add debug zero

weed/filesys/page_writer.go

@@ -84,6 +84,8 @@ func (pw *PageWriter) ReadDirtyDataAt(data []byte, offset int64) (maxStop int64)
 		data = data[readSize:]
 	}
 
+	checkByteZero("page writer read", p, 0, maxStop-offset)
+
 	return
 }
 

weed/filesys/page_writer/chunked_file_writer.go

@@ -73,6 +73,7 @@ func (cw *ChunkedFileWriter) ReadDataAt(p []byte, off int64) (maxStop int64) {
 					glog.Errorf("reading temp file: %v", err)
 					break
 				}
+				checkByteZero("temp file writer read", p, logicStart-off, logicStop-off)
 				maxStop = max(maxStop, logicStop)
 			}
 		}

weed/filesys/page_writer/chunked_stream_writer.go

@@ -1,7 +1,6 @@
 package page_writer
 
 import (
-	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/util"
 	"github.com/chrislusf/seaweedfs/weed/util/mem"
 	"io"
@@ -82,16 +81,7 @@ func (cw *ChunkedStreamWriter) ReadDataAt(p []byte, off int64) (maxStop int64) {
 			copy(p[logicStart-off:logicStop-off], memChunk.buf[logicStart-memChunkBaseOffset:logicStop-memChunkBaseOffset])
 			maxStop = max(maxStop, logicStop)
 
-			isAllZero := true
-			for i := logicStart - off; i < logicStop-off; i++ {
-				if p[i] != 0 {
-					isAllZero = false
-					break
-				}
-			}
-			if isAllZero {
-				glog.Errorf("Copied content is all Zero [%d,%d)", logicStart-off, logicStop-off)
-			}
+			checkByteZero("stream writer read", p, logicStart-off, logicStop-off)
 
 		}
 	}

weed/filesys/page_writer/debug_content.go

@@ -0,0 +1,17 @@
+package page_writer
+
+import "github.com/chrislusf/seaweedfs/weed/glog"
+
+func checkByteZero(message string, p []byte, start, stop int64) {
+	isAllZero := true
+	for i := start; i < stop; i++ {
+		if p[i] != 0 {
+			isAllZero = false
+			break
+		}
+	}
+	if isAllZero {
+		glog.Errorf("%s is all zeros [%d,%d)", message, start, stop)
+	}
+
+}