Move read access part of IDocumentMetaStoreContext to searchlib.

1 files changed, 42 insertions, 0 deletions

diff --git a/searchlib/src/vespa/searchlib/common/i_document_meta_store_context.h b/searchlib/src/vespa/searchlib/common/i_document_meta_store_context.h
new file mode 100644
index 00000000000..7e2e3def0d2
--- /dev/null
+++ b/searchlib/src/vespa/searchlib/common/i_document_meta_store_context.h
@@ -0,0 +1,42 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#pragma once
+
+#include <memory>
+
+namespace search {
+
+class IDocumentMetaStore;
+
+/**
+ * API for providing read interface to the document meta store.
+ */
+struct IDocumentMetaStoreContext {
+
+    /**
+     * Guard for access to the read interface.
+     * This guard should be alive as long as read interface is used.
+     */
+    struct IReadGuard {
+
+        typedef std::unique_ptr<IReadGuard> UP;
+
+        virtual ~IReadGuard() {}
+
+        /**
+         * Access to read interface.
+         */
+        virtual const search::IDocumentMetaStore &get() const = 0;
+    };
+
+    virtual ~IDocumentMetaStoreContext() {}
+
+    /**
+     * Access to read interface.
+     * Should be used by all reader threads.
+     */
+    virtual IReadGuard::UP getReadGuard() const = 0;
+
+};
+
+}