// Flush writes the content of the buffer to a given resource and resets the
// internal state, i.e. the buffer is empty after a call to Flush.
// Writing will be done in a separate go routine to be non-blocking.
//
// The validate callback will be called after messages have been successfully
// written to the io.Writer.
// If validate returns false the buffer will not be resetted (automatic retry).
// If validate is nil a return value of true is assumed (buffer reset).
//
// The onError callback will be called if the io.Writer returned an error.
// If onError returns false the buffer will not be resetted (automatic retry).
// If onError is nil a return value of true is assumed (buffer reset).
func (batch *MessageBatch) Flush(assemble AssemblyFunc) {
if batch.IsEmpty() {
return // ### return, nothing to do ###
}
// Only one flush at a time
batch.flushing.IncWhenDone()
// Switch the buffers so writers can go on writing
flushSet := atomic.SwapUint32(&batch.activeSet, (batch.activeSet&messageBatchIndexMask)^messageBatchIndexMask)
flushIdx := flushSet >> messageBatchIndexShift
writerCount := flushSet & messageBatchCountMask
flushQueue := &batch.queue[flushIdx]
spin := shared.NewSpinner(shared.SpinPriorityHigh)
// Wait for remaining writers to finish
for writerCount != atomic.LoadUint32(&flushQueue.doneCount) {
spin.Yield()
}
// Write data and reset buffer asynchronously
go shared.DontPanic(func() {
defer batch.flushing.Done()
messageCount := shared.MinI(int(writerCount), len(flushQueue.messages))
assemble(flushQueue.messages[:messageCount])
atomic.StoreUint32(&flushQueue.doneCount, 0)
batch.Touch()
})
}
// Enqueue is a convenience function to push a message to a channel while
// waiting for a timeout instead of just blocking.
// Passing a timeout of -1 will discard the message.
// Passing a timout of 0 will always block.
// Messages that time out will be passed to the dropped queue if a Dropped
// consumer exists.
// The source parameter is used when a message is dropped, i.e. it is passed
// to the Drop function.
func (msg Message) Enqueue(channel chan<- Message, timeout time.Duration) MessageState {
if timeout == 0 {
channel <- msg
return MessageStateOk // ### return, done ###
}
start := time.Time{}
spin := shared.Spinner{}
for {
select {
case channel <- msg:
return MessageStateOk // ### return, done ###
default:
switch {
// Start timeout based retries
case start.IsZero():
if timeout < 0 {
return MessageStateDiscard // ### return, discard and ignore ###
}
start = time.Now()
spin = shared.NewSpinner(shared.SpinPriorityHigh)
// Discard message after timeout
case time.Since(start) > timeout:
return MessageStateTimeout // ### return, drop and retry ###
// Yield and try again
default:
spin.Yield()
}
}
}
}
// AppendOrBlock works like Append but will block until Append returns true.
// If the batch was closed during this call, false is returned.
func (batch *MessageBatch) AppendOrBlock(msg Message) bool {
spin := shared.NewSpinner(shared.SpinPriorityMedium)
for !batch.IsClosed() {
if batch.Append(msg) {
return true // ### return, success ###
}
spin.Yield()
}
return false
}
// Main fetch loop for kafka events
func (cons *Kafka) readFromPartition(partitionID int32) {
partCons, err := cons.consumer.ConsumePartition(cons.topic, partitionID, cons.offsets[partitionID])
if err != nil {
if !cons.client.Closed() {
go shared.DontPanic(func() {
cons.retry(partitionID, err)
})
}
return // ### return, stop this consumer ###
}
// Make sure we wait for all consumers to end
cons.AddWorker()
defer func() {
if !cons.client.Closed() {
partCons.Close()
}
cons.WorkerDone()
}()
// Loop over worker
spin := shared.NewSpinner(shared.SpinPriorityLow)
for !cons.client.Closed() {
cons.WaitOnFuse()
select {
case event := <-partCons.Messages():
cons.offsets[partitionID] = event.Offset
// Offset is always relative to the partition, so we create "buckets"
// i.e. we are able to reconstruct partiton and local offset from
// the sequence number.
//
// To generate this we use:
// seq = offset * numPartition + partitionId
//
// Reading can be done via:
// seq % numPartition = partitionId
// seq / numPartition = offset
sequence := uint64(event.Offset*int64(cons.MaxPartitionID) + int64(partitionID))
cons.Enqueue(event.Value, sequence)
case err := <-partCons.Errors():
Log.Error.Print("Kafka consumer error:", err)
default:
spin.Yield()
}
}
}
// WaitForDependencies waits until all dependencies reach the given runstate.
// A timeout > 0 can be given to work around possible blocking situations.
func (prod *ProducerBase) WaitForDependencies(waitForState PluginState, timeout time.Duration) {
spinner := shared.NewSpinner(shared.SpinPriorityMedium)
for _, dep := range prod.dependencies {
start := time.Now()
for dep.GetState() < waitForState {
spinner.Yield()
if timeout > 0 && time.Since(start) > timeout {
Log.Warning.Printf("WaitForDependencies call timed out for %T", dep)
break // ### break loop, timeout ###
}
}
}
}
func (prod *Websocket) pushMessage(msg core.Message) {
messageText, _ := prod.ProducerBase.Format(msg)
if prod.clientIdx&0x7FFFFFFF > 0 {
// There are new clients available
currentIdx := prod.clientIdx >> 31
activeIdx := (currentIdx + 1) & 1
// Store away the current client list and reset it
activeConns := &prod.clients[activeIdx]
oldConns := activeConns.conns
activeConns.conns = activeConns.conns[:]
activeConns.doneCount = 0
// Switch new and current client list
if currentIdx == 0 {
currentIdx = atomic.SwapUint32(&prod.clientIdx, 1<<31)
} else {
currentIdx = atomic.SwapUint32(&prod.clientIdx, 0)
}
// Wait for new list writer to finish
count := currentIdx & 0x7FFFFFFF
currentIdx = currentIdx >> 31
spin := shared.NewSpinner(shared.SpinPriorityHigh)
for prod.clients[currentIdx].doneCount != count {
spin.Yield()
}
// Add new connections to old connections
newConns := &prod.clients[currentIdx]
newConns.conns = append(oldConns, newConns.conns...)
}
// Process the active connections
activeIdx := ((prod.clientIdx >> 31) + 1) & 1
activeConns := &prod.clients[activeIdx]
for i := 0; i < len(activeConns.conns); i++ {
client := activeConns.conns[i]
if _, err := client.Write(messageText); err != nil {
activeConns.conns = append(activeConns.conns[:i], activeConns.conns[i+1:]...)
if closeErr := client.Close(); closeErr == nil {
Log.Error.Print("Websocket: ", err)
}
i--
}
}
}
func (state *fileState) compressAndCloseLog(sourceFile *os.File) {
state.bgWriter.Add(1)
defer state.bgWriter.Done()
// Generate file to zip into
sourceFileName := sourceFile.Name()
sourceDir, sourceBase, _ := shared.SplitPath(sourceFileName)
targetFileName := fmt.Sprintf("%s/%s.gz", sourceDir, sourceBase)
targetFile, err := os.OpenFile(targetFileName, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0666)
if err != nil {
Log.Error.Print("File compress error:", err)
sourceFile.Close()
return
}
// Create zipfile and compress data
Log.Note.Print("Compressing " + sourceFileName)
sourceFile.Seek(0, 0)
targetWriter := gzip.NewWriter(targetFile)
spin := shared.NewSpinner(shared.SpinPriorityHigh)
for err == nil {
_, err = io.CopyN(targetWriter, sourceFile, 1<<20) // 1 MB chunks
spin.Yield() // Be async!
}
// Cleanup
sourceFile.Close()
targetWriter.Close()
targetFile.Close()
if err != nil && err != io.EOF {
Log.Warning.Print("Compression failed:", err)
err = os.Remove(targetFileName)
if err != nil {
Log.Error.Print("Compressed file remove failed:", err)
}
return
}
// Remove original log
err = os.Remove(sourceFileName)
if err != nil {
Log.Error.Print("Uncompressed file remove failed:", err)
}
}
func (cons *ConsumerBase) fuseControlLoop() {
if cons.fuse == nil {
return // ### return, no fuse attached ###
}
spin := shared.NewSpinner(shared.SpinPrioritySuspend)
for cons.IsActive() {
// If the fuse is burned: callback, wait, callback
if cons.IsFuseBurned() {
cons.Control() <- PluginControlFuseBurn
cons.WaitOnFuse()
cons.Control() <- PluginControlFuseActive
} else {
spin.Yield()
}
}
}
func (cons *File) read() {
defer cons.close()
sendFunction := cons.Enqueue
if cons.offsetFileName != "" {
sendFunction = cons.enqueueAndPersist
}
spin := shared.NewSpinner(shared.SpinPriorityLow)
buffer := shared.NewBufferedReader(fileBufferGrowSize, 0, 0, cons.delimiter)
printFileOpenError := true
for cons.state != fileStateDone {
// Initialize the seek state if requested
// Try to read the remains of the file first
if cons.state == fileStateOpen {
if cons.file != nil {
buffer.ReadAll(cons.file, sendFunction)
}
cons.initFile()
buffer.Reset(uint64(cons.seekOffset))
}
// Try to open the file to read from
if cons.state == fileStateRead && cons.file == nil {
file, err := os.OpenFile(cons.realFileName(), os.O_RDONLY, 0666)
switch {
case err != nil:
if printFileOpenError {
Log.Error.Print("File open error - ", err)
printFileOpenError = false
}
time.Sleep(3 * time.Second)
continue // ### continue, retry ###
default:
cons.file = file
cons.seekOffset, _ = cons.file.Seek(cons.seekOffset, cons.seek)
printFileOpenError = true
}
}
// Try to read from the file
if cons.state == fileStateRead && cons.file != nil {
err := buffer.ReadAll(cons.file, sendFunction)
cons.WaitOnFuse()
switch {
case err == nil: // ok
spin.Reset()
case err == io.EOF:
spin.Yield()
case cons.state == fileStateRead:
Log.Error.Print("Error reading file - ", err)
cons.file.Close()
cons.file = nil
}
}
}
}
