[tor-commits] [snowflake/master] Add locks to safelog

[cohosh at torproject.org]

commit 3c28380bc651885ea79deab21c20a40b10c4ac7c
Author: Cecylia Bocovich <cohosh at torproject.org>
Date:   Fri Sep 13 12:26:27 2019 -0400

    Add locks to safelog
    
    The safelog Write function can be called from multiple go routines, and
    it was not thread safe. These locks in particular allow us to pass the
    logscrubber's output io.Writer to other libraries, such as pion.
---
 common/safelog/log.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/common/safelog/log.go b/common/safelog/log.go
index 1241676..9148e53 100644
--- a/common/safelog/log.go
+++ b/common/safelog/log.go
@@ -7,6 +7,7 @@ import (
 	"bytes"
 	"io"
 	"regexp"
+	"sync"
 )
 
 const ipv4Address = `\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}`
@@ -30,8 +31,13 @@ var addressRegexp = regexp.MustCompile(addressPattern)
 type LogScrubber struct {
 	Output io.Writer
 	buffer []byte
+
+	lock sync.Mutex
 }
 
+func (ls *LogScrubber) Lock()   { (*ls).lock.Lock() }
+func (ls *LogScrubber) Unlock() { (*ls).lock.Unlock() }
+
 func scrub(b []byte) []byte {
 	scrubbedBytes := b
 	for _, pattern := range scrubberPatterns {
@@ -45,6 +51,9 @@ func scrub(b []byte) []byte {
 }
 
 func (ls *LogScrubber) Write(b []byte) (n int, err error) {
+	ls.Lock()
+	defer ls.Unlock()
+
 	n = len(b)
 	ls.buffer = append(ls.buffer, b...)
 	for {