初始化仓库

core/atomicwrite.go

@@ -0,0 +1,50 @@
+package core
+
+import (
+	"os"
+	"path/filepath"
+)
+
+// AtomicWriteFile writes data to a file atomically by first writing to a
+// temporary file in the same directory, syncing, then renaming over the target.
+// This prevents data loss / corruption on crash.
+func AtomicWriteFile(path string, data []byte, perm os.FileMode) error {
+	dir := filepath.Dir(path)
+	tmp, err := os.CreateTemp(dir, ".tmp-*")
+	if err != nil {
+		return err
+	}
+	tmpPath := tmp.Name()
+
+	if _, err := tmp.Write(data); err != nil {
+		tmp.Close()
+		os.Remove(tmpPath)
+		return err
+	}
+	if err := tmp.Sync(); err != nil {
+		tmp.Close()
+		os.Remove(tmpPath)
+		return err
+	}
+	if err := tmp.Close(); err != nil {
+		os.Remove(tmpPath)
+		return err
+	}
+	if err := os.Chmod(tmpPath, perm); err != nil {
+		os.Remove(tmpPath)
+		return err
+	}
+	if err := os.Rename(tmpPath, path); err != nil {
+		// Rename can fail when the destination is a directory, the
+		// destination's filesystem differs from the temp dir's (rare given
+		// CreateTemp uses the same dir, but possible with bind mounts), or
+		// the destination is locked by another process on Windows. In any
+		// of those cases the temp file is now an orphaned `.tmp-*` we
+		// created — clean it up so repeated failures don't litter the
+		// directory and confuse later directory scans (e.g. cron / session
+		// stores that walk their parent dir).
+		os.Remove(tmpPath)
+		return err
+	}
+	return nil
+}