From 96339daf40989072ff2a9e8b476da6698da45dc7 Mon Sep 17 00:00:00 2001
From: Domino Valdano <dominoplural@gmail.com>
Date: Sat, 12 May 2018 02:20:46 -0700
Subject: [PATCH] eth/filters, ethereum: EIP-234 add blockHash param for
 eth_getLogs

---
 eth/filters/api.go                | 56 ++++++++++++++++++++++++-------
 eth/filters/filter_system_test.go | 27 +++++++++++++++
 interfaces.go                     |  1 +
 3 files changed, 71 insertions(+), 13 deletions(-)

diff --git a/eth/filters/api.go b/eth/filters/api.go
index 592ad3b82..f964d9232 100644
--- a/eth/filters/api.go
+++ b/eth/filters/api.go
@@ -28,6 +28,7 @@ import (
 	ethereum "github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
@@ -324,15 +325,35 @@ func (api *PublicFilterAPI) NewFilter(crit FilterCriteria) (rpc.ID, error) {
 //
 // https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_getlogs
 func (api *PublicFilterAPI) GetLogs(ctx context.Context, crit FilterCriteria) ([]*types.Log, error) {
-	// Convert the RPC block numbers into internal representations
-	if crit.FromBlock == nil {
-		crit.FromBlock = big.NewInt(rpc.LatestBlockNumber.Int64())
-	}
-	if crit.ToBlock == nil {
-		crit.ToBlock = big.NewInt(rpc.LatestBlockNumber.Int64())
+	var (
+		fromBlock int64
+		toBlock   int64
+	)
+
+	if crit.BlockHash != nil {
+		// look up block number from block hash
+		if block := rawdb.ReadHeaderNumber(api.chainDb, *crit.BlockHash); block != nil {
+			// verify block is part of canonical chain
+			if canonical := rawdb.ReadCanonicalHash(api.chainDb, *block); canonical != *crit.BlockHash {
+				return nil, fmt.Errorf("Block with hash %s was removed from canonical chain", crit.BlockHash.Hex())
+			}
+			fromBlock = int64(*block)
+			toBlock = fromBlock
+		} else {
+			return nil, fmt.Errorf("Block with hash %s was not found", crit.BlockHash.Hex())
+		}
+	} else {
+		// Convert the RPC block numbers into internal representations
+		if crit.FromBlock == nil {
+			fromBlock = int64(rpc.LatestBlockNumber)
+		}
+		if crit.ToBlock == nil {
+			toBlock = int64(rpc.LatestBlockNumber)
+		}
 	}
+
 	// Create and run the filter to get all the logs
-	filter := New(api.backend, crit.FromBlock.Int64(), crit.ToBlock.Int64(), crit.Addresses, crit.Topics)
+	filter := New(api.backend, fromBlock, toBlock, crit.Addresses, crit.Topics)
 
 	logs, err := filter.Logs(ctx)
 	if err != nil {
@@ -444,7 +465,8 @@ func returnLogs(logs []*types.Log) []*types.Log {
 // UnmarshalJSON sets *args fields with given data.
 func (args *FilterCriteria) UnmarshalJSON(data []byte) error {
 	type input struct {
-		From      *rpc.BlockNumber `json:"fromBlock"`
+		BlockHash *common.Hash     `json:"blockHash"`
+		FromBlock *rpc.BlockNumber `json:"fromBlock"`
 		ToBlock   *rpc.BlockNumber `json:"toBlock"`
 		Addresses interface{}      `json:"address"`
 		Topics    []interface{}    `json:"topics"`
@@ -455,12 +477,20 @@ func (args *FilterCriteria) UnmarshalJSON(data []byte) error {
 		return err
 	}
 
-	if raw.From != nil {
-		args.FromBlock = big.NewInt(raw.From.Int64())
-	}
+	if raw.BlockHash != nil {
+		if raw.FromBlock != nil || raw.ToBlock != nil {
+			// BlockHash is mutually exclusive with FromBlock/ToBlock criteria
+			return fmt.Errorf("cannot specify both BlockHash and FromBlock/ToBlock, choose one or the other")
+		}
+		args.BlockHash = raw.BlockHash
+	} else {
+		if raw.FromBlock != nil {
+			args.FromBlock = big.NewInt(raw.FromBlock.Int64())
+		}
 
-	if raw.ToBlock != nil {
-		args.ToBlock = big.NewInt(raw.ToBlock.Int64())
+		if raw.ToBlock != nil {
+			args.ToBlock = big.NewInt(raw.ToBlock.Int64())
+		}
 	}
 
 	args.Addresses = []common.Address{}
diff --git a/eth/filters/filter_system_test.go b/eth/filters/filter_system_test.go
index ff1af85a8..2c1e8a2eb 100644
--- a/eth/filters/filter_system_test.go
+++ b/eth/filters/filter_system_test.go
@@ -343,6 +343,33 @@ func TestInvalidLogFilterCreation(t *testing.T) {
 	}
 }
 
+func TestInvalidGetLogsRequest(t *testing.T) {
+	var (
+		mux        = new(event.TypeMux)
+		db         = ethdb.NewMemDatabase()
+		txFeed     = new(event.Feed)
+		rmLogsFeed = new(event.Feed)
+		logsFeed   = new(event.Feed)
+		chainFeed  = new(event.Feed)
+		backend    = &testBackend{mux, db, 0, txFeed, rmLogsFeed, logsFeed, chainFeed}
+		api        = NewPublicFilterAPI(backend, false)
+		blockHash  = common.HexToHash("0x1111111111111111111111111111111111111111111111111111111111111111")
+	)
+
+	// Reason: Cannot specify both BlockHash and FromBlock/ToBlock)
+	testCases := []FilterCriteria{
+		0: {BlockHash: &blockHash, FromBlock: big.NewInt(100)},
+		1: {BlockHash: &blockHash, ToBlock: big.NewInt(500)},
+		2: {BlockHash: &blockHash, FromBlock: big.NewInt(rpc.LatestBlockNumber.Int64())},
+	}
+
+	for i, test := range testCases {
+		if _, err := api.GetLogs(context.Background(), test); err == nil {
+			t.Errorf("Expected Logs for case #%d to fail", i)
+		}
+	}
+}
+
 // TestLogFilter tests whether log filters match the correct logs that are posted to the event feed.
 func TestLogFilter(t *testing.T) {
 	t.Parallel()
diff --git a/interfaces.go b/interfaces.go
index a8b48c93d..26b0fcbc1 100644
--- a/interfaces.go
+++ b/interfaces.go
@@ -131,6 +131,7 @@ type ContractCaller interface {
 
 // FilterQuery contains options for contract log filtering.
 type FilterQuery struct {
+	BlockHash *common.Hash     // used by eth_getLogs, return logs only from block with this hash
 	FromBlock *big.Int         // beginning of the queried range, nil means genesis block
 	ToBlock   *big.Int         // end of the range, nil means latest block
 	Addresses []common.Address // restricts matches to events created by specific contracts