path: root/core/state/sync_test.go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum 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 go-ethereum 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 go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package state

import (
    "bytes"
    "math/big"
    "testing"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/ethdb"
    "github.com/ethereum/go-ethereum/trie"
)

// testAccount is the data associated with an account used by the state tests.
type testAccount struct {
    address common.Address
    balance *big.Int
    nonce   uint64
    code    []byte
}

// makeTestState create a sample test state to test node-wise reconstruction.
func makeTestState() (ethdb.Database, common.Hash, []*testAccount) {
    // Create an empty state
    db, _ := ethdb.NewMemDatabase()
    state, _ := New(common.Hash{}, db)

    // Fill it with some arbitrary data
    accounts := []*testAccount{}
    for i := byte(0); i < 96; i++ {
        obj := state.GetOrNewStateObject(common.BytesToAddress([]byte{i}))
        acc := &testAccount{address: common.BytesToAddress([]byte{i})}

        obj.AddBalance(big.NewInt(int64(11 * i)))
        acc.balance = big.NewInt(int64(11 * i))

        obj.SetNonce(uint64(42 * i))
        acc.nonce = uint64(42 * i)

        if i%3 == 0 {
            obj.SetCode([]byte{i, i, i, i, i})
            acc.code = []byte{i, i, i, i, i}
        }
        state.UpdateStateObject(obj)
        accounts = append(accounts, acc)
    }
    root, _ := state.Commit()

    // Remove any potentially cached data from the test state creation
    trie.ClearGlobalCache()

    // Return the generated state
    return db, root, accounts
}

// checkStateAccounts cross references a reconstructed state with an expected
// account array.
func checkStateAccounts(t *testing.T, db ethdb.Database, root common.Hash, accounts []*testAccount) {
    // Remove any potentially cached data from the state synchronisation
    trie.ClearGlobalCache()

    // Check root availability and state contents
    state, err := New(root, db)
    if err != nil {
        t.Fatalf("failed to create state trie at %x: %v", root, err)
    }
    if err := checkStateConsistency(db, root); err != nil {
        t.Fatalf("inconsistent state trie at %x: %v", root, err)
    }
    for i, acc := range accounts {
        if balance := state.GetBalance(acc.address); balance.Cmp(acc.balance) != 0 {
            t.Errorf("account %d: balance mismatch: have %v, want %v", i, balance, acc.balance)
        }
        if nonce := state.GetNonce(acc.address); nonce != acc.nonce {
            t.Errorf("account %d: nonce mismatch: have %v, want %v", i, nonce, acc.nonce)
        }
        if code := state.GetCode(acc.address); bytes.Compare(code, acc.code) != 0 {
            t.Errorf("account %d: code mismatch: have %x, want %x", i, code, acc.code)
        }
    }
}

// checkStateConsistency checks that all nodes in a state trie are indeed present.
func checkStateConsistency(db ethdb.Database, root common.Hash) error {
    // Remove any potentially cached data from the test state creation or previous checks
    trie.ClearGlobalCache()

    // Create and iterate a state trie rooted in a sub-node
    if _, err := db.Get(root.Bytes()); err != nil {
        return nil // Consider a non existent state consistent
    }
    state, err := New(root, db)
    if err != nil {
        return err
    }
    it := NewNodeIterator(state)
    for it.Next() {
    }
    return it.Error
}

// Tests that an empty state is not scheduled for syncing.
func TestEmptyStateSync(t *testing.T) {
    empty := common.HexToHash("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421")
    db, _ := ethdb.NewMemDatabase()
    if req := NewStateSync(empty, db).Missing(1); len(req) != 0 {
        t.Errorf("content requested for empty state: %v", req)
    }
}

// Tests that given a root hash, a state can sync iteratively on a single thread,
// requesting retrieval tasks and returning all of them in one go.
func TestIterativeStateSyncIndividual(t *testing.T) { testIterativeStateSync(t, 1) }
func TestIterativeStateSyncBatched(t *testing.T)    { testIterativeStateSync(t, 100) }

func testIterativeStateSync(t *testing.T, batch int) {
    // Create a random state to copy
    srcDb, srcRoot, srcAccounts := makeTestState()

    // Create a destination state and sync with the scheduler
    dstDb, _ := ethdb.NewMemDatabase()
    sched := NewStateSync(srcRoot, dstDb)

    queue := append([]common.Hash{}, sched.Missing(batch)...)
    for len(queue) > 0 {
        results := make([]trie.SyncResult, len(queue))
        for i, hash := range queue {
            data, err := srcDb.Get(hash.Bytes())
            if err != nil {
                t.Fatalf("failed to retrieve node data for %x: %v", hash, err)
            }
            results[i] = trie.SyncResult{Hash: hash, Data: data}
        }
        if index, err := sched.Process(results); err != nil {
            t.Fatalf("failed to process result #%d: %v", index, err)
        }
        queue = append(queue[:0], sched.Missing(batch)...)
    }
    // Cross check that the two states are in sync
    checkStateAccounts(t, dstDb, srcRoot, srcAccounts)
}

// Tests that the trie scheduler can correctly reconstruct the state even if only
// partial results are returned, and the others sent only later.
func TestIterativeDelayedStateSync(t *testing.T) {
    // Create a random state to copy
    srcDb, srcRoot, srcAccounts := makeTestState()

    // Create a destination state and sync with the scheduler
    dstDb, _ := ethdb.NewMemDatabase()
    sched := NewStateSync(srcRoot, dstDb)

    queue := append([]common.Hash{}, sched.Missing(0)...)
    for len(queue) > 0 {
        // Sync only half of the scheduled nodes
        results := make([]trie.SyncResult, len(queue)/2+1)
        for i, hash := range queue[:len(results)] {
            data, err := srcDb.Get(hash.Bytes())
            if err != nil {
                t.Fatalf("failed to retrieve node data for %x: %v", hash, err)
            }
            results[i] = trie.SyncResult{Hash: hash, Data: data}
        }
        if index, err := sched.Process(results); err != nil {
            t.Fatalf("failed to process result #%d: %v", index, err)
        }
        queue = append(queue[len(results):], sched.Missing(0)...)
    }
    // Cross check that the two states are in sync
    checkStateAccounts(t, dstDb, srcRoot, srcAccounts)
}

// Tests that given a root hash, a trie can sync iteratively on a single thread,
// requesting retrieval tasks and returning all of them in one go, however in a
// random order.
func TestIterativeRandomStateSyncIndividual(t *testing.T) { testIterativeRandomStateSync(t, 1) }
func TestIterativeRandomStateSyncBatched(t *testing.T)    { testIterativeRandomStateSync(t, 100) }

func testIterativeRandomStateSync(t *testing.T, batch int) {
    // Create a random state to copy
    srcDb, srcRoot, srcAccounts := makeTestState()

    // Create a destination state and sync with the scheduler
    dstDb, _ := ethdb.NewMemDatabase()
    sched := NewStateSync(srcRoot, dstDb)

    queue := make(map[common.Hash]struct{})
    for _, hash := range sched.Missing(batch) {
        queue[hash] = struct{}{}
    }
    for len(queue) > 0 {
        // Fetch all the queued nodes in a random order
        results := make([]trie.SyncResult, 0, len(queue))
        for hash, _ := range queue {
            data, err := srcDb.Get(hash.Bytes())
            if err != nil {
                t.Fatalf("failed to retrieve node data for %x: %v", hash, err)
            }
            results = append(results, trie.SyncResult{Hash: hash, Data: data})
        }
        // Feed the retrieved results back and queue new tasks
        if index, err := sched.Process(results); err != nil {
            t.Fatalf("failed to process result #%d: %v", index, err)
        }
        queue = make(map[common.Hash]struct{})
        for _, hash := range sched.Missing(batch) {
            queue[hash] = struct{}{}
        }
    }
    // Cross check that the two states are in sync
    checkStateAccounts(t, dstDb, srcRoot, srcAccounts)
}

// Tests that the trie scheduler can correctly reconstruct the state even if only
// partial results are returned (Even those randomly), others sent only later.
func TestIterativeRandomDelayedStateSync(t *testing.T) {
    // Create a random state to copy
    srcDb, srcRoot, srcAccounts := makeTestState()

    // Create a destination state and sync with the scheduler
    dstDb, _ := ethdb.NewMemDatabase()
    sched := NewStateSync(srcRoot, dstDb)

    queue := make(map[common.Hash]struct{})
    for _, hash := range sched.Missing(0) {
        queue[hash] = struct{}{}
    }
    for len(queue) > 0 {
        // Sync only half of the scheduled nodes, even those in random order
        results := make([]trie.SyncResult, 0, len(queue)/2+1)
        for hash, _ := range queue {
            delete(queue, hash)

            data, err := srcDb.Get(hash.Bytes())
            if err != nil {
                t.Fatalf("failed to retrieve node data for %x: %v", hash, err)
            }
            results = append(results, trie.SyncResult{Hash: hash, Data: data})

            if len(results) >= cap(results) {
                break
            }
        }
        // Feed the retrieved results back and queue new tasks
        if index, err := sched.Process(results); err != nil {
            t.Fatalf("failed to process result #%d: %v", index, err)
        }
        for _, hash := range sched.Missing(0) {
            queue[hash] = struct{}{}
        }
    }
    // Cross check that the two states are in sync
    checkStateAccounts(t, dstDb, srcRoot, srcAccounts)
}

// Tests that at any point in time during a sync, only complete sub-tries are in
// the database.
func TestIncompleteStateSync(t *testing.T) {
    // Create a random state to copy
    srcDb, srcRoot, srcAccounts := makeTestState()

    // Create a destination state and sync with the scheduler
    dstDb, _ := ethdb.NewMemDatabase()
    sched := NewStateSync(srcRoot, dstDb)

    added := []common.Hash{}
    queue := append([]common.Hash{}, sched.Missing(1)...)
    for len(queue) > 0 {
        // Fetch a batch of state nodes
        results := make([]trie.SyncResult, len(queue))
        for i, hash := range queue {
            data, err := srcDb.Get(hash.Bytes())
            if err != nil {
                t.Fatalf("failed to retrieve node data for %x: %v", hash, err)
            }
            results[i] = trie.SyncResult{Hash: hash, Data: data}
        }
        // Process each of the state nodes
        if index, err := sched.Process(results); err != nil {
            t.Fatalf("failed to process result #%d: %v", index, err)
        }
        for _, result := range results {
            added = append(added, result.Hash)
        }
        // Check that all known sub-tries in the synced state is complete
        for _, root := range added {
            // Skim through the accounts and make sure the root hash is not a code node
            codeHash := false
            for _, acc := range srcAccounts {
                if bytes.Compare(root.Bytes(), crypto.Sha3(acc.code)) == 0 {
                    codeHash = true
                    break
                }
            }
            // If the root is a real trie node, check consistency
            if !codeHash {
                if err := checkStateConsistency(dstDb, root); err != nil {
                    t.Fatalf("state inconsistent: %v", err)
                }
            }
        }
        // Fetch the next batch to retrieve
        queue = append(queue[:0], sched.Missing(1)...)
    }
    // Sanity check that removing any node from the database is detected
    for _, node := range added[1:] {
        key := node.Bytes()
        value, _ := dstDb.Get(key)

        dstDb.Delete(key)
        if err := checkStateConsistency(dstDb, added[0]); err == nil {
            t.Fatalf("trie inconsistency not caught, missing: %x", key)
        }
        dstDb.Put(key, value)
    }
}