[infinispan-dev] New API to iterate over current entries in cache

While working on ISPN-4068 to add the current state to listeners that were added I found that what I essentially needed was a way to iterate over the entries of the cache. I am thinking of adding this to the public API available on the AdvancedCache interface. I wanted to get your guy's opinions if you don't think we should add it or any changes you might suggest. My thought was to add 2 overloaded methods: <C> Iterator<Map.Entry<K, C>> entryIterator(KeyValueFilter<? super K, ? super V> filter, Converter<? super K, ? super V, C> converter); and Iterator<Map.Entry<K, V>> entryIterator(KeyValueFilter<? super K, ? super V> filter); The method would return almost immediately after invocation and the iterator would queue entries and block as entries are required to be returned. The filter and converter are applied on each of the remote nodes and are required to be serializable or have an externalizer registered. Internally the iterator would use chunking to help prevent memory saturation. The max memory usage would be (chunkSize * N) + local entries where N is the number of nodes. These methods would be different than other methods on the Cache/AdvancedCache in the following things: 1. This operation is treated as nontx and thus won't store them into the context and thus repeatable read semantics would not be guaranteed. This doesn't preclude manually adding values to the context. Also prior writes in the current context would be ignored (current data returned), although this could be changed if desired. 2. Values are not activated from loaders and visited listeners would not be notified of access. The latter could be sensibly changed if desired. - Will