Make JavaCompatiblePartitioner new default

docs/Producing.md

@@ -213,16 +213,20 @@ kafka.producer({ createPartitioner: MyPartitioner })
 
 ### Default Partitioners
 
-KafkaJS ships with 2 partitioners: `DefaultPartitioner` and `JavaCompatiblePartitioner`.
-
-The `JavaCompatiblePartitioner` should be compatible with the default partitioner that ships with the Java Kafka client. This can be important to meet the [co-partitioning requirement](https://docs.confluent.io/current/ksql/docs/developer-guide/partition-data.html#co-partitioning-requirements) when joining multiple topics.
-
-Use the `JavaCompatiblePartitioner` by importing it and providing it to the Producer constructor:
-
-```javascript
-const { Partitioners } = require('kafkajs')
-kafka.producer({ createPartitioner: Partitioners.JavaCompatiblePartitioner })
-```
+KafkaJS ships with 2 partitioners: `DefaultPartitioner` and `LegacyPartitioner`.
+
+The `DefaultPartitioner` should be compatible with the default partitioner that ships with the Java Kafka client. This can be important to meet the [co-partitioning requirement](https://docs.confluent.io/current/ksql/docs/developer-guide/partition-data.html#co-partitioning-requirements) when joining multiple topics.
+
+> 🚨 **Important**  🚨
+> 
+> **The `LegacyPartitioner` was the default until v2.0.0. If you are upgrading from a version
+older and want to retain the previous partitioning behavior, use the `LegacyPartitioner`
+by importing it and providing it to the Producer constructor:**
+> 
+> ```javascript
+> const { Partitioners } = require('kafkajs')
+> kafka.producer({ createPartitioner: Partitioners.LegacyPartitioner })
+> ```
 
 ## <a name="retry"></a> Retry
 

src/index.js

@@ -11,6 +11,8 @@ const createConsumer = require('./consumer')
 const createAdmin = require('./admin')
 const ISOLATION_LEVEL = require('./protocol/isolationLevel')
 const defaultSocketFactory = require('./network/socketFactory')
+const once = require('./utils/once')
+const websiteUrl = require('./utils/websiteUrl')
 
 const PRIVATE = {
   CREATE_CLUSTER: Symbol('private:Kafka:createCluster'),
@@ -20,6 +22,16 @@ const PRIVATE = {
 }
 
 const DEFAULT_METADATA_MAX_AGE = 300000
+const warnOfDefaultPartitioner = once(logger => {
+  if (process.env.KAFKAJS_NO_PARTITIONER_WARNING == null) {
+    logger.warn(
+      `KafkaJS v2.0.0 switched default partitioner. To retain the same partitioning behavior as in previous versions, create the producer with the option "createPartitioner: Partitioners.LegacyPartitioner". See ${websiteUrl(
+        'docs/producing',
+        'default-partitioners'
+      )} for details. Silence this warning by setting the environment variable "KAFKAJS_NO_PARTITIONER_WARNING=1"`
+    )
+  }
+})
 
 module.exports = class Client {
   /**
@@ -104,6 +116,10 @@ module.exports = class Client {
       instrumentationEmitter,
     })
 
+    if (createPartitioner == null) {
+      warnOfDefaultPartitioner(this[PRIVATE.LOGGER])
+    }
+
     return createProducer({
       retry: { ...this[PRIVATE.CLUSTER_RETRY], ...retry },
       logger: this[PRIVATE.LOGGER],

src/producer/partitioners/default/index.js

@@ -1,4 +1,4 @@
 const murmur2 = require('./murmur2')
-const createDefaultPartitioner = require('./partitioner')
+const createDefaultPartitioner = require('../legacy/partitioner')
 
 module.exports = createDefaultPartitioner(murmur2)

src/producer/partitioners/default/murmur2.js

@@ -1,22 +1,23 @@
 /* eslint-disable */
+const Long = require('../../../utils/long')
 
 // Based on the kafka client 0.10.2 murmur2 implementation
 // https://github.com/apache/kafka/blob/0.10.2/clients/src/main/java/org/apache/kafka/common/utils/Utils.java#L364
 
-const SEED = 0x9747b28c
+const SEED = Long.fromValue(0x9747b28c)
 
 // 'm' and 'r' are mixing constants generated offline.
 // They're not really 'magic', they just happen to work well.
-const M = 0x5bd1e995
-const R = 24
+const M = Long.fromValue(0x5bd1e995)
+const R = Long.fromValue(24)
 
 module.exports = key => {
   const data = Buffer.isBuffer(key) ? key : Buffer.from(String(key))
   const length = data.length
 
   // Initialize the hash to a random value
-  let h = SEED ^ length
-  let length4 = length / 4
+  let h = Long.fromValue(SEED.xor(length))
+  let length4 = Math.floor(length / 4)
 
   for (let i = 0; i < length4; i++) {
     const i4 = i * 4
@@ -25,27 +26,28 @@ module.exports = key => {
       ((data[i4 + 1] & 0xff) << 8) +
       ((data[i4 + 2] & 0xff) << 16) +
       ((data[i4 + 3] & 0xff) << 24)
-    k *= M
-    k ^= k >>> R
-    k *= M
-    h *= M
-    h ^= k
+    k = Long.fromValue(k)
+    k = k.multiply(M)
+    k = k.xor(k.toInt() >>> R)
+    k = Long.fromValue(k).multiply(M)
+    h = h.multiply(M)
+    h = h.xor(k)
   }
 
   // Handle the last few bytes of the input array
   switch (length % 4) {
     case 3:
-      h ^= (data[(length & ~3) + 2] & 0xff) << 16
+      h = h.xor((data[(length & ~3) + 2] & 0xff) << 16)
     case 2:
-      h ^= (data[(length & ~3) + 1] & 0xff) << 8
+      h = h.xor((data[(length & ~3) + 1] & 0xff) << 8)
     case 1:
-      h ^= data[length & ~3] & 0xff
-      h *= M
+      h = h.xor(data[length & ~3] & 0xff)
+      h = h.multiply(M)
   }
 
-  h ^= h >>> 13
-  h *= M
-  h ^= h >>> 15
+  h = h.xor(h.toInt() >>> 13)
+  h = h.multiply(M)
+  h = h.xor(h.toInt() >>> 15)
 
-  return h
+  return h.toInt()
 }

src/producer/partitioners/default/murmur2.spec.js

@@ -8,29 +8,31 @@ describe('Producer > Partitioner > Default > murmur2', () => {
   })
 
   test('it handles numeric input', () => {
-    expect(murmur2(0)).toEqual(272173970)
+    expect(murmur2(0)).toEqual(971027396)
   })
 
   test('it handles buffer input', () => {
-    expect(murmur2(Buffer.from('1'))).toEqual(1311020360)
+    expect(murmur2(Buffer.from('1'))).toEqual(-1993445489)
   })
 })
 
+// Generated with src/producer/partitioners/defaultJava/Test.java
 const testData = {
-  '0': 272173970,
-  '1': 1311020360,
-  '128': 2053105854,
-  '2187': -2081355488,
-  '16384': 204404061,
-  '78125': -677491393,
-  '279936': -622460209,
-  '823543': 651276451,
-  '2097152': 944683677,
-  '4782969': -892695770,
-  '10000000': -1778616326,
-  '19487171': -518311627,
-  '35831808': 556972389,
-  '62748517': -233806557,
-  '105413504': -109398538,
-  '170859375': 102939717,
+  '0': 971027396,
+  '1': -1993445489,
+  '128': -326012175,
+  '2187': -1508407203,
+  '16384': -325739742,
+  '78125': -1654490814,
+  '279936': 1462227128,
+  '823543': -2014198330,
+  '2097152': 607668903,
+  '4782969': -1182699775,
+  '10000000': -1830336757,
+  '19487171': -1603849305,
+  '35831808': -857013643,
+  '62748517': -1167431028,
+  '105413504': -381294639,
+  '170859375': -1658323481,
+  '100:48069': 1009543857,
 }

src/producer/partitioners/index.js

@@ -1,7 +1,14 @@
 const DefaultPartitioner = require('./default')
-const JavaCompatiblePartitioner = require('./defaultJava')
+const LegacyPartitioner = require('./legacy')
 
 module.exports = {
   DefaultPartitioner,
-  JavaCompatiblePartitioner,
+  LegacyPartitioner,
+  /**
+   * @deprecated Use DefaultPartitioner instead
+   *
+   * The JavaCompatiblePartitioner was renamed DefaultPartitioner
+   * and made to be the default in 2.0.0.
+   */
+  JavaCompatiblePartitioner: DefaultPartitioner,
 }

src/producer/partitioners/legacy/index.js

@@ -0,0 +1,4 @@
+const murmur2 = require('./murmur2')
+const createLegacyPartitioner = require('./partitioner')
+
+module.exports = createLegacyPartitioner(murmur2)

src/producer/partitioners/default/index.spec.js → src/producer/partitioners/legacy/index.spec.js

@@ -1,6 +1,6 @@
 const createPartitioner = require('./index')
 
-describe('Producer > Partitioner > Default', () => {
+describe('Producer > Partitioner > Legacy', () => {
   let topic, partitioner, partitionMetadata
 
   beforeEach(() => {

src/producer/partitioners/defaultJava/murmur2.js → src/producer/partitioners/legacy/murmur2.js

@@ -1,23 +1,22 @@
 /* eslint-disable */
-const Long = require('../../../utils/long')
 
 // Based on the kafka client 0.10.2 murmur2 implementation
 // https://github.com/apache/kafka/blob/0.10.2/clients/src/main/java/org/apache/kafka/common/utils/Utils.java#L364
 
-const SEED = Long.fromValue(0x9747b28c)
+const SEED = 0x9747b28c
 
 // 'm' and 'r' are mixing constants generated offline.
 // They're not really 'magic', they just happen to work well.
-const M = Long.fromValue(0x5bd1e995)
-const R = Long.fromValue(24)
+const M = 0x5bd1e995
+const R = 24
 
 module.exports = key => {
   const data = Buffer.isBuffer(key) ? key : Buffer.from(String(key))
   const length = data.length
 
   // Initialize the hash to a random value
-  let h = Long.fromValue(SEED.xor(length))
-  let length4 = Math.floor(length / 4)
+  let h = SEED ^ length
+  let length4 = length / 4
 
   for (let i = 0; i < length4; i++) {
     const i4 = i * 4
@@ -26,28 +25,27 @@ module.exports = key => {
       ((data[i4 + 1] & 0xff) << 8) +
       ((data[i4 + 2] & 0xff) << 16) +
       ((data[i4 + 3] & 0xff) << 24)
-    k = Long.fromValue(k)
-    k = k.multiply(M)
-    k = k.xor(k.toInt() >>> R)
-    k = Long.fromValue(k).multiply(M)
-    h = h.multiply(M)
-    h = h.xor(k)
+    k *= M
+    k ^= k >>> R
+    k *= M
+    h *= M
+    h ^= k
   }
 
   // Handle the last few bytes of the input array
   switch (length % 4) {
     case 3:
-      h = h.xor((data[(length & ~3) + 2] & 0xff) << 16)
+      h ^= (data[(length & ~3) + 2] & 0xff) << 16
     case 2:
-      h = h.xor((data[(length & ~3) + 1] & 0xff) << 8)
+      h ^= (data[(length & ~3) + 1] & 0xff) << 8
     case 1:
-      h = h.xor(data[length & ~3] & 0xff)
-      h = h.multiply(M)
+      h ^= data[length & ~3] & 0xff
+      h *= M
   }
 
-  h = h.xor(h.toInt() >>> 13)
-  h = h.multiply(M)
-  h = h.xor(h.toInt() >>> 15)
+  h ^= h >>> 13
+  h *= M
+  h ^= h >>> 15
 
-  return h.toInt()
+  return h
 }

src/producer/partitioners/legacy/murmur2.spec.js

@@ -0,0 +1,36 @@
+const murmur2 = require('./murmur2')
+
+describe('Producer > Partitioner > Default > murmur2', () => {
+  test('it works', () => {
+    Object.keys(testData).forEach(key => {
+      expect(murmur2(key)).toEqual(testData[key])
+    })
+  })
+
+  test('it handles numeric input', () => {
+    expect(murmur2(0)).toEqual(272173970)
+  })
+
+  test('it handles buffer input', () => {
+    expect(murmur2(Buffer.from('1'))).toEqual(1311020360)
+  })
+})
+
+const testData = {
+  '0': 272173970,
+  '1': 1311020360,
+  '128': 2053105854,
+  '2187': -2081355488,
+  '16384': 204404061,
+  '78125': -677491393,
+  '279936': -622460209,
+  '823543': 651276451,
+  '2097152': 944683677,
+  '4782969': -892695770,
+  '10000000': -1778616326,
+  '19487171': -518311627,
+  '35831808': 556972389,
+  '62748517': -233806557,
+  '105413504': -109398538,
+  '170859375': 102939717,
+}

src/utils/once.js

@@ -0,0 +1,10 @@
+module.exports = fn => {
+  let called = false
+
+  return (...args) => {
+    if (!called) {
+      called = true
+      return fn(...args)
+    }
+  }
+}