feat: adding delta_reset_ms to TAKE and TAKEELEVATED responses (#80)

* adding delta_reset_ms to TAKE and TAKEELEVATED responses

* fix tests in makefile

* avoid negative delta_reset_ms

* added test coverage on delta_reset_ms for unlimited buckets

Makefile

@@ -1,16 +1,16 @@
 export CLUSTER_NO_TLS_VALIDATION=true
 
 test-standalone-setup:
-	docker-compose up -d
+	docker compose up -d
 
 test-standalone-teardown:
-	docker-compose down
+	docker compose down
 
 test-cluster-setup:
-	docker-compose -f docker-compose-cluster.yml up -d
+	docker compose -f docker-compose-cluster.yml up -d
 
 test-cluster-teardown:
-	docker-compose -f docker-compose-cluster.yml down
+	docker compose -f docker-compose-cluster.yml down
 
 test-cluster:
 	npm run test-cluster

README.md

@@ -267,7 +267,8 @@ The result object has:
 -  `conformant` (boolean): true if the requested amount is conformant to the limit.
 -  `remaining` (int): the amount of remaining tokens in the bucket.
 -  `reset` (int / unix timestamp): unix timestamp of the date when the bucket will be full again.
--  `limit` (int): the size of the bucket.
+-  `limit` (int): the size of the bucket. 
+-  `delta_reset_ms` (int): the time remaining until the bucket is full again, expressed in milliseconds from the current time.
 
 ## TAKEELEVATED
 
@@ -305,6 +306,7 @@ The result object has:
 -  `remaining` (int): the amount of remaining tokens in the bucket.
 -  `reset` (int / unix timestamp): unix timestamp of the date when the bucket will be full again.
 -  `limit` (int): the size of the bucket.
+-  `delta_reset_ms` (int): the time remaining until the bucket is full again, expressed in milliseconds from the current time.
 -  `elevated_limits` (object)
   -  `triggered` (boolean): true if ERL was triggered in the current request.
   -  `activated` (boolean): true if ERL is activated. Not necessarily triggered in this call.

lib/db.js

@@ -223,6 +223,7 @@ class LimitDBRedis extends EventEmitter {
         conformant: true,
         remaining: bucketKeyConfig.size,
         reset: Math.ceil(Date.now() / 1000),
+        delta_reset_ms: 0,
         limit: bucketKeyConfig.size,
         delayed: false,
       });
@@ -283,6 +284,7 @@ class LimitDBRedis extends EventEmitter {
             reset: Math.ceil(reset / 1000),
             limit: bucketKeyConfig.size,
             delayed: false,
+            delta_reset_ms: Math.max(reset - currentMS, 0)
           };
           if (bucketKeyConfig.skip_n_calls > 0) {
             this.callCounts.set(key, { res, count: 0 });
@@ -345,6 +347,7 @@ class LimitDBRedis extends EventEmitter {
               quota_allocated: elevated_limits.erl_quota,
               erl_activation_period_seconds: elevated_limits.erl_activation_period_seconds,
             },
+            delta_reset_ms: Math.max(reset - currentMS, 0),
           };
           if (bucketKeyConfig.skip_n_calls > 0) {
             this.callCounts.set(key, { res, count: 0 });

test/db.tests.js

@@ -272,6 +272,7 @@ module.exports.tests = (clientCreator) => {
                   assert.ok(result.conformant);
                   assert.equal(result.remaining, 9);
                   assert.closeTo(result.reset, now / 1000, 3);
+                  assert.closeTo(result.delta_reset_ms, (result.limit - result.remaining) * 1000/buckets.ip.per_second, 3);
                   assert.equal(result.limit, 10);
                   done();
                 });
@@ -291,6 +292,7 @@ module.exports.tests = (clientCreator) => {
               assert.ok(result.conformant);
               assert.equal(result.remaining, 9);
               assert.closeTo(result.reset, now / 1000, 3);
+              assert.closeTo(result.delta_reset_ms, (result.limit - result.remaining) * 1000/buckets.ip.per_second, 3);
               assert.equal(result.limit, 10);
               done();
             });
@@ -309,6 +311,7 @@ module.exports.tests = (clientCreator) => {
               assert.notOk(result.conformant);
               assert.equal(result.remaining, 10);
               assert.closeTo(result.reset, now / 1000, 3);
+              assert.closeTo(result.delta_reset_ms, (result.limit - result.remaining) * 1000/buckets.ip.per_second, 3);
               assert.equal(result.limit, 10);
               done();
             });
@@ -431,6 +434,7 @@ module.exports.tests = (clientCreator) => {
               assert.ok(lastResult.conformant);
               assert.equal(lastResult.remaining, 1);
               assert.closeTo(lastResult.reset, now / 1000, 3);
+              assert.closeTo(lastResult.delta_reset_ms, (lastResult.limit - lastResult.remaining) * 1000/buckets.ip.per_second, 100);
               assert.equal(lastResult.limit, 10);
               done();
             });
@@ -446,6 +450,7 @@ module.exports.tests = (clientCreator) => {
               assert.ok(result.conformant);
               assert.equal(result.remaining, 0);
               assert.closeTo(result.reset, now / 1000 + 1800, 1);
+              assert.closeTo(result.delta_reset_ms, (result.limit - result.remaining) * 3600000/buckets.ip.overrides['10.0.0.1'].per_hour, 1);
               assert.equal(result.limit, 1);
               done();
             });
@@ -460,6 +465,7 @@ module.exports.tests = (clientCreator) => {
               assert.equal(response.limit, 100);
               assert.equal(response.remaining, 100);
               assert.closeTo(response.reset, now / 1000, 1);
+              assert.closeTo(response.delta_reset_ms, (response.limit - response.remaining) * 1000/buckets.ip.per_second, 1);
               done();
             });
           });
@@ -695,6 +701,46 @@ module.exports.tests = (clientCreator) => {
               });
             });
           });
+
+          describe(`${testParams.name} delta_reset_ms`, () => {
+            it('should reset the bucket after the specified interval', (done) => {
+              db.configurateBuckets({ 'test_bucket': { size: 100, per_second: 100 } });
+              const params = { ...testParams.params, type: 'test_bucket', key: 'delta_key', count: 100 };
+              testParams.take(params, (err, res) => {
+                if (err) {
+                  done(err);
+                }
+                assert.isTrue(res.conformant);
+                assert.equal(res.remaining, 0);
+                assert.notEqual(res.delta_reset_ms, 0);
+
+                setTimeout(() => {
+                  params.count = 1;
+                  testParams.take(params, (err, res) => {
+                    if (err) {
+                      done(err);
+                    }
+                    assert.isTrue(res.conformant);
+                    assert.notEqual(res.delta_reset_ms, 0);
+                    done();
+                  });
+                }, res.delta_reset_ms);
+              });
+            });
+
+            it('should set delta_reset_ms to 0 when bucket is unlimited', (done) => {
+              db.configurateBuckets({ 'test_bucket': { size: 100, unlimited: true } });
+              const params = { ...testParams.params, type: 'test_bucket', key: 'delta_key', count: 100 };
+              testParams.take(params, (err, res) => {
+                if (err) {
+                  done(err);
+                }
+                assert.isTrue(res.conformant);
+                assert.equal(res.delta_reset_ms, 0);
+                done();
+              });
+            });
+          });
         });
       });
 
@@ -720,6 +766,7 @@ module.exports.tests = (clientCreator) => {
           }
           const dayFromNow = Date.now() + oneDayInMs;
           assert.closeTo(response.reset, dayFromNow / 1000, 3);
+          assert.closeTo(response.delta_reset_ms, (response.limit - response.remaining) * 24*60*60*1000, 3);
           done();
         });
       });
@@ -737,6 +784,7 @@ module.exports.tests = (clientCreator) => {
 
           const dayFromNow = Date.now() + oneDayInMs;
           assert.closeTo(response.reset, dayFromNow / 1000, 3);
+          assert.closeTo(response.delta_reset_ms, (response.limit - response.remaining) * 24*60*60*1000, 3);
           done();
         });
       });
@@ -2146,6 +2194,7 @@ module.exports.tests = (clientCreator) => {
               if (err) return done(err);
               const dayFromNow = Date.now() + oneDayInMs;
               assert.closeTo(response.reset, dayFromNow / 1000, 3);
+              assert.closeTo(response.delta_reset_ms, (response.limit - response.remaining) * 24*60*60*1000, 3);
               done();
             });
           });
@@ -2165,6 +2214,7 @@ module.exports.tests = (clientCreator) => {
               assert.equal(response.remaining, 3);
               const dayFromNow = Date.now() + oneDayInMs;
               assert.closeTo(response.reset, dayFromNow / 1000, 3);
+              assert.closeTo(response.delta_reset_ms, (response.limit - response.remaining) * 24*60*60*1000, 3);
               done();
             });
           });
@@ -2297,6 +2347,7 @@ module.exports.tests = (clientCreator) => {
           assert.notOk(response.delayed);
           assert.equal(response.remaining, 9);
           assert.closeTo(response.reset, now / 1000, 3);
+          assert.closeTo(response.delta_reset_ms, (response.limit - response.remaining) * 1000/buckets.ip.per_second, 3);
           done();
         });
       });