Backfill Frob log events

pkg/transformers/shared/TransformerREADME.md

@@ -0,0 +1,27 @@
+# Transformers
+
+## Description
+Transformers must be defined in order to define what events should trigger data updates and how those are performed.
+
+## Interface
+
+### Initializer
+Accepts DB and Blockchain from Vulcanize and returns a new transformer. E.g. for a new object "Cup":
+`func NewCupTransformer(db *postgres.DB, blockchain core.ContractDataFetcher) transformers.Transformer`
+
+### Execute
+Triggers operations to take in response to a given log event.
+Can persist data from logs, fetch and persist arbitrary data from outside services (e.g. contract state), or take any number of other actions. E.g.:
+`func (cupTransformer *CupTransformer) Execute() error`
+
+## Additional Requirements
+Transformers must define log filters and create them so that relevant watched events can be identified and retrieved. E.g.:
+```$xslt
+	{
+		Name:      "CupsBite",
+		FromBlock: 0,
+		ToBlock:   -1,
+		Address:   "0x448a5065aebb8e423f0896e6c5d525c040f59af3",
+		Topics:    core.Topics{"0x40cc885400000000000000000000000000000000000000000000000000000000"},
+	},
+```

pkg/transformers/shared/fetcher.go

@@ -0,0 +1,51 @@
+// Copyright 2018 Vulcanize
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shared
+
+import (
+	"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"
+)
+
+type LogFetcher interface {
+	FetchLogs(contractAddress string, topics [][]common.Hash, blockNumber int64) ([]types.Log, error)
+}
+
+type Fetcher struct {
+	blockChain core.BlockChain
+}
+
+func NewFetcher(blockchain core.BlockChain) Fetcher {
+	return Fetcher{
+		blockChain: blockchain,
+	}
+}
+
+func (fetcher Fetcher) FetchLogs(contractAddress string, topics [][]common.Hash, blockNumber int64) ([]types.Log, error) {
+	block := big.NewInt(blockNumber)
+	address := common.HexToAddress(contractAddress)
+	query := ethereum.FilterQuery{
+		FromBlock: block,
+		ToBlock:   block,
+		Addresses: []common.Address{address},
+		Topics:    topics,
+	}
+	return fetcher.blockChain.GetEthLogsWithCustomQuery(query)
+}

pkg/transformers/shared/fetcher_test.go

@@ -0,0 +1,63 @@
+// Copyright 2018 Vulcanize
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shared_test
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"github.com/vulcanize/vulcanizedb/pkg/fakes"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/shared"
+)
+
+var _ = Describe("Fetcher", func() {
+	Describe("FetchLogs", func() {
+
+		It("fetches logs based on the given query", func() {
+			blockChain := fakes.NewMockBlockChain()
+			fetcher := shared.NewFetcher(blockChain)
+			blockNumber := int64(123)
+			address := "0xfakeAddress"
+			topicZeros := [][]common.Hash{{common.BytesToHash([]byte{1, 2, 3, 4, 5})}}
+
+			_, err := fetcher.FetchLogs(address, topicZeros, blockNumber)
+
+			Expect(err).NotTo(HaveOccurred())
+			expectedQuery := ethereum.FilterQuery{
+				FromBlock: big.NewInt(blockNumber),
+				ToBlock:   big.NewInt(blockNumber),
+				Addresses: []common.Address{common.HexToAddress(address)},
+				Topics:    topicZeros,
+			}
+			blockChain.AssertGetEthLogsWithCustomQueryCalledWith(expectedQuery)
+
+		})
+
+		It("returns an error if fetching the logs fails", func() {
+			blockChain := fakes.NewMockBlockChain()
+			blockChain.SetGetLogsErr(fakes.FakeError)
+			fetcher := shared.NewFetcher(blockChain)
+
+			_, err := fetcher.FetchLogs("", [][]common.Hash{}, int64(1))
+
+			Expect(err).To(HaveOccurred())
+			Expect(err).To(MatchError(fakes.FakeError))
+		})
+	})
+})

pkg/transformers/shared/shared_suite_test.go

@@ -0,0 +1,27 @@
+// Copyright 2018 Vulcanize
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shared_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+func TestShared(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Shared Suite")
+}

pkg/transformers/shared/transformer.go

@@ -0,0 +1,38 @@
+// Copyright 2018 Vulcanize
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shared
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+
+	"github.com/vulcanize/vulcanizedb/pkg/core"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+)
+
+type Transformer interface {
+	Execute() error
+}
+
+type TransformerInitializer func(db *postgres.DB, blockChain core.BlockChain) Transformer
+
+func HexToInt64(byteString string) int64 {
+	value := common.HexToHash(byteString)
+	return value.Big().Int64()
+}
+
+func HexToString(byteString string) string {
+	value := common.HexToHash(byteString)
+	return value.Big().String()
+}