VOL-1967 move api-server to separate repository
Current with voltha-go acf0adaf2d91ae72b55192cc8a939e0485918d16
Change-Id: I000ea6be0789e20c922bd671562b58a7120892ae
diff --git a/vendor/github.com/Shopify/sarama/partitioner.go b/vendor/github.com/Shopify/sarama/partitioner.go
new file mode 100644
index 0000000..6a708e7
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/partitioner.go
@@ -0,0 +1,217 @@
+package sarama
+
+import (
+ "hash"
+ "hash/fnv"
+ "math/rand"
+ "time"
+)
+
+// Partitioner is anything that, given a Kafka message and a number of partitions indexed [0...numPartitions-1],
+// decides to which partition to send the message. RandomPartitioner, RoundRobinPartitioner and HashPartitioner are provided
+// as simple default implementations.
+type Partitioner interface {
+ // Partition takes a message and partition count and chooses a partition
+ Partition(message *ProducerMessage, numPartitions int32) (int32, error)
+
+ // RequiresConsistency indicates to the user of the partitioner whether the
+ // mapping of key->partition is consistent or not. Specifically, if a
+ // partitioner requires consistency then it must be allowed to choose from all
+ // partitions (even ones known to be unavailable), and its choice must be
+ // respected by the caller. The obvious example is the HashPartitioner.
+ RequiresConsistency() bool
+}
+
+// DynamicConsistencyPartitioner can optionally be implemented by Partitioners
+// in order to allow more flexibility than is originally allowed by the
+// RequiresConsistency method in the Partitioner interface. This allows
+// partitioners to require consistency sometimes, but not all times. It's useful
+// for, e.g., the HashPartitioner, which does not require consistency if the
+// message key is nil.
+type DynamicConsistencyPartitioner interface {
+ Partitioner
+
+ // MessageRequiresConsistency is similar to Partitioner.RequiresConsistency,
+ // but takes in the message being partitioned so that the partitioner can
+ // make a per-message determination.
+ MessageRequiresConsistency(message *ProducerMessage) bool
+}
+
+// PartitionerConstructor is the type for a function capable of constructing new Partitioners.
+type PartitionerConstructor func(topic string) Partitioner
+
+type manualPartitioner struct{}
+
+// HashPartitionOption lets you modify default values of the partitioner
+type HashPartitionerOption func(*hashPartitioner)
+
+// WithAbsFirst means that the partitioner handles absolute values
+// in the same way as the reference Java implementation
+func WithAbsFirst() HashPartitionerOption {
+ return func(hp *hashPartitioner) {
+ hp.referenceAbs = true
+ }
+}
+
+// WithCustomHashFunction lets you specify what hash function to use for the partitioning
+func WithCustomHashFunction(hasher func() hash.Hash32) HashPartitionerOption {
+ return func(hp *hashPartitioner) {
+ hp.hasher = hasher()
+ }
+}
+
+// WithCustomFallbackPartitioner lets you specify what HashPartitioner should be used in case a Distribution Key is empty
+func WithCustomFallbackPartitioner(randomHP *hashPartitioner) HashPartitionerOption {
+ return func(hp *hashPartitioner) {
+ hp.random = hp
+ }
+}
+
+// NewManualPartitioner returns a Partitioner which uses the partition manually set in the provided
+// ProducerMessage's Partition field as the partition to produce to.
+func NewManualPartitioner(topic string) Partitioner {
+ return new(manualPartitioner)
+}
+
+func (p *manualPartitioner) Partition(message *ProducerMessage, numPartitions int32) (int32, error) {
+ return message.Partition, nil
+}
+
+func (p *manualPartitioner) RequiresConsistency() bool {
+ return true
+}
+
+type randomPartitioner struct {
+ generator *rand.Rand
+}
+
+// NewRandomPartitioner returns a Partitioner which chooses a random partition each time.
+func NewRandomPartitioner(topic string) Partitioner {
+ p := new(randomPartitioner)
+ p.generator = rand.New(rand.NewSource(time.Now().UTC().UnixNano()))
+ return p
+}
+
+func (p *randomPartitioner) Partition(message *ProducerMessage, numPartitions int32) (int32, error) {
+ return int32(p.generator.Intn(int(numPartitions))), nil
+}
+
+func (p *randomPartitioner) RequiresConsistency() bool {
+ return false
+}
+
+type roundRobinPartitioner struct {
+ partition int32
+}
+
+// NewRoundRobinPartitioner returns a Partitioner which walks through the available partitions one at a time.
+func NewRoundRobinPartitioner(topic string) Partitioner {
+ return &roundRobinPartitioner{}
+}
+
+func (p *roundRobinPartitioner) Partition(message *ProducerMessage, numPartitions int32) (int32, error) {
+ if p.partition >= numPartitions {
+ p.partition = 0
+ }
+ ret := p.partition
+ p.partition++
+ return ret, nil
+}
+
+func (p *roundRobinPartitioner) RequiresConsistency() bool {
+ return false
+}
+
+type hashPartitioner struct {
+ random Partitioner
+ hasher hash.Hash32
+ referenceAbs bool
+}
+
+// NewCustomHashPartitioner is a wrapper around NewHashPartitioner, allowing the use of custom hasher.
+// The argument is a function providing the instance, implementing the hash.Hash32 interface. This is to ensure that
+// each partition dispatcher gets its own hasher, to avoid concurrency issues by sharing an instance.
+func NewCustomHashPartitioner(hasher func() hash.Hash32) PartitionerConstructor {
+ return func(topic string) Partitioner {
+ p := new(hashPartitioner)
+ p.random = NewRandomPartitioner(topic)
+ p.hasher = hasher()
+ p.referenceAbs = false
+ return p
+ }
+}
+
+// NewCustomPartitioner creates a default Partitioner but lets you specify the behavior of each component via options
+func NewCustomPartitioner(options ...HashPartitionerOption) PartitionerConstructor {
+ return func(topic string) Partitioner {
+ p := new(hashPartitioner)
+ p.random = NewRandomPartitioner(topic)
+ p.hasher = fnv.New32a()
+ p.referenceAbs = false
+ for _, option := range options {
+ option(p)
+ }
+ return p
+ }
+}
+
+// NewHashPartitioner returns a Partitioner which behaves as follows. If the message's key is nil then a
+// random partition is chosen. Otherwise the FNV-1a hash of the encoded bytes of the message key is used,
+// modulus the number of partitions. This ensures that messages with the same key always end up on the
+// same partition.
+func NewHashPartitioner(topic string) Partitioner {
+ p := new(hashPartitioner)
+ p.random = NewRandomPartitioner(topic)
+ p.hasher = fnv.New32a()
+ p.referenceAbs = false
+ return p
+}
+
+// NewReferenceHashPartitioner is like NewHashPartitioner except that it handles absolute values
+// in the same way as the reference Java implementation. NewHashPartitioner was supposed to do
+// that but it had a mistake and now there are people depending on both behaviours. This will
+// all go away on the next major version bump.
+func NewReferenceHashPartitioner(topic string) Partitioner {
+ p := new(hashPartitioner)
+ p.random = NewRandomPartitioner(topic)
+ p.hasher = fnv.New32a()
+ p.referenceAbs = true
+ return p
+}
+
+func (p *hashPartitioner) Partition(message *ProducerMessage, numPartitions int32) (int32, error) {
+ if message.Key == nil {
+ return p.random.Partition(message, numPartitions)
+ }
+ bytes, err := message.Key.Encode()
+ if err != nil {
+ return -1, err
+ }
+ p.hasher.Reset()
+ _, err = p.hasher.Write(bytes)
+ if err != nil {
+ return -1, err
+ }
+ var partition int32
+ // Turns out we were doing our absolute value in a subtly different way from the upstream
+ // implementation, but now we need to maintain backwards compat for people who started using
+ // the old version; if referenceAbs is set we are compatible with the reference java client
+ // but not past Sarama versions
+ if p.referenceAbs {
+ partition = (int32(p.hasher.Sum32()) & 0x7fffffff) % numPartitions
+ } else {
+ partition = int32(p.hasher.Sum32()) % numPartitions
+ if partition < 0 {
+ partition = -partition
+ }
+ }
+ return partition, nil
+}
+
+func (p *hashPartitioner) RequiresConsistency() bool {
+ return true
+}
+
+func (p *hashPartitioner) MessageRequiresConsistency(message *ProducerMessage) bool {
+ return message.Key != nil
+}