ipld-eth-server/pkg/contract_watcher/shared/repository/method_repository.go
2019-03-21 18:33:56 -05:00

228 lines
7.2 KiB
Go

// 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 repository
import (
"errors"
"fmt"
"strings"
"github.com/hashicorp/golang-lru"
"github.com/vulcanize/vulcanizedb/pkg/contract_watcher/shared/types"
"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
)
const methodCacheSize = 1000
type MethodRepository interface {
PersistResults(results []types.Result, methodInfo types.Method, contractAddr, contractName string) error
CreateMethodTable(contractAddr string, method types.Method) (bool, error)
CreateContractSchema(contractAddr string) (bool, error)
CheckSchemaCache(key string) (interface{}, bool)
CheckTableCache(key string) (interface{}, bool)
}
type methodRepository struct {
*postgres.DB
mode types.Mode
schemas *lru.Cache // Cache names of recently used schemas to minimize db connections
tables *lru.Cache // Cache names of recently used tables to minimize db connections
}
func NewMethodRepository(db *postgres.DB, mode types.Mode) *methodRepository {
ccs, _ := lru.New(contractCacheSize)
mcs, _ := lru.New(methodCacheSize)
return &methodRepository{
DB: db,
mode: mode,
schemas: ccs,
tables: mcs,
}
}
// Creates a schema for the contract if needed
// Creates table for the contract method if needed
// Persists method polling data into this custom table
func (r *methodRepository) PersistResults(results []types.Result, methodInfo types.Method, contractAddr, contractName string) error {
if len(results) == 0 {
return errors.New("method repository error: passed empty results slice")
}
_, err := r.CreateContractSchema(contractAddr)
if err != nil {
return err
}
_, err = r.CreateMethodTable(contractAddr, methodInfo)
if err != nil {
return err
}
return r.persistResults(results, methodInfo, contractAddr, contractName)
}
// Creates a custom postgres command to persist logs for the given event
func (r *methodRepository) persistResults(results []types.Result, methodInfo types.Method, contractAddr, contractName string) error {
tx, err := r.DB.Begin()
if err != nil {
return err
}
for _, result := range results {
// Begin postgres string
pgStr := fmt.Sprintf("INSERT INTO %s_%s.%s_method ", r.mode.String(), strings.ToLower(contractAddr), strings.ToLower(result.Name))
pgStr = pgStr + "(token_name, block"
ml := len(result.Args)
// Preallocate slice of needed capacity and proceed to pack variables into it in same order they appear in string
data := make([]interface{}, 0, 3+ml)
data = append(data,
contractName,
result.Block)
// Iterate over method args and return value, adding names
// to the string and pushing values to the slice
for i, arg := range result.Args {
pgStr = pgStr + fmt.Sprintf(", %s_", strings.ToLower(arg.Name)) // Add underscore after to avoid any collisions with reserved pg words
data = append(data, result.Inputs[i])
}
pgStr = pgStr + ", returned) VALUES ($1, $2"
data = append(data, result.Output)
// For each input entry we created we add its postgres command variable to the string
for i := 0; i <= ml; i++ {
pgStr = pgStr + fmt.Sprintf(", $%d", i+3)
}
pgStr = pgStr + ")"
// Add this query to the transaction
_, err = tx.Exec(pgStr, data...)
if err != nil {
tx.Rollback()
return err
}
}
return tx.Commit()
}
// Checks for event table and creates it if it does not already exist
func (r *methodRepository) CreateMethodTable(contractAddr string, method types.Method) (bool, error) {
tableID := fmt.Sprintf("%s_%s.%s_method", r.mode.String(), strings.ToLower(contractAddr), strings.ToLower(method.Name))
// Check cache before querying pq to see if table exists
_, ok := r.tables.Get(tableID)
if ok {
return false, nil
}
tableExists, err := r.checkForTable(contractAddr, method.Name)
if err != nil {
return false, err
}
if !tableExists {
err = r.newMethodTable(tableID, method)
if err != nil {
return false, err
}
}
// Add schema name to cache
r.tables.Add(tableID, true)
return !tableExists, nil
}
// Creates a table for the given contract and event
func (r *methodRepository) newMethodTable(tableID string, method types.Method) error {
// Begin pg string
pgStr := fmt.Sprintf("CREATE TABLE IF NOT EXISTS %s ", tableID)
pgStr = pgStr + "(id SERIAL, token_name CHARACTER VARYING(66) NOT NULL, block INTEGER NOT NULL,"
// Iterate over method inputs and outputs, using their name and pgType to grow the string
for _, arg := range method.Args {
pgStr = pgStr + fmt.Sprintf(" %s_ %s NOT NULL,", strings.ToLower(arg.Name), arg.PgType)
}
pgStr = pgStr + fmt.Sprintf(" returned %s NOT NULL)", method.Return[0].PgType)
_, err := r.DB.Exec(pgStr)
return err
}
// Checks if a table already exists for the given contract and event
func (r *methodRepository) checkForTable(contractAddr string, methodName string) (bool, error) {
pgStr := fmt.Sprintf("SELECT EXISTS (SELECT 1 FROM information_schema.tables WHERE table_schema = '%s_%s' AND table_name = '%s_method')", r.mode.String(), strings.ToLower(contractAddr), strings.ToLower(methodName))
var exists bool
err := r.DB.Get(&exists, pgStr)
return exists, err
}
// Checks for contract schema and creates it if it does not already exist
func (r *methodRepository) CreateContractSchema(contractAddr string) (bool, error) {
if contractAddr == "" {
return false, errors.New("error: no contract address specified")
}
// Check cache before querying pq to see if schema exists
_, ok := r.schemas.Get(contractAddr)
if ok {
return false, nil
}
schemaExists, err := r.checkForSchema(contractAddr)
if err != nil {
return false, err
}
if !schemaExists {
err = r.newContractSchema(contractAddr)
if err != nil {
return false, err
}
}
// Add schema name to cache
r.schemas.Add(contractAddr, true)
return !schemaExists, nil
}
// Creates a schema for the given contract
func (r *methodRepository) newContractSchema(contractAddr string) error {
_, err := r.DB.Exec("CREATE SCHEMA IF NOT EXISTS " + r.mode.String() + "_" + strings.ToLower(contractAddr))
return err
}
// Checks if a schema already exists for the given contract
func (r *methodRepository) checkForSchema(contractAddr string) (bool, error) {
pgStr := fmt.Sprintf("SELECT EXISTS (SELECT schema_name FROM information_schema.schemata WHERE schema_name = '%s_%s')", r.mode.String(), strings.ToLower(contractAddr))
var exists bool
err := r.DB.Get(&exists, pgStr)
return exists, err
}
func (r *methodRepository) CheckSchemaCache(key string) (interface{}, bool) {
return r.schemas.Get(key)
}
func (r *methodRepository) CheckTableCache(key string) (interface{}, bool) {
return r.tables.Get(key)
}