surrealpatch/db/executor.go
Tobie Morgan Hitchcock 37e015b482 Only return an executor to the pool once
The executor was being returned to the pool twice, which was resulting in nil interface{} errors when creating new executors concurrently, as the transaction would not be set properly.
2017-11-24 01:45:56 +00:00

473 lines
9.7 KiB
Go

// Copyright © 2016 Abcum Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package db
import (
"fmt"
"time"
"context"
"runtime/debug"
"cloud.google.com/go/trace"
"github.com/abcum/surreal/kvs"
"github.com/abcum/surreal/log"
"github.com/abcum/surreal/mem"
"github.com/abcum/surreal/sql"
)
type executor struct {
dbo *mem.Cache
send chan *Response
}
func newExecutor() (e *executor) {
e = executorPool.Get().(*executor)
e.dbo = mem.New()
e.send = make(chan *Response)
return
}
func (e *executor) execute(ctx context.Context, ast *sql.Query) {
var err error
var now time.Time
var rsp *Response
var buf []*Response
var res []interface{}
// Ensure that the executor is added back into
// the executor pool when the executor has
// finished processing the request.
defer executorPool.Put(e)
// Ensure that the query responses channel is
// closed when the full query has been processed
// and dealt with.
defer close(e.send)
// If we are making use of a global transaction
// which is not committed at the end of the
// query set, then cancel the transaction.
defer func() {
if e.dbo.TX != nil {
e.dbo.Cancel()
clear()
}
}()
// If we have panicked during query execution
// then ensure that we recover from the error
// and print the error to the log.
defer func() {
if err := recover(); err != nil {
log.WithPrefix("db").WithFields(map[string]interface{}{
"id": ctx.Value(ctxKeyId), "stack": string(debug.Stack()),
}).Errorln(err)
}
}()
// Loop over the defined query statements and
// process them, while listening for the quit
// channel to see if the client has gone away.
for _, stm := range ast.Statements {
select {
case <-ctx.Done():
return
default:
trc := trace.FromContext(ctx).NewChild(fmt.Sprint(stm))
ctx := trace.NewContext(ctx, trc)
// When in debugging mode, log every sql
// query, along with the query execution
// speed, so we can analyse slow queries.
log := log.WithPrefix("sql").WithFields(map[string]interface{}{
"id": ctx.Value(ctxKeyId),
"kind": ctx.Value(ctxKeyKind),
"auth": ctx.Value(ctxKeyAuth),
})
if stm, ok := stm.(sql.AuthableStatement); ok {
ns, db := stm.Auth()
log = log.WithField("ns", ns).WithField("db", db)
}
log.Debugln(stm)
// If we are not inside a global transaction
// then reset the error to nil so that the
// next statement is not ignored.
if e.dbo.TX == nil {
err, now = nil, time.Now()
}
// Check to see if the current statement is
// a TRANSACTION statement, and if it is
// then deal with it and move on to the next.
switch stm.(type) {
case *sql.BeginStatement:
err = e.begin(true)
trc.Finish()
continue
case *sql.CancelStatement:
err, buf = e.cancel(buf, err, e.send)
trc.Finish()
clear()
continue
case *sql.CommitStatement:
err, buf = e.commit(buf, err, e.send)
trc.Finish()
flush()
continue
}
// If an error has occured and we are inside
// a global transaction, then ignore all
// subsequent statements in the transaction.
if err == nil {
res, err = e.operate(ctx, stm)
} else {
res, err = []interface{}{}, queryNotExecuted
}
rsp = &Response{
Time: time.Since(now).String(),
Status: status(err),
Detail: detail(err),
Result: append([]interface{}{}, res...),
}
// If we are not inside a global transaction
// then we can output the statement response
// immediately to the channel.
if e.dbo.TX == nil {
e.send <- rsp
}
// If we are inside a global transaction we
// must buffer the responses for output at
// the end of the transaction.
if e.dbo.TX != nil {
switch stm.(type) {
case *sql.ReturnStatement:
buf = groupd(buf, rsp)
default:
buf = append(buf, rsp)
}
}
trc.Finish()
}
}
}
func (e *executor) operate(ctx context.Context, stm sql.Statement) (res []interface{}, err error) {
var loc bool
var trw bool
var canc context.CancelFunc
// If the statement is a UseStatement then
// there is no need to create a transaction
// as the query does not do anything.
if _, ok := stm.(*sql.UseStatement); ok {
return
}
// If we are not inside a global transaction
// then grab a new transaction, ensuring that
// it is closed at the end.
if e.dbo.TX == nil {
loc = true
switch stm := stm.(type) {
case sql.WriteableStatement:
trw = stm.Writeable()
default:
trw = false
}
err = e.begin(trw)
if err != nil {
return
}
defer e.dbo.Cancel()
}
// Mark the beginning of this statement so we
// can monitor the running time, and ensure
// it runs no longer than specified.
if stm, ok := stm.(sql.KillableStatement); ok {
if stm.Duration() > 0 {
ctx, canc = context.WithTimeout(ctx, stm.Duration())
defer func() {
if tim := ctx.Err(); err == nil && tim != nil {
res, err = nil, &TimerError{timer: stm.Duration()}
}
}()
defer canc()
}
}
// Execute the defined statement, receiving the
// result set, and any errors which occured
// while processing the query.
switch stm := stm.(type) {
case *sql.IfStatement:
res, err = e.executeIf(ctx, stm)
case *sql.InfoStatement:
res, err = e.executeInfo(ctx, stm)
case *sql.LetStatement:
res, err = e.executeLet(ctx, stm)
case *sql.ReturnStatement:
res, err = e.executeReturn(ctx, stm)
case *sql.LiveStatement:
res, err = e.executeLive(ctx, stm)
case *sql.KillStatement:
res, err = e.executeKill(ctx, stm)
case *sql.SelectStatement:
res, err = e.executeSelect(ctx, stm)
case *sql.CreateStatement:
res, err = e.executeCreate(ctx, stm)
case *sql.UpdateStatement:
res, err = e.executeUpdate(ctx, stm)
case *sql.DeleteStatement:
res, err = e.executeDelete(ctx, stm)
case *sql.RelateStatement:
res, err = e.executeRelate(ctx, stm)
case *sql.InsertStatement:
res, err = e.executeInsert(ctx, stm)
case *sql.UpsertStatement:
res, err = e.executeUpsert(ctx, stm)
case *sql.DefineNamespaceStatement:
res, err = e.executeDefineNamespace(ctx, stm)
case *sql.RemoveNamespaceStatement:
res, err = e.executeRemoveNamespace(ctx, stm)
case *sql.DefineDatabaseStatement:
res, err = e.executeDefineDatabase(ctx, stm)
case *sql.RemoveDatabaseStatement:
res, err = e.executeRemoveDatabase(ctx, stm)
case *sql.DefineLoginStatement:
res, err = e.executeDefineLogin(ctx, stm)
case *sql.RemoveLoginStatement:
res, err = e.executeRemoveLogin(ctx, stm)
case *sql.DefineTokenStatement:
res, err = e.executeDefineToken(ctx, stm)
case *sql.RemoveTokenStatement:
res, err = e.executeRemoveToken(ctx, stm)
case *sql.DefineScopeStatement:
res, err = e.executeDefineScope(ctx, stm)
case *sql.RemoveScopeStatement:
res, err = e.executeRemoveScope(ctx, stm)
case *sql.DefineTableStatement:
res, err = e.executeDefineTable(ctx, stm)
case *sql.RemoveTableStatement:
res, err = e.executeRemoveTable(ctx, stm)
case *sql.DefineEventStatement:
res, err = e.executeDefineEvent(ctx, stm)
case *sql.RemoveEventStatement:
res, err = e.executeRemoveEvent(ctx, stm)
case *sql.DefineFieldStatement:
res, err = e.executeDefineField(ctx, stm)
case *sql.RemoveFieldStatement:
res, err = e.executeRemoveField(ctx, stm)
case *sql.DefineIndexStatement:
res, err = e.executeDefineIndex(ctx, stm)
case *sql.RemoveIndexStatement:
res, err = e.executeRemoveIndex(ctx, stm)
}
// If this is a local transaction for only the
// current statement, then commit or cancel
// depending on the result error.
select {
case <-ctx.Done():
e.dbo.Cancel()
e.dbo.Reset()
clear()
default:
if loc && e.dbo.Closed() == false {
if !trw || err != nil {
e.dbo.Cancel()
e.dbo.Reset()
clear()
} else {
e.dbo.Commit()
e.dbo.Reset()
flush()
}
}
}
return
}
func (e *executor) begin(rw bool) (err error) {
if e.dbo.TX == nil {
e.dbo.TX, err = db.Begin(rw)
}
return
}
func (e *executor) cancel(buf []*Response, err error, chn chan<- *Response) (error, []*Response) {
defer func() {
e.dbo.Reset()
}()
if e.dbo.TX == nil {
return nil, buf
}
e.dbo.Cancel()
for _, v := range buf {
v.Status = "ERR"
chn <- v
}
for i := len(buf) - 1; i >= 0; i-- {
buf[len(buf)-1] = nil
buf = buf[:len(buf)-1]
}
return nil, buf
}
func (e *executor) commit(buf []*Response, err error, chn chan<- *Response) (error, []*Response) {
defer func() {
e.dbo.Reset()
}()
if e.dbo.TX == nil {
return nil, buf
}
if err != nil {
e.dbo.Cancel()
} else {
e.dbo.Commit()
}
for _, v := range buf {
if err != nil {
v.Status = "ERR"
}
chn <- v
}
for i := len(buf) - 1; i >= 0; i-- {
buf[len(buf)-1] = nil
buf = buf[:len(buf)-1]
}
return nil, buf
}
func status(e error) (s string) {
switch e.(type) {
default:
return "OK"
case *kvs.DBError:
return "ERR_DB"
case *kvs.KVError:
return "ERR_KV"
case *PermsError:
return "ERR_PE"
case *ExistError:
return "ERR_KV"
case *FieldError:
return "ERR_FD"
case *IndexError:
return "ERR_IX"
case error:
return "ERR"
}
}
func detail(e error) (s string) {
switch err := e.(type) {
default:
return
case error:
return err.Error()
}
}
func groupd(buf []*Response, rsp *Response) []*Response {
for i := len(buf) - 1; i >= 0; i-- {
buf[len(buf)-1] = nil
buf = buf[:len(buf)-1]
}
return append(buf, rsp)
}