Modified from go-ethereum under GNU Lesser General Public License.

NewCommonEngine returns the common engine mixin.

ErrFutureBlock is returned when a block's timestamp is in the future according to the current node.

Various error messages to mark blocks invalid.

Various error messages to mark blocks invalid.

ErrInvalidNumber is returned if a block's number doesn't equal it's parent's plus one.

Various error messages to mark blocks invalid.

ErrNotRemote is returned if GetWork be called in local mining is not remote.

Various error messages to mark blocks invalid.

ErrPrunedAncestor is returned when validating a block requires an ancestor that is known, but the state of which is not available.

ErrUnknownAncestor is returned when validating a block requires an ancestor that is unknown.

CommonEngine contains the common parts for consensus engines, where engine-specific logic is provided in func args as template pattern.

MiningResult represents the found digest and result bytes.

MiningSpec contains a PoW algo's basic info and hash algo.

MiningWork represents the params of mining work.

ChainReader defines a small collection of methods needed to access the local blockchain during header verification.

Engine is an algorithm agnostic consensus engine.

PoW is the quarkchain version of PoW consensus engine, with a conveninent method for remote miners.