Изменение путей к модулям

server/core/Reader/ReaderStorage.js

@@ -0,0 +1,126 @@
+const SQL = require('sql-template-strings');
+const _ = require('lodash');
+
+const ConnManager = require('../../db/ConnManager');//singleton
+
+let instance = null;
+
+//singleton
+class ReaderStorage {
+    constructor() {
+        if (!instance) {
+            this.connManager = new ConnManager();
+            this.storagePool = this.connManager.pool.readerStorage;
+            this.periodicCleanCache(3*3600*1000);//1 раз в 3 часа
+
+            instance = this;
+        }
+
+        return instance;
+    }
+
+    async doAction(act) {
+        if (!_.isObject(act.items))
+            throw new Error('items is not an object');
+
+        let result = {};
+        switch (act.action) {
+            case 'check':
+                result = await this.checkItems(act.items);
+                break;
+            case 'get':
+                result = await this.getItems(act.items);
+                break;
+            case 'set':
+                result = await this.setItems(act.items, act.force);
+                break;
+            default:
+                throw new Error('Unknown action');
+        }
+
+        return result;
+    }
+
+    async checkItems(items) {
+        let result = {state: 'success', items: {}};
+
+        const dbh = await this.storagePool.get();
+        try {
+            for (const id of Object.keys(items)) {
+                if (this.cache[id]) {
+                    result.items[id] = this.cache[id];
+                } else {
+                    const rows = await dbh.all(SQL`SELECT rev FROM storage WHERE id = ${id}`);
+                    const rev = (rows.length && rows[0].rev ? rows[0].rev : 0);
+                    result.items[id] = {rev};
+                    this.cache[id] = result.items[id];
+                }
+            }
+        } finally {
+            dbh.ret();
+        }
+
+        return result;
+    }
+
+    async getItems(items) {
+        let result = {state: 'success', items: {}};
+
+        const dbh = await this.storagePool.get();
+        try {
+            for (const id of Object.keys(items)) {
+                const rows = await dbh.all(SQL`SELECT rev, data FROM storage WHERE id = ${id}`);                
+                const rev = (rows.length && rows[0].rev ? rows[0].rev : 0);
+                const data = (rows.length && rows[0].data ? rows[0].data : '');
+                result.items[id] = {rev, data};
+            }
+        } finally {
+            dbh.ret();
+        }
+
+        return result;
+    }
+
+    async setItems(items, force) {
+        let check = await this.checkItems(items);
+
+        //сначала проверим совпадение ревизий
+        for (const id of Object.keys(items)) {
+            if (!_.isString(items[id].data))
+                throw new Error('items.data is not a string');
+
+            if (!force && check.items[id].rev + 1 !== items[id].rev)
+                return {state: 'reject', items: check.items};
+        }
+
+        const dbh = await this.storagePool.get();
+        await dbh.run('BEGIN');
+        try {
+            const newRev = {};
+            for (const id of Object.keys(items)) {
+                await dbh.run(SQL`INSERT OR REPLACE INTO storage (id, rev, time, data) VALUES (${id}, ${items[id].rev}, strftime('%s','now'), ${items[id].data})`);
+                newRev[id] = {rev: items[id].rev};
+            }
+            await dbh.run('COMMIT');
+            
+            Object.assign(this.cache, newRev);
+        } catch (e) {
+            await dbh.run('ROLLBACK');
+            throw e;
+        } finally {
+            dbh.ret();
+        }
+
+        return {state: 'success'};
+    }
+
+    periodicCleanCache(timeout) {
+        this.cache = {};
+
+        setTimeout(() => {
+            this.periodicCleanCache(timeout);
+        }, timeout);
+    }
+}
+
+module.exports = ReaderStorage;