pip-services3-components-nodex
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Component definitions for Pip.Services in Node.js / ES2017
172 lines • 6.1 kB
JavaScript
;
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.MemoryStateStore = void 0;
const StateEntry_1 = require("./StateEntry");
/**
* State store that keeps states in the process memory.
*
* Remember: This implementation is not suitable for synchronization of distributed processes.
*
* ### Configuration parameters ###
*
* __options:__
* - timeout: default caching timeout in milliseconds (default: disabled)
*
* @see [[ICache]]
*
* ### Example ###
*
* let store = new MemoryStateStore();
*
* let value = await store.load("123", "key1");
* ...
* await store.save("123", "key1", "ABC");
*
*/
class MemoryStateStore {
/**
* Creates a new instance of the state store.
*/
constructor() {
this._states = {};
this._timeout = 0;
}
/**
* Configures component by passing configuration parameters.
*
* @param config configuration parameters to be set.
*/
configure(config) {
this._timeout = config.getAsLongWithDefault("options.timeout", this._timeout);
}
/**
* Clears component state.
*
* @param correlationId (optional) transaction id to trace execution through call chain.
* @param callback callback function that receives error or null no errors occured.
*/
cleanup() {
if (this._timeout == 0)
return;
let cutOffTime = new Date().getTime() - this._timeout;
// Cleanup obsolete entries
for (let prop in this._states) {
let entry = this._states[prop];
// Remove obsolete entry
if (entry.getLastUpdateTime() < cutOffTime) {
delete this._states[prop];
}
}
}
/**
* Loads stored value from the store using its key.
* If value is missing in the store it returns null.
*
* @param correlationId (optional) transaction id to trace execution through call chain.
* @param key a unique state key.
* @returns the state value or <code>null</code> if value wasn't found.
*/
load(correlationId, key) {
return __awaiter(this, void 0, void 0, function* () {
if (key == null) {
throw new Error('Key cannot be null');
}
// Cleanup the stored states
this.cleanup();
// Get entry from the store
let entry = this._states[key];
// Store has nothing
if (entry == null) {
return null;
}
return entry.getValue();
});
}
/**
* Loads an array of states from the store using their keys.
*
* @param correlationId (optional) transaction id to trace execution through call chain.
* @param keys unique state keys.
* @returns an array with state values.
*/
loadBulk(correlationId, keys) {
return __awaiter(this, void 0, void 0, function* () {
// Cleanup the stored states
this.cleanup();
let result = [];
for (let key of keys) {
let value = yield this.load(correlationId, key);
result.push({ key: key, value: value });
}
return result;
});
}
/**
* Saves state into the store
*
* @param correlationId (optional) transaction id to trace execution through call chain.
* @param key a unique state key.
* @param value a state value to store.
* @returns The value that was stored in the cache.
*/
save(correlationId, key, value) {
return __awaiter(this, void 0, void 0, function* () {
if (key == null) {
throw new Error('Key cannot be null');
}
// Cleanup the stored states
this.cleanup();
// Get the entry
let entry = this._states[key];
// Shortcut to remove entry from the cache
if (value == null) {
delete this._states[key];
return value;
}
// Update the entry
if (entry != null) {
entry.setValue(value);
}
// Or create a new entry
else {
entry = new StateEntry_1.StateEntry(key, value);
this._states[key] = entry;
}
return value;
});
}
/**
* Deletes a state from the store by its key.
*
* @param correlationId (optional) transaction id to trace execution through call chain.
* @param key a unique state key.
*/
delete(correlationId, key) {
return __awaiter(this, void 0, void 0, function* () {
if (key == null) {
throw new Error('Key cannot be null');
}
// Cleanup the stored states
this.cleanup();
// Get the entry
let entry = this._states[key];
// Remove entry from the cache
if (entry != null) {
delete this._states[key];
return entry.getValue();
}
return null;
});
}
}
exports.MemoryStateStore = MemoryStateStore;
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