func (f *RealIntervalIterFactory) Make(analyzerType string, mysqlConn mysql.Connector, tickChan chan time.Time) qan.IntervalIter {
switch analyzerType {
case "slowlog":
// The interval iter gets the slow log file (@@global.slow_query_log_file)
// every tick because it can change (not typical, but possible). If it changes,
// the start offset is reset to 0 for the new file.
getSlowLogFunc := func() (string, error) {
if err := mysqlConn.Connect(1); err != nil {
return "", err
}
defer mysqlConn.Close()
// Slow log file can be absolute or relative. If it's relative,
// then prepend the datadir.
dataDir := mysqlConn.GetGlobalVarString("datadir")
filename := AbsDataFile(dataDir, mysqlConn.GetGlobalVarString("slow_query_log_file"))
return filename, nil
}
return slowlog.NewIter(pct.NewLogger(f.logChan, "qan-interval"), getSlowLogFunc, tickChan)
case "perfschema":
return perfschema.NewIter(pct.NewLogger(f.logChan, "qan-interval"), tickChan)
default:
panic("Invalid analyzerType: " + analyzerType)
}
}
func (s *IterTestSuite) TestIterFile(t *C) {
tickChan := make(chan time.Time)
// This is the file we iterate. It's 3 bytes large to start,
// so that should be the StartOffset.
tmpFile, _ := ioutil.TempFile("/tmp", "interval_test.")
tmpFile.Close()
fileName = tmpFile.Name()
_ = ioutil.WriteFile(tmpFile.Name(), []byte("123"), 0777)
defer func() { os.Remove(tmpFile.Name()) }()
// Start interating the file, waiting for ticks.
i := slowlog.NewIter(s.logger, getFilename, tickChan)
i.Start()
// Send a tick to start the interval
t1 := time.Now()
tickChan <- t1
// Write more data to the file, pretend time passes...
_ = ioutil.WriteFile(tmpFile.Name(), []byte("123456"), 0777)
// Send a 2nd tick to finish the interval
t2 := time.Now()
tickChan <- t2
// Get the interval
got := <-i.IntervalChan()
expect := &qan.Interval{
Number: 1,
Filename: fileName,
StartTime: t1,
StopTime: t2,
StartOffset: 3,
EndOffset: 6,
}
t.Check(got, test.DeepEquals, expect)
/**
* Rename the file, then re-create it. The file change should be detected.
*/
oldFileName := tmpFile.Name() + "-old"
os.Rename(tmpFile.Name(), oldFileName)
defer os.Remove(oldFileName)
// Re-create original file and write new data. We expect StartOffset=0
// because the file is new, and EndOffset=10 because that's the len of
// the new data. The old ^ file/data had start/stop offset 3/6, so those
// should not appear in next interval; if they do, then iter failed to
// detect file change and is still reading old file.
tmpFile, _ = os.Create(fileName)
tmpFile.Close()
_ = ioutil.WriteFile(fileName, []byte("123456789A"), 0777)
t3 := time.Now()
tickChan <- t3
got = <-i.IntervalChan()
expect = &qan.Interval{
Number: 2,
Filename: fileName,
StartTime: t2,
StopTime: t3,
StartOffset: 0,
EndOffset: 10,
}
t.Check(got, test.DeepEquals, expect)
// Iter should no longer detect file change.
_ = ioutil.WriteFile(fileName, []byte("123456789ABCDEF"), 0777)
// ^^^^^ new data
t4 := time.Now()
tickChan <- t4
got = <-i.IntervalChan()
expect = &qan.Interval{
Number: 3,
Filename: fileName,
StartTime: t3,
StopTime: t4,
StartOffset: 10,
EndOffset: 15,
}
t.Check(got, test.DeepEquals, expect)
i.Stop()
}