results.go

package badger

import (
	"errors"
	"fmt"

	"github.com/dgraph-io/badger/v2"

	"github.com/onflow/flow-go/model/flow"
	"github.com/onflow/flow-go/module"
	"github.com/onflow/flow-go/module/metrics"
	"github.com/onflow/flow-go/storage"
	"github.com/onflow/flow-go/storage/badger/operation"
	"github.com/onflow/flow-go/storage/badger/transaction"
)

// ExecutionResults implements persistent storage for execution results.
type ExecutionResults struct {
	db    *badger.DB
	cache *Cache
}

func NewExecutionResults(collector module.CacheMetrics, db *badger.DB) *ExecutionResults {

	store := func(key interface{}, val interface{}) func(*transaction.Tx) error {
		result := val.(*flow.ExecutionResult)
		return transaction.WithTx(operation.SkipDuplicates(operation.InsertExecutionResult(result)))
	}

	retrieve := func(key interface{}) func(tx *badger.Txn) (interface{}, error) {
		resultID := key.(flow.Identifier)
		var result flow.ExecutionResult
		return func(tx *badger.Txn) (interface{}, error) {
			err := operation.RetrieveExecutionResult(resultID, &result)(tx)
			return &result, err
		}
	}

	res := &ExecutionResults{
		db: db,
		cache: newCache(collector, metrics.ResourceResult,
			withLimit(flow.DefaultTransactionExpiry+100),
			withStore(store),
			withRetrieve(retrieve)),
	}

	return res
}

func (r *ExecutionResults) store(result *flow.ExecutionResult) func(*transaction.Tx) error {
	return r.cache.PutTx(result.ID(), result)
}

func (r *ExecutionResults) byID(resultID flow.Identifier) func(*badger.Txn) (*flow.ExecutionResult, error) {
	return func(tx *badger.Txn) (*flow.ExecutionResult, error) {
		val, err := r.cache.Get(resultID)(tx)
		if err != nil {
			return nil, err
		}
		return val.(*flow.ExecutionResult), nil
	}
}

func (r *ExecutionResults) byBlockID(blockID flow.Identifier) func(*badger.Txn) (*flow.ExecutionResult, error) {
	return func(tx *badger.Txn) (*flow.ExecutionResult, error) {
		var resultID flow.Identifier
		err := operation.LookupExecutionResult(blockID, &resultID)(tx)
		if err != nil {
			return nil, fmt.Errorf("could not lookup execution result ID: %w", err)
		}
		return r.byID(resultID)(tx)
	}
}

func (r *ExecutionResults) index(blockID, resultID flow.Identifier) func(*transaction.Tx) error {
	return func(tx *transaction.Tx) error {
		err := transaction.WithTx(operation.IndexExecutionResult(blockID, resultID))(tx)
		if err == nil {
			return nil
		}

		if !errors.Is(err, storage.ErrAlreadyExists) {
			return err
		}

		// when trying to index a result for a block, and there is already a result indexed for this block,
		// double check if the indexed result is the same
		var storedResultID flow.Identifier
		err = transaction.WithTx(operation.LookupExecutionResult(blockID, &storedResultID))(tx)
		if err != nil {
			return fmt.Errorf("there is a result stored already, but cannot retrieve it: %w", err)
		}

		if storedResultID != resultID {
			return fmt.Errorf("storing result that is different from the already stored one for block: %v, storing result: %v, stored result: %v. %w",
				blockID, resultID, storedResultID, storage.ErrDataMismatch)
		}

		return nil
	}
}

func (r *ExecutionResults) Store(result *flow.ExecutionResult) error {
	return operation.RetryOnConflictTx(r.db, transaction.Update, r.store(result))
}

func (r *ExecutionResults) BatchStore(result *flow.ExecutionResult, batch storage.BatchStorage) error {
	writeBatch := batch.GetWriter()
	return operation.BatchInsertExecutionResult(result)(writeBatch)
}

func (r *ExecutionResults) BatchIndex(blockID flow.Identifier, resultID flow.Identifier, batch storage.BatchStorage) error {
	writeBatch := batch.GetWriter()
	return operation.BatchIndexExecutionResult(blockID, resultID)(writeBatch)
}

func (r *ExecutionResults) ByID(resultID flow.Identifier) (*flow.ExecutionResult, error) {
	tx := r.db.NewTransaction(false)
	defer tx.Discard()
	return r.byID(resultID)(tx)
}

func (r *ExecutionResults) Index(blockID flow.Identifier, resultID flow.Identifier) error {
	err := operation.RetryOnConflictTx(r.db, transaction.Update, r.index(blockID, resultID))
	if err != nil {
		return fmt.Errorf("could not index execution result: %w", err)
	}
	return nil
}

func (r *ExecutionResults) ByBlockID(blockID flow.Identifier) (*flow.ExecutionResult, error) {
	tx := r.db.NewTransaction(false)
	defer tx.Discard()
	return r.byBlockID(blockID)(tx)
}