Add ability to populate missing blocks

* The command populates up to the highest known block number
 * The anticipated use case is that the listener will be running
   in parallel to the populateBlocks command
    * This will mean that the listener is responsible for picking up
      new blocks, and the populateBlocks command is reposible for
      historical blocks
 * Reformat SQL statements

Gododir/main.go

@@ -25,6 +25,16 @@ func tasks(p *do.Project) {
 			do.M{"environment": environment, "$in": "cmd/run"})
 	})
 
+	p.Task("populateBlocks", nil, func(context *do.Context) {
+		environment := parseEnvironment(context)
+		startingNumber := context.Args.MayInt(-1, "starting-number")
+		if startingNumber < 0 {
+			log.Fatalln("--starting-number required")
+		}
+		context.Start(`go run main.go --environment={{.environment}} --starting-number={{.startingNumber}}`,
+			do.M{"environment": environment, "startingNumber": startingNumber, "$in": "cmd/populate_blocks"})
+	})
+
 	p.Task("migrate", nil, func(context *do.Context) {
 		environment := parseEnvironment(context)
 		cfg := config.NewConfig(environment)

README.md

@@ -66,6 +66,12 @@ The default location for Ethereum is:
 2. In a separate terminal start listener (ipcDir location)
     - `godo run -- --environment=<some-environment>`
     
+## Retrieving Historical Data
+
+1. Start a blockchain.
+2. In a separate terminal start listener (ipcDir location)
+    - `godo populateBlocks -- --environment=<some-environment> --starting-number=<starting-block-number>`
+
 ### Configuring Additional Environments
 
 You can create configuration files for additional environments.

cmd/populate_blocks/main.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"flag"
+
+	"log"
+
+	"fmt"
+
+	"github.com/8thlight/vulcanizedb/pkg/config"
+	"github.com/8thlight/vulcanizedb/pkg/geth"
+	"github.com/8thlight/vulcanizedb/pkg/history"
+	"github.com/8thlight/vulcanizedb/pkg/repositories"
+	"github.com/jmoiron/sqlx"
+)
+
+func main() {
+	environment := flag.String("environment", "", "Environment name")
+	startingBlockNumber := flag.Int("starting-number", -1, "First block to fill from")
+	flag.Parse()
+	cfg := config.NewConfig(*environment)
+
+	blockchain := geth.NewGethBlockchain(cfg.Client.IPCPath)
+	connectString := config.DbConnectionString(cfg.Database)
+	db, err := sqlx.Connect("postgres", connectString)
+	if err != nil {
+		log.Fatalf("Error connecting to DB: %v\n", err)
+	}
+	repository := repositories.NewPostgres(db)
+	numberOfBlocksCreated := history.PopulateBlocks(blockchain, repository, int64(*startingBlockNumber))
+	fmt.Printf("Populated %d blocks", numberOfBlocksCreated)
+}

integration_test/geth_blockchain_test.go

@@ -14,11 +14,12 @@ var _ = Describe("Reading from the Geth blockchain", func() {
 
 	var listener blockchain_listener.BlockchainListener
 	var observer *fakes.BlockchainObserver
+	var blockchain *geth.GethBlockchain
 
 	BeforeEach(func() {
 		observer = fakes.NewFakeBlockchainObserver()
 		cfg := config.NewConfig("private")
-		blockchain := geth.NewGethBlockchain(cfg.Client.IPCPath)
+		blockchain = geth.NewGethBlockchain(cfg.Client.IPCPath)
 		observers := []core.BlockchainObserver{observer}
 		listener = blockchain_listener.NewBlockchainListener(blockchain, observers)
 	})
@@ -43,4 +44,14 @@ var _ = Describe("Reading from the Geth blockchain", func() {
 		close(done)
 	}, 10)
 
+	It("retrieves the genesis block and first block", func(done Done) {
+		genesisBlock := blockchain.GetBlockByNumber(int64(0))
+		firstBlock := blockchain.GetBlockByNumber(int64(1))
+
+		Expect(genesisBlock.Number).To(Equal(int64(0)))
+		Expect(firstBlock.Number).To(Equal(int64(1)))
+
+		close(done)
+	}, 10)
+
 })

pkg/blockchain_listener/blockchain_listener_test.go

@@ -12,7 +12,7 @@ var _ = Describe("Blockchain listeners", func() {
 
 	It("starts with no blocks", func(done Done) {
 		observer := fakes.NewFakeBlockchainObserver()
-		blockchain := &fakes.Blockchain{}
+		blockchain := fakes.NewBlockchain()
 
 		blockchain_listener.NewBlockchainListener(blockchain, []core.BlockchainObserver{observer})
 
@@ -22,7 +22,7 @@ var _ = Describe("Blockchain listeners", func() {
 
 	It("sees when one block was added", func(done Done) {
 		observer := fakes.NewFakeBlockchainObserver()
-		blockchain := &fakes.Blockchain{}
+		blockchain := fakes.NewBlockchain()
 		listener := blockchain_listener.NewBlockchainListener(blockchain, []core.BlockchainObserver{observer})
 		go listener.Start()
 
@@ -38,7 +38,7 @@ var _ = Describe("Blockchain listeners", func() {
 
 	It("sees a second block", func(done Done) {
 		observer := fakes.NewFakeBlockchainObserver()
-		blockchain := &fakes.Blockchain{}
+		blockchain := fakes.NewBlockchain()
 		listener := blockchain_listener.NewBlockchainListener(blockchain, []core.BlockchainObserver{observer})
 		go listener.Start()
 
@@ -56,7 +56,7 @@ var _ = Describe("Blockchain listeners", func() {
 
 	It("stops listening", func(done Done) {
 		observer := fakes.NewFakeBlockchainObserver()
-		blockchain := &fakes.Blockchain{}
+		blockchain := fakes.NewBlockchain()
 		listener := blockchain_listener.NewBlockchainListener(blockchain, []core.BlockchainObserver{observer})
 		go listener.Start()
 

pkg/core/blockchain.go

@@ -1,6 +1,7 @@
 package core
 
 type Blockchain interface {
+	GetBlockByNumber(blockNumber int64) Block
 	SubscribeToBlocks(blocks chan Block)
 	StartListening()
 	StopListening()

pkg/fakes/blockchain.go

@@ -3,16 +3,36 @@ package fakes
 import "github.com/8thlight/vulcanizedb/pkg/core"
 
 type Blockchain struct {
-	outputBlocks  chan core.Block
+	blocks        map[int64]core.Block
+	blocksChannel chan core.Block
 	WasToldToStop bool
 }
 
-func (blockchain *Blockchain) SubscribeToBlocks(outputBlocks chan core.Block) {
-	blockchain.outputBlocks = outputBlocks
+func NewBlockchain() *Blockchain {
+	return &Blockchain{blocks: make(map[int64]core.Block)}
 }
 
-func (blockchain Blockchain) AddBlock(block core.Block) {
-	blockchain.outputBlocks <- block
+func NewBlockchainWithBlocks(blocks []core.Block) *Blockchain {
+	blockNumberToBlocks := make(map[int64]core.Block)
+	for _, block := range blocks {
+		blockNumberToBlocks[block.Number] = block
+	}
+	return &Blockchain{
+		blocks: blockNumberToBlocks,
+	}
+}
+
+func (blockchain *Blockchain) GetBlockByNumber(blockNumber int64) core.Block {
+	return blockchain.blocks[blockNumber]
+}
+
+func (blockchain *Blockchain) SubscribeToBlocks(outputBlocks chan core.Block) {
+	blockchain.blocksChannel = outputBlocks
+}
+
+func (blockchain *Blockchain) AddBlock(block core.Block) {
+	blockchain.blocks[block.Number] = block
+	blockchain.blocksChannel <- block
 }
 
 func (*Blockchain) StartListening() {}

pkg/geth/geth_blockchain.go

@@ -3,6 +3,8 @@ package geth
 import (
 	"fmt"
 
+	"math/big"
+
 	"github.com/8thlight/vulcanizedb/pkg/core"
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/core/types"
@@ -17,6 +19,11 @@ type GethBlockchain struct {
 	newHeadSubscription ethereum.Subscription
 }
 
+func (blockchain *GethBlockchain) GetBlockByNumber(blockNumber int64) core.Block {
+	gethBlock, _ := blockchain.client.BlockByNumber(context.Background(), big.NewInt(blockNumber))
+	return GethBlockToCoreBlock(gethBlock)
+}
+
 func NewGethBlockchain(ipcPath string) *GethBlockchain {
 	fmt.Printf("Creating Geth Blockchain to: %s\n", ipcPath)
 	blockchain := GethBlockchain{}
@@ -36,10 +43,8 @@ func (blockchain *GethBlockchain) SubscribeToBlocks(blocks chan core.Block) {
 }
 
 func (blockchain *GethBlockchain) StartListening() {
-	myContext := context.Background()
 	for header := range blockchain.readGethHeaders {
-		gethBlock, _ := blockchain.client.BlockByNumber(myContext, header.Number)
-		block := GethBlockToCoreBlock(gethBlock)
+		block := blockchain.GetBlockByNumber(header.Number.Int64())
 		blockchain.outputBlocks <- block
 	}
 }

pkg/history/history_suite_test.go

@@ -0,0 +1,13 @@
+package history_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"testing"
+)
+
+func TestHistory(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "History Suite")
+}

pkg/history/populate_blocks.go

@@ -0,0 +1,15 @@
+package history
+
+import (
+	"github.com/8thlight/vulcanizedb/pkg/core"
+	"github.com/8thlight/vulcanizedb/pkg/repositories"
+)
+
+func PopulateBlocks(blockchain core.Blockchain, repository repositories.Repository, startingBlockNumber int64) int {
+	blockNumbers := repository.MissingBlockNumbers(startingBlockNumber, repository.MaxBlockNumber())
+	for _, blockNumber := range blockNumbers {
+		block := blockchain.GetBlockByNumber(blockNumber)
+		repository.CreateBlock(block)
+	}
+	return len(blockNumbers)
+}

pkg/history/populate_blocks_test.go

@@ -0,0 +1,69 @@
+package history_test
+
+import (
+	"github.com/8thlight/vulcanizedb/pkg/core"
+	"github.com/8thlight/vulcanizedb/pkg/fakes"
+	"github.com/8thlight/vulcanizedb/pkg/history"
+	"github.com/8thlight/vulcanizedb/pkg/repositories"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Populating blocks", func() {
+
+	It("fills in the only missing block", func() {
+		blocks := []core.Block{{Number: 1, Hash: "x012343"}}
+		blockchain := fakes.NewBlockchainWithBlocks(blocks)
+		repository := repositories.NewInMemory()
+		repository.CreateBlock(core.Block{Number: 2})
+
+		history.PopulateBlocks(blockchain, repository, 1)
+
+		block := repository.FindBlockByNumber(1)
+		Expect(block).NotTo(BeNil())
+		Expect(block.Hash).To(Equal("x012343"))
+	})
+
+	It("fills in two missing blocks", func() {
+		blockchain := fakes.NewBlockchainWithBlocks([]core.Block{
+			{Number: 4},
+			{Number: 5},
+			{Number: 8},
+			{Number: 10},
+			{Number: 13},
+		})
+		repository := repositories.NewInMemory()
+		repository.CreateBlock(core.Block{Number: 1})
+		repository.CreateBlock(core.Block{Number: 2})
+		repository.CreateBlock(core.Block{Number: 3})
+		repository.CreateBlock(core.Block{Number: 6})
+		repository.CreateBlock(core.Block{Number: 7})
+		repository.CreateBlock(core.Block{Number: 9})
+		repository.CreateBlock(core.Block{Number: 11})
+		repository.CreateBlock(core.Block{Number: 12})
+
+		history.PopulateBlocks(blockchain, repository, 5)
+
+		Expect(repository.BlockCount()).To(Equal(11))
+		Expect(repository.FindBlockByNumber(4)).To(BeNil())
+		Expect(repository.FindBlockByNumber(5)).NotTo(BeNil())
+		Expect(repository.FindBlockByNumber(8)).NotTo(BeNil())
+		Expect(repository.FindBlockByNumber(10)).NotTo(BeNil())
+		Expect(repository.FindBlockByNumber(13)).To(BeNil())
+	})
+
+	It("returns the number of blocks created", func() {
+		blockchain := fakes.NewBlockchainWithBlocks([]core.Block{
+			{Number: 4},
+			{Number: 5},
+		})
+		repository := repositories.NewInMemory()
+		repository.CreateBlock(core.Block{Number: 3})
+		repository.CreateBlock(core.Block{Number: 6})
+
+		numberOfBlocksCreated := history.PopulateBlocks(blockchain, repository, 3)
+
+		Expect(numberOfBlocksCreated).To(Equal(2))
+	})
+
+})

pkg/repositories/in_memory.go

@@ -8,6 +8,16 @@ type InMemory struct {
 	blocks map[int64]*core.Block
 }
 
+func (repository *InMemory) MissingBlockNumbers(startingBlockNumber int64, endingBlockNumber int64) []int64 {
+	missingNumbers := []int64{}
+	for blockNumber := int64(startingBlockNumber); blockNumber <= endingBlockNumber; blockNumber++ {
+		if repository.blocks[blockNumber] == nil {
+			missingNumbers = append(missingNumbers, blockNumber)
+		}
+	}
+	return missingNumbers
+}
+
 func NewInMemory() *InMemory {
 	return &InMemory{
 		blocks: make(map[int64]*core.Block),
@@ -25,3 +35,13 @@ func (repository *InMemory) BlockCount() int {
 func (repository *InMemory) FindBlockByNumber(blockNumber int64) *core.Block {
 	return repository.blocks[blockNumber]
 }
+
+func (repository *InMemory) MaxBlockNumber() int64 {
+	highestBlockNumber := int64(-1)
+	for key := range repository.blocks {
+		if key > highestBlockNumber {
+			highestBlockNumber = key
+		}
+	}
+	return highestBlockNumber
+}

pkg/repositories/postgres.go

@@ -12,12 +12,33 @@ type Postgres struct {
 	Db *sqlx.DB
 }
 
+func (repository Postgres) MaxBlockNumber() int64 {
+	var highestBlockNumber int64
+	repository.Db.Get(&highestBlockNumber, `SELECT MAX(block_number) FROM blocks`)
+	return highestBlockNumber
+}
+
+func (repository Postgres) MissingBlockNumbers(startingBlockNumber int64, highestBlockNumber int64) []int64 {
+	numbers := []int64{}
+	repository.Db.Select(&numbers,
+		`SELECT all_block_numbers
+			FROM (
+				SELECT generate_series($1::INT, $2::INT) AS all_block_numbers) series
+				LEFT JOIN blocks
+					ON block_number = all_block_numbers
+			WHERE block_number ISNULL`,
+		startingBlockNumber,
+		highestBlockNumber)
+	return numbers
+}
+
 func NewPostgres(db *sqlx.DB) Postgres {
 	return Postgres{Db: db}
 }
 
 func (repository Postgres) FindBlockByNumber(blockNumber int64) *core.Block {
-	blockRows, _ := repository.Db.Query("SELECT id, block_number, block_gaslimit, block_gasused, block_time, block_difficulty, block_hash, block_nonce, block_parenthash, block_size, uncle_hash FROM blocks")
+	blockRows, _ := repository.Db.Query(
+		`SELECT id, block_number, block_gaslimit, block_gasused, block_time, block_difficulty, block_hash, block_nonce, block_parenthash, block_size, uncle_hash FROM blocks`)
 	var savedBlocks []core.Block
 	for blockRows.Next() {
 		savedBlock := repository.loadBlock(blockRows)
@@ -38,9 +59,9 @@ func (repository Postgres) BlockCount() int {
 
 func (repository Postgres) CreateBlock(block core.Block) {
 	insertedBlock := repository.Db.QueryRow(
-		"Insert INTO blocks "+
-			"(block_number, block_gaslimit, block_gasused, block_time, block_difficulty, block_hash, block_nonce, block_parenthash, block_size, uncle_hash) "+
-			"VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10) RETURNING id",
+		`INSERT INTO blocks
+			(block_number, block_gaslimit, block_gasused, block_time, block_difficulty, block_hash, block_nonce, block_parenthash, block_size, uncle_hash)
+			VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10) RETURNING id`,
 		block.Number, block.GasLimit, block.GasUsed, block.Time, block.Difficulty, block.Hash, block.Nonce, block.ParentHash, block.Size, block.UncleHash)
 	var blockId int64
 	insertedBlock.Scan(&blockId)
@@ -49,8 +70,10 @@ func (repository Postgres) CreateBlock(block core.Block) {
 
 func (repository Postgres) createTransactions(blockId int64, transactions []core.Transaction) {
 	for _, transaction := range transactions {
-		repository.Db.MustExec("Insert INTO transactions "+
-			"(block_id, tx_hash, tx_nonce, tx_to, tx_gaslimit, tx_gasprice, tx_value) VALUES ($1, $2, $3, $4, $5, $6, $7)",
+		repository.Db.MustExec(
+			`INSERT INTO transactions
+			(block_id, tx_hash, tx_nonce, tx_to, tx_gaslimit, tx_gasprice, tx_value)
+			VALUES ($1, $2, $3, $4, $5, $6, $7)`,
 			blockId, transaction.Hash, transaction.Nonce, transaction.To, transaction.GasLimit, transaction.GasPrice, transaction.Value)
 	}
 }

pkg/repositories/repository.go

@@ -6,4 +6,6 @@ type Repository interface {
 	CreateBlock(block core.Block)
 	BlockCount() int
 	FindBlockByNumber(blockNumber int64) *core.Block
+	MaxBlockNumber() int64
+	MissingBlockNumbers(startingBlockNumber int64, endingBlockNumber int64) []int64
 }

pkg/repositories/repository_test.go

@@ -134,6 +134,75 @@ var _ = Describe("Repositories", func() {
 				Expect(savedTransaction.Value).To(Equal(value))
 			})
 		})
+
+		Describe("The missing block numbers", func() {
+			It("is empty the starting block number is the highest known block number", func() {
+				repository.CreateBlock(core.Block{Number: 1})
+
+				Expect(len(repository.MissingBlockNumbers(1, 1))).To(Equal(0))
+			})
+
+			It("is the only missing block number", func() {
+				repository.CreateBlock(core.Block{Number: 2})
+
+				Expect(repository.MissingBlockNumbers(1, 2)).To(Equal([]int64{1}))
+			})
+
+			It("is both missing block numbers", func() {
+				repository.CreateBlock(core.Block{Number: 3})
+
+				Expect(repository.MissingBlockNumbers(1, 3)).To(Equal([]int64{1, 2}))
+			})
+
+			It("goes back to the starting block number", func() {
+				repository.CreateBlock(core.Block{Number: 6})
+
+				Expect(repository.MissingBlockNumbers(4, 6)).To(Equal([]int64{4, 5}))
+			})
+
+			It("only includes missing block numbers", func() {
+				repository.CreateBlock(core.Block{Number: 4})
+				repository.CreateBlock(core.Block{Number: 6})
+
+				Expect(repository.MissingBlockNumbers(4, 6)).To(Equal([]int64{5}))
+			})
+
+			It("is a list with multiple gaps", func() {
+				repository.CreateBlock(core.Block{Number: 4})
+				repository.CreateBlock(core.Block{Number: 5})
+				repository.CreateBlock(core.Block{Number: 8})
+				repository.CreateBlock(core.Block{Number: 10})
+
+				Expect(repository.MissingBlockNumbers(3, 10)).To(Equal([]int64{3, 6, 7, 9}))
+			})
+
+			It("returns empty array when lower bound exceeds upper bound", func() {
+				Expect(repository.MissingBlockNumbers(10000, 1)).To(Equal([]int64{}))
+			})
+
+			It("only returns requested range even when other gaps exist", func() {
+				repository.CreateBlock(core.Block{Number: 3})
+				repository.CreateBlock(core.Block{Number: 8})
+
+				Expect(repository.MissingBlockNumbers(1, 5)).To(Equal([]int64{1, 2, 4, 5}))
+			})
+
+		})
+
+		Describe("The max block numbers", func() {
+			It("returns the block number when a single block", func() {
+				repository.CreateBlock(core.Block{Number: 1})
+
+				Expect(repository.MaxBlockNumber()).To(Equal(int64(1)))
+			})
+
+			It("returns highest known block number when multiple blocks", func() {
+				repository.CreateBlock(core.Block{Number: 1})
+				repository.CreateBlock(core.Block{Number: 10})
+
+				Expect(repository.MaxBlockNumber()).To(Equal(int64(10)))
+			})
+		})
 	}
 
 	Describe("In memory repository", func() {