github.com/klaytn/klaytn@v1.12.1/blockchain/blockchain_sethead_test.go

// Copyright 2021 The klaytn Authors
// This file is part of the klaytn library.
//
// The klaytn library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The klaytn library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the klaytn library. If not, see <http://www.gnu.org/licenses/>.

package blockchain

import (
	"testing"

	"github.com/klaytn/klaytn/blockchain/types"
	"github.com/klaytn/klaytn/consensus/gxhash"
	"github.com/klaytn/klaytn/params"
	"github.com/stretchr/testify/assert"
)

// Tests a sethead for a short canonical chain where a recent block was already
// committed to disk and then the sethead called. In this case we expect the full
// chain to be rolled back to the committed block. Everything above the sethead
// point should be deleted. In between the committed block and the requested head
// the data can remain as "fast sync" data to avoid redownloading it.
type rewindTest struct {
	canonicalBlocks int     // Number of blocks to generate for the canonical chain (heavier)
	sidechainBlocks int     // Number of blocks to generate for the side chain (lighter)
	commitBlock     uint64  // Block number for which to commit the state to disk
	pivotBlock      *uint64 // Pivot block number in case of fast sync

	setheadBlock       uint64 // Block number to set head back to
	expCanonicalBlocks int    // Number of canonical blocks expected to remain in the database (excl. genesis)
	expSidechainBlocks int    // Number of sidechain blocks expected to remain in the database (excl. genesis)
	expHeadHeader      uint64 // Block number of the expected head header
	expHeadFastBlock   uint64 // Block number of the expected head fast sync block
	expHeadBlock       uint64 // Block number of the expected head full block
}

func TestShortSetHead(t *testing.T) { testShortSetHead(t) }

func testShortSetHead(t *testing.T) {
	// Chain:
	//   G->C1->C2->C3->C4->C5->C6->C7->C8 (HEAD)
	//
	// Frozen: none
	// Commit: G, C4
	// Pivot : none
	//
	// SetHead(7)
	//
	// ------------------------------
	//
	// Expected in leveldb:
	//   G->C1->C2->C3->C4->C5->C6->C7
	//
	// Expected head header    : C7
	// Expected head fast block: C7
	// Expected head block     : C7
	testSetHead(t, &rewindTest{
		canonicalBlocks:    8,
		sidechainBlocks:    0,
		commitBlock:        4,
		pivotBlock:         nil,
		setheadBlock:       7,
		expCanonicalBlocks: 7,
		expSidechainBlocks: 0,
		expHeadHeader:      7,
		expHeadFastBlock:   7,
		expHeadBlock:       7,
	})
}

// Tests a sethead for a short canonical chain and a shorter side chain, where a
// recent block was already committed to disk and then sethead was called. In this
// test scenario the side chain is below the committed block. In this case we expect
// the canonical full chain to be rolled back to the committed block. Everything
// above the sethead point should be deleted. In between the committed block and
// the requested head the data can remain as "fast sync" data to avoid redownloading
// it. The side chain should be left alone as it was shorter.

func TestLongDeepSetHead(t *testing.T) { testLongDeepSetHead(t, false) }

func testLongDeepSetHead(t *testing.T, snapshots bool) {
	// Chain:
	//   G->C1->C2->C3->C4->C5->C6->C7->C8->C9->C10->C11->C12->C13->C14->C15->C16->C17->C18->C19->C20->C21->C22->C23->C24 (HEAD)
	//
	//
	// Commit: G, C4
	// Pivot : none
	//
	// SetHead(6)
	//
	// -----------------------------
	//
	// Expected in leveldb: none
	//
	// Expected head header    : C4
	// Expected head fast block: C4
	// Expected head block     : C4
	testSetHead(t, &rewindTest{
		canonicalBlocks:    24,
		sidechainBlocks:    0,
		commitBlock:        4,
		pivotBlock:         nil,
		setheadBlock:       6,
		expCanonicalBlocks: 6,
		expSidechainBlocks: 0,
		expHeadHeader:      6,
		expHeadFastBlock:   6,
		expHeadBlock:       6,
	})
}

func testSetHead(t *testing.T, tt *rewindTest) {
	db, chain, err := newCanonical(gxhash.NewFullFaker(), 0, true)
	if err != nil {
		t.Fatalf("failed to create pristine chain: %v", err)
	}
	defer chain.Stop()
	chain.Config().Istanbul = params.GetDefaultIstanbulConfig()

	// If sidechain blocks are needed, make a light chain and import it
	var sideblocks types.Blocks
	if tt.sidechainBlocks > 0 {
		sideblocks, _ = GenerateChain(params.TestChainConfig, chain.CurrentBlock(), gxhash.NewFaker(), db, tt.canonicalBlocks, func(i int, b *BlockGen) {})
		if _, err := chain.InsertChain(sideblocks); err != nil {
			t.Fatalf("Failed to import side chain: %v", err)
		}
	}

	canonblocks, _ := GenerateChain(params.TestChainConfig, chain.CurrentBlock(), gxhash.NewFaker(), db, tt.canonicalBlocks, func(i int, b *BlockGen) {})
	if _, err := chain.InsertChain(canonblocks[:tt.commitBlock]); err != nil {
		t.Fatalf("Failed to import canonical chain start: %v", err)
	}
	if tt.commitBlock > 0 {
		chain.stateCache.TrieDB().Commit(canonblocks[tt.commitBlock-1].Root(), true, tt.commitBlock)
	}
	if _, err := chain.InsertChain(canonblocks[tt.commitBlock:]); err != nil {
		t.Fatalf("Failed to import canonical chain tail: %v", err)
	}
	// Manually dereference anything not committed to not have to work with 128+ tries
	for _, block := range sideblocks {
		chain.stateCache.TrieDB().Dereference(block.Root())
	}
	for _, block := range canonblocks {
		chain.stateCache.TrieDB().Dereference(block.Root())
	}

	// Set the head of the chain back to the requested number
	chain.SetHead(tt.setheadBlock)

	// Iterate over all the remaining blocks and ensure there are no gaps
	verifyNoGaps(t, chain, true, canonblocks)
	verifyNoGaps(t, chain, false, sideblocks)
	verifyCutoff(t, chain, true, canonblocks, tt.expCanonicalBlocks)
	verifyCutoff(t, chain, false, sideblocks, tt.expSidechainBlocks)

	if head := chain.CurrentHeader(); head.Number.Uint64() != tt.expHeadHeader {
		t.Errorf("Head header mismatch!: have %d, want %d", head.Number, tt.expHeadHeader)
	}
	if head := chain.CurrentFastBlock(); head.NumberU64() != tt.expHeadFastBlock {
		t.Errorf("Head fast block mismatch: have %d, want %d", head.NumberU64(), tt.expHeadFastBlock)
	}
	if head := chain.CurrentBlock(); head.NumberU64() != tt.expHeadBlock {
		t.Errorf("Head block mismatch!!: have %d, want %d", head.NumberU64(), tt.expHeadBlock)
	}
}

// verifyNoGaps checks that there are no gaps after the initial set of blocks in
// the database and errors if found.
func verifyNoGaps(t *testing.T, chain *BlockChain, canonical bool, inserted types.Blocks) {
	t.Helper()

	var end uint64
	for i := uint64(0); i <= uint64(len(inserted)); i++ {
		header := chain.GetHeaderByNumber(i)
		if header == nil && end == 0 {
			end = i
		}
		if header != nil && end > 0 {
			if canonical {
				t.Errorf("Canonical header gap between #%d-#%d", end, i-1)
			} else {
				t.Errorf("Sidechain header gap between #%d-#%d", end, i-1)
			}
			end = 0 // Reset for further gap detection
		}
	}
	end = 0
	for i := uint64(0); i <= uint64(len(inserted)); i++ {
		block := chain.GetBlockByNumber(i)
		if block == nil && end == 0 {
			end = i
		}
		if block != nil && end > 0 {
			if canonical {
				t.Errorf("Canonical block gap between #%d-#%d", end, i-1)
			} else {
				t.Errorf("Sidechain block gap between #%d-#%d", end, i-1)
			}
			end = 0 // Reset for further gap detection
		}
	}
	end = 0
	for i := uint64(1); i <= uint64(len(inserted)); i++ {
		receipts := chain.GetReceiptsByBlockHash(inserted[i-1].Hash())
		if receipts == nil && end == 0 {
			end = i
		}
		if receipts != nil && end > 0 {
			if canonical {
				t.Errorf("Canonical receipt gap between #%d-#%d", end, i-1)
			} else {
				t.Errorf("Sidechain receipt gap between #%d-#%d", end, i-1)
			}
			end = 0 // Reset for further gap detection
		}
	}
}

// verifyCutoff checks that there are no chain data available in the chain after
// the specified limit, but that it is available before.
func verifyCutoff(t *testing.T, chain *BlockChain, canonical bool, inserted types.Blocks, head int) {
	t.Helper()

	for i := 1; i <= len(inserted); i++ {
		if i <= head {
			if header := chain.GetHeader(inserted[i-1].Hash(), uint64(i)); header == nil {
				if canonical {
					t.Errorf("Canonical header   #%2d [%x...] missing before cap %d", inserted[i-1].Number(), inserted[i-1].Hash().Bytes()[:3], head)
				} else {
					t.Errorf("Sidechain header   #%2d [%x...] missing before cap %d", inserted[i-1].Number(), inserted[i-1].Hash().Bytes()[:3], head)
				}
			}
			if block := chain.GetBlock(inserted[i-1].Hash(), uint64(i)); block == nil {
				if canonical {
					t.Errorf("Canonical block    #%2d [%x...] missing before cap %d", inserted[i-1].Number(), inserted[i-1].Hash().Bytes()[:3], head)
				} else {
					t.Errorf("Sidechain block    #%2d [%x...] missing before cap %d", inserted[i-1].Number(), inserted[i-1].Hash().Bytes()[:3], head)
				}
			}
			if receipts := chain.GetReceiptsByBlockHash(inserted[i-1].Hash()); receipts == nil {
				if canonical {
					t.Errorf("Canonical receipts #%2d [%x...] missing before cap %d", inserted[i-1].Number(), inserted[i-1].Hash().Bytes()[:3], head)
				} else {
					t.Errorf("Sidechain receipts #%2d [%x...] missing before cap %d", inserted[i-1].Number(), inserted[i-1].Hash().Bytes()[:3], head)
				}
			}
		} else {
			if header := chain.GetHeader(inserted[i-1].Hash(), uint64(i)); header != nil {
				if canonical {
					t.Errorf("Canonical header   #%2d [%x...] present after cap %d", inserted[i-1].Number(), inserted[i-1].Hash().Bytes()[:3], head)
				} else {
					t.Errorf("Sidechain header   #%2d [%x...] present after cap %d", inserted[i-1].Number(), inserted[i-1].Hash().Bytes()[:3], head)
				}
			}
			if block := chain.GetBlock(inserted[i-1].Hash(), uint64(i)); block != nil {
				if canonical {
					t.Errorf("Canonical block    #%2d [%x...] present after cap %d", inserted[i-1].Number(), inserted[i-1].Hash().Bytes()[:3], head)
				} else {
					t.Errorf("Sidechain block    #%2d [%x...] present after cap %d", inserted[i-1].Number(), inserted[i-1].Hash().Bytes()[:3], head)
				}
			}
			if receipts := chain.GetReceiptsByBlockHash(inserted[i-1].Hash()); receipts != nil {
				if canonical {
					t.Errorf("Canonical receipts #%2d [%x...] present after cap %d", inserted[i-1].Number(), inserted[i-1].Hash().Bytes()[:3], head)
				} else {
					t.Errorf("Sidechain receipts #%2d [%x...] present after cap %d", inserted[i-1].Number(), inserted[i-1].Hash().Bytes()[:3], head)
				}
			}
		}
	}
}

func TestSetHeadEarlyExit(t *testing.T) {
	testSetHeadEarlyExit(t, &rewindTest{
		canonicalBlocks: 8,
		setheadBlock:    3,
	})
}

func testSetHeadEarlyExit(t *testing.T, tt *rewindTest) {
	db, chain, err := newCanonical(gxhash.NewFullFaker(), 0, true)
	if err != nil {
		t.Fatalf("failed to create pristine chain: %v", err)
	}
	defer chain.Stop()
	chain.Config().Istanbul = params.GetDefaultIstanbulConfig()

	canonblocks, _ := GenerateChain(params.TestChainConfig, chain.CurrentBlock(), gxhash.NewFaker(), db, tt.canonicalBlocks, func(i int, b *BlockGen) {})
	if _, err := chain.InsertChain(canonblocks); err != nil {
		t.Fatalf("Failed to import canonical chain start: %v", err)
	}

	db.WriteLastPrunedBlockNumber(tt.setheadBlock + 1)
	assert.Error(t, chain.SetHead(tt.setheadBlock))

	db.WriteLastPrunedBlockNumber(tt.setheadBlock)
	assert.Error(t, chain.SetHead(tt.setheadBlock))

	db.WriteLastPrunedBlockNumber(tt.setheadBlock - 1)
	assert.Nil(t, chain.SetHead(tt.setheadBlock))
}