Merge pull request #322 from markusressel/bugfix/#317-atomic-writes

atomic file writes for file fan
markusressel · Oct 8, 2024 · 6847c90 · 6847c90
2 parents 380f590 + e673a17
commit 6847c90
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Showing 4 changed files with 21 additions and 2 deletions.
diff --git a/go.mod b/go.mod
@@ -12,6 +12,7 @@ require (
 	github.com/mgutz/ansi v0.0.0-20200706080929-d51e80ef957d
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/mitchellh/mapstructure v1.5.0
+	github.com/natefinch/atomic v1.0.1
 	github.com/oklog/run v1.1.0
 	github.com/orcaman/concurrent-map/v2 v2.0.1
 	github.com/prometheus/client_golang v1.20.4

diff --git a/go.sum b/go.sum
@@ -96,6 +96,8 @@ github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyua
 github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
+github.com/natefinch/atomic v1.0.1 h1:ZPYKxkqQOx3KZ+RsbnP/YsgvxWQPGxjC0oBt2AhwV0A=
+github.com/natefinch/atomic v1.0.1/go.mod h1:N/D/ELrljoqDyT3rZrsUmtsuzvHkeB/wWjHV22AZRbM=
 github.com/oklog/run v1.1.0 h1:GEenZ1cK0+q0+wsJew9qUg/DyD8k3JzYsZAi5gYi2mA=
 github.com/oklog/run v1.1.0/go.mod h1:sVPdnTZT1zYwAJeCMu2Th4T21pA3FPOQRfWjQlk7DVU=
 github.com/orcaman/concurrent-map/v2 v2.0.1 h1:jOJ5Pg2w1oeB6PeDurIYf6k9PQ+aTITr/6lP/L/zp6c=

diff --git a/internal/fans/file.go b/internal/fans/file.go
@@ -106,7 +106,7 @@ func (fan *FileFan) SetPwm(pwm int) (err error) {
 		filePath = filepath.Join(currentUser.HomeDir, filePath[1:])
 	}
 
-	err = util.WriteIntToFile(pwm, filePath)
+	err = util.WriteIntToFileAtomic(pwm, filePath)
 	if err != nil {
 		ui.Error("Unable to write to file: %v", fan.Config.File.Path)
 		return err

diff --git a/internal/util/file.go b/internal/util/file.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"github.com/markusressel/fan2go/internal/ui"
+	"github.com/natefinch/atomic"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -64,15 +65,30 @@ func ReadIntFromFile(path string) (value int, err error) {
 
 // WriteIntToFile write a single integer to a file.go path
 func WriteIntToFile(value int, path string) error {
-	evaluatedPath, err := filepath.EvalSymlinks(path)
+	evaluatedPath, err := resolvePath(path)
 	if len(evaluatedPath) > 0 && err == nil {
 		path = evaluatedPath
 	}
 	valueAsString := fmt.Sprintf("%d", value)
+
 	err = os.WriteFile(path, []byte(valueAsString), 0644)
 	return err
 }
 
+func resolvePath(path string) (string, error) {
+	return filepath.EvalSymlinks(path)
+}
+
+func WriteIntToFileAtomic(value int, path string) error {
+	evaluatedPath, err := resolvePath(path)
+	if len(evaluatedPath) > 0 && err == nil {
+		path = evaluatedPath
+	}
+	valueAsString := fmt.Sprintf("%d", value)
+	valueReader := strings.NewReader(valueAsString)
+	return atomic.WriteFile(path, valueReader)
+}
+
 // FindFilesMatching finds all files in a given directory, matching the given regex
 func FindFilesMatching(path string, expr *regexp.Regexp) []string {
 	var result []string