Handle events

- Adds interfaces for developers to build handlers that update data in
response to log events
- Resolves #29

pkg/datastore/repository.go

@@ -0,0 +1,55 @@
+package datastore
+
+import (
+	"fmt"
+
+	"github.com/vulcanize/vulcanizedb/pkg/core"
+	"github.com/vulcanize/vulcanizedb/pkg/filters"
+)
+
+var ErrBlockDoesNotExist = func(blockNumber int64) error {
+	return fmt.Errorf("Block number %d does not exist", blockNumber)
+}
+
+type BlockRepository interface {
+	CreateOrUpdateBlock(block core.Block) error
+	GetBlock(blockNumber int64) (core.Block, error)
+	MissingBlockNumbers(startingBlockNumber int64, endingBlockNumber int64) []int64
+	SetBlocksStatus(chainHead int64)
+}
+
+var ErrContractDoesNotExist = func(contractHash string) error {
+	return fmt.Errorf("Contract %v does not exist", contractHash)
+}
+
+type ContractRepository interface {
+	CreateContract(contract core.Contract) error
+	GetContract(contractHash string) (core.Contract, error)
+	ContractExists(contractHash string) bool
+}
+
+var ErrFilterDoesNotExist = func(name string) error {
+	return fmt.Errorf("filter %s does not exist", name)
+}
+
+type FilterRepository interface {
+	CreateFilter(filter filters.LogFilter) error
+	GetFilter(name string) (filters.LogFilter, error)
+}
+
+type LogRepository interface {
+	CreateLogs(logs []core.Log) error
+	GetLogs(address string, blockNumber int64) []core.Log
+}
+
+var ErrReceiptDoesNotExist = func(txHash string) error {
+	return fmt.Errorf("Receipt for tx: %v does not exist", txHash)
+}
+
+type ReceiptRepository interface {
+	GetReceipt(txHash string) (core.Receipt, error)
+}
+
+type WatchedEventRepository interface {
+	GetWatchedEvents(name string) ([]*core.WatchedEvent, error)
+}