Add a helper for doing concurrent writes to files.

1 files changed, 24 insertions, 0 deletions

diff --git a/ccw/ccw.go b/ccw/ccw.go
new file mode 100644
index 0000000..ea207e5
--- /dev/null
+++ b/ccw/ccw.go
@@ -0,0 +1,24 @@
+package ccw
+
+import (
+	"os"
+	"sync"
+)
+
+type ConcurrentWriter struct {
+	lock sync.Mutex
+	file *os.File
+}
+
+func NewConcurrentFileWriter(file *os.File) *ConcurrentWriter {
+	return &ConcurrentWriter{sync.Mutex{}, file}
+}
+
+func (ccw *ConcurrentWriter) Write(p []byte) (n int, err error) {
+	ccw.lock.Lock()
+	defer func() {
+		ccw.file.Sync()
+		ccw.lock.Unlock()
+	}()
+	return ccw.file.Write(p)
+}