merge current message queue code changes (#6201)

* listing files to convert to parquet

* write parquet files

* save logs into parquet files

* pass by value

* compact logs into parquet format

* can skip existing files

* refactor

* refactor

* fix compilation

* when no partition found

* refactor

* add untested parquet file read

* rename package

* refactor

* rename files

* remove unused

* add merged log read func

* parquet wants to know the file size

* rewind by time

* pass in stop ts

* add stop ts

* adjust log

* minor

* adjust log

* skip .parquet files when reading message logs

* skip non message files

* Update subscriber_record.go

* send messages

* skip message data with only ts

* skip non log files

* update parquet-go package

* ensure a valid record type

* add new field to a record type

* Update read_parquet_to_log.go

* fix parquet file name generation

* separating reading parquet and logs

* add key field

* add skipped logs

* use in memory cache

* refactor

* refactor

* refactor

* refactor, and change compact log

* refactor

* rename

* refactor

* fix format

* prefix v to version directory

weed/mq/logstore/merged_read.go

@@ -0,0 +1,41 @@
+package logstore
+
+import (
+	"github.com/seaweedfs/seaweedfs/weed/mq/topic"
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+	"github.com/seaweedfs/seaweedfs/weed/util/log_buffer"
+)
+
+func GenMergedReadFunc(filerClient filer_pb.FilerClient, t topic.Topic, p topic.Partition) log_buffer.LogReadFromDiskFuncType {
+	fromParquetFn := GenParquetReadFunc(filerClient, t, p)
+	readLogDirectFn := GenLogOnDiskReadFunc(filerClient, t, p)
+	return mergeReadFuncs(fromParquetFn, readLogDirectFn)
+}
+
+func mergeReadFuncs(fromParquetFn, readLogDirectFn log_buffer.LogReadFromDiskFuncType) log_buffer.LogReadFromDiskFuncType {
+	var exhaustedParquet bool
+	var lastProcessedPosition log_buffer.MessagePosition
+	return func(startPosition log_buffer.MessagePosition, stopTsNs int64, eachLogEntryFn log_buffer.EachLogEntryFuncType) (lastReadPosition log_buffer.MessagePosition, isDone bool, err error) {
+		if !exhaustedParquet {
+			// glog.V(4).Infof("reading from parquet startPosition: %v\n", startPosition.UTC())
+			lastReadPosition, isDone, err = fromParquetFn(startPosition, stopTsNs, eachLogEntryFn)
+			// glog.V(4).Infof("read from parquet: %v %v %v %v\n", startPosition, lastReadPosition, isDone, err)
+			if isDone {
+				isDone = false
+			}
+			if err != nil {
+				return
+			}
+			lastProcessedPosition = lastReadPosition
+		}
+		exhaustedParquet = true
+
+		if startPosition.Before(lastProcessedPosition.Time) {
+			startPosition = lastProcessedPosition
+		}
+
+		// glog.V(4).Infof("reading from direct log startPosition: %v\n", startPosition.UTC())
+		lastReadPosition, isDone, err = readLogDirectFn(startPosition, stopTsNs, eachLogEntryFn)
+		return
+	}
+}