1// Copyright 2017 The go-ethereum Authors
2// This file is part of the go-ethereum library.
3//
4// The go-ethereum library is free software: you can redistribute it and/or modify
5// it under the terms of the GNU Lesser General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8//
9// The go-ethereum library is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12// GNU Lesser General Public License for more details.
13//
14// You should have received a copy of the GNU Lesser General Public License
15// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
16
17package core
18
19import (
20	"context"
21	"errors"
22	"fmt"
23	"math/big"
24	"math/rand"
25	"testing"
26	"time"
27
28	"github.com/ethereum/go-ethereum/common"
29	"github.com/ethereum/go-ethereum/core/rawdb"
30	"github.com/ethereum/go-ethereum/core/types"
31)
32
33// Runs multiple tests with randomized parameters.
34func TestChainIndexerSingle(t *testing.T) {
35	for i := 0; i < 10; i++ {
36		testChainIndexer(t, 1)
37	}
38}
39
40// Runs multiple tests with randomized parameters and different number of
41// chain backends.
42func TestChainIndexerWithChildren(t *testing.T) {
43	for i := 2; i < 8; i++ {
44		testChainIndexer(t, i)
45	}
46}
47
48// testChainIndexer runs a test with either a single chain indexer or a chain of
49// multiple backends. The section size and required confirmation count parameters
50// are randomized.
51func testChainIndexer(t *testing.T, count int) {
52	db := rawdb.NewMemoryDatabase()
53	defer db.Close()
54
55	// Create a chain of indexers and ensure they all report empty
56	backends := make([]*testChainIndexBackend, count)
57	for i := 0; i < count; i++ {
58		var (
59			sectionSize = uint64(rand.Intn(100) + 1)
60			confirmsReq = uint64(rand.Intn(10))
61		)
62		backends[i] = &testChainIndexBackend{t: t, processCh: make(chan uint64)}
63		backends[i].indexer = NewChainIndexer(db, rawdb.NewTable(db, string([]byte{byte(i)})), backends[i], sectionSize, confirmsReq, 0, fmt.Sprintf("indexer-%d", i))
64
65		if sections, _, _ := backends[i].indexer.Sections(); sections != 0 {
66			t.Fatalf("Canonical section count mismatch: have %v, want %v", sections, 0)
67		}
68		if i > 0 {
69			backends[i-1].indexer.AddChildIndexer(backends[i].indexer)
70		}
71	}
72	defer backends[0].indexer.Close() // parent indexer shuts down children
73	// notify pings the root indexer about a new head or reorg, then expect
74	// processed blocks if a section is processable
75	notify := func(headNum, failNum uint64, reorg bool) {
76		backends[0].indexer.newHead(headNum, reorg)
77		if reorg {
78			for _, backend := range backends {
79				headNum = backend.reorg(headNum)
80				backend.assertSections()
81			}
82			return
83		}
84		var cascade bool
85		for _, backend := range backends {
86			headNum, cascade = backend.assertBlocks(headNum, failNum)
87			if !cascade {
88				break
89			}
90			backend.assertSections()
91		}
92	}
93	// inject inserts a new random canonical header into the database directly
94	inject := func(number uint64) {
95		header := &types.Header{Number: big.NewInt(int64(number)), Extra: big.NewInt(rand.Int63()).Bytes()}
96		if number > 0 {
97			header.ParentHash = rawdb.ReadCanonicalHash(db, number-1)
98		}
99		rawdb.WriteHeader(db, header)
100		rawdb.WriteCanonicalHash(db, header.Hash(), number)
101	}
102	// Start indexer with an already existing chain
103	for i := uint64(0); i <= 100; i++ {
104		inject(i)
105	}
106	notify(100, 100, false)
107
108	// Add new blocks one by one
109	for i := uint64(101); i <= 1000; i++ {
110		inject(i)
111		notify(i, i, false)
112	}
113	// Do a reorg
114	notify(500, 500, true)
115
116	// Create new fork
117	for i := uint64(501); i <= 1000; i++ {
118		inject(i)
119		notify(i, i, false)
120	}
121	for i := uint64(1001); i <= 1500; i++ {
122		inject(i)
123	}
124	// Failed processing scenario where less blocks are available than notified
125	notify(2000, 1500, false)
126
127	// Notify about a reorg (which could have caused the missing blocks if happened during processing)
128	notify(1500, 1500, true)
129
130	// Create new fork
131	for i := uint64(1501); i <= 2000; i++ {
132		inject(i)
133		notify(i, i, false)
134	}
135}
136
137// testChainIndexBackend implements ChainIndexerBackend
138type testChainIndexBackend struct {
139	t                          *testing.T
140	indexer                    *ChainIndexer
141	section, headerCnt, stored uint64
142	processCh                  chan uint64
143}
144
145// assertSections verifies if a chain indexer has the correct number of section.
146func (b *testChainIndexBackend) assertSections() {
147	// Keep trying for 3 seconds if it does not match
148	var sections uint64
149	for i := 0; i < 300; i++ {
150		sections, _, _ = b.indexer.Sections()
151		if sections == b.stored {
152			return
153		}
154		time.Sleep(10 * time.Millisecond)
155	}
156	b.t.Fatalf("Canonical section count mismatch: have %v, want %v", sections, b.stored)
157}
158
159// assertBlocks expects processing calls after new blocks have arrived. If the
160// failNum < headNum then we are simulating a scenario where a reorg has happened
161// after the processing has started and the processing of a section fails.
162func (b *testChainIndexBackend) assertBlocks(headNum, failNum uint64) (uint64, bool) {
163	var sections uint64
164	if headNum >= b.indexer.confirmsReq {
165		sections = (headNum + 1 - b.indexer.confirmsReq) / b.indexer.sectionSize
166		if sections > b.stored {
167			// expect processed blocks
168			for expectd := b.stored * b.indexer.sectionSize; expectd < sections*b.indexer.sectionSize; expectd++ {
169				if expectd > failNum {
170					// rolled back after processing started, no more process calls expected
171					// wait until updating is done to make sure that processing actually fails
172					var updating bool
173					for i := 0; i < 300; i++ {
174						b.indexer.lock.Lock()
175						updating = b.indexer.knownSections > b.indexer.storedSections
176						b.indexer.lock.Unlock()
177						if !updating {
178							break
179						}
180						time.Sleep(10 * time.Millisecond)
181					}
182					if updating {
183						b.t.Fatalf("update did not finish")
184					}
185					sections = expectd / b.indexer.sectionSize
186					break
187				}
188				select {
189				case <-time.After(10 * time.Second):
190					b.t.Fatalf("Expected processed block #%d, got nothing", expectd)
191				case processed := <-b.processCh:
192					if processed != expectd {
193						b.t.Errorf("Expected processed block #%d, got #%d", expectd, processed)
194					}
195				}
196			}
197			b.stored = sections
198		}
199	}
200	if b.stored == 0 {
201		return 0, false
202	}
203	return b.stored*b.indexer.sectionSize - 1, true
204}
205
206func (b *testChainIndexBackend) reorg(headNum uint64) uint64 {
207	firstChanged := (headNum + 1) / b.indexer.sectionSize
208	if firstChanged < b.stored {
209		b.stored = firstChanged
210	}
211	return b.stored * b.indexer.sectionSize
212}
213
214func (b *testChainIndexBackend) Reset(ctx context.Context, section uint64, prevHead common.Hash) error {
215	b.section = section
216	b.headerCnt = 0
217	return nil
218}
219
220func (b *testChainIndexBackend) Process(ctx context.Context, header *types.Header) error {
221	b.headerCnt++
222	if b.headerCnt > b.indexer.sectionSize {
223		b.t.Error("Processing too many headers")
224	}
225	//t.processCh <- header.Number.Uint64()
226	select {
227	case <-time.After(10 * time.Second):
228		b.t.Error("Unexpected call to Process")
229		// Can't use Fatal since this is not the test's goroutine.
230		// Returning error stops the chainIndexer's updateLoop
231		return errors.New("Unexpected call to Process")
232	case b.processCh <- header.Number.Uint64():
233	}
234	return nil
235}
236
237func (b *testChainIndexBackend) Commit() error {
238	if b.headerCnt != b.indexer.sectionSize {
239		b.t.Error("Not enough headers processed")
240	}
241	return nil
242}
243
244func (b *testChainIndexBackend) Prune(threshold uint64) error {
245	return nil
246}
247