v0.5.0: manifests, filters, logging, docs

internal/manifest/file_log.go

@@ -0,0 +1,39 @@
+package manifest
+
+import (
+	"encoding/json"
+	"os"
+	"sync"
+)
+
+type fileLogWriter struct {
+	mu sync.Mutex
+	f  *os.File
+}
+
+func NewFileLogWriter(path string) (LogWriter, error) {
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
+	if err != nil {
+		return nil, err
+	}
+	return &fileLogWriter{f: f}, nil
+}
+
+func (w *fileLogWriter) Log(e LogEntry) {
+	data, _ := json.Marshal(e)
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.f != nil {
+		w.f.Write(data)
+		w.f.Write([]byte("\n"))
+	}
+}
+
+func (w *fileLogWriter) Close() {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.f != nil {
+		w.f.Close()
+		w.f = nil
+	}
+}