Add Pip price feed

cmd/syncPriceFeeds.go

@@ -32,7 +32,8 @@ import (
 	"github.com/vulcanize/vulcanizedb/pkg/geth/node"
 	"github.com/vulcanize/vulcanizedb/pkg/history"
 	"github.com/vulcanize/vulcanizedb/pkg/transformers"
-	"github.com/vulcanize/vulcanizedb/pkg/transformers/pep"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds/pep"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds/pip"
 	"github.com/vulcanize/vulcanizedb/utils"
 )
 
@@ -87,10 +88,12 @@ func syncPriceFeeds() {
 
 	db := utils.LoadPostgres(databaseConfig, blockChain.Node())
 	headerRepository := repositories.NewHeaderRepository(&db)
+	// TODO: add transformers to validation so we don't miss events on new block headers
 	validator := history.NewHeaderValidator(blockChain, headerRepository, validationWindow)
 	missingBlocksPopulated := make(chan int)
 	transformers := []transformers.Transformer{
 		pep.NewPepTransformer(blockChain, &db),
+		pip.NewPipTransformer(blockChain, &db),
 	}
 	go backFillPriceFeeds(blockChain, headerRepository, missingBlocksPopulated, startingBlockNumber, transformers)
 

db/migrations/1532623709_create_pips_table.down.sql

@@ -0,0 +1 @@
+DROP TABLE maker.pips;

db/migrations/1532623709_create_pips_table.up.sql

@@ -0,0 +1,9 @@
+CREATE TABLE maker.pips (
+  id           SERIAL PRIMARY KEY,
+  block_number BIGINT  NOT NULL,
+  header_id    INTEGER NOT NULL,
+  usd_value    NUMERIC,
+  CONSTRAINT headers_fk FOREIGN KEY (header_id)
+  REFERENCES headers (id)
+  ON DELETE CASCADE
+);

db/schema.sql

@@ -151,6 +151,38 @@ CREATE SEQUENCE maker.peps_id_seq
 ALTER SEQUENCE maker.peps_id_seq OWNED BY maker.peps.id;
 
 
+--
+-- Name: pips; Type: TABLE; Schema: maker; Owner: -
+--
+
+CREATE TABLE maker.pips (
+    id integer NOT NULL,
+    block_number bigint NOT NULL,
+    header_id integer NOT NULL,
+    usd_value numeric
+);
+
+
+--
+-- Name: pips_id_seq; Type: SEQUENCE; Schema: maker; Owner: -
+--
+
+CREATE SEQUENCE maker.pips_id_seq
+    AS integer
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1;
+
+
+--
+-- Name: pips_id_seq; Type: SEQUENCE OWNED BY; Schema: maker; Owner: -
+--
+
+ALTER SEQUENCE maker.pips_id_seq OWNED BY maker.pips.id;
+
+
 --
 -- Name: logs; Type: TABLE; Schema: public; Owner: -
 --
@@ -544,6 +576,13 @@ ALTER TABLE ONLY maker.frob ALTER COLUMN id SET DEFAULT nextval('maker.frob_id_s
 ALTER TABLE ONLY maker.peps ALTER COLUMN id SET DEFAULT nextval('maker.peps_id_seq'::regclass);
 
 
+--
+-- Name: pips id; Type: DEFAULT; Schema: maker; Owner: -
+--
+
+ALTER TABLE ONLY maker.pips ALTER COLUMN id SET DEFAULT nextval('maker.pips_id_seq'::regclass);
+
+
 --
 -- Name: blocks id; Type: DEFAULT; Schema: public; Owner: -
 --
@@ -647,6 +686,14 @@ ALTER TABLE ONLY maker.peps
     ADD CONSTRAINT peps_pkey PRIMARY KEY (id);
 
 
+--
+-- Name: pips pips_pkey; Type: CONSTRAINT; Schema: maker; Owner: -
+--
+
+ALTER TABLE ONLY maker.pips
+    ADD CONSTRAINT pips_pkey PRIMARY KEY (id);
+
+
 --
 -- Name: blocks blocks_pkey; Type: CONSTRAINT; Schema: public; Owner: -
 --
@@ -802,6 +849,14 @@ ALTER TABLE ONLY maker.peps
     ADD CONSTRAINT headers_fk FOREIGN KEY (header_id) REFERENCES public.headers(id) ON DELETE CASCADE;
 
 
+--
+-- Name: pips headers_fk; Type: FK CONSTRAINT; Schema: maker; Owner: -
+--
+
+ALTER TABLE ONLY maker.pips
+    ADD CONSTRAINT headers_fk FOREIGN KEY (header_id) REFERENCES public.headers(id) ON DELETE CASCADE;
+
+
 --
 -- Name: transactions blocks_fk; Type: FK CONSTRAINT; Schema: public; Owner: -
 --

environments/infura.toml

@@ -1,5 +1,5 @@
 [database]
-name = "vulcanize_private"
+name = "vulcanize_public"
 hostname = "localhost"
 port = 5432
 

pkg/fakes/mock_blockchain.go

@@ -65,7 +65,7 @@ func (chain *MockBlockChain) SetGetLogsReturnLogs(logs []core.Log) {
 	chain.getLogsReturnLogs = logs
 }
 
-func (chain *MockBlockChain) FetchContractData(abiJSON string, address string, method string, methodArg interface{}, result interface{}, blockNumber int64) error {
+func (chain *MockBlockChain) FetchContractData(abiJSON, address, method string, methodArg, result interface{}, blockNumber int64) error {
 	chain.fetchContractDataPassedAbi = abiJSON
 	chain.fetchContractDataPassedAddress = address
 	chain.fetchContractDataPassedMethod = method
@@ -114,7 +114,7 @@ func (chain *MockBlockChain) AssertFetchContractDataCalledWith(abiJSON string, a
 	if methodArg != nil {
 		Expect(chain.fetchContractDataPassedMethodArg).To(Equal(methodArg))
 	}
-	Expect(chain.fetchContractDataPassedResult).To(Equal(result))
+	Expect(chain.fetchContractDataPassedResult).To(BeAssignableToTypeOf(result))
 	Expect(chain.fetchContractDataPassedBlockNumber).To(Equal(blockNumber))
 }
 

pkg/transformers/pep/constants.go

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

pkg/transformers/pep/pep.go

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

pkg/transformers/price_feeds/constants.go

@@ -0,0 +1,19 @@
+package price_feeds
+
+import (
+	"errors"
+	"math/big"
+)
+
+var (
+	ErrMultipleLogs  = errors.New("multiple matching logs found in block")
+	ErrNoMatchingLog = errors.New("no matching log")
+	PeekMethodName   = "peek"
+	PepLogTopic0     = "0x296ba4ca62c6c21c95e828080cb8aec7481b71390585605300a8a76f9e95b527"
+	PipLogTopic0     = "0x1817835800000000000000000000000000000000000000000000000000000000"
+	PepAddress       = "0x99041F808D598B782D5a3e498681C2452A31da08"
+	PipAddress       = "0x729D19f657BD0614b4985Cf1D82531c67569197B"
+	PipMedianizerABI = `[{"constant":false,"inputs":[{"name":"owner_","type":"address"}],"name":"setOwner","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"","type":"bytes32"}],"name":"poke","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"poke","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"compute","outputs":[{"name":"","type":"bytes32"},{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"wat","type":"address"}],"name":"set","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"wat","type":"address"}],"name":"unset","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"indexes","outputs":[{"name":"","type":"bytes12"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"next","outputs":[{"name":"","type":"bytes12"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"read","outputs":[{"name":"","type":"bytes32"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"peek","outputs":[{"name":"","type":"bytes32"},{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"","type":"bytes12"}],"name":"values","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"min_","type":"uint96"}],"name":"setMin","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"authority_","type":"address"}],"name":"setAuthority","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"void","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"pos","type":"bytes12"},{"name":"wat","type":"address"}],"name":"set","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"authority","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"pos","type":"bytes12"}],"name":"unset","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"next_","type":"bytes12"}],"name":"setNext","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"min","outputs":[{"name":"","type":"uint96"}],"payable":false,"type":"function"},{"anonymous":true,"inputs":[{"indexed":true,"name":"sig","type":"bytes4"},{"indexed":true,"name":"guy","type":"address"},{"indexed":true,"name":"foo","type":"bytes32"},{"indexed":true,"name":"bar","type":"bytes32"},{"indexed":false,"name":"wad","type":"uint256"},{"indexed":false,"name":"fax","type":"bytes"}],"name":"LogNote","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"authority","type":"address"}],"name":"LogSetAuthority","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"owner","type":"address"}],"name":"LogSetOwner","type":"event"}]`
+	Ether            = big.NewFloat(1e18)
+	Ray              = big.NewFloat(1e27)
+)

pkg/transformers/price_feeds/pep/fetcher.go

@@ -1,17 +1,14 @@
 package pep
 
 import (
-	"errors"
+	"math/big"
+
 	"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 (
+	"github.com/vulcanize/vulcanizedb/pkg/core"
-	ErrMultipleLogs  = errors.New("multiple matching logs found in block")
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds"
-	ErrNoMatchingLog = errors.New("no matching log")
 )
 
 type IPepFetcher interface {
@@ -33,8 +30,8 @@ func (fetcher PepFetcher) FetchPepValue(header core.Header) (string, error) {
 	query := ethereum.FilterQuery{
 		FromBlock: blockNumber,
 		ToBlock:   blockNumber,
-		Addresses: []common.Address{common.HexToAddress(PepAddress)},
+		Addresses: []common.Address{common.HexToAddress(price_feeds.PepAddress)},
-		Topics:    [][]common.Hash{{common.HexToHash(LogValueTopic0)}},
+		Topics:    [][]common.Hash{{common.HexToHash(price_feeds.PepLogTopic0)}},
 	}
 	logs, err := fetcher.blockChain.GetEthLogsWithCustomQuery(query)
 	return fetcher.getLogValue(logs, err)
@@ -45,10 +42,10 @@ func (fetcher PepFetcher) getLogValue(logs []types.Log, err error) (string, erro
 		return "", err
 	}
 	if len(logs) < 1 {
-		return "", ErrNoMatchingLog
+		return "", price_feeds.ErrNoMatchingLog
 	}
 	if len(logs) > 1 {
-		return "", ErrMultipleLogs
+		return "", price_feeds.ErrMultipleLogs
 	}
 	return string(logs[0].Data), nil
 }

pkg/transformers/price_feeds/pep/fetcher_test.go

@@ -9,12 +9,13 @@ import (
 	"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"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds/pep"
 	"math/big"
 )
 
 var _ = Describe("Pep fetcher", func() {
-	It("calls contract to peek mkr/usd value", func() {
+	It("gets logs describing updated mkr/usd value", func() {
 		mockBlockChain := fakes.NewMockBlockChain()
 		mockBlockChain.SetGetEthLogsWithCustomQueryReturnLogs([]types.Log{{}})
 		fetcher := pep.NewPepFetcher(mockBlockChain)
@@ -31,13 +32,13 @@ var _ = Describe("Pep fetcher", func() {
 		expectedQuery := ethereum.FilterQuery{
 			FromBlock: big.NewInt(blockNumber),
 			ToBlock:   big.NewInt(blockNumber),
-			Addresses: []common.Address{common.HexToAddress(pep.PepAddress)},
+			Addresses: []common.Address{common.HexToAddress(price_feeds.PepAddress)},
-			Topics:    [][]common.Hash{{common.HexToHash(pep.LogValueTopic0)}},
+			Topics:    [][]common.Hash{{common.HexToHash(price_feeds.PepLogTopic0)}},
 		}
 		mockBlockChain.AssertGetEthLogsWithCustomQueryCalledWith(expectedQuery)
 	})
 
-	It("returns error if contract call fails", func() {
+	It("returns error if getting logs fails", func() {
 		mockBlockChain := fakes.NewMockBlockChain()
 		mockBlockChain.SetGetEthLogsWithCustomQueryReturnLogs([]types.Log{{}})
 		mockBlockChain.SetGetEthLogsWithCustomQueryErr(fakes.FakeError)
@@ -56,7 +57,7 @@ var _ = Describe("Pep fetcher", func() {
 		_, err := fetcher.FetchPepValue(core.Header{})
 
 		Expect(err).To(HaveOccurred())
-		Expect(err).To(MatchError(pep.ErrNoMatchingLog))
+		Expect(err).To(MatchError(price_feeds.ErrNoMatchingLog))
 	})
 
 	It("returns error if more than one matching logs returned", func() {
@@ -67,6 +68,6 @@ var _ = Describe("Pep fetcher", func() {
 		_, err := fetcher.FetchPepValue(core.Header{})
 
 		Expect(err).To(HaveOccurred())
-		Expect(err).To(MatchError(pep.ErrMultipleLogs))
+		Expect(err).To(MatchError(price_feeds.ErrMultipleLogs))
 	})
 })

pkg/transformers/price_feeds/pep/pep_suite_test.go

@@ -1,4 +1,4 @@
-package pep_test
+package pep
 
 import (
 	"testing"

pkg/transformers/price_feeds/pep/repository.go

@@ -2,10 +2,11 @@ package pep
 
 import (
 	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds"
 )
 
 type IPepRepository interface {
-	CreatePep(pep Pep) error
+	CreatePep(pep price_feeds.PriceUpdate) error
 }
 
 type PepRepository struct {
@@ -18,10 +19,7 @@ func NewPepRepository(db *postgres.DB) PepRepository {
 	}
 }
 
-func (repository PepRepository) CreatePep(pep Pep) error {
+func (repository PepRepository) CreatePep(pep price_feeds.PriceUpdate) 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/price_feeds/pep/repository_test.go

@@ -6,12 +6,27 @@ import (
 
 	"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/pkg/transformers/price_feeds"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds/pep"
 	"github.com/vulcanize/vulcanizedb/test_config"
 )
 
 var _ = Describe("Pep repository", func() {
-	It("creates a pep", func() {
+	It("returns header if matching header does not exist", func() {
+		db := test_config.NewTestDB(core.Node{})
+		repository := pep.NewPepRepository(db)
+		pepToAdd := price_feeds.PriceUpdate{
+			BlockNumber: 0,
+			HeaderID:    0,
+			UsdValue:    "123.456",
+		}
+
+		err := repository.CreatePep(pepToAdd)
+
+		Expect(err).To(HaveOccurred())
+	})
+
+	It("creates a pep when matching header exists", func() {
 		db := test_config.NewTestDB(core.Node{})
 		test_config.CleanTestDB(db)
 		repository := pep.NewPepRepository(db)
@@ -19,7 +34,7 @@ var _ = Describe("Pep repository", func() {
 		headerRepository := repositories.NewHeaderRepository(db)
 		headerID, err := headerRepository.CreateOrUpdateHeader(header)
 		Expect(err).NotTo(HaveOccurred())
-		pepToAdd := pep.Pep{
+		pepToAdd := price_feeds.PriceUpdate{
 			BlockNumber: header.BlockNumber,
 			HeaderID:    headerID,
 			UsdValue:    "123.456",
@@ -28,7 +43,7 @@ var _ = Describe("Pep repository", func() {
 		err = repository.CreatePep(pepToAdd)
 
 		Expect(err).NotTo(HaveOccurred())
-		var dbPep pep.Pep
+		var dbPep price_feeds.PriceUpdate
 		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/price_feeds/pep/transformer.go

@@ -1,15 +1,11 @@
 package pep
 
 import (
-	"math/big"
-
 	"github.com/vulcanize/vulcanizedb/pkg/core"
 	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds"
 )
 
-var Ether = big.NewFloat(1e18)
-var Ray = big.NewFloat(1e27)
-
 type PepTransformer struct {
 	fetcher    IPepFetcher
 	repository IPepRepository
@@ -27,7 +23,7 @@ func NewPepTransformer(chain core.BlockChain, db *postgres.DB) PepTransformer {
 func (transformer PepTransformer) Execute(header core.Header, headerID int64) error {
 	logValue, err := transformer.fetcher.FetchPepValue(header)
 	if err != nil {
-		if err == ErrNoMatchingLog {
+		if err == price_feeds.ErrNoMatchingLog {
 			return nil
 		}
 		return err
@@ -36,24 +32,12 @@ func (transformer PepTransformer) Execute(header core.Header, headerID int64) er
 	return transformer.repository.CreatePep(pep)
 }
 
-func getPep(logValue string, header core.Header, headerID int64) Pep {
+func getPep(logValue string, header core.Header, headerID int64) price_feeds.PriceUpdate {
-	valueInUSD := convert("wad", logValue, 15)
+	valueInUSD := price_feeds.Convert("wad", logValue, 15)
-	pep := Pep{
+	pep := price_feeds.PriceUpdate{
 		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/price_feeds/pep/transformer_test.go

@@ -8,7 +8,8 @@ import (
 	"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/pkg/transformers/price_feeds"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds/pep"
 	"github.com/vulcanize/vulcanizedb/test_config"
 )
 
@@ -27,6 +28,7 @@ var _ = Describe("Pep transformer", func() {
 		chain := fakes.NewMockBlockChain()
 		chain.SetGetEthLogsWithCustomQueryReturnLogs([]types.Log{{Data: []byte{1, 2, 3, 4, 5}}})
 		db := test_config.NewTestDB(core.Node{})
+		test_config.CleanTestDB(db)
 		headerRepository := repositories.NewHeaderRepository(db)
 		header := core.Header{BlockNumber: 12345}
 		headerID, err := headerRepository.CreateOrUpdateHeader(header)
@@ -36,7 +38,7 @@ var _ = Describe("Pep transformer", func() {
 		err = transformer.Execute(header, headerID)
 
 		Expect(err).NotTo(HaveOccurred())
-		var dbPep pep.Pep
+		var dbPep price_feeds.PriceUpdate
 		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/price_feeds/pip/fetcher.go

@@ -0,0 +1,75 @@
+package pip
+
+import (
+	"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/transformers/price_feeds"
+	"math/big"
+)
+
+type IPipFetcher interface {
+	FetchPipValue(header core.Header) (string, error)
+}
+
+type PipFetcher struct {
+	blockChain core.BlockChain
+}
+
+func NewPipFetcher(chain core.BlockChain) PipFetcher {
+	return PipFetcher{
+		blockChain: chain,
+	}
+}
+
+func (fetcher PipFetcher) FetchPipValue(header core.Header) (string, error) {
+	blockNumber := big.NewInt(header.BlockNumber)
+	query := ethereum.FilterQuery{
+		FromBlock: blockNumber,
+		ToBlock:   blockNumber,
+		Addresses: []common.Address{common.HexToAddress(price_feeds.PipAddress)},
+		Topics:    [][]common.Hash{{common.HexToHash(price_feeds.PipLogTopic0)}},
+	}
+	logs, err := fetcher.blockChain.GetEthLogsWithCustomQuery(query)
+	if err != nil {
+		return "", err
+	}
+	if len(logs) > 0 {
+		return fetcher.getLogValue(logs, err)
+	}
+	return "", price_feeds.ErrNoMatchingLog
+}
+
+func (fetcher PipFetcher) getLogValue(logs []types.Log, err error) (string, error) {
+	var (
+		ret0 = new([32]byte)
+		ret1 = new(bool)
+	)
+	var r = &[]interface{}{
+		ret0,
+		ret1,
+	}
+	err = fetcher.blockChain.FetchContractData(price_feeds.PipMedianizerABI, price_feeds.PipAddress, price_feeds.PeekMethodName, nil, r, int64(logs[0].BlockNumber))
+	if err != nil {
+		return "", err
+	}
+	result := newResult(*ret0, *ret1)
+	return result.Value.String(), nil
+}
+
+type Value [32]byte
+
+type Peek struct {
+	Value
+	OK bool
+}
+
+func (value Value) String() string {
+	bi := big.NewInt(0).SetBytes(value[:])
+	return bi.String()
+}
+
+func newResult(value [32]byte, ok bool) *Peek {
+	return &Peek{Value: value, OK: ok}
+}

pkg/transformers/price_feeds/pip/fetcher_test.go

@@ -0,0 +1,60 @@
+package pip_test
+
+import (
+	"github.com/ethereum/go-ethereum/core/types"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/vulcanize/vulcanizedb/pkg/core"
+	"github.com/vulcanize/vulcanizedb/pkg/fakes"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds/pip"
+)
+
+var _ = Describe("Pip fetcher", func() {
+	It("returns error if fetching logs fails", func() {
+		chain := fakes.NewMockBlockChain()
+		chain.SetGetEthLogsWithCustomQueryErr(fakes.FakeError)
+		fetcher := pip.NewPipFetcher(chain)
+
+		_, err := fetcher.FetchPipValue(core.Header{})
+
+		Expect(err).To(HaveOccurred())
+		Expect(err).To(MatchError(fakes.FakeError))
+	})
+
+	It("returns no matching logs error if no logs returned", func() {
+		chain := fakes.NewMockBlockChain()
+		fetcher := pip.NewPipFetcher(chain)
+
+		_, err := fetcher.FetchPipValue(core.Header{})
+
+		Expect(err).To(HaveOccurred())
+		Expect(err).To(MatchError(price_feeds.ErrNoMatchingLog))
+	})
+
+	Describe("when matching log found", func() {
+		It("calls contract to peek current eth/usd value", func() {
+			blockNumber := uint64(12345)
+			chain := fakes.NewMockBlockChain()
+			chain.SetGetEthLogsWithCustomQueryReturnLogs([]types.Log{{BlockNumber: blockNumber}})
+			fetcher := pip.NewPipFetcher(chain)
+
+			_, err := fetcher.FetchPipValue(core.Header{})
+
+			Expect(err).NotTo(HaveOccurred())
+			chain.AssertFetchContractDataCalledWith(price_feeds.PipMedianizerABI, price_feeds.PipAddress, price_feeds.PeekMethodName, nil, &[]interface{}{[32]byte{}, false}, int64(blockNumber))
+		})
+
+		It("returns error if contract call fails", func() {
+			chain := fakes.NewMockBlockChain()
+			chain.SetGetEthLogsWithCustomQueryReturnLogs([]types.Log{{BlockNumber: uint64(12345)}})
+			chain.SetFetchContractDataErr(fakes.FakeError)
+			fetcher := pip.NewPipFetcher(chain)
+
+			_, err := fetcher.FetchPipValue(core.Header{})
+
+			Expect(err).To(HaveOccurred())
+			Expect(err).To(MatchError(fakes.FakeError))
+		})
+	})
+})

pkg/transformers/price_feeds/pip/pip_suite_test.go

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

pkg/transformers/price_feeds/pip/repository.go

@@ -0,0 +1,25 @@
+package pip
+
+import (
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds"
+)
+
+type IPipRepository interface {
+	CreatePip(pip price_feeds.PriceUpdate) error
+}
+
+type PipRepository struct {
+	db *postgres.DB
+}
+
+func NewPipRepository(db *postgres.DB) PipRepository {
+	return PipRepository{
+		db: db,
+	}
+}
+
+func (repository PipRepository) CreatePip(pip price_feeds.PriceUpdate) error {
+	_, err := repository.db.Exec(`INSERT INTO maker.pips (block_number, header_id, usd_value) VALUES ($1, $2, $3::NUMERIC)`, pip.BlockNumber, pip.HeaderID, pip.UsdValue)
+	return err
+}

pkg/transformers/price_feeds/pip/repository_test.go

@@ -0,0 +1,51 @@
+package pip_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/price_feeds"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds/pip"
+	"github.com/vulcanize/vulcanizedb/test_config"
+)
+
+var _ = Describe("Pip repository", func() {
+	It("does not create a pip if no matching header", func() {
+		db := test_config.NewTestDB(core.Node{})
+		repository := pip.NewPipRepository(db)
+		priceUpdate := price_feeds.PriceUpdate{
+			BlockNumber: 0,
+			HeaderID:    0,
+			UsdValue:    "123",
+		}
+
+		err := repository.CreatePip(priceUpdate)
+
+		Expect(err).To(HaveOccurred())
+	})
+
+	It("creates a pip when header exists", func() {
+		db := test_config.NewTestDB(core.Node{})
+		test_config.CleanTestDB(db)
+		repository := pip.NewPipRepository(db)
+		headerRepository := repositories.NewHeaderRepository(db)
+		header := core.Header{BlockNumber: 12345}
+		headerID, err := headerRepository.CreateOrUpdateHeader(header)
+		Expect(err).NotTo(HaveOccurred())
+		priceUpdate := price_feeds.PriceUpdate{
+			BlockNumber: header.BlockNumber,
+			HeaderID:    headerID,
+			UsdValue:    "777.777",
+		}
+
+		err = repository.CreatePip(priceUpdate)
+
+		Expect(err).NotTo(HaveOccurred())
+		var dbPip price_feeds.PriceUpdate
+		err = db.Get(&dbPip, `SELECT block_number, header_id, usd_value FROM maker.pips WHERE block_number = $1`, header.BlockNumber)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(dbPip).To(Equal(priceUpdate))
+	})
+})

pkg/transformers/price_feeds/pip/transformer.go

@@ -0,0 +1,43 @@
+package pip
+
+import (
+	"github.com/vulcanize/vulcanizedb/pkg/core"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds"
+)
+
+type PipTransformer struct {
+	fetcher    IPipFetcher
+	repository IPipRepository
+}
+
+func NewPipTransformer(chain core.BlockChain, db *postgres.DB) PipTransformer {
+	fetcher := NewPipFetcher(chain)
+	repository := NewPipRepository(db)
+	return PipTransformer{
+		fetcher:    fetcher,
+		repository: repository,
+	}
+}
+
+func (transformer PipTransformer) Execute(header core.Header, headerID int64) error {
+	value, err := transformer.fetcher.FetchPipValue(header)
+	if err != nil {
+		if err == price_feeds.ErrNoMatchingLog {
+			return nil
+		}
+		return err
+	}
+	pip := getPip(value, header, headerID)
+	return transformer.repository.CreatePip(pip)
+}
+
+func getPip(logValue string, header core.Header, headerID int64) price_feeds.PriceUpdate {
+	valueInUSD := price_feeds.Convert("wad", logValue, 15)
+	pep := price_feeds.PriceUpdate{
+		BlockNumber: header.BlockNumber,
+		HeaderID:    headerID,
+		UsdValue:    valueInUSD,
+	}
+	return pep
+}

pkg/transformers/price_feeds/pip/transformer_test.go

@@ -0,0 +1,45 @@
+package pip_test
+
+import (
+	"github.com/ethereum/go-ethereum/core/types"
+	. "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/fakes"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/price_feeds/pip"
+	"github.com/vulcanize/vulcanizedb/test_config"
+)
+
+var _ = Describe("Pip transformer", func() {
+	It("returns nil if no logs found", func() {
+		chain := fakes.NewMockBlockChain()
+		db := test_config.NewTestDB(core.Node{})
+		transformer := pip.NewPipTransformer(chain, db)
+
+		err := transformer.Execute(core.Header{}, 123)
+
+		Expect(err).NotTo(HaveOccurred())
+	})
+
+	It("creates pip 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{})
+		test_config.CleanTestDB(db)
+		headerRepository := repositories.NewHeaderRepository(db)
+		header := core.Header{BlockNumber: 12345}
+		headerID, err := headerRepository.CreateOrUpdateHeader(header)
+		Expect(err).NotTo(HaveOccurred())
+		transformer := pip.NewPipTransformer(chain, db)
+
+		err = transformer.Execute(header, headerID)
+
+		Expect(err).NotTo(HaveOccurred())
+		var dbPip price_feeds.PriceUpdate
+		err = db.Get(&dbPip, `SELECT block_number, header_id, usd_value FROM maker.pips WHERE header_id = $1`, headerID)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(dbPip.BlockNumber).To(Equal(header.BlockNumber))
+	})
+})

pkg/transformers/price_feeds/price_update.go

@@ -0,0 +1,21 @@
+package price_feeds
+
+import "math/big"
+
+type PriceUpdate struct {
+	BlockNumber int64  `db:"block_number"`
+	HeaderID    int64  `db:"header_id"`
+	UsdValue    string `db:"usd_value"`
+}
+
+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)
+}

test_config/test_config.go

@@ -78,6 +78,7 @@ func CleanTestDB(db *postgres.DB) {
 	db.MustExec("DELETE FROM log_filters")
 	db.MustExec("DELETE FROM logs")
 	db.MustExec("DELETE FROM maker.peps")
+	db.MustExec("DELETE FROM maker.pips")
 	db.MustExec("DELETE FROM receipts")
 	db.MustExec("DELETE FROM transactions")
 	db.MustExec("DELETE FROM watched_contracts")