light: CHT and bloom trie indexers working in light mode (#16534)

This PR enables the indexers to work in light client mode by
downloading a part of these tries (the Merkle proofs of the last
values of the last known section) in order to be able to add new
values and recalculate subsequent hashes. It also adds CHT data to
NodeInfo.

2 files changed, 26 insertions, 10 deletions

diff --git a/core/chain_indexer.go b/core/chain_indexer.go
index 0b927116d..11a7c96fa 100644
--- a/core/chain_indexer.go
+++ b/core/chain_indexer.go
@@ -17,6 +17,7 @@
 package core
 
 import (
+	"context"
 	"encoding/binary"
 	"fmt"
 	"sync"
@@ -37,11 +38,11 @@ import (
 type ChainIndexerBackend interface {
 	// Reset initiates the processing of a new chain segment, potentially terminating
 	// any partially completed operations (in case of a reorg).
-	Reset(section uint64, prevHead common.Hash) error
+	Reset(ctx context.Context, section uint64, prevHead common.Hash) error
 
 	// Process crunches through the next header in the chain segment. The caller
 	// will ensure a sequential order of headers.
-	Process(header *types.Header)
+	Process(ctx context.Context, header *types.Header) error
 
 	// Commit finalizes the section metadata and stores it into the database.
 	Commit() error
@@ -71,9 +72,11 @@ type ChainIndexer struct {
 	backend  ChainIndexerBackend // Background processor generating the index data content
 	children []*ChainIndexer     // Child indexers to cascade chain updates to
 
-	active uint32          // Flag whether the event loop was started
-	update chan struct{}   // Notification channel that headers should be processed
-	quit   chan chan error // Quit channel to tear down running goroutines
+	active    uint32          // Flag whether the event loop was started
+	update    chan struct{}   // Notification channel that headers should be processed
+	quit      chan chan error // Quit channel to tear down running goroutines
+	ctx       context.Context
+	ctxCancel func()
 
 	sectionSize uint64 // Number of blocks in a single chain segment to process
 	confirmsReq uint64 // Number of confirmations before processing a completed segment
@@ -105,6 +108,8 @@ func NewChainIndexer(chainDb, indexDb ethdb.Database, backend ChainIndexerBacken
 	}
 	// Initialize database dependent fields and start the updater
 	c.loadValidSections()
+	c.ctx, c.ctxCancel = context.WithCancel(context.Background())
+
 	go c.updateLoop()
 
 	return c
@@ -138,6 +143,8 @@ func (c *ChainIndexer) Start(chain ChainIndexerChain) {
 func (c *ChainIndexer) Close() error {
 	var errs []error
 
+	c.ctxCancel()
+
 	// Tear down the primary update loop
 	errc := make(chan error)
 	c.quit <- errc
@@ -297,6 +304,12 @@ func (c *ChainIndexer) updateLoop() {
 				c.lock.Unlock()
 				newHead, err := c.processSection(section, oldHead)
 				if err != nil {
+					select {
+					case <-c.ctx.Done():
+						<-c.quit <- nil
+						return
+					default:
+					}
 					c.log.Error("Section processing failed", "error", err)
 				}
 				c.lock.Lock()
@@ -344,7 +357,7 @@ func (c *ChainIndexer) processSection(section uint64, lastHead common.Hash) (com
 
 	// Reset and partial processing
 
-	if err := c.backend.Reset(section, lastHead); err != nil {
+	if err := c.backend.Reset(c.ctx, section, lastHead); err != nil {
 		c.setValidSections(0)
 		return common.Hash{}, err
 	}
@@ -360,11 +373,12 @@ func (c *ChainIndexer) processSection(section uint64, lastHead common.Hash) (com
 		} else if header.ParentHash != lastHead {
 			return common.Hash{}, fmt.Errorf("chain reorged during section processing")
 		}
-		c.backend.Process(header)
+		if err := c.backend.Process(c.ctx, header); err != nil {
+			return common.Hash{}, err
+		}
 		lastHead = header.Hash()
 	}
 	if err := c.backend.Commit(); err != nil {
-		c.log.Error("Section commit failed", "error", err)
 		return common.Hash{}, err
 	}
 	return lastHead, nil
diff --git a/core/chain_indexer_test.go b/core/chain_indexer_test.go
index 550caf556..a029dec62 100644
--- a/core/chain_indexer_test.go
+++ b/core/chain_indexer_test.go
@@ -17,6 +17,7 @@
 package core
 
 import (
+	"context"
 	"fmt"
 	"math/big"
 	"math/rand"
@@ -210,13 +211,13 @@ func (b *testChainIndexBackend) reorg(headNum uint64) uint64 {
 	return b.stored * b.indexer.sectionSize
 }
 
-func (b *testChainIndexBackend) Reset(section uint64, prevHead common.Hash) error {
+func (b *testChainIndexBackend) Reset(ctx context.Context, section uint64, prevHead common.Hash) error {
 	b.section = section
 	b.headerCnt = 0
 	return nil
 }
 
-func (b *testChainIndexBackend) Process(header *types.Header) {
+func (b *testChainIndexBackend) Process(ctx context.Context, header *types.Header) error {
 	b.headerCnt++
 	if b.headerCnt > b.indexer.sectionSize {
 		b.t.Error("Processing too many headers")
@@ -227,6 +228,7 @@ func (b *testChainIndexBackend) Process(header *types.Header) {
 		b.t.Fatal("Unexpected call to Process")
 	case b.processCh <- header.Number.Uint64():
 	}
+	return nil
 }
 
 func (b *testChainIndexBackend) Commit() error {