Add Pep price feed

pkg/transformers/pep/constants.go

@@ -0,0 +1,6 @@
+package pep
+
+var (
+	LogValueTopic0 = "0x296ba4ca62c6c21c95e828080cb8aec7481b71390585605300a8a76f9e95b527"
+	PepAddress     = "0x99041f808d598b782d5a3e498681c2452a31da08"
+)

pkg/transformers/pep/fetcher.go

@@ -0,0 +1,54 @@
+package pep
+
+import (
+	"errors"
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/vulcanize/vulcanizedb/pkg/core"
+	"math/big"
+)
+
+var (
+	ErrMultipleLogs  = errors.New("multiple matching logs found in block")
+	ErrNoMatchingLog = errors.New("no matching log")
+)
+
+type IPepFetcher interface {
+	FetchPepValue(header core.Header) (string, error)
+}
+
+type PepFetcher struct {
+	blockChain core.BlockChain
+}
+
+func NewPepFetcher(chain core.BlockChain) PepFetcher {
+	return PepFetcher{
+		blockChain: chain,
+	}
+}
+
+func (fetcher PepFetcher) FetchPepValue(header core.Header) (string, error) {
+	blockNumber := big.NewInt(header.BlockNumber)
+	query := ethereum.FilterQuery{
+		FromBlock: blockNumber,
+		ToBlock:   blockNumber,
+		Addresses: []common.Address{common.HexToAddress(PepAddress)},
+		Topics:    [][]common.Hash{{common.HexToHash(LogValueTopic0)}},
+	}
+	logs, err := fetcher.blockChain.GetEthLogsWithCustomQuery(query)
+	return fetcher.getLogValue(logs, err)
+}
+
+func (fetcher PepFetcher) getLogValue(logs []types.Log, err error) (string, error) {
+	if err != nil {
+		return "", err
+	}
+	if len(logs) < 1 {
+		return "", ErrNoMatchingLog
+	}
+	if len(logs) > 1 {
+		return "", ErrMultipleLogs
+	}
+	return string(logs[0].Data), nil
+}

pkg/transformers/pep/fetcher_test.go

@@ -0,0 +1,72 @@
+package pep_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/vulcanize/vulcanizedb/pkg/core"
+	"github.com/vulcanize/vulcanizedb/pkg/fakes"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/pep"
+	"math/big"
+)
+
+var _ = Describe("Pep fetcher", func() {
+	It("calls contract to peek mkr/usd value", func() {
+		mockBlockChain := fakes.NewMockBlockChain()
+		mockBlockChain.SetGetEthLogsWithCustomQueryReturnLogs([]types.Log{{}})
+		fetcher := pep.NewPepFetcher(mockBlockChain)
+		blockNumber := int64(100)
+		header := core.Header{
+			BlockNumber: blockNumber,
+			Hash:        "",
+			Raw:         nil,
+		}
+
+		_, err := fetcher.FetchPepValue(header)
+
+		Expect(err).NotTo(HaveOccurred())
+		expectedQuery := ethereum.FilterQuery{
+			FromBlock: big.NewInt(blockNumber),
+			ToBlock:   big.NewInt(blockNumber),
+			Addresses: []common.Address{common.HexToAddress(pep.PepAddress)},
+			Topics:    [][]common.Hash{{common.HexToHash(pep.LogValueTopic0)}},
+		}
+		mockBlockChain.AssertGetEthLogsWithCustomQueryCalledWith(expectedQuery)
+	})
+
+	It("returns error if contract call fails", func() {
+		mockBlockChain := fakes.NewMockBlockChain()
+		mockBlockChain.SetGetEthLogsWithCustomQueryReturnLogs([]types.Log{{}})
+		mockBlockChain.SetGetEthLogsWithCustomQueryErr(fakes.FakeError)
+		fetcher := pep.NewPepFetcher(mockBlockChain)
+
+		_, err := fetcher.FetchPepValue(core.Header{})
+
+		Expect(err).To(HaveOccurred())
+		Expect(err).To(MatchError(fakes.FakeError))
+	})
+
+	It("returns no matching logs error if no logs returned", func() {
+		mockBlockChain := fakes.NewMockBlockChain()
+		fetcher := pep.NewPepFetcher(mockBlockChain)
+
+		_, err := fetcher.FetchPepValue(core.Header{})
+
+		Expect(err).To(HaveOccurred())
+		Expect(err).To(MatchError(pep.ErrNoMatchingLog))
+	})
+
+	It("returns error if more than one matching logs returned", func() {
+		mockBlockChain := fakes.NewMockBlockChain()
+		mockBlockChain.SetGetEthLogsWithCustomQueryReturnLogs([]types.Log{{}, {}})
+		fetcher := pep.NewPepFetcher(mockBlockChain)
+
+		_, err := fetcher.FetchPepValue(core.Header{})
+
+		Expect(err).To(HaveOccurred())
+		Expect(err).To(MatchError(pep.ErrMultipleLogs))
+	})
+})

pkg/transformers/pep/pep.go

@@ -0,0 +1,7 @@
+package pep
+
+type Pep struct {
+	BlockNumber int64  `db:"block_number"`
+	HeaderID    int64  `db:"header_id"`
+	UsdValue    string `db:"usd_value"`
+}

pkg/transformers/pep/pep_suite_test.go

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

pkg/transformers/pep/repository.go

@@ -0,0 +1,27 @@
+package pep
+
+import (
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+)
+
+type IPepRepository interface {
+	CreatePep(pep Pep) error
+}
+
+type PepRepository struct {
+	db *postgres.DB
+}
+
+func NewPepRepository(db *postgres.DB) PepRepository {
+	return PepRepository{
+		db: db,
+	}
+}
+
+func (repository PepRepository) CreatePep(pep Pep) error {
+	_, err := repository.db.Exec(`INSERT INTO maker.peps (block_number, header_id, usd_value) VALUES ($1, $2, $3::NUMERIC)`, pep.BlockNumber, pep.HeaderID, pep.UsdValue)
+	if err != nil {
+		return err
+	}
+	return nil
+}

pkg/transformers/pep/repository_test.go

@@ -0,0 +1,36 @@
+package pep_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"github.com/vulcanize/vulcanizedb/pkg/core"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres/repositories"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/pep"
+	"github.com/vulcanize/vulcanizedb/test_config"
+)
+
+var _ = Describe("Pep repository", func() {
+	It("creates a pep", func() {
+		db := test_config.NewTestDB(core.Node{})
+		test_config.CleanTestDB(db)
+		repository := pep.NewPepRepository(db)
+		header := core.Header{BlockNumber: 12345}
+		headerRepository := repositories.NewHeaderRepository(db)
+		headerID, err := headerRepository.CreateOrUpdateHeader(header)
+		Expect(err).NotTo(HaveOccurred())
+		pepToAdd := pep.Pep{
+			BlockNumber: header.BlockNumber,
+			HeaderID:    headerID,
+			UsdValue:    "123.456",
+		}
+
+		err = repository.CreatePep(pepToAdd)
+
+		Expect(err).NotTo(HaveOccurred())
+		var dbPep pep.Pep
+		err = db.Get(&dbPep, `SELECT block_number, header_id, usd_value FROM maker.peps WHERE header_id = $1`, pepToAdd.HeaderID)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(dbPep).To(Equal(pepToAdd))
+	})
+})

pkg/transformers/pep/transformer.go

@@ -0,0 +1,59 @@
+package pep
+
+import (
+	"math/big"
+
+	"github.com/vulcanize/vulcanizedb/pkg/core"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+)
+
+var Ether = big.NewFloat(1e18)
+var Ray = big.NewFloat(1e27)
+
+type PepTransformer struct {
+	fetcher    IPepFetcher
+	repository IPepRepository
+}
+
+func NewPepTransformer(chain core.BlockChain, db *postgres.DB) PepTransformer {
+	fetcher := NewPepFetcher(chain)
+	repository := NewPepRepository(db)
+	return PepTransformer{
+		fetcher:    fetcher,
+		repository: repository,
+	}
+}
+
+func (transformer PepTransformer) Execute(header core.Header, headerID int64) error {
+	logValue, err := transformer.fetcher.FetchPepValue(header)
+	if err != nil {
+		if err == ErrNoMatchingLog {
+			return nil
+		}
+		return err
+	}
+	pep := getPep(logValue, header, headerID)
+	return transformer.repository.CreatePep(pep)
+}
+
+func getPep(logValue string, header core.Header, headerID int64) Pep {
+	valueInUSD := convert("wad", logValue, 15)
+	pep := Pep{
+		BlockNumber: header.BlockNumber,
+		HeaderID:    headerID,
+		UsdValue:    valueInUSD,
+	}
+	return pep
+}
+
+func convert(conversion string, value string, prec int) string {
+	var bgflt = big.NewFloat(0.0)
+	bgflt.SetString(value)
+	switch conversion {
+	case "ray":
+		bgflt.Quo(bgflt, Ray)
+	case "wad":
+		bgflt.Quo(bgflt, Ether)
+	}
+	return bgflt.Text('g', prec)
+}

pkg/transformers/pep/transformer_test.go

@@ -0,0 +1,44 @@
+package pep_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/vulcanize/vulcanizedb/pkg/core"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres/repositories"
+	"github.com/vulcanize/vulcanizedb/pkg/fakes"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/pep"
+	"github.com/vulcanize/vulcanizedb/test_config"
+)
+
+var _ = Describe("Pep transformer", func() {
+	It("returns nil if no logs found", func() {
+		chain := fakes.NewMockBlockChain()
+		db := test_config.NewTestDB(core.Node{})
+		transformer := pep.NewPepTransformer(chain, db)
+
+		err := transformer.Execute(core.Header{}, 123)
+
+		Expect(err).NotTo(HaveOccurred())
+	})
+
+	It("creates pep row for found log", func() {
+		chain := fakes.NewMockBlockChain()
+		chain.SetGetEthLogsWithCustomQueryReturnLogs([]types.Log{{Data: []byte{1, 2, 3, 4, 5}}})
+		db := test_config.NewTestDB(core.Node{})
+		headerRepository := repositories.NewHeaderRepository(db)
+		header := core.Header{BlockNumber: 12345}
+		headerID, err := headerRepository.CreateOrUpdateHeader(header)
+		Expect(err).NotTo(HaveOccurred())
+		transformer := pep.NewPepTransformer(chain, db)
+
+		err = transformer.Execute(header, headerID)
+
+		Expect(err).NotTo(HaveOccurred())
+		var dbPep pep.Pep
+		err = db.Get(&dbPep, `SELECT block_number, header_id, usd_value FROM maker.peps WHERE header_id = $1`, headerID)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(dbPep.BlockNumber).To(Equal(header.BlockNumber))
+	})
+})

pkg/transformers/shared/fetcher_test.go

@@ -51,7 +51,7 @@ var _ = Describe("Fetcher", func() {
 
 		It("returns an error if fetching the logs fails", func() {
 			blockChain := fakes.NewMockBlockChain()
-			blockChain.SetGetLogsErr(fakes.FakeError)
+			blockChain.SetGetEthLogsWithCustomQueryErr(fakes.FakeError)
 			fetcher := shared.NewFetcher(blockChain)
 
 			_, err := fetcher.FetchLogs("", [][]common.Hash{}, int64(1))

pkg/transformers/transformer.go

@@ -0,0 +1,9 @@
+package transformers
+
+import (
+	"github.com/vulcanize/vulcanizedb/pkg/core"
+)
+
+type Transformer interface {
+	Execute(header core.Header, headerID int64) error
+}