messaging can compile now

weed/messaging/broker/topic_lock.go

@@ -0,0 +1,80 @@
+package broker
+
+import (
+	"sync"
+	"time"
+
+	"github.com/chrislusf/seaweedfs/weed/util/log_buffer"
+)
+
+type TopicPartition struct {
+	Namespace string
+	Topic     string
+	Partition int32
+}
+type TopicLock struct {
+	sync.Mutex
+	subscriberCount int
+	publisherCount  int
+	logBuffer       *log_buffer.LogBuffer
+}
+
+type TopicLocks struct {
+	sync.Mutex
+	locks map[TopicPartition]*TopicLock
+}
+
+func NewTopicLocks() *TopicLocks {
+	return &TopicLocks{
+		locks: make(map[TopicPartition]*TopicLock),
+	}
+}
+
+func (tl *TopicLocks) RequestSubscriberLock(partition TopicPartition) *TopicLock {
+	tl.Lock()
+	defer tl.Unlock()
+
+	lock, found := tl.locks[partition]
+	if !found {
+		lock = &TopicLock{}
+		tl.locks[partition] = lock
+	}
+	lock.subscriberCount++
+
+	return lock
+}
+
+func (tl *TopicLocks) RequestPublisherLock(partition TopicPartition, flushFn func(startTime, stopTime time.Time, buf []byte)) *log_buffer.LogBuffer {
+	tl.Lock()
+	defer tl.Unlock()
+
+	lock, found := tl.locks[partition]
+	if !found {
+		lock = &TopicLock{}
+		tl.locks[partition] = lock
+	}
+	lock.publisherCount++
+	cond := sync.NewCond(&lock.Mutex)
+	lock.logBuffer = log_buffer.NewLogBuffer(time.Minute, flushFn, func() {
+		cond.Broadcast()
+	})
+	return lock.logBuffer
+}
+
+func (tl *TopicLocks) ReleaseLock(partition TopicPartition, isPublisher bool) {
+	tl.Lock()
+	defer tl.Unlock()
+
+	lock, found := tl.locks[partition]
+	if !found {
+		return
+	}
+	if isPublisher {
+		lock.publisherCount--
+	} else {
+		lock.subscriberCount--
+	}
+	if lock.subscriberCount <= 0 && lock.publisherCount <= 0 {
+		delete(tl.locks, partition)
+	}
+}