Add lock on put.

Author: RubenVerborgh

lib/ldp.js

@@ -255,16 +255,24 @@ class LDP {
     }
 
     // Directory created, now write the file
-    return await new Promise((resolve, reject) => {
-      const file = stream.pipe(fs.createWriteStream(path))
-      file.on('error', function () {
-        reject(error(500, 'Error writing data'))
-      })
-      file.on('finish', function () {
-        debug.handlers('PUT -- Wrote data to: ' + path)
-        resolve()
+    let releaseLock
+    try {
+      releaseLock = await lock(path, { retries: 10, realpath: false })
+      return await new Promise((resolve, reject) => {
+        const file = stream.pipe(fs.createWriteStream(path))
+        file.on('error', function () {
+          reject(error(500, 'Error writing data'))
+        })
+        file.on('finish', function () {
+          debug.handlers('PUT -- Wrote data to: ' + path)
+          resolve()
+        })
       })
-    })
+    } finally {
+      if (releaseLock) {
+        await releaseLock()
+      }
+    }
   }
 
   async exists (hostname, path, searchIndex = true) {