(VDB-929) Minimize storage key lookup bespoke code

- Extract shared namespace for looking up and hashing keys
- Require storage transformers only to implement a loader that
  associates known keys with metadata
- Move key loader/lookup utils to utils directory to avoid
  multiple "storage" packages in imports

libraries/shared/factories/storage/README.md

@@ -31,15 +31,15 @@ The storage transformer depends on contract-specific implementations of code cap
 
 ```golang
 func (transformer Transformer) Execute(row shared.StorageDiffRow) error {
-	metadata, lookupErr := transformer.Mappings.Lookup(row.StorageKey)
+	metadata, lookupErr := transformer.StorageKeysLookup.Lookup(diff.StorageKey)
 	if lookupErr != nil {
 		return lookupErr
 	}
-	value, decodeErr := shared.Decode(row, metadata)
+	value, decodeErr := utils.Decode(diff, metadata)
 	if decodeErr != nil {
 		return decodeErr
 	}
-	return transformer.Repository.Create(row.BlockHeight, row.BlockHash.Hex(), metadata, value)
+	return transformer.Repository.Create(diff.BlockHeight, diff.BlockHash.Hex(), metadata, value)
 }
 ```
 
@@ -47,20 +47,36 @@ func (transformer Transformer) Execute(row shared.StorageDiffRow) error {
 
 In order to watch an additional smart contract, a developer must create three things:
 
-1. Mappings - specify how to identify keys in the contract's storage trie.
+1. StorageKeysLoader - identify keys in the contract's storage trie, providing metadata to describe how associated values should be decoded.
 1. Repository - specify how to persist a parsed version of the storage value matching the recognized storage key.
 1. Instance - create an instance of the storage transformer that uses your mappings and repository.
 
-### Mappings
+### StorageKeysLoader
+
+A `StorageKeysLoader` is used by the `StorageKeysLookup` object on a storage transformer.
 
 ```golang
-type Mappings interface {
-	Lookup(key common.Hash) (shared.StorageValueMetadata, error)
+type KeysLoader interface {
+	LoadMappings() (map[common.Hash]utils.StorageValueMetadata, error)
 	SetDB(db *postgres.DB)
 }
 ```
 
-A contract-specific implementation of the mappings interface enables the storage transformer to fetch metadata associated with a storage key.
+When a key is not found, the lookup object refreshes its known keys by calling the loader.
+
+```golang
+func (lookup *keysLookup) refreshMappings() error {
+	var err error
+	lookup.mappings, err = lookup.loader.LoadMappings()
+	if err != nil {
+		return err
+	}
+	lookup.mappings = utils.AddHashedKeys(lookup.mappings)
+	return nil
+}
+```
+
+A contract-specific implementation of the loader enables the storage transformer to fetch metadata associated with a storage key.
 
 Storage metadata contains: the name of the variable matching the storage key, a raw version of any keys associated with the variable (if the variable is a mapping), and the variable's type.
 
@@ -72,7 +88,7 @@ type StorageValueMetadata struct {
 }
 ```
 
-Keys are only relevant if the variable is a mapping. For example, in the following Solidity code:
+The `Keys` field on the metadata is only relevant if the variable is a mapping. For example, in the following Solidity code:
 
 ```solidity
 pragma solidity ^0.4.0;
@@ -85,7 +101,7 @@ contract Contract {
 
 The metadata for variable `x` would not have any associated keys, but the metadata for a storage key associated with `y` would include the address used to specify that key's index in the mapping.
 
-The `SetDB` function is required for the mappings to connect to the database.
+The `SetDB` function is required for the storage key loader to connect to the database.
 A database connection may be desired when keys in a mapping variable need to be read from log events (e.g. to lookup what addresses may exist in `y`, above).
 
 ### Repository

libraries/shared/factories/storage/keys_loader.go

@@ -0,0 +1,28 @@
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package storage
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/vulcanize/vulcanizedb/libraries/shared/storage/utils"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+)
+
+type KeysLoader interface {
+	LoadMappings() (map[common.Hash]utils.StorageValueMetadata, error)
+	SetDB(db *postgres.DB)
+}

libraries/shared/factories/storage/keys_lookup.go

@@ -0,0 +1,66 @@
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package storage
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/vulcanize/vulcanizedb/libraries/shared/storage/utils"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+)
+
+type KeysLookup interface {
+	Lookup(key common.Hash) (utils.StorageValueMetadata, error)
+	SetDB(db *postgres.DB)
+}
+
+type keysLookup struct {
+	loader   KeysLoader
+	mappings map[common.Hash]utils.StorageValueMetadata
+}
+
+func NewKeysLookup(loader KeysLoader) KeysLookup {
+	return &keysLookup{loader: loader, mappings: make(map[common.Hash]utils.StorageValueMetadata)}
+}
+
+func (lookup *keysLookup) Lookup(key common.Hash) (utils.StorageValueMetadata, error) {
+	metadata, ok := lookup.mappings[key]
+	if !ok {
+		refreshErr := lookup.refreshMappings()
+		if refreshErr != nil {
+			return metadata, refreshErr
+		}
+		metadata, ok = lookup.mappings[key]
+		if !ok {
+			return metadata, utils.ErrStorageKeyNotFound{Key: key.Hex()}
+		}
+	}
+	return metadata, nil
+}
+
+func (lookup *keysLookup) refreshMappings() error {
+	var err error
+	lookup.mappings, err = lookup.loader.LoadMappings()
+	if err != nil {
+		return err
+	}
+	lookup.mappings = utils.AddHashedKeys(lookup.mappings)
+	return nil
+}
+
+func (lookup *keysLookup) SetDB(db *postgres.DB) {
+	lookup.loader.SetDB(db)
+}

libraries/shared/factories/storage/keys_lookup_test.go

@@ -0,0 +1,113 @@
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package storage_test
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/vulcanize/vulcanizedb/libraries/shared/factories/storage"
+	"github.com/vulcanize/vulcanizedb/libraries/shared/mocks"
+	"github.com/vulcanize/vulcanizedb/libraries/shared/storage/utils"
+	"github.com/vulcanize/vulcanizedb/pkg/fakes"
+	"github.com/vulcanize/vulcanizedb/test_config"
+)
+
+var _ = Describe("Storage keys lookup", func() {
+	var (
+		fakeMetadata = utils.GetStorageValueMetadata("name", map[utils.Key]string{}, utils.Uint256)
+		lookup       storage.KeysLookup
+		loader       *mocks.MockStorageKeysLoader
+	)
+
+	BeforeEach(func() {
+		loader = &mocks.MockStorageKeysLoader{}
+		lookup = storage.NewKeysLookup(loader)
+	})
+
+	Describe("Lookup", func() {
+		Describe("when key not found", func() {
+			It("refreshes keys", func() {
+				loader.StorageKeyMappings = map[common.Hash]utils.StorageValueMetadata{fakes.FakeHash: fakeMetadata}
+				_, err := lookup.Lookup(fakes.FakeHash)
+
+				Expect(err).NotTo(HaveOccurred())
+				Expect(loader.LoadMappingsCallCount).To(Equal(1))
+			})
+
+			It("returns error if refreshing keys fails", func() {
+				loader.LoadMappingsError = fakes.FakeError
+
+				_, err := lookup.Lookup(fakes.FakeHash)
+
+				Expect(err).To(HaveOccurred())
+				Expect(err).To(MatchError(fakes.FakeError))
+			})
+		})
+
+		Describe("when key found", func() {
+			BeforeEach(func() {
+				loader.StorageKeyMappings = map[common.Hash]utils.StorageValueMetadata{fakes.FakeHash: fakeMetadata}
+				_, err := lookup.Lookup(fakes.FakeHash)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(loader.LoadMappingsCallCount).To(Equal(1))
+			})
+
+			It("does not refresh keys", func() {
+				_, err := lookup.Lookup(fakes.FakeHash)
+
+				Expect(err).NotTo(HaveOccurred())
+				Expect(loader.LoadMappingsCallCount).To(Equal(1))
+			})
+		})
+
+		It("returns metadata for loaded static key", func() {
+			loader.StorageKeyMappings = map[common.Hash]utils.StorageValueMetadata{fakes.FakeHash: fakeMetadata}
+
+			metadata, err := lookup.Lookup(fakes.FakeHash)
+
+			Expect(err).NotTo(HaveOccurred())
+			Expect(metadata).To(Equal(fakeMetadata))
+		})
+
+		It("returns metadata for hashed version of key (accommodates keys emitted from Geth)", func() {
+			loader.StorageKeyMappings = map[common.Hash]utils.StorageValueMetadata{fakes.FakeHash: fakeMetadata}
+
+			hashedKey := common.BytesToHash(crypto.Keccak256(fakes.FakeHash.Bytes()))
+			metadata, err := lookup.Lookup(hashedKey)
+
+			Expect(err).NotTo(HaveOccurred())
+			Expect(metadata).To(Equal(fakeMetadata))
+		})
+
+		It("returns key not found error if key not found", func() {
+			_, err := lookup.Lookup(fakes.FakeHash)
+
+			Expect(err).To(HaveOccurred())
+			Expect(err).To(MatchError(utils.ErrStorageKeyNotFound{Key: fakes.FakeHash.Hex()}))
+		})
+	})
+
+	Describe("SetDB", func() {
+		It("sets the db on the loader", func() {
+			lookup.SetDB(test_config.NewTestDB(test_config.NewTestNode()))
+
+			Expect(loader.SetDBCalled).To(BeTrue())
+		})
+	})
+})

libraries/shared/factories/storage/transformer.go

@@ -18,20 +18,19 @@ package storage
 
 import (
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/vulcanize/vulcanizedb/libraries/shared/storage"
 	"github.com/vulcanize/vulcanizedb/libraries/shared/storage/utils"
 	"github.com/vulcanize/vulcanizedb/libraries/shared/transformer"
 	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
 )
 
 type Transformer struct {
-	HashedAddress common.Hash
-	Mappings      storage.Mappings
-	Repository    Repository
+	HashedAddress     common.Hash
+	StorageKeysLookup KeysLookup
+	Repository        Repository
 }
 
 func (transformer Transformer) NewTransformer(db *postgres.DB) transformer.StorageTransformer {
-	transformer.Mappings.SetDB(db)
+	transformer.StorageKeysLookup.SetDB(db)
 	transformer.Repository.SetDB(db)
 	return transformer
 }
@@ -41,7 +40,7 @@ func (transformer Transformer) KeccakContractAddress() common.Hash {
 }
 
 func (transformer Transformer) Execute(diff utils.StorageDiff) error {
-	metadata, lookupErr := transformer.Mappings.Lookup(diff.StorageKey)
+	metadata, lookupErr := transformer.StorageKeysLookup.Lookup(diff.StorageKey)
 	if lookupErr != nil {
 		return lookupErr
 	}

libraries/shared/factories/storage/transformer_test.go

@@ -28,18 +28,18 @@ import (
 
 var _ = Describe("Storage transformer", func() {
 	var (
-		mappings   *mocks.MockMappings
-		repository *mocks.MockStorageRepository
-		t          storage.Transformer
+		storageKeysLookup *mocks.MockStorageKeysLookup
+		repository        *mocks.MockStorageRepository
+		t                 storage.Transformer
 	)
 
 	BeforeEach(func() {
-		mappings = &mocks.MockMappings{}
+		storageKeysLookup = &mocks.MockStorageKeysLookup{}
 		repository = &mocks.MockStorageRepository{}
 		t = storage.Transformer{
-			HashedAddress: common.Hash{},
-			Mappings:      mappings,
-			Repository:    repository,
+			HashedAddress:     common.Hash{},
+			StorageKeysLookup: storageKeysLookup,
+			Repository:        repository,
 		}
 	})
 
@@ -53,11 +53,11 @@ var _ = Describe("Storage transformer", func() {
 	It("looks up metadata for storage key", func() {
 		t.Execute(utils.StorageDiff{})
 
-		Expect(mappings.LookupCalled).To(BeTrue())
+		Expect(storageKeysLookup.LookupCalled).To(BeTrue())
 	})
 
 	It("returns error if lookup fails", func() {
-		mappings.LookupErr = fakes.FakeError
+		storageKeysLookup.LookupErr = fakes.FakeError
 
 		err := t.Execute(utils.StorageDiff{})
 
@@ -67,7 +67,7 @@ var _ = Describe("Storage transformer", func() {
 
 	It("creates storage row with decoded data", func() {
 		fakeMetadata := utils.StorageValueMetadata{Type: utils.Address}
-		mappings.Metadata = fakeMetadata
+		storageKeysLookup.Metadata = fakeMetadata
 		rawValue := common.HexToAddress("0x12345")
 		fakeBlockNumber := 123
 		fakeBlockHash := "0x67890"
@@ -91,7 +91,7 @@ var _ = Describe("Storage transformer", func() {
 	It("returns error if creating row fails", func() {
 		rawValue := common.HexToAddress("0x12345")
 		fakeMetadata := utils.StorageValueMetadata{Type: utils.Address}
-		mappings.Metadata = fakeMetadata
+		storageKeysLookup.Metadata = fakeMetadata
 		repository.CreateErr = fakes.FakeError
 
 		err := t.Execute(utils.StorageDiff{StorageValue: rawValue.Hash()})
@@ -118,7 +118,7 @@ var _ = Describe("Storage transformer", func() {
 		}
 
 		It("passes the decoded data items to the repository", func() {
-			mappings.Metadata = fakeMetadata
+			storageKeysLookup.Metadata = fakeMetadata
 			fakeRow := utils.StorageDiff{
 				HashedAddress: common.Hash{},
 				BlockHash:     common.HexToHash(fakeBlockHash),
@@ -140,7 +140,7 @@ var _ = Describe("Storage transformer", func() {
 		})
 
 		It("returns error if creating a row fails", func() {
-			mappings.Metadata = fakeMetadata
+			storageKeysLookup.Metadata = fakeMetadata
 			repository.CreateErr = fakes.FakeError
 
 			err := t.Execute(utils.StorageDiff{StorageValue: rawValue.Hash()})

libraries/shared/mocks/storage_keys_loader.go

@@ -0,0 +1,39 @@
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package mocks
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/vulcanize/vulcanizedb/libraries/shared/storage/utils"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+)
+
+type MockStorageKeysLoader struct {
+	LoadMappingsCallCount int
+	LoadMappingsError     error
+	SetDBCalled           bool
+	StorageKeyMappings    map[common.Hash]utils.StorageValueMetadata
+}
+
+func (loader *MockStorageKeysLoader) LoadMappings() (map[common.Hash]utils.StorageValueMetadata, error) {
+	loader.LoadMappingsCallCount++
+	return loader.StorageKeyMappings, loader.LoadMappingsError
+}
+
+func (loader *MockStorageKeysLoader) SetDB(db *postgres.DB) {
+	loader.SetDBCalled = true
+}

libraries/shared/mocks/storage_keys_lookup.go

@@ -18,22 +18,21 @@ package mocks
 
 import (
 	"github.com/ethereum/go-ethereum/common"
-
 	"github.com/vulcanize/vulcanizedb/libraries/shared/storage/utils"
 	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
 )
 
-type MockMappings struct {
+type MockStorageKeysLookup struct {
 	Metadata     utils.StorageValueMetadata
 	LookupCalled bool
 	LookupErr    error
 }
 
-func (mappings *MockMappings) Lookup(key common.Hash) (utils.StorageValueMetadata, error) {
+func (mappings *MockStorageKeysLookup) Lookup(key common.Hash) (utils.StorageValueMetadata, error) {
 	mappings.LookupCalled = true
 	return mappings.Metadata, mappings.LookupErr
 }
 
-func (*MockMappings) SetDB(db *postgres.DB) {
+func (*MockStorageKeysLookup) SetDB(db *postgres.DB) {
 	panic("implement me")
 }

libraries/shared/storage/utils/keys_loader.go

@@ -14,23 +14,14 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-package storage
+package utils
 
 import (
-	"math/big"
-
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
-
-	"github.com/vulcanize/vulcanizedb/libraries/shared/storage/utils"
-	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+	"math/big"
 )
 
-type Mappings interface {
-	Lookup(key common.Hash) (utils.StorageValueMetadata, error)
-	SetDB(db *postgres.DB)
-}
-
 const (
 	IndexZero   = "0000000000000000000000000000000000000000000000000000000000000000"
 	IndexOne    = "0000000000000000000000000000000000000000000000000000000000000001"
@@ -46,32 +37,17 @@ const (
 	IndexEleven = "000000000000000000000000000000000000000000000000000000000000000b"
 )
 
-func AddHashedKeys(currentMappings map[common.Hash]utils.StorageValueMetadata) map[common.Hash]utils.StorageValueMetadata {
-	copyOfCurrentMappings := make(map[common.Hash]utils.StorageValueMetadata)
-	for k, v := range currentMappings {
-		copyOfCurrentMappings[k] = v
-	}
-	for k, v := range copyOfCurrentMappings {
-		currentMappings[hashKey(k)] = v
-	}
-	return currentMappings
-}
-
-func hashKey(key common.Hash) common.Hash {
-	return crypto.Keccak256Hash(key.Bytes())
-}
-
-func GetMapping(indexOnContract, key string) common.Hash {
+func GetStorageKeyForMapping(indexOnContract, key string) common.Hash {
 	keyBytes := common.FromHex(key + indexOnContract)
 	return crypto.Keccak256Hash(keyBytes)
 }
 
-func GetNestedMapping(indexOnContract, primaryKey, secondaryKey string) common.Hash {
+func GetStorageKeyForNestedMapping(indexOnContract, primaryKey, secondaryKey string) common.Hash {
 	primaryMappingIndex := crypto.Keccak256(common.FromHex(primaryKey + indexOnContract))
 	return crypto.Keccak256Hash(common.FromHex(secondaryKey), primaryMappingIndex)
 }
 
-func GetIncrementedKey(original common.Hash, incrementBy int64) common.Hash {
+func GetIncrementedStorageKey(original common.Hash, incrementBy int64) common.Hash {
 	originalMappingAsInt := original.Big()
 	incremented := big.NewInt(0).Add(originalMappingAsInt, big.NewInt(incrementBy))
 	return common.BytesToHash(incremented.Bytes())

libraries/shared/storage/utils/keys_loader_test.go

@@ -1,78 +1,72 @@
-package storage_test
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package utils_test
 
 import (
 	"github.com/ethereum/go-ethereum/common"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
-	"github.com/vulcanize/vulcanizedb/libraries/shared/storage"
 	"github.com/vulcanize/vulcanizedb/libraries/shared/storage/utils"
 )
 
-var _ = Describe("Mappings", func() {
-	Describe("AddHashedKeys", func() {
-		It("returns a copy of the map with an additional slot for the hashed version of every key", func() {
-			fakeMap := map[common.Hash]utils.StorageValueMetadata{}
-			fakeStorageKey := common.HexToHash("72c72de6b203d67cb6cd54fc93300109fcc6fd6eac88e390271a3d548794d800")
-			var fakeMappingKey utils.Key = "fakeKey"
-			fakeMetadata := utils.StorageValueMetadata{
-				Name: "fakeName",
-				Keys: map[utils.Key]string{fakeMappingKey: "fakeValue"},
-				Type: utils.Uint48,
-			}
-			fakeMap[fakeStorageKey] = fakeMetadata
-
-			result := storage.AddHashedKeys(fakeMap)
-
-			Expect(len(result)).To(Equal(2))
-			expectedHashedStorageKey := common.HexToHash("2165edb4e1c37b99b60fa510d84f939dd35d5cd1d1c8f299d6456ea09df65a76")
-			Expect(fakeMap[fakeStorageKey]).To(Equal(fakeMetadata))
-			Expect(fakeMap[expectedHashedStorageKey]).To(Equal(fakeMetadata))
-		})
-	})
-
-	Describe("GetMapping", func() {
+var _ = Describe("Storage keys loader utils", func() {
+	Describe("GetStorageKeyForMapping", func() {
 		It("returns the storage key for a mapping when passed the mapping's index on the contract and the desired value's key", func() {
 			// ex. solidity:
 			//    	mapping (bytes32 => uint) public amounts
 			// to access amounts, pass in the index of the mapping on the contract + the bytes32 key for the uint val being looked up
-			indexOfMappingOnContract := storage.IndexZero
+			indexOfMappingOnContract := utils.IndexZero
 			keyForDesiredValueInMapping := "1234567890abcdef"
 
-			storageKey := storage.GetMapping(indexOfMappingOnContract, keyForDesiredValueInMapping)
+			storageKey := utils.GetStorageKeyForMapping(indexOfMappingOnContract, keyForDesiredValueInMapping)
 
 			expectedStorageKey := common.HexToHash("0xee0c1b59a3856bafbfb8730e7694c4badc271eb5f01ce4a8d7a53d8a6499676f")
 			Expect(storageKey).To(Equal(expectedStorageKey))
 		})
 
 		It("returns same result if value includes hex prefix", func() {
-			indexOfMappingOnContract := storage.IndexZero
+			indexOfMappingOnContract := utils.IndexZero
 			keyForDesiredValueInMapping := "0x1234567890abcdef"
 
-			storageKey := storage.GetMapping(indexOfMappingOnContract, keyForDesiredValueInMapping)
+			storageKey := utils.GetStorageKeyForMapping(indexOfMappingOnContract, keyForDesiredValueInMapping)
 
 			expectedStorageKey := common.HexToHash("0xee0c1b59a3856bafbfb8730e7694c4badc271eb5f01ce4a8d7a53d8a6499676f")
 			Expect(storageKey).To(Equal(expectedStorageKey))
 		})
 	})
 
-	Describe("GetNestedMapping", func() {
+	Describe("GetStorageKeyForNestedMapping", func() {
 		It("returns the storage key for a nested mapping when passed the mapping's index on the contract and the desired value's keys", func() {
 			// ex. solidity:
 			//    	mapping (bytes32 => uint) public amounts
 			//    	mapping (address => mapping (uint => bytes32)) public addressNames
 			// to access addressNames, pass in the index of the mapping on the contract + the address and uint keys for the bytes32 val being looked up
-			indexOfMappingOnContract := storage.IndexOne
+			indexOfMappingOnContract := utils.IndexOne
 			keyForOuterMapping := "1234567890abcdef"
 			keyForInnerMapping := "123"
 
-			storageKey := storage.GetNestedMapping(indexOfMappingOnContract, keyForOuterMapping, keyForInnerMapping)
+			storageKey := utils.GetStorageKeyForNestedMapping(indexOfMappingOnContract, keyForOuterMapping, keyForInnerMapping)
 
 			expectedStorageKey := common.HexToHash("0x82113529f6cd61061d1a6f0de53f2bdd067a1addd3d2b46be50a99abfcdb1661")
 			Expect(storageKey).To(Equal(expectedStorageKey))
 		})
 	})
 
-	Describe("GetIncrementedKey", func() {
+	Describe("GetIncrementedStorageKey", func() {
 		It("returns the storage key for later values sharing an index on the contract with other earlier values", func() {
 			// ex. solidity:
 			//    	mapping (bytes32 => uint) public amounts
@@ -84,11 +78,11 @@ var _ = Describe("Mappings", func() {
 			//    	mapping (bytes32 => Data) public itemData;
 			// to access quality from itemData, pass in the storage key for the zero-indexed value (quantity) + the number of increments required.
 			// (For "quality", we must increment the storage key for the corresponding "quantity" by 1).
-			indexOfMappingOnContract := storage.IndexTwo
+			indexOfMappingOnContract := utils.IndexTwo
 			keyForDesiredValueInMapping := "1234567890abcdef"
-			storageKeyForFirstPropertyOnStruct := storage.GetMapping(indexOfMappingOnContract, keyForDesiredValueInMapping)
+			storageKeyForFirstPropertyOnStruct := utils.GetStorageKeyForMapping(indexOfMappingOnContract, keyForDesiredValueInMapping)
 
-			storageKey := storage.GetIncrementedKey(storageKeyForFirstPropertyOnStruct, 1)
+			storageKey := utils.GetIncrementedStorageKey(storageKeyForFirstPropertyOnStruct, 1)
 
 			expectedStorageKey := common.HexToHash("0x69b38749f0a8ed5d505c8474f7fb62c7828aad8a7627f1c67e07af1d2368cad4")
 			Expect(storageKey).To(Equal(expectedStorageKey))

libraries/shared/storage/utils/keys_lookup.go

@@ -0,0 +1,37 @@
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package utils
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+func AddHashedKeys(currentMappings map[common.Hash]StorageValueMetadata) map[common.Hash]StorageValueMetadata {
+	copyOfCurrentMappings := make(map[common.Hash]StorageValueMetadata)
+	for k, v := range currentMappings {
+		copyOfCurrentMappings[k] = v
+	}
+	for k, v := range copyOfCurrentMappings {
+		currentMappings[hashKey(k)] = v
+	}
+	return currentMappings
+}
+
+func hashKey(key common.Hash) common.Hash {
+	return crypto.Keccak256Hash(key.Bytes())
+}

libraries/shared/storage/utils/keys_lookup_test.go

@@ -0,0 +1,47 @@
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package utils_test
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/vulcanize/vulcanizedb/libraries/shared/storage/utils"
+)
+
+var _ = Describe("Storage keys lookup utils", func() {
+	Describe("AddHashedKeys", func() {
+		It("returns a copy of the map with an additional slot for the hashed version of every key", func() {
+			fakeMap := map[common.Hash]utils.StorageValueMetadata{}
+			fakeStorageKey := common.HexToHash("72c72de6b203d67cb6cd54fc93300109fcc6fd6eac88e390271a3d548794d800")
+			var fakeMappingKey utils.Key = "fakeKey"
+			fakeMetadata := utils.StorageValueMetadata{
+				Name: "fakeName",
+				Keys: map[utils.Key]string{fakeMappingKey: "fakeValue"},
+				Type: utils.Uint48,
+			}
+			fakeMap[fakeStorageKey] = fakeMetadata
+
+			result := utils.AddHashedKeys(fakeMap)
+
+			Expect(len(result)).To(Equal(2))
+			expectedHashedStorageKey := common.HexToHash("2165edb4e1c37b99b60fa510d84f939dd35d5cd1d1c8f299d6456ea09df65a76")
+			Expect(fakeMap[fakeStorageKey]).To(Equal(fakeMetadata))
+			Expect(fakeMap[expectedHashedStorageKey]).To(Equal(fakeMetadata))
+		})
+	})
+})