This changes how the downloader works, a little bit. Previously, when block sync started,
we immediately started filling up to 8192 blocks. Usually this is fine, blocks are small
in the early numbers. The threshold then is lowered as we measure the size of the blocks
that are filled.
However, if the node is shut down and restarts syncing while we're in a heavy segment,
that might be bad. This PR introduces a more conservative initial threshold of 2K blocks
instead.
This change introduces garbage collection for the light client. Historical
chain data is deleted periodically. If you want to disable the GC, use
the --light.nopruning flag.
* core: speed up GenerateChain
Use a mock implementation of ChainReader instead of creating
and destroying a BlockChain object for each generated block.
* eth/downloader: speed up tests by generating chain only once
This change reworks the downloader tests so they share a common test
blockchain instead of generating a chain in every test. The tests are
roughly twice as fast now.
Martin Holst Swende
gary rong
Péter Szilágyi
Felix Lange