Ledger Package

This package implements the ledger, which includes the blockchain and global state.

YA-fabric has refactored this module and provided a more robust implement, with entries easy to be used

Mutiple ledgers

In YA-fabric, developer can run mutiple ledger objects in an instance. All of them have their separated blockchain, state and block indexes. And they share a storage pool for graphics of states, and transactions, which can be accessed from the globalLedger singleton (Each ledger object also integrated the entry of globalLedger)

GetNewLedger API can be used to create new ledger, replace of the legacy "GetLedger". The later function can still be used for accessing a default ledger object

Concurrent supporting

A ledger object now can be read by mutiple-thread and written by single-thread (Single Write Mutiple Reads, or SWMR). User can use a snapshot of database to get data consistent in a query transction, even another transaction is just changing the underlying database

Execution and committing entries

TxExecState, a new designed object, is provided for executing transactions, replace the old API for world-states. The new object allow concurrent execution of txs, and in combination of the committing entries form a new environment for chaincode platform.

A series of committing objects, see ledger_commit.go and ledger_commit_sync.go is used for updating ledger now. They have a unified interface on handling each elements in the ledger (blocks, states and indexes) and can be applied by requirement of different scenes like committing a new block after executing a bunch of transactions, inserting a block, or syncing the whole world-state, etc.

Syncing of world-state

A practical syncing implement for the whole world-state, via the new Dividable interface, is avaliable now. So peers can transfer their world-state data with resumable, verifiable process, which may be able to save much traffic and computational cost.

Currently only buckettree has implied the 'diviable' interface