fix(runner): use os.CreateTemp and mutex serialization for atomic resume on Windows

runner/atomic_resume.go

@@ -0,0 +1,71 @@
+package runner
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"sync"
+
+	"gopkg.in/yaml.v3"
+)
+
+var atomicResumeMutex sync.Mutex
+
+// syncDir attempts to fsync the directory containing targetPath on POSIX platforms.
+func syncDir(dirPath string) error {
+	if runtime.GOOS == "windows" {
+		return nil
+	}
+	d, err := os.Open(dirPath)
+	if err != nil {
+		return err
+	}
+	defer d.Close()
+	return d.Sync()
+}
+
+func SaveAtomic(targetPath string, data []byte) error {
+	atomicResumeMutex.Lock()
+	defer atomicResumeMutex.Unlock()
+
+	dir := filepath.Dir(targetPath)
+	tmpFile, err := os.CreateTemp(dir, "httpx-resume-*.tmp")
+	if err != nil {
+		return err
+	}
+	tmpName := tmpFile.Name()
+	defer os.Remove(tmpName)
+
+	if _, err := tmpFile.Write(data); err != nil {
+		tmpFile.Close()
+		return err
+	}
+	if err := tmpFile.Sync(); err != nil {
+		tmpFile.Close()
+		return err
+	}
+	if err := tmpFile.Close(); err != nil {
+		return err
+	}
+
+	if err := os.Rename(tmpName, targetPath); err != nil {
+		return err
+	}
+
+	return syncDir(dir)
+}
+
+// SaveResumeConfigAtomic serializes the resume config and writes it using SaveAtomic.
+func (r *Runner) SaveResumeConfigAtomic() error {
+	if r.options == nil || r.options.resumeCfg == nil {
+		return nil
+	}
+	var resumeCfg ResumeCfg
+	resumeCfg.Index = r.options.resumeCfg.currentIndex
+	resumeCfg.ResumeFrom = r.options.resumeCfg.current
+	data, err := yaml.Marshal(resumeCfg)
+	if err != nil {
+		return err
+	}
+	return SaveAtomic(DefaultResumeFile, data)
+}

runner/runner.go

@@ -2939,10 +2939,7 @@ func extractPotentialFavIconsURLs(resp []byte) (candidates []string, baseHref st
 
 // SaveResumeConfig to file
 func (r *Runner) SaveResumeConfig() error {
-	var resumeCfg ResumeCfg
-	resumeCfg.Index = r.options.resumeCfg.currentIndex
-	resumeCfg.ResumeFrom = r.options.resumeCfg.current
-	return goconfig.Save(resumeCfg, DefaultResumeFile)
+	return r.SaveResumeConfigAtomic()
 }
 
 // JSON the result