server-ts: Port share/sql

src/share/sql.ts

@@ -0,0 +1,34 @@
+"use strict";
+
+import Database = require('better-sqlite3');
+import dataDir = require('../services/data_dir');
+
+const dbConnection = new Database(dataDir.DOCUMENT_PATH, { readonly: true });
+
+[`exit`, `SIGINT`, `SIGUSR1`, `SIGUSR2`, `SIGTERM`].forEach(eventType => {
+    process.on(eventType, () => {
+        if (dbConnection) {
+            // closing connection is especially important to fold -wal file into the main DB file
+            // (see https://sqlite.org/tempfiles.html for details)
+            dbConnection.close();
+        }
+    });
+});
+
+function getRawRows<T>(query: string, params = []): T[] {
+    return dbConnection.prepare(query).raw().all(params) as T[];
+}
+
+function getRow<T>(query: string, params = []): T {
+    return dbConnection.prepare(query).get(params) as T;
+}
+
+function getColumn<T>(query: string, params = []): T[] {
+    return dbConnection.prepare(query).pluck().all(params) as T[];
+}
+
+export = {
+    getRawRows,
+    getRow,
+    getColumn
+};