* Implement RemoteStore::queryValidPaths().

src/libstore/remote-store.cc

@@ -214,7 +214,9 @@ bool RemoteStore::isValidPath(const Path & path)
 PathSet RemoteStore::queryValidPaths()
 {
     openConnection();
-    throw Error("not implemented");
+    writeInt(wopQueryValidPaths, to);
+    processStderr();
+    return readStorePaths(from);
 }
 
 

src/libstore/worker-protocol.hh

@@ -35,6 +35,7 @@ typedef enum {
     wopCollectGarbage = 20,
     wopQuerySubstitutablePathInfo = 21,
     wopQueryDerivationOutputs = 22,
+    wopQueryValidPaths = 23,
 } WorkerOp;
 
 

src/nix-worker/nix-worker.cc

@@ -520,6 +520,14 @@ static void performOp(unsigned int clientVersion,
         break;
     }
             
+    case wopQueryValidPaths: {
+        startWork();
+        PathSet paths = store->queryValidPaths();
+        stopWork();
+        writeStringSet(paths, to);
+        break;
+    }
+
     default:
         throw Error(format("invalid operation %1%") % op);
     }