core, eth: clean up bloom filtering, add some tests

1 files changed, 142 insertions, 0 deletions

diff --git a/eth/bloombits.go b/eth/bloombits.go
new file mode 100644
index 000000000..02de408b0
--- /dev/null
+++ b/eth/bloombits.go
@@ -0,0 +1,142 @@
+// Copyright 2017 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 eth
+
+import (
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/bitutil"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/bloombits"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+const (
+	// bloomServiceThreads is the number of goroutines used globally by an Ethereum
+	// instance to service bloombits lookups for all running filters.
+	bloomServiceThreads = 16
+
+	// bloomFilterThreads is the number of goroutines used locally per filter to
+	// multiplex requests onto the global servicing goroutines.
+	bloomFilterThreads = 3
+
+	// bloomRetrievalBatch is the maximum number of bloom bit retrievals to service
+	// in a single batch.
+	bloomRetrievalBatch = 16
+
+	// bloomRetrievalWait is the maximum time to wait for enough bloom bit requests
+	// to accumulate request an entire batch (avoiding hysteresis).
+	bloomRetrievalWait = time.Duration(0)
+)
+
+// startBloomHandlers starts a batch of goroutines to accept bloom bit database
+// retrievals from possibly a range of filters and serving the data to satisfy.
+func (eth *Ethereum) startBloomHandlers() {
+	for i := 0; i < bloomServiceThreads; i++ {
+		go func() {
+			for {
+				select {
+				case <-eth.shutdownChan:
+					return
+
+				case request := <-eth.bloomRequests:
+					task := <-request
+
+					task.Bitsets = make([][]byte, len(task.Sections))
+					for i, section := range task.Sections {
+						head := core.GetCanonicalHash(eth.chainDb, (section+1)*params.BloomBitsBlocks-1)
+						blob, err := bitutil.DecompressBytes(core.GetBloomBits(eth.chainDb, task.Bit, section, head), int(params.BloomBitsBlocks)/8)
+						if err != nil {
+							panic(err)
+						}
+						task.Bitsets[i] = blob
+					}
+					request <- task
+				}
+			}
+		}()
+	}
+}
+
+const (
+	// bloomConfirms is the number of confirmation blocks before a bloom section is
+	// considered probably final and its rotated bits are calculated.
+	bloomConfirms = 256
+
+	// bloomThrottling is the time to wait between processing two consecutive index
+	// sections. It's useful during chain upgrades to prevent disk overload.
+	bloomThrottling = 100 * time.Millisecond
+)
+
+// BloomIndexer implements a core.ChainIndexer, building up a rotated bloom bits index
+// for the Ethereum header bloom filters, permitting blazing fast filtering.
+type BloomIndexer struct {
+	size uint64 // section size to generate bloombits for
+
+	db  ethdb.Database       // database instance to write index data and metadata into
+	gen *bloombits.Generator // generator to rotate the bloom bits crating the bloom index
+
+	section uint64      // Section is the section number being processed currently
+	head    common.Hash // Head is the hash of the last header processed
+}
+
+// NewBloomIndexer returns a chain indexer that generates bloom bits data for the
+// canonical chain for fast logs filtering.
+func NewBloomIndexer(db ethdb.Database, size uint64) *core.ChainIndexer {
+	backend := &BloomIndexer{
+		db:   db,
+		size: size,
+	}
+	table := ethdb.NewTable(db, string(core.BloomBitsIndexPrefix))
+
+	return core.NewChainIndexer(db, table, backend, size, bloomConfirms, bloomThrottling, "bloombits")
+}
+
+// Reset implements core.ChainIndexerBackend, starting a new bloombits index
+// section.
+func (b *BloomIndexer) Reset(section uint64) {
+	gen, err := bloombits.NewGenerator(uint(b.size))
+	if err != nil {
+		panic(err)
+	}
+	b.gen, b.section, b.head = gen, section, common.Hash{}
+}
+
+// Process implements core.ChainIndexerBackend, adding a new header's bloom into
+// the index.
+func (b *BloomIndexer) Process(header *types.Header) {
+	b.gen.AddBloom(header.Bloom)
+	b.head = header.Hash()
+}
+
+// Commit implements core.ChainIndexerBackend, finalizing the bloom section and
+// writing it out into the database.
+func (b *BloomIndexer) Commit() error {
+	batch := b.db.NewBatch()
+
+	for i := 0; i < types.BloomBitLength; i++ {
+		bits, err := b.gen.Bitset(uint(i))
+		if err != nil {
+			return err
+		}
+		core.WriteBloomBits(batch, uint(i), b.section, b.head, bitutil.CompressBytes(bits))
+	}
+	return batch.Write()
+}