Golang TxnExecOptions.AutoRetry方法代碼示例

// execRequest executes the request using the provided planner.
// It parses the sql into statements, iterates through the statements, creates
// KV transactions and automatically retries them when possible, executes the
// (synchronous attempt of) schema changes.
// It will accumulate a result in Response for each statement.
// It will resume a SQL transaction, if one was previously open for this client.
//
// execRequest handles the mismatch between the SQL interface that the Executor
// provides, based on statements being streamed from the client in the context
// of a session, and the KV client.Txn interface, based on (possibly-retriable)
// callbacks passed to be executed in the context of a transaction. Actual
// execution of statements in the context of a KV txn is delegated to
// runTxnAttempt().
//
// Args:
//  txnState: State about about ongoing transaction (if any). The state will be
//   updated.
func (e *Executor) execRequest(session *Session, sql string) StatementResults {
	var res StatementResults
	txnState := &session.TxnState
	planMaker := &session.planner
	stmts, err := planMaker.parser.Parse(sql, parser.Syntax(session.Syntax))
	if err != nil {
		pErr := roachpb.NewError(err)
		// A parse error occurred: we can't determine if there were multiple
		// statements or only one, so just pretend there was one.
		if txnState.txn != nil {
			// Rollback the txn.
			txnState.txn.CleanupOnError(pErr)
			txnState.resetStateAndTxn(Aborted)
		}
		res.ResultList = append(res.ResultList, Result{PErr: pErr})
		return res
	}
	if len(stmts) == 0 {
		res.Empty = true
		return res
	}

	// If the planMaker wants config updates to be blocked, then block them.
	defer planMaker.blockConfigUpdatesMaybe(e)()

	for len(stmts) > 0 {
		// Each iteration consumes a transaction's worth of statements.

		inTxn := txnState.State != NoTxn
		var execOpt client.TxnExecOptions
		// Figure out the statements out of which we're going to try to consume
		// this iteration. If we need to create an implicit txn, only one statement
		// can be consumed.
		stmtsToExec := stmts
		// We can AutoRetry the next batch of statements if we're in a clean state
		// (i.e. the next statements we're going to see are the first statements in
		// a transaction).
		if !inTxn {
			// Detect implicit transactions.
			if _, isBegin := stmts[0].(*parser.BeginTransaction); !isBegin {
				execOpt.AutoCommit = true
				stmtsToExec = stmtsToExec[0:1]
			}
			txnState.reset(e, session)
			txnState.State = Open
			txnState.autoRetry = true
			execOpt.MinInitialTimestamp = e.ctx.Clock.Now()
			if execOpt.AutoCommit {
				txnState.txn.SetDebugName(sqlImplicitTxnName, 0)
			} else {
				txnState.txn.SetDebugName(sqlTxnName, 0)
			}
		} else {
			txnState.autoRetry = false
		}
		execOpt.AutoRetry = txnState.autoRetry
		if txnState.State == NoTxn {
			panic("we failed to initialize a txn")
		}
		// Now actually run some statements.
		var remainingStmts parser.StatementList
		var results []Result
		origState := txnState.State

		txnClosure := func(txn *client.Txn, opt *client.TxnExecOptions) *roachpb.Error {
			if txnState.State == Open && txnState.txn != txn {
				panic(fmt.Sprintf("closure wasn't called in the txn we set up for it."+
					"\ntxnState.txn:%+v\ntxn:%+v\ntxnState:%+v", txnState.txn, txn, txnState))
			}
			txnState.txn = txn
			return runTxnAttempt(e, planMaker, origState, txnState, opt, stmtsToExec,
				&results, &remainingStmts)
		}
		// This is where the magic happens - we ask db to run a KV txn and possibly retry it.
		txn := txnState.txn // this might be nil if the txn was already aborted.
		pErr := txnState.txn.Exec(execOpt, txnClosure)
		res.ResultList = append(res.ResultList, results...)
		// Now make sense of the state we got into and update txnState.
		if txnState.State == RestartWait && txnState.commitSeen {
			// A COMMIT got a retriable error. Too bad, this txn is toast. After we
			// return a result for COMMIT (with the COMMIT pgwire tag), the user can't
			// send any more commands.
			e.txnAbortCount.Inc(1)
//.........這裏部分代碼省略.........

// execRequest executes the request using the provided planner.
// It parses the sql into statements, iterates through the statements, creates
// KV transactions and automatically retries them when possible, executes the
// (synchronous attempt of) schema changes.
// It will accumulate a result in Response for each statement.
// It will resume a SQL transaction, if one was previously open for this client.
//
// execRequest handles the mismatch between the SQL interface that the Executor
// provides, based on statements being streamed from the client in the context
// of a session, and the KV client.Txn interface, based on (possibly-retriable)
// callbacks passed to be executed in the context of a transaction. Actual
// execution of statements in the context of a KV txn is delegated to
// runTxnAttempt().
//
// Args:
//  txnState: State about about ongoing transaction (if any). The state will be
//   updated.
func (e *Executor) execRequest(
	txnState *txnState, sql string, planMaker *planner) StatementResults {
	var res StatementResults
	stmts, err := planMaker.parser.Parse(sql, parser.Syntax(planMaker.session.Syntax))
	if err != nil {
		pErr := roachpb.NewError(err)
		// A parse error occurred: we can't determine if there were multiple
		// statements or only one, so just pretend there was one.
		if txnState.txn != nil {
			// Rollback the txn.
			txnState.txn.Cleanup(pErr)
			txnState.aborted = true
			txnState.txn = nil
		}
		res.ResultList = append(res.ResultList, Result{PErr: pErr})
		return res
	}
	if len(stmts) == 0 {
		res.Empty = true
		return res
	}

	if e.ctx.TestingMocker.WaitForGossipUpdate {
		// We might need to verify metadata. Lock the system config so that no
		// gossip updates sneak in under us. The point is to be able to assert
		// that the verify callback only succeeds after a gossip update.
		//
		// This lock does not change semantics. Even outside of tests, the
		// planner is initialized with a static systemConfig, so locking
		// the Executor's systemConfig cannot change the semantics of the
		// SQL operation being performed under lock.
		//
		// The case of a multi-request transaction is not handled here,
		// because those transactions outlive the verification callback.
		// TODO(andrei): consider putting this callback on the Session, not
		// on the executor, after Session is not a proto any more. Also, #4646.
		e.systemConfigCond.L.Lock()
		defer func() {
			e.systemConfigCond.L.Unlock()
		}()
	}

	for len(stmts) > 0 {
		// Each iteration consumes a transaction's worth of statements.

		inTxn := txnState.state() != noTransaction
		var execOpt client.TxnExecOptions
		// Figure out the statements out of which we're going to try to consume
		// this iteration. If we need to create an implicit txn, only one statement
		// can be consumed.
		stmtsToExec := stmts
		// We can AutoRetry the next batch of statements if we're in a clean state
		// (i.e. the next statements we're going to see are the first statements in
		// a transaction).
		if !inTxn {
			// Detect implicit transactions.
			if _, isBegin := stmts[0].(*parser.BeginTransaction); !isBegin {
				execOpt.AutoCommit = true
				stmtsToExec = stmtsToExec[0:1]
			}
			txnState.txn = e.newTxn(planMaker.session)
			execOpt.AutoRetry = true
			execOpt.MinInitialTimestamp = e.ctx.Clock.Now()
			txnState.txn.SetDebugName(fmt.Sprintf("sql implicit: %t", execOpt.AutoCommit), 0)
		}
		if txnState.state() == noTransaction {
			panic("we failed to initialize a txn")
		}
		// Now actually run some statements.
		var remainingStmts parser.StatementList
		var results []Result
		origAborted := txnState.state() == abortedTransaction

		txnClosure := func(txn *client.Txn, opt *client.TxnExecOptions) *roachpb.Error {
			return runTxnAttempt(e, planMaker, origAborted, txnState, txn, opt, stmtsToExec,
				&results, &remainingStmts)
		}
		// This is where the magic happens - we ask db to run a KV txn and possibly retry it.
		pErr := txnState.txn.Exec(execOpt, txnClosure)
		res.ResultList = append(res.ResultList, results...)
		// Now make sense of the state we got into and update txnState.
		if pErr != nil {
			// If we got an error, the txn has been aborted (or it might be already
//.........這裏部分代碼省略.........

// execRequest executes the request using the provided planner.
// It parses the sql into statements, iterates through the statements, creates
// KV transactions and automatically retries them when possible, executes the
// (synchronous attempt of) schema changes.
// It will accumulate a result in Response for each statement.
// It will resume a SQL transaction, if one was previously open for this client.
//
// execRequest handles the mismatch between the SQL interface that the Executor
// provides, based on statements being streamed from the client in the context
// of a session, and the KV client.Txn interface, based on (possibly-retriable)
// callbacks passed to be executed in the context of a transaction. Actual
// execution of statements in the context of a KV txn is delegated to
// runTxnAttempt().
//
// Args:
//  txnState: State about about ongoing transaction (if any). The state will be
//   updated.
func (e *Executor) execRequest(
	txnState *txnState, sql string, planMaker *planner) StatementResults {
	var res StatementResults
	stmts, err := planMaker.parser.Parse(sql, parser.Syntax(planMaker.session.Syntax))
	if err != nil {
		pErr := roachpb.NewError(err)
		// A parse error occurred: we can't determine if there were multiple
		// statements or only one, so just pretend there was one.
		if txnState.txn != nil {
			// Rollback the txn.
			txnState.txn.CleanupOnError(pErr)
			txnState.resetStateAndTxn(Aborted)
		}
		res.ResultList = append(res.ResultList, Result{PErr: pErr})
		return res
	}
	if len(stmts) == 0 {
		res.Empty = true
		return res
	}

	if e.ctx.TestingKnobs.WaitForGossipUpdate {
		// We might need to verify metadata. Lock the system config so that no
		// gossip updates sneak in under us. The point is to be able to assert
		// that the verify callback only succeeds after a gossip update.
		//
		// This lock does not change semantics. Even outside of tests, the
		// planner is initialized with a static systemConfig, so locking
		// the Executor's systemConfig cannot change the semantics of the
		// SQL operation being performed under lock.
		//
		// The case of a multi-request transaction is not handled here,
		// because those transactions outlive the verification callback.
		// TODO(andrei): consider putting this callback on the Session, not
		// on the executor, after Session is not a proto any more. Also, #4646.
		e.systemConfigCond.L.Lock()
		defer func() {
			e.systemConfigCond.L.Unlock()
		}()
	}

	for len(stmts) > 0 {
		// Each iteration consumes a transaction's worth of statements.

		inTxn := txnState.State != NoTxn
		var execOpt client.TxnExecOptions
		// Figure out the statements out of which we're going to try to consume
		// this iteration. If we need to create an implicit txn, only one statement
		// can be consumed.
		stmtsToExec := stmts
		// We can AutoRetry the next batch of statements if we're in a clean state
		// (i.e. the next statements we're going to see are the first statements in
		// a transaction).
		if !inTxn {
			// Detect implicit transactions.
			if _, isBegin := stmts[0].(*parser.BeginTransaction); !isBegin {
				execOpt.AutoCommit = true
				stmtsToExec = stmtsToExec[0:1]
			}
			txnState.reset(e, planMaker.session)
			txnState.State = Open
			txnState.autoRetry = true
			execOpt.MinInitialTimestamp = e.ctx.Clock.Now()
			if execOpt.AutoCommit {
				txnState.txn.SetDebugName(sqlImplicitTxnName, 0)
			} else {
				txnState.txn.SetDebugName(sqlTxnName, 0)
			}
		} else {
			txnState.autoRetry = false
		}
		execOpt.AutoRetry = txnState.autoRetry
		if txnState.State == NoTxn {
			panic("we failed to initialize a txn")
		}
		// Now actually run some statements.
		var remainingStmts parser.StatementList
		var results []Result
		origState := txnState.State

		txnClosure := func(txn *client.Txn, opt *client.TxnExecOptions) *roachpb.Error {
			if txnState.State == Open && txnState.txn != txn {
				panic(fmt.Sprintf("closure wasn't called in the txn we set up for it."+
//.........這裏部分代碼省略.........