context.error-loading-module",{module:pluginName,message:err.toString()})));
}
} else {
// Plugin does not specify a 'module'
return reject(new Error(log._("context.error-module-not-defined", {storage:pluginName})));
}
}
}
// Open all of the configured contexts
for (var plugin in externalContexts) {
if (externalContexts.hasOwnProperty(plugin)) {
promises.push(externalContexts[plugin].open());
}
}
// If 'default' is an alias, point it at the right module - we have already
// checked that it exists
if (defaultIsAlias) {
externalContexts["default"] = externalContexts[plugins["default"]];
}
}
if (promises.length === 0) {
promises.push(externalContexts["_"].open())
} else {
hasExternalContext = true;
}
return resolve(Promise.all(promises));
});
}
function copySettings(config, settings){
var copy = ["userDir"]
config.settings = {};
copy.forEach(function(setting){
config.settings[setting] = clone(settings[setting]);
});
}
function getContextStorage(storage) {
if (externalContexts.hasOwnProperty(storage)) {
// A known context
return externalContexts[storage];
} else if (externalContexts.hasOwnProperty("default")) {
// Not known, but we have a default to fall back to
return externalContexts["default"];
} else {
// Not known and no default configured
var contextError = new Error(log._("context.error-use-undefined-storage", {storage:storage}));
contextError.name = "ContextError";
throw contextError;
}
}
function createContext(id,seed) {
var scope = id;
var obj = seed || {};
obj.get = function(key, storage, callback) {
var context;
if (!storage && !callback) {
context = externalContexts["_"];
} else {
if (typeof storage === 'function') {
callback = storage;
storage = "default";
}
if (typeof callback !== 'function'){
throw new Error("Callback must be a function");
}
context = getContextStorage(storage);
}
return context.get(scope, key, callback);
};
obj.set = function(key, value, storage, callback) {
var context;
if (!storage && !callback) {
context = externalContexts["_"];
} else {
if (typeof storage === 'function') {
callback = storage;
storage = "default";
}
if (callback && typeof callback !== 'function') {
throw new Error("Callback must be a function");
}
context = getContextStorage(storage);
}
context.set(scope, key, value, callback);
};
obj.keys = function(storage, callback) {
var context;
if (!storage && !callback) {
context = externalContexts["_"];
} else {
if (typeof storage === 'function') {
callback = storage;
storage = "default";
}
if (typeof callback !== 'function') {
throw new Error("Callback must be a function");
}
context = getContextStorage(storage);
}
return context.keys(scope, callback);
};
return obj;
}
function getContext(localId,flowId) {
var contextId = localId;
if (flowId) {
contextId = localId+":"+flowId;
}
if (contexts.hasOwnProperty(contextId)) {
return contexts[contextId];
}
var newContext = createContext(contextId);
if (flowId) {
newContext.flow = getContext(flowId);
}
if (globalContext) {
newContext.global = globalContext;
}
contexts[contextId] = newContext;
return newContext;
}
function deleteContext(id,flowId) {
if(!hasExternalContext){
var contextId = id;
if (flowId) {
contextId = id+":"+flowId;
}
delete contexts[contextId];
return externalContexts["_"].delete(contextId);
}else{
return Promise.resolve();
}
}
function clean(flowConfig) {
var promises = [];
for(var plugin in externalContexts){
if(externalContexts.hasOwnProperty(plugin)){
promises.push(externalContexts[plugin].clean(Object.keys(flowConfig.allNodes)));
}
}
for (var id in contexts) {
if (contexts.hasOwnProperty(id) && id !== "global") {
var idParts = id.split(":");
if (!flowConfig.allNodes.hasOwnProperty(idParts[0])) {
delete contexts[id];
}
}
}
return Promise.all(promises);
}
function close() {
var promises = [];
for(var plugin in externalContexts){
if(externalContexts.hasOwnProperty(plugin)){
promises.push(externalContexts[plugin].close());
}
}
return Promise.all(promises);
}
module.exports = {
init: init,
load: load,
get: getContext,
delete: deleteContext,
clean: clean,
close: close
};