Lisk-sdk: Split block processing steps into separate functions and expose them from module/blocks

Created on 26 Jun 2019 · 5Comments · Source: LiskHQ/lisk-sdk

Expected behavior

Block processing includes block and transactions validation, verification and applying into the blockchain. Each step is an expensive operation and should be called only once for each block. As part of BFT, we execute these steps at different stages, and block processing should allow calling these functions independently.

Actual behavior

process.js file only exports applyBlock and processBlock functions which encapsulate all the work related to validating, verifying and applying a block. It does not allow executing these steps separately.

Which version(s) does this affect? (Environment, OS, etc...)

feature/introduce_bft_consensus

framewornode

Source

SargeKhan

👍1

Most helpful comment

While at this I would also encapsulate this methods in different objects so we can switch between different processing models on the fly.

pablitovicente on 26 Jun 2019

👍2

All 5 comments

This could be a way of implementing this based on the steps defined in the section Processing Blocks of LIP-0014:

    async _validateAndVerifyInMemory(block, lastBlock, broadcast) {
        const enhancedBlock = !broadcast
            ? blocksUtils.addBlockProperties(block)
            : block;
        const normalizedBlock = blocksLogic.objectNormalize(
            enhancedBlock,
            this.exceptions
        );
        const { verified, errors } = this.blocksVerify.verifyBlock(
            normalizedBlock,
            lastBlock
        );
        await this.blocksVerify.validateBlockSlot(normalizedBlock);
    }

    async _verifyBlockAgainsState() {
        await this.blocksVerify.checkExists(normalizedBlock); // Step 4
        await this.blocksVerify.checkTransactions(normalizedBlock); // Step 4
    }

    async processValidatedBlock(block, lastBlock, broadcast) {
        this.BFTConsensusManager.validateBlockHeader(block); //Step 2

        if (typeof broadcast === 'function') {
            broadcast(normalizedBlock); // Step3
        }

        await this.verifyBlockAgainsState(); // Step4
        await this.blocksChain.applyBlock(normalizedBlock, true); // Step 5

        this.BFTConsensusManager.addBlockHeader(
            normalizedBlock
        ); // Step 6: Compute prevotes and precommits

        this.channel.publish('chain:blocks:processing:succeeded', {
            block: {
                id: block.id,
                height: block.height,
                heightPrevoted: block.heightPrevoted
            }
        });

        return normalizedBlock;
    }

    async processBlock(block, lastBlock, broadcast) {
        const validatedVerifiedBlock = this._validateAndVerifyInMemory(block, lastBlock); // Step 1
        this.processValidatedBlock(validatedVerifiedBlock, lastBlock, broadcast);
    }