1 files changed, 15 insertions, 0 deletions
diff --git a/include/leveldb/write_batch.h b/include/leveldb/write_batch.h
index 3411952..b4446c2 100644
--- a/include/leveldb/write_batch.h
+++ b/include/leveldb/write_batch.h
@@ -12,11 +12,17 @@
 //    batch.Delete("key");
 //    batch.Put("key", "v2");
 //    batch.Put("key", "v3");
+//
+// Multiple threads can invoke const methods on a WriteBatch without
+// external synchronization, but if any of the threads may call a
+// non-const method, all threads accessing the same WriteBatch must use
+// external synchronization.
 
 #ifndef STORAGE_LEVELDB_INCLUDE_WRITE_BATCH_H_
 #define STORAGE_LEVELDB_INCLUDE_WRITE_BATCH_H_
 
 #include <string>
+#include "leveldb/status.h"
 
 namespace leveldb {
 
@@ -36,6 +42,15 @@ class WriteBatch {
   // Clear all updates buffered in this batch.
   void Clear();
 
+  // Support for iterating over the contents of a batch.
+  class Handler {
+   public:
+    virtual ~Handler();
+    virtual void Put(const Slice& key, const Slice& value) = 0;
+    virtual void Delete(const Slice& key) = 0;
+  };
+  Status Iterate(Handler* handler) const;
+
  private:
   friend class WriteBatchInternal;