Implement query API function

server/api-functions.js

@@ -0,0 +1,106 @@
+"use strict";
+
+const http = require("http");
+const https = require("https");
+const url = require("url");
+const querystring = require("querystring");
+
+const config = require("./config");
+
+const commaAscii = ",".charCodeAt(0);
+const newLineAscii = "\n".charCodeAt(0);
+
+function filtersToQuery(filters) {
+  if (!Array.isArray(filters)) filters = [filters];
+
+  let queries = [];
+  for (let filter of filters) {
+    let q = {};
+    for (let [k, v] of Object.entries(filter)) {
+      let [param, op] = k.split(/([^a-zA-Z0-9\-_.].*)/, 2);
+      if (!op || op === "=") q[param] = v;
+      else throw new Error(`Operator "${op}" not recognized`);
+    }
+    queries.push(q);
+  }
+
+  if (queries.length === 1) return queries[0];
+  else return { $or: queries };
+}
+
+function query(resource, filters, limit, callback) {
+  return new Promise((resolve, reject) => {
+    let ret;
+    if (!callback) ret = [];
+    let q = {};
+    if (filters) q.query = JSON.stringify(filtersToQuery(filters));
+
+    if (limit) q.limit = limit;
+
+    let options = url.parse(
+      `${config.GENIEACS_NBI}${resource}?${querystring.stringify(q)}`
+    );
+
+    let _http = options.protocol === "https:" ? https : http;
+
+    _http.get(options, res => {
+      let chunks = [];
+      let bytes = 0;
+      res.on("data", chunk => {
+        let i;
+        while ((i = chunk.indexOf(newLineAscii)) !== -1) {
+          let buf;
+          if (chunk[chunk.length - 2] === commaAscii) {
+            i -= 1;
+            buf = new Buffer(bytes + i);
+            chunk.copy(buf, buf.length - i, 0, i);
+            chunk = chunk.slice(i + 2);
+          } else {
+            buf = new Buffer(bytes + i);
+            chunk.copy(buf, buf.length - i, 0, i);
+            chunk = chunk.slice(i + 1);
+          }
+
+          let o = 0;
+          for (let c of chunks) {
+            c.copy(buf, o, 0, c.length);
+            o += c.length;
+          }
+
+          if (buf.length > 1) {
+            let obj = JSON.parse(buf);
+            if (ret) ret.push(obj);
+            else callback(obj);
+          }
+
+          bytes = 0;
+          chunks = [];
+        }
+        bytes += chunk.length;
+        chunks.push(chunk);
+      });
+
+      res.on("end", () => {
+        let buf = new Buffer(bytes);
+        let o = 0;
+        for (let c of chunks) {
+          c.copy(buf, o, 0, c.length);
+          o += c.length;
+        }
+        if (buf.length > 1) {
+          let obj = JSON.parse(buf);
+          if (ret) ret.push(obj);
+          else callback(obj);
+        }
+        resolve(ret);
+      });
+
+      res.on("aborted", () => {
+        res.removeAllListeners("end");
+        reject(new Error("Timeout"));
+      });
+    });
+  });
+}
+
+exports.query = query;

server/config.js

@@ -1,3 +1,4 @@
 "use strict";
 
 exports.PORT = 3000;
+exports.GENIEACS_NBI = "http://127.0.0.1:7557/";