Consistently use transactions to update database

For any action which is multi-step (requires updating more than 1 DB
key), use transaction to make update atomic.

Also pack big chunks of updates (importing packages for importing and
mirror updates) into single transaction to improve aptly performance and
get some isolation.

Note that still layers up (Collections) provide some level of isolation,
so this is going to shine with the future PRs to remove collection
locks.

Spin-off of #459

api/repos.go

@@ -327,7 +327,7 @@ func apiReposPackageFromDir(c *gin.Context) {
 	}
 
 	processedFiles, failedFiles2, err = deb.ImportPackageFiles(list, packageFiles, forceReplace, verifier, context.PackagePool(),
-		context.CollectionFactory().PackageCollection(), reporter, nil, context.CollectionFactory().ChecksumCollection())
+		context.CollectionFactory().PackageCollection(), reporter, nil, context.CollectionFactory().ChecksumCollection)
 	failedFiles = append(failedFiles, failedFiles2...)
 
 	processedFiles = append(processedFiles, otherFiles...)
@@ -420,7 +420,7 @@ func apiReposIncludePackageFromDir(c *gin.Context) {
 	_, failedFiles2, err = deb.ImportChangesFiles(
 		changesFiles, reporter, acceptUnsigned, ignoreSignature, forceReplace, noRemoveFiles, verifier,
 		repoTemplateString, context.Progress(), localRepoCollection, context.CollectionFactory().PackageCollection(),
-		context.PackagePool(), context.CollectionFactory().ChecksumCollection(), nil, query.Parse)
+		context.PackagePool(), context.CollectionFactory().ChecksumCollection, nil, query.Parse)
 	failedFiles = append(failedFiles, failedFiles2...)
 
 	if err != nil {

aptly/interfaces.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"os"
 
+	"github.com/aptly-dev/aptly/database"
 	"github.com/aptly-dev/aptly/utils"
 )
 
@@ -134,6 +135,9 @@ type Downloader interface {
 	GetLength(ctx context.Context, url string) (int64, error)
 }
 
+// ChecksumStorageProvider creates ChecksumStorage based on DB
+type ChecksumStorageProvider func(db database.ReaderWriter) ChecksumStorage
+
 // ChecksumStorage is stores checksums in some (persistent) storage
 type ChecksumStorage interface {
 	// Get finds checksums in DB by path

cmd/mirror_update.go

@@ -84,7 +84,7 @@ func aptlyMirrorUpdate(cmd *commander.Command, args []string) error {
 
 	context.Progress().Printf("Building download queue...\n")
 	queue, downloadSize, err = repo.BuildDownloadQueue(context.PackagePool(), context.CollectionFactory().PackageCollection(),
-		context.CollectionFactory().ChecksumCollection(), skipExistingPackages)
+		context.CollectionFactory().ChecksumCollection(nil), skipExistingPackages)
 
 	if err != nil {
 		return fmt.Errorf("unable to update: %s", err)
@@ -210,7 +210,7 @@ func aptlyMirrorUpdate(cmd *commander.Command, args []string) error {
 		}
 
 		// and import it back to the pool
-		task.File.PoolPath, err = context.PackagePool().Import(task.TempDownPath, task.File.Filename, &task.File.Checksums, true, context.CollectionFactory().ChecksumCollection())
+		task.File.PoolPath, err = context.PackagePool().Import(task.TempDownPath, task.File.Filename, &task.File.Checksums, true, context.CollectionFactory().ChecksumCollection(nil))
 		if err != nil {
 			return fmt.Errorf("unable to import file: %s", err)
 		}

cmd/repo_add.go

@@ -49,7 +49,7 @@ func aptlyRepoAdd(cmd *commander.Command, args []string) error {
 
 	processedFiles, failedFiles2, err = deb.ImportPackageFiles(list, packageFiles, forceReplace, verifier, context.PackagePool(),
 		context.CollectionFactory().PackageCollection(), &aptly.ConsoleResultReporter{Progress: context.Progress()}, nil,
-		context.CollectionFactory().ChecksumCollection())
+		context.CollectionFactory().ChecksumCollection)
 	failedFiles = append(failedFiles, failedFiles2...)
 	if err != nil {
 		return fmt.Errorf("unable to import package files: %s", err)

cmd/repo_include.go

@@ -56,7 +56,7 @@ func aptlyRepoInclude(cmd *commander.Command, args []string) error {
 	_, failedFiles2, err = deb.ImportChangesFiles(
 		changesFiles, reporter, acceptUnsigned, ignoreSignatures, forceReplace, noRemoveFiles, verifier, repoTemplateString,
 		context.Progress(), context.CollectionFactory().LocalRepoCollection(), context.CollectionFactory().PackageCollection(),
-		context.PackagePool(), context.CollectionFactory().ChecksumCollection(),
+		context.PackagePool(), context.CollectionFactory().ChecksumCollection,
 		uploaders, query.Parse)
 	failedFiles = append(failedFiles, failedFiles2...)
 

database/database.go

@@ -30,6 +30,12 @@ type Writer interface {
 	Delete(key []byte) error
 }
 
+// ReaderWriter combines Reader and Writer
+type ReaderWriter interface {
+	Reader
+	Writer
+}
+
 // Storage is an interface to KV storage
 type Storage interface {
 	Reader

deb/changes.go

@@ -294,7 +294,7 @@ func CollectChangesFiles(locations []string, reporter aptly.ResultReporter) (cha
 // ImportChangesFiles imports referenced files in changes files into local repository
 func ImportChangesFiles(changesFiles []string, reporter aptly.ResultReporter, acceptUnsigned, ignoreSignatures, forceReplace, noRemoveFiles bool,
 	verifier pgp.Verifier, repoTemplateString string, progress aptly.Progress, localRepoCollection *LocalRepoCollection, packageCollection *PackageCollection,
-	pool aptly.PackagePool, checksumStorage aptly.ChecksumStorage, uploaders *Uploaders, parseQuery parseQuery) (processedFiles []string, failedFiles []string, err error) {
+	pool aptly.PackagePool, checksumStorageProvider aptly.ChecksumStorageProvider, uploaders *Uploaders, parseQuery parseQuery) (processedFiles []string, failedFiles []string, err error) {
 
 	var repoTemplate *template.Template
 	repoTemplate, err = template.New("repo").Parse(repoTemplateString)
@@ -384,7 +384,7 @@ func ImportChangesFiles(changesFiles []string, reporter aptly.ResultReporter, ac
 		var processedFiles2, failedFiles2 []string
 
 		processedFiles2, failedFiles2, err = ImportPackageFiles(list, packageFiles, forceReplace, verifier, pool,
-			packageCollection, reporter, restriction, checksumStorage)
+			packageCollection, reporter, restriction, checksumStorageProvider)
 
 		if err != nil {
 			return nil, nil, fmt.Errorf("unable to import package files: %s", err)

deb/changes_test.go

@@ -123,7 +123,7 @@ func (s *ChangesSuite) TestImportChangesFiles(c *C) {
 	processedFiles, failedFiles, err := ImportChangesFiles(
 		append(changesFiles, "testdata/changes/notexistent.changes"),
 		s.Reporter, true, true, false, false, &NullVerifier{},
-		"test", s.progress, s.localRepoCollection, s.packageCollection, s.packagePool, s.checksumStorage,
+		"test", s.progress, s.localRepoCollection, s.packageCollection, s.packagePool, func(database.ReaderWriter) aptly.ChecksumStorage { return s.checksumStorage },
 		nil, nil)
 	c.Assert(err, IsNil)
 	c.Check(failedFiles, DeepEquals, append(expectedFailedFiles, "testdata/changes/notexistent.changes"))

deb/checksum_collection.go

@@ -11,12 +11,12 @@ import (
 
 // ChecksumCollection does management of ChecksumInfo in DB
 type ChecksumCollection struct {
-	db          database.Storage
+	db          database.ReaderWriter
 	codecHandle *codec.MsgpackHandle
 }
 
 // NewChecksumCollection creates new ChecksumCollection and binds it to database
-func NewChecksumCollection(db database.Storage) *ChecksumCollection {
+func NewChecksumCollection(db database.ReaderWriter) *ChecksumCollection {
 	return &ChecksumCollection{
 		db:          db,
 		codecHandle: &codec.MsgpackHandle{},

deb/collections.go

@@ -3,6 +3,7 @@ package deb
 import (
 	"sync"
 
+	"github.com/aptly-dev/aptly/aptly"
 	"github.com/aptly-dev/aptly/database"
 )
 
@@ -91,10 +92,14 @@ func (factory *CollectionFactory) PublishedRepoCollection() *PublishedRepoCollec
 }
 
 // ChecksumCollection returns (or creates) new ChecksumCollection
-func (factory *CollectionFactory) ChecksumCollection() *ChecksumCollection {
+func (factory *CollectionFactory) ChecksumCollection(db database.ReaderWriter) aptly.ChecksumStorage {
 	factory.Lock()
 	defer factory.Unlock()
 
+	if db != nil {
+		return NewChecksumCollection(db)
+	}
+
 	if factory.checksums == nil {
 		factory.checksums = NewChecksumCollection(factory.db)
 	}

deb/import.go

@@ -66,11 +66,19 @@ func CollectPackageFiles(locations []string, reporter aptly.ResultReporter) (pac
 // ImportPackageFiles imports files into local repository
 func ImportPackageFiles(list *PackageList, packageFiles []string, forceReplace bool, verifier pgp.Verifier,
 	pool aptly.PackagePool, collection *PackageCollection, reporter aptly.ResultReporter, restriction PackageQuery,
-	checksumStorage aptly.ChecksumStorage) (processedFiles []string, failedFiles []string, err error) {
+	checksumStorageProvider aptly.ChecksumStorageProvider) (processedFiles []string, failedFiles []string, err error) {
 	if forceReplace {
 		list.PrepareIndex()
 	}
 
+	transaction, err := collection.db.OpenTransaction()
+	if err != nil {
+		return nil, nil, err
+	}
+	defer transaction.Discard()
+
+	checksumStorage := checksumStorageProvider(transaction)
+
 	for _, file := range packageFiles {
 		var (
 			stanza Stanza
@@ -193,7 +201,7 @@ func ImportPackageFiles(list *PackageList, packageFiles []string, forceReplace b
 			continue
 		}
 
-		err = collection.Update(p)
+		err = collection.UpdateInTransaction(p, transaction)
 		if err != nil {
 			reporter.Warning("Unable to save package %s: %s", p, err)
 			failedFiles = append(failedFiles, file)
@@ -219,6 +227,6 @@ func ImportPackageFiles(list *PackageList, packageFiles []string, forceReplace b
 		processedFiles = append(processedFiles, candidateProcessedFiles...)
 	}
 
-	err = nil
+	err = transaction.Commit()
 	return
 }

deb/local.go

@@ -161,17 +161,23 @@ func (collection *LocalRepoCollection) Add(repo *LocalRepo) error {
 
 // Update stores updated information about repo in DB
 func (collection *LocalRepoCollection) Update(repo *LocalRepo) error {
-	err := collection.db.Put(repo.Key(), repo.Encode())
+	transaction, err := collection.db.OpenTransaction()
+	if err != nil {
+		return err
+	}
+	defer transaction.Discard()
+
+	err = transaction.Put(repo.Key(), repo.Encode())
 	if err != nil {
 		return err
 	}
 	if repo.packageRefs != nil {
-		err = collection.db.Put(repo.RefKey(), repo.packageRefs.Encode())
+		err = transaction.Put(repo.RefKey(), repo.packageRefs.Encode())
 		if err != nil {
 			return err
 		}
 	}
-	return nil
+	return transaction.Commit()
 }
 
 // LoadComplete loads additional information for local repo
@@ -245,16 +251,28 @@ func (collection *LocalRepoCollection) Len() int {
 
 // Drop removes remote repo from collection
 func (collection *LocalRepoCollection) Drop(repo *LocalRepo) error {
-	if _, err := collection.db.Get(repo.Key()); err == database.ErrNotFound {
-		panic("local repo not found!")
+	transaction, err := collection.db.OpenTransaction()
+	if err != nil {
+		return err
 	}
+	defer transaction.Discard()
 
 	delete(collection.cache, repo.UUID)
 
-	err := collection.db.Delete(repo.Key())
-	if err != nil {
+	if _, err = transaction.Get(repo.Key()); err != nil {
+		if err == database.ErrNotFound {
+			return errors.New("local repo not found")
+		}
+		return err
+	}
+
+	if err = transaction.Delete(repo.Key()); err != nil {
+		return err
+	}
+
+	if err = transaction.Delete(repo.RefKey()); err != nil {
 		return err
 	}
 
-	return collection.db.Delete(repo.RefKey())
+	return transaction.Commit()
 }

deb/local_test.go

@@ -199,5 +199,5 @@ func (s *LocalRepoCollectionSuite) TestDrop(c *C) {
 	r2, _ := collection.ByName("local2")
 	c.Check(r2.String(), Equals, repo2.String())
 
-	c.Check(func() { s.collection.Drop(repo1) }, Panics, "local repo not found!")
+	c.Check(s.collection.Drop(repo1), ErrorMatches, "local repo not found")
 }

deb/package_collection.go

@@ -201,21 +201,35 @@ func (collection *PackageCollection) loadContents(p *Package, packagePool aptly.
 	return contents
 }
 
-// Update adds or updates information about package in DB checking for conficts first
+// Update adds or updates information about package in DB
 func (collection *PackageCollection) Update(p *Package) error {
+	transaction, err := collection.db.OpenTransaction()
+	if err != nil {
+		return err
+	}
+	defer transaction.Discard()
+
+	if err = collection.UpdateInTransaction(p, transaction); err != nil {
+		return err
+	}
+
+	return transaction.Commit()
+}
+
+// UpdateInTransaction updates/creates package info in the context of the outer transaction
+func (collection *PackageCollection) UpdateInTransaction(p *Package, transaction database.Transaction) error {
 	var encodeBuffer bytes.Buffer
 
 	encoder := codec.NewEncoder(&encodeBuffer, collection.codecHandle)
 
 	encodeBuffer.Reset()
 	encodeBuffer.WriteByte(0xc1)
 	encodeBuffer.WriteByte(0x1)
-	err := encoder.Encode(p)
-	if err != nil {
+	if err := encoder.Encode(p); err != nil {
 		return err
 	}
 
-	err = collection.db.Put(p.Key(""), encodeBuffer.Bytes())
+	err := transaction.Put(p.Key(""), encodeBuffer.Bytes())
 	if err != nil {
 		return err
 	}
@@ -228,7 +242,7 @@ func (collection *PackageCollection) Update(p *Package) error {
 			return err
 		}
 
-		err = collection.db.Put(p.Key("xF"), encodeBuffer.Bytes())
+		err = transaction.Put(p.Key("xF"), encodeBuffer.Bytes())
 		if err != nil {
 			return err
 		}
@@ -241,7 +255,7 @@ func (collection *PackageCollection) Update(p *Package) error {
 			return err
 		}
 
-		err = collection.db.Put(p.Key("xD"), encodeBuffer.Bytes())
+		err = transaction.Put(p.Key("xD"), encodeBuffer.Bytes())
 		if err != nil {
 			return err
 		}
@@ -256,7 +270,7 @@ func (collection *PackageCollection) Update(p *Package) error {
 			return err
 		}
 
-		err = collection.db.Put(p.Key("xE"), encodeBuffer.Bytes())
+		err = transaction.Put(p.Key("xE"), encodeBuffer.Bytes())
 		if err != nil {
 			return err
 		}

deb/publish.go

@@ -914,21 +914,27 @@ func (collection *PublishedRepoCollection) CheckDuplicate(repo *PublishedRepo) *
 }
 
 // Update stores updated information about repo in DB
-func (collection *PublishedRepoCollection) Update(repo *PublishedRepo) (err error) {
-	err = collection.db.Put(repo.Key(), repo.Encode())
+func (collection *PublishedRepoCollection) Update(repo *PublishedRepo) error {
+	transaction, err := collection.db.OpenTransaction()
 	if err != nil {
-		return
+		return err
+	}
+	defer transaction.Discard()
+
+	err = transaction.Put(repo.Key(), repo.Encode())
+	if err != nil {
+		return err
 	}
 
 	if repo.SourceKind == SourceLocalRepo {
 		for component, item := range repo.sourceItems {
-			err = collection.db.Put(repo.RefKey(component), item.packageRefs.Encode())
+			err = transaction.Put(repo.RefKey(component), item.packageRefs.Encode())
 			if err != nil {
-				return
+				return err
 			}
 		}
 	}
-	return
+	return transaction.Commit()
 }
 
 // LoadComplete loads additional information for remote repo
@@ -1170,6 +1176,13 @@ func (collection *PublishedRepoCollection) Remove(publishedStorageProvider aptly
 	storage, prefix, distribution string, collectionFactory *CollectionFactory, progress aptly.Progress,
 	force, skipCleanup bool) error {
 
+	transaction, err := collection.db.OpenTransaction()
+	if err != nil {
+		return err
+	}
+	defer transaction.Discard()
+
+	// TODO: load via transaction
 	collection.loadList()
 
 	repo, err := collection.ByStoragePrefixDistribution(storage, prefix, distribution)
@@ -1221,17 +1234,17 @@ func (collection *PublishedRepoCollection) Remove(publishedStorageProvider aptly
 		}
 	}
 
-	err = collection.db.Delete(repo.Key())
+	err = transaction.Delete(repo.Key())
 	if err != nil {
 		return err
 	}
 
 	for _, component := range repo.Components() {
-		err = collection.db.Delete(repo.RefKey(component))
+		err = transaction.Delete(repo.RefKey(component))
 		if err != nil {
 			return err
 		}
 	}
 
-	return nil
+	return transaction.Commit()
 }