First commit

framework/node_modules/node-rate-limiter-flexible/lib/RateLimiterMemcache.js

@@ -0,0 +1,150 @@
+const RateLimiterStoreAbstract = require('./RateLimiterStoreAbstract');
+const RateLimiterRes = require('./RateLimiterRes');
+
+class RateLimiterMemcache extends RateLimiterStoreAbstract {
+  /**
+   *
+   * @param {Object} opts
+   * Defaults {
+   *   ... see other in RateLimiterStoreAbstract
+   *
+   *   storeClient: memcacheClient
+   * }
+   */
+  constructor(opts) {
+    super(opts);
+
+    this.client = opts.storeClient;
+  }
+
+  _getRateLimiterRes(rlKey, changedPoints, result) {
+    const res = new RateLimiterRes();
+    res.consumedPoints = parseInt(result.consumedPoints);
+    res.isFirstInDuration = result.consumedPoints === changedPoints;
+    res.remainingPoints = Math.max(this.points - res.consumedPoints, 0);
+    res.msBeforeNext = result.msBeforeNext;
+
+    return res;
+  }
+
+  _upsert(rlKey, points, msDuration, forceExpire = false, options = {}) {
+    return new Promise((resolve, reject) => {
+      const nowMs = Date.now();
+      const secDuration = Math.floor(msDuration / 1000);
+
+      if (forceExpire) {
+        this.client.set(rlKey, points, secDuration, (err) => {
+          if (!err) {
+            this.client.set(
+              `${rlKey}_expire`,
+              secDuration > 0 ? nowMs + (secDuration * 1000) : -1,
+              secDuration,
+              () => {
+                const res = {
+                  consumedPoints: points,
+                  msBeforeNext: secDuration > 0 ? secDuration * 1000 : -1,
+                };
+                resolve(res);
+              }
+            );
+          } else {
+            reject(err);
+          }
+        });
+      } else {
+        this.client.incr(rlKey, points, (err, consumedPoints) => {
+          if (err || consumedPoints === false) {
+            this.client.add(rlKey, points, secDuration, (errAddKey, createdNew) => {
+              if (errAddKey || !createdNew) {
+                // Try to upsert again in case of race condition
+                if (typeof options.attemptNumber === 'undefined' || options.attemptNumber < 3) {
+                  const nextOptions = Object.assign({}, options);
+                  nextOptions.attemptNumber = nextOptions.attemptNumber ? (nextOptions.attemptNumber + 1) : 1;
+
+                  this._upsert(rlKey, points, msDuration, forceExpire, nextOptions)
+                    .then(resUpsert => resolve(resUpsert))
+                    .catch(errUpsert => reject(errUpsert));
+                } else {
+                  reject(new Error('Can not add key'));
+                }
+              } else {
+                this.client.add(
+                  `${rlKey}_expire`,
+                  secDuration > 0 ? nowMs + (secDuration * 1000) : -1,
+                  secDuration,
+                  () => {
+                    const res = {
+                      consumedPoints: points,
+                      msBeforeNext: secDuration > 0 ? secDuration * 1000 : -1,
+                    };
+                    resolve(res);
+                  }
+                );
+              }
+            });
+          } else {
+            this.client.get(`${rlKey}_expire`, (errGetExpire, resGetExpireMs) => {
+              if (errGetExpire) {
+                reject(errGetExpire);
+              } else {
+                const expireMs = resGetExpireMs === false ? 0 : resGetExpireMs;
+                const res = {
+                  consumedPoints,
+                  msBeforeNext: expireMs >= 0 ? Math.max(expireMs - nowMs, 0) : -1,
+                };
+                resolve(res);
+              }
+            });
+          }
+        });
+      }
+    });
+  }
+
+  _get(rlKey) {
+    return new Promise((resolve, reject) => {
+      const nowMs = Date.now();
+
+      this.client.get(rlKey, (err, consumedPoints) => {
+        if (!consumedPoints) {
+          resolve(null);
+        } else {
+          this.client.get(`${rlKey}_expire`, (errGetExpire, resGetExpireMs) => {
+            if (errGetExpire) {
+              reject(errGetExpire);
+            } else {
+              const expireMs = resGetExpireMs === false ? 0 : resGetExpireMs;
+              const res = {
+                consumedPoints,
+                msBeforeNext: expireMs >= 0 ? Math.max(expireMs - nowMs, 0) : -1,
+              };
+              resolve(res);
+            }
+          });
+        }
+      });
+    });
+  }
+
+  _delete(rlKey) {
+    return new Promise((resolve, reject) => {
+      this.client.del(rlKey, (err, res) => {
+        if (err) {
+          reject(err);
+        } else if (res === false) {
+          resolve(res);
+        } else {
+          this.client.del(`${rlKey}_expire`, (errDelExpire) => {
+            if (errDelExpire) {
+              reject(errDelExpire);
+            } else {
+              resolve(res);
+            }
+          });
+        }
+      });
+    });
+  }
+}
+
+module.exports = RateLimiterMemcache;