Implemented streaming of the datastore file
Implemented streaming of the datastore file


Former-commit-id: 4f0a323f19e7042b320e8a0e46172a42cea7faac [formerly 83a720d45d36901b1639d94880bb7737faff0523]
Former-commit-id: 4ea7b79f7fd5897c93c5267bed17cc503aecb048
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine