[tool/oplog] Handles empty logs properly

easegress-io · Jan 9, 2018 · a0d5b7f · a0d5b7f
1 parent 57279b4
commit a0d5b7f
Showing 1 changed file with 15 additions and 7 deletions.
diff --git a/src/tool/oplog/oplog.go b/src/tool/oplog/oplog.go
@@ -24,17 +24,21 @@ func RetrieveOpLog(c *cli.Context) error {
  opLogPath := c.String("path")
  opLog, err := gateway.NewOPLog(opLogPath)
  if err != nil {
- return cli.NewExitError(fmt.Sprintf("open oplog failed: %v", err), 2)
+ return cli.NewExitError(fmt.Sprintf("open oplog failed: %v", err), 1)
  }
  defer opLog.Close()
 
  maxSeq := opLog.MaxSeq()
  begin := c.Uint64("begin")
  if begin > maxSeq {
- return cli.NewExitError(fmt.Sprintf("`begin` parameter invalid, it must be equal or lower than current max sequence: %d", maxSeq), 1)
+ return cli.NewExitError(
+ fmt.Sprintf("`begin` parameter invalid, it must be equal or lower than current max sequence: %d", maxSeq),
+ 3)
  }
  count := c.Uint64("count")
- if begin+count > maxSeq {
+ if maxSeq == 0 {
+ count = 0
+ } else if begin+count > maxSeq {
  count = maxSeq - begin + 1
  }
 
@@ -46,9 +50,12 @@ func RetrieveOpLog(c *cli.Context) error {
  Count: count,
  }
 
- operations, err, _ := opLog.Retrieve(begin, count)
- if err != nil {
- return cli.NewExitError(fmt.Sprintf("retrieve oplog failed: %v", err), 3)
+ var operations []*gateway.Operation
+ if maxSeq > 0 {
+ operations, err, _ = opLog.Retrieve(begin, count)
+ if err != nil {
+ return cli.NewExitError(fmt.Sprintf("retrieve oplog failed: %v", err), 4)
+ }
  }
 
  oplogs.Operations = make([]json.RawMessage, len(operations))
@@ -61,8 +68,9 @@ func RetrieveOpLog(c *cli.Context) error {
  }
 
  if byt, err = json.Marshal(oplogs); err != nil {
- return cli.NewExitError(fmt.Sprintf("marshal oplogs failed: %v", err), 4)
+ return cli.NewExitError(fmt.Sprintf("marshal oplogs failed: %v", err), 5)
  }
+
  fmt.Printf("%s\n", byt)
  return nil
 }