Wrap the code indexer (#9476)

* Wrap the code indexer

In order to prevent a data race in the code indexer it must be wrapped
with a holder otherwise it is possible to Search/Index on an
incompletely initialised indexer, and search will fail with a nil
pointer until the repository indexer is initialised.

Further a completely initialised repository indexer should not be closed
until Termination otherwise actions in Hammer/Shutdown phases could
block or be lost.

Finally, there is a complex dance of shutdown etiquette should the index
initialisation fail. This PR restores that.

* Always return err if closed whilst waiting

Co-authored-by: techknowlogick <matti@mdranta.net>
This commit is contained in:
zeripath 2019-12-24 07:26:34 +00:00 committed by Lunny Xiao
parent 34688e1db3
commit 30181d459d
3 changed files with 132 additions and 13 deletions

View file

@ -5,6 +5,8 @@
package code
import (
"context"
"os"
"time"
"code.gitea.io/gitea/modules/graceful"
@ -12,10 +14,6 @@ import (
"code.gitea.io/gitea/modules/setting"
)
var (
indexer Indexer
)
// SearchResult result of performing a search in a repo
type SearchResult struct {
RepoID int64
@ -36,28 +34,45 @@ type Indexer interface {
// Init initialize the repo indexer
func Init() {
if !setting.Indexer.RepoIndexerEnabled {
indexer.Close()
return
}
ctx, cancel := context.WithCancel(context.Background())
graceful.GetManager().RunAtTerminate(ctx, func() {
log.Debug("Closing repository indexer")
indexer.Close()
log.Info("PID: %d Repository Indexer closed", os.Getpid())
})
waitChannel := make(chan time.Duration)
go func() {
start := time.Now()
log.Info("Initializing Repository Indexer")
var created bool
var err error
indexer, created, err = NewBleveIndexer(setting.Indexer.RepoPath)
log.Info("PID: %d Initializing Repository Indexer at: %s", os.Getpid(), setting.Indexer.RepoPath)
bleveIndexer, created, err := NewBleveIndexer(setting.Indexer.RepoPath)
if err != nil {
if bleveIndexer != nil {
bleveIndexer.Close()
}
cancel()
indexer.Close()
log.Fatal("indexer.Init: %v", err)
close(waitChannel)
log.Fatal("PID: %d Unable to initialize the Repository Indexer at path: %s Error: %v", os.Getpid(), setting.Indexer.RepoPath, err)
}
indexer.set(bleveIndexer)
go processRepoIndexerOperationQueue(indexer)
if created {
go populateRepoIndexer()
}
select {
case waitChannel <- time.Since(start):
case <-graceful.GetManager().IsShutdown():
}
waitChannel <- time.Since(start)
close(waitChannel)
}()
if setting.Indexer.StartupTimeout > 0 {
@ -67,9 +82,21 @@ func Init() {
timeout += setting.GracefulHammerTime
}
select {
case duration := <-waitChannel:
case <-graceful.GetManager().IsShutdown():
log.Warn("Shutdown before Repository Indexer completed initialization")
cancel()
indexer.Close()
case duration, ok := <-waitChannel:
if !ok {
log.Warn("Repository Indexer Initialization failed")
cancel()
indexer.Close()
return
}
log.Info("Repository Indexer Initialization took %v", duration)
case <-time.After(timeout):
cancel()
indexer.Close()
log.Fatal("Repository Indexer Initialization Timed-Out after: %v", timeout)
}
}()

View file

@ -22,8 +22,6 @@ type repoIndexerOperation struct {
var repoIndexerOperationQueue chan repoIndexerOperation
func processRepoIndexerOperationQueue(indexer Indexer) {
defer indexer.Close()
repoIndexerOperationQueue = make(chan repoIndexerOperation, setting.Indexer.UpdateQueueLength)
for {
select {

View file

@ -0,0 +1,94 @@
// Copyright 2019 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package code
import (
"fmt"
"sync"
)
var (
indexer = newWrappedIndexer()
)
// ErrWrappedIndexerClosed is the error returned if the indexer was closed before it was ready
var ErrWrappedIndexerClosed = fmt.Errorf("Indexer closed before ready")
type wrappedIndexer struct {
internal Indexer
lock sync.RWMutex
cond *sync.Cond
closed bool
}
func newWrappedIndexer() *wrappedIndexer {
w := &wrappedIndexer{}
w.cond = sync.NewCond(w.lock.RLocker())
return w
}
func (w *wrappedIndexer) set(indexer Indexer) {
w.lock.Lock()
defer w.lock.Unlock()
if w.closed {
// Too late!
indexer.Close()
}
w.internal = indexer
w.cond.Broadcast()
}
func (w *wrappedIndexer) get() (Indexer, error) {
w.lock.RLock()
defer w.lock.RUnlock()
if w.internal == nil {
if w.closed {
return nil, ErrWrappedIndexerClosed
}
w.cond.Wait()
if w.closed {
return nil, ErrWrappedIndexerClosed
}
}
return w.internal, nil
}
func (w *wrappedIndexer) Index(repoID int64) error {
indexer, err := w.get()
if err != nil {
return err
}
return indexer.Index(repoID)
}
func (w *wrappedIndexer) Delete(repoID int64) error {
indexer, err := w.get()
if err != nil {
return err
}
return indexer.Delete(repoID)
}
func (w *wrappedIndexer) Search(repoIDs []int64, keyword string, page, pageSize int) (int64, []*SearchResult, error) {
indexer, err := w.get()
if err != nil {
return 0, nil, err
}
return indexer.Search(repoIDs, keyword, page, pageSize)
}
func (w *wrappedIndexer) Close() {
w.lock.Lock()
defer w.lock.Unlock()
if w.closed {
return
}
w.closed = true
w.cond.Broadcast()
if w.internal != nil {
w.internal.Close()
}
}