services/crunchstat/crunchstat_test.go

   1 package main
   2
   3 import (
   4         "bufio"
   5         "bytes"
   6         "io"
   7         "log"
   8         "math/rand"
   9         "testing"
  10         "time"
  11 )
  12
  13 // Test that CopyPipeToChildLog works even on lines longer than
  14 // bufio.MaxScanTokenSize.
  15 func TestCopyPipeToChildLogLongLines(t *testing.T) {
  16         logger, logBuf := bufLogger()
  17
  18         pipeIn, pipeOut := io.Pipe()
  19         copied := make(chan bool)
  20         go func() {
  21                 copyPipeToChildLog(pipeIn, logger)
  22                 close(copied)
  23         }()
  24
  25         sentBytes := make([]byte, bufio.MaxScanTokenSize+MaxLogLine+(1<<22))
  26         go func() {
  27                 pipeOut.Write([]byte("before\n"))
  28
  29                 for i := range sentBytes {
  30                         // Some bytes that aren't newlines:
  31                         sentBytes[i] = byte((rand.Int() & 0xff) | 0x80)
  32                 }
  33                 sentBytes[len(sentBytes)-1] = '\n'
  34                 pipeOut.Write(sentBytes)
  35
  36                 pipeOut.Write([]byte("after"))
  37                 pipeOut.Close()
  38         }()
  39
  40         if before, err := logBuf.ReadBytes('\n'); err != nil || string(before) != "before\n" {
  41                 t.Fatalf("\"before\n\" not received (got \"%s\", %s)", before, err)
  42         }
  43
  44         var receivedBytes []byte
  45         done := false
  46         for !done {
  47                 line, err := logBuf.ReadBytes('\n')
  48                 if err != nil {
  49                         t.Fatal(err)
  50                 }
  51                 if len(line) >= 5 && string(line[0:5]) == "[...]" {
  52                         if receivedBytes == nil {
  53                                 t.Fatal("Beginning of line reported as continuation")
  54                         }
  55                         line = line[5:]
  56                 }
  57                 if len(line) >= 6 && string(line[len(line)-6:]) == "[...]\n" {
  58                         line = line[:len(line)-6]
  59                 } else {
  60                         done = true
  61                 }
  62                 receivedBytes = append(receivedBytes, line...)
  63         }
  64         if bytes.Compare(receivedBytes, sentBytes) != 0 {
  65                 t.Fatalf("sent %d bytes, got %d different bytes", len(sentBytes), len(receivedBytes))
  66         }
  67
  68         if after, err := logBuf.ReadBytes('\n'); err != nil || string(after) != "after\n" {
  69                 t.Fatalf("\"after\n\" not received (got \"%s\", %s)", after, err)
  70         }
  71
  72         select {
  73         case <-time.After(time.Second):
  74                 t.Fatal("Timeout")
  75         case <-copied:
  76                 // Done.
  77         }
  78 }
  79
  80 func bufLogger() (*log.Logger, *bufio.Reader) {
  81         r, w := io.Pipe()
  82         logger := log.New(w, "", 0)
  83         return logger, bufio.NewReader(r)
  84 }