add flatbuffer serde for message

go.mod

@@ -183,6 +183,7 @@ require (
 	github.com/fatih/color v1.13.0 // indirect
 	github.com/fclairamb/go-log v0.3.0 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/google/flatbuffers v2.0.6+incompatible // indirect
 	github.com/googleapis/enterprise-certificate-proxy v0.1.0 // indirect
 	github.com/grpc-ecosystem/go-grpc-middleware v1.1.0 // indirect
 	github.com/hashicorp/go-hclog v1.2.0 // indirect

go.sum

@@ -411,6 +411,8 @@ github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Z
 github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/btree v1.1.2 h1:xf4v41cLI2Z6FxbKm+8Bu+m8ifhj15JuZ9sa0jZCMUU=
 github.com/google/btree v1.1.2/go.mod h1:qOPhT0dTNdNzV6Z/lhRX0YXUafgPLFUh+gZMl761Gm4=
+github.com/google/flatbuffers v2.0.6+incompatible h1:XHFReMv7nFFusa+CEokzWbzaYocKXI6C7hdU5Kgh9Lw=
+github.com/google/flatbuffers v2.0.6+incompatible/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=

weed/mq/README.md

@@ -0,0 +1,66 @@
+# SeaweedMQ Message Queue on SeaweedFS (WIP, not ready)
+
+## What are the use cases it is designed for?
+
+Message queues are like water pipes. Messages flow in the pipes to their destinations.
+
+However, what if a flood comes? Of course, you can increase the number of partitions, add more brokers, restart, 
+and watch the traffic level closely.
+
+Sometimes the flood is expected. For example, backfill some old data in batch, and switch to online messages. 
+You may want to ensure enough brokers to handle the data and reduce them later to cut cost.
+
+SeaweedMQ is designed for use cases that need to:
+* Receive and save large number of messages.
+* Handle spike traffic automatically.
+
+## What is special about SeaweedMQ?
+
+* Separate computation and storage nodes that scales independently.
+  * Offline messages can be operated as normal files.
+  * Unlimited storage space by adding volume servers.
+  * Unlimited message brokers.
+* Scale up and down with auto split and merge message topics.
+  * Topics can automatically split into segments when traffic increases, and vice verse.
+  * 
+
+# Design
+
+# How it works?
+
+Brokers are just computation nodes without storage. When a broker starts, it reports itself to masters.
+Among all the brokers, one of them will be selected as the leader by the masters.
+
+A topic needs to define its partition key on its messages.
+
+Messages for a topic are divided into segments. 
+
+During write time, the client will ask the broker leader for a few brokers to process the segment.
+
+The broker leader will check whether the segment already has assigned the brokers. If not, select a few based
+on their loads, save the selection into filer, and tell the client.
+
+The client will write the messages for this segment to the selected brokers.
+
+## Failover
+
+The broker leader does not contain any state. If it fails, the masters will select a different broker.
+
+For a segment, if any one of the selected brokers is down, the remaining brokers should try to write received messages
+to the filer, and close the segment to the clients.
+
+Then the clients should start a new segment. The masters should other healthy brokers to handle the new segment.
+
+So any brokers can go down without losing data.
+
+## Auto Split or Merge
+
+(The idea is learned from Pravega.)
+
+The brokers should report its traffic load to the broker leader periodically.
+
+If any segment has too much load, the broker leader will ask the brokers to tell the client to 
+close current one and create two new segments.
+
+If 2 neighboring segments have the combined load below average load per segment, the broker leader will ask 
+the brokers to tell the client to close this 2 segments and create a new segment.

weed/mq/segment/message_serde.go

@@ -0,0 +1,48 @@
+package segment
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/pb/message_fbs"
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+func CreateMessage(b *flatbuffers.Builder, producerId int32, producerSeq int64, segmentId int32, segmentSeq int64,
+	eventTsNs int64, recvTsNs int64, properties map[string]string, key []byte, value []byte) {
+	b.Reset()
+
+	var names, values, pairs []flatbuffers.UOffsetT
+	for k, v := range properties {
+		names = append(names, b.CreateString(k))
+		values = append(values, b.CreateString(v))
+	}
+
+	for i, _ := range names {
+		message_fbs.NameValueStart(b)
+		message_fbs.NameValueAddName(b, names[i])
+		message_fbs.NameValueAddValue(b, values[i])
+		pair := message_fbs.NameValueEnd(b)
+		pairs = append(pairs, pair)
+	}
+	message_fbs.MessageStartPropertiesVector(b, len(properties))
+	for i := len(pairs) - 1; i >= 0; i-- {
+		b.PrependUOffsetT(pairs[i])
+	}
+	prop := b.EndVector(len(properties))
+
+	k := b.CreateByteVector(key)
+	v := b.CreateByteVector(value)
+
+	message_fbs.MessageStart(b)
+	message_fbs.MessageAddProducerId(b, producerId)
+	message_fbs.MessageAddProducerSeq(b, producerSeq)
+	message_fbs.MessageAddSegmentId(b, segmentId)
+	message_fbs.MessageAddSegmentSeq(b, segmentSeq)
+	message_fbs.MessageAddEventTsNs(b, eventTsNs)
+	message_fbs.MessageAddRecvTsNs(b, recvTsNs)
+
+	message_fbs.MessageAddProperties(b, prop)
+	message_fbs.MessageAddKey(b, k)
+	message_fbs.MessageAddData(b, v)
+	message := message_fbs.MessageEnd(b)
+
+	b.Finish(message)
+}

weed/mq/segment/message_serde_test.go

@@ -0,0 +1,47 @@
+package segment
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/pb/message_fbs"
+	flatbuffers "github.com/google/flatbuffers/go"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestMessageSerde(t *testing.T) {
+	b := flatbuffers.NewBuilder(1024)
+
+	prop := make(map[string]string)
+	prop["n1"] = "v1"
+	prop["n2"] = "v2"
+
+	CreateMessage(b, 1, 2, 3, 4, 5, 6, prop,
+		[]byte("the primary key"), []byte("body is here"))
+
+	buf := b.FinishedBytes()
+
+	println("serialized size", len(buf))
+
+	m := message_fbs.GetRootAsMessage(buf, 0)
+
+	assert.Equal(t, int32(1), m.ProducerId())
+	assert.Equal(t, int64(2), m.ProducerSeq())
+	assert.Equal(t, int32(3), m.SegmentId())
+	assert.Equal(t, int64(4), m.SegmentSeq())
+	assert.Equal(t, int64(5), m.EventTsNs())
+	assert.Equal(t, int64(6), m.RecvTsNs())
+
+	assert.Equal(t, 2, m.PropertiesLength())
+	nv := &message_fbs.NameValue{}
+	m.Properties(nv, 0)
+	assert.Equal(t, "n1", string(nv.Name()))
+	assert.Equal(t, "v1", string(nv.Value()))
+	m.Properties(nv, 1)
+	assert.Equal(t, "n2", string(nv.Name()))
+	assert.Equal(t, "v2", string(nv.Value()))
+	assert.Equal(t, []byte("the primary key"), m.Key())
+	assert.Equal(t, []byte("body is here"), m.Data())
+
+	m.MutateSegmentSeq(123)
+	assert.Equal(t, int64(123), m.SegmentSeq())
+
+}

weed/mq/segment/segment_serde.go

@@ -0,0 +1 @@
+package segment

weed/pb/Makefile

@@ -13,3 +13,6 @@ gen:
 	protoc mq.proto --go_out=./mq_pb --go-grpc_out=./mq_pb --go_opt=paths=source_relative --go-grpc_opt=paths=source_relative
 	# protoc filer.proto --java_out=../../other/java/client/src/main/java
 	cp filer.proto ../../other/java/client/src/main/proto
+
+fbs:
+	flatc --go -o . --go-namespace message_fbs message.fbs

weed/pb/message.fbs

@@ -0,0 +1,15 @@
+table NameValue {
+    name:string (key);
+    value:string;
+}
+table Message {
+    producer_id:int32  (id:0);
+    producer_seq:int64 (id:2);
+    segment_id:int32   (id:1);
+    segment_seq:int64  (id:3);
+    event_ts_ns:int64  (id:4);
+    recv_ts_ns:int64   (id:5);
+    properties:[NameValue] (id:6);
+    key:string         (id:7); // bytes
+    data:string        (id:8); // bytes
+}

weed/pb/message_fbs/Message.go

@@ -0,0 +1,179 @@
+// Code generated by the FlatBuffers compiler. DO NOT EDIT.
+
+package message_fbs
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type Message struct {
+	_tab flatbuffers.Table
+}
+
+func GetRootAsMessage(buf []byte, offset flatbuffers.UOffsetT) *Message {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &Message{}
+	x.Init(buf, n+offset)
+	return x
+}
+
+func GetSizePrefixedRootAsMessage(buf []byte, offset flatbuffers.UOffsetT) *Message {
+	n := flatbuffers.GetUOffsetT(buf[offset+flatbuffers.SizeUint32:])
+	x := &Message{}
+	x.Init(buf, n+offset+flatbuffers.SizeUint32)
+	return x
+}
+
+func (rcv *Message) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *Message) Table() flatbuffers.Table {
+	return rcv._tab
+}
+
+func (rcv *Message) ProducerId() int32 {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
+	if o != 0 {
+		return rcv._tab.GetInt32(o + rcv._tab.Pos)
+	}
+	return 0
+}
+
+func (rcv *Message) MutateProducerId(n int32) bool {
+	return rcv._tab.MutateInt32Slot(4, n)
+}
+
+func (rcv *Message) SegmentId() int32 {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(6))
+	if o != 0 {
+		return rcv._tab.GetInt32(o + rcv._tab.Pos)
+	}
+	return 0
+}
+
+func (rcv *Message) MutateSegmentId(n int32) bool {
+	return rcv._tab.MutateInt32Slot(6, n)
+}
+
+func (rcv *Message) ProducerSeq() int64 {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(8))
+	if o != 0 {
+		return rcv._tab.GetInt64(o + rcv._tab.Pos)
+	}
+	return 0
+}
+
+func (rcv *Message) MutateProducerSeq(n int64) bool {
+	return rcv._tab.MutateInt64Slot(8, n)
+}
+
+func (rcv *Message) SegmentSeq() int64 {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(10))
+	if o != 0 {
+		return rcv._tab.GetInt64(o + rcv._tab.Pos)
+	}
+	return 0
+}
+
+func (rcv *Message) MutateSegmentSeq(n int64) bool {
+	return rcv._tab.MutateInt64Slot(10, n)
+}
+
+func (rcv *Message) EventTsNs() int64 {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(12))
+	if o != 0 {
+		return rcv._tab.GetInt64(o + rcv._tab.Pos)
+	}
+	return 0
+}
+
+func (rcv *Message) MutateEventTsNs(n int64) bool {
+	return rcv._tab.MutateInt64Slot(12, n)
+}
+
+func (rcv *Message) RecvTsNs() int64 {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(14))
+	if o != 0 {
+		return rcv._tab.GetInt64(o + rcv._tab.Pos)
+	}
+	return 0
+}
+
+func (rcv *Message) MutateRecvTsNs(n int64) bool {
+	return rcv._tab.MutateInt64Slot(14, n)
+}
+
+func (rcv *Message) Properties(obj *NameValue, j int) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(16))
+	if o != 0 {
+		x := rcv._tab.Vector(o)
+		x += flatbuffers.UOffsetT(j) * 4
+		x = rcv._tab.Indirect(x)
+		obj.Init(rcv._tab.Bytes, x)
+		return true
+	}
+	return false
+}
+
+func (rcv *Message) PropertiesLength() int {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(16))
+	if o != 0 {
+		return rcv._tab.VectorLen(o)
+	}
+	return 0
+}
+
+func (rcv *Message) Key() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(18))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *Message) Data() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(20))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func MessageStart(builder *flatbuffers.Builder) {
+	builder.StartObject(9)
+}
+func MessageAddProducerId(builder *flatbuffers.Builder, producerId int32) {
+	builder.PrependInt32Slot(0, producerId, 0)
+}
+func MessageAddSegmentId(builder *flatbuffers.Builder, segmentId int32) {
+	builder.PrependInt32Slot(1, segmentId, 0)
+}
+func MessageAddProducerSeq(builder *flatbuffers.Builder, producerSeq int64) {
+	builder.PrependInt64Slot(2, producerSeq, 0)
+}
+func MessageAddSegmentSeq(builder *flatbuffers.Builder, segmentSeq int64) {
+	builder.PrependInt64Slot(3, segmentSeq, 0)
+}
+func MessageAddEventTsNs(builder *flatbuffers.Builder, eventTsNs int64) {
+	builder.PrependInt64Slot(4, eventTsNs, 0)
+}
+func MessageAddRecvTsNs(builder *flatbuffers.Builder, recvTsNs int64) {
+	builder.PrependInt64Slot(5, recvTsNs, 0)
+}
+func MessageAddProperties(builder *flatbuffers.Builder, properties flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(6, flatbuffers.UOffsetT(properties), 0)
+}
+func MessageStartPropertiesVector(builder *flatbuffers.Builder, numElems int) flatbuffers.UOffsetT {
+	return builder.StartVector(4, numElems, 4)
+}
+func MessageAddKey(builder *flatbuffers.Builder, key flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(7, flatbuffers.UOffsetT(key), 0)
+}
+func MessageAddData(builder *flatbuffers.Builder, data flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(8, flatbuffers.UOffsetT(data), 0)
+}
+func MessageEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
+	return builder.EndObject()
+}

weed/pb/message_fbs/NameValue.go

@@ -0,0 +1,63 @@
+// Code generated by the FlatBuffers compiler. DO NOT EDIT.
+
+package message_fbs
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type NameValue struct {
+	_tab flatbuffers.Table
+}
+
+func GetRootAsNameValue(buf []byte, offset flatbuffers.UOffsetT) *NameValue {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &NameValue{}
+	x.Init(buf, n+offset)
+	return x
+}
+
+func GetSizePrefixedRootAsNameValue(buf []byte, offset flatbuffers.UOffsetT) *NameValue {
+	n := flatbuffers.GetUOffsetT(buf[offset+flatbuffers.SizeUint32:])
+	x := &NameValue{}
+	x.Init(buf, n+offset+flatbuffers.SizeUint32)
+	return x
+}
+
+func (rcv *NameValue) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *NameValue) Table() flatbuffers.Table {
+	return rcv._tab
+}
+
+func (rcv *NameValue) Name() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *NameValue) Value() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(6))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func NameValueStart(builder *flatbuffers.Builder) {
+	builder.StartObject(2)
+}
+func NameValueAddName(builder *flatbuffers.Builder, name flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(name), 0)
+}
+func NameValueAddValue(builder *flatbuffers.Builder, value flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(1, flatbuffers.UOffsetT(value), 0)
+}
+func NameValueEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
+	return builder.EndObject()
+}