feat(storage): add revision number to documents

ref #13

pkg/storage/document_store.go

@@ -9,12 +9,16 @@ import (
 	"github.com/oklog/ulid/v2"
 )
 
-var ErrDocumentNotFound = errors.New("document not found")
+var (
+	ErrDocumentNotFound         = errors.New("document not found")
+	ErrDocumentRevisionConflict = errors.New("document revision conflict")
+)
 
 type DocumentID string
 
 const (
 	DocumentAttrID        = "_id"
+	DocumentAttrRevision  = "_revision"
 	DocumentAttrCreatedAt = "_createdAt"
 	DocumentAttrUpdatedAt = "_updatedAt"
 )
@@ -44,6 +48,20 @@ func (d Document) ID() (DocumentID, bool) {
 	return "", false
 }
 
+func (d Document) Revision() (int, bool) {
+	rawRevision, exists := d[DocumentAttrRevision]
+	if !exists {
+		return 0, false
+	}
+
+	revision, ok := rawRevision.(int)
+	if ok {
+		return revision, true
+	}
+
+	return 0, false
+}
+
 func (d Document) CreatedAt() (time.Time, bool) {
 	return d.timeAttr(DocumentAttrCreatedAt)
 }

pkg/storage/driver/sqlite/blob_store_test.go

@@ -24,7 +24,7 @@ func TestBlobStore(t *testing.T) {
 		t.Fatalf("%+v", errors.WithStack(err))
 	}
 
-	dsn := fmt.Sprintf("%s?_pragma=foreign_keys(1)&_pragma=busy_timeout=%d", file, (60 * time.Second).Milliseconds())
+	dsn := fmt.Sprintf("%s?_pragma=foreign_keys(1)&_pragma=busy_timeout=%d&_pragma=journal_mode=wal", file, (60 * time.Second).Milliseconds())
 	store := NewBlobStore(dsn)
 
 	testsuite.TestBlobStore(context.Background(), t, store)

pkg/storage/driver/sqlite/document_store.go

@@ -13,9 +13,14 @@ import (
 	"github.com/pkg/errors"
 	"gitlab.com/wpetit/goweb/logger"
 
+	_ "embed"
+
 	_ "modernc.org/sqlite"
 )
 
+//go:embed document_store.sql
+var documentStoreSchema string
+
 type DocumentStore struct {
 	getDB GetDBFunc
 }
@@ -48,7 +53,7 @@ func (s *DocumentStore) Get(ctx context.Context, collection string, id storage.D
 
 	err := s.withTx(ctx, func(tx *sql.Tx) error {
 		query := `
-		SELECT id, data, created_at, updated_at 
+		SELECT id, revision, data, created_at, updated_at 
 		FROM documents 
 		WHERE collection = $1 AND id = $2 
 		`
@@ -59,9 +64,10 @@ func (s *DocumentStore) Get(ctx context.Context, collection string, id storage.D
 			createdAt time.Time
 			updatedAt time.Time
 			data      JSONMap
+			revision  int
 		)
 
-		err := row.Scan(&id, &data, &createdAt, &updatedAt)
+		err := row.Scan(&id, &revision, &data, &createdAt, &updatedAt)
 		if err != nil {
 			if errors.Is(err, sql.ErrNoRows) {
 				return errors.WithStack(storage.ErrDocumentNotFound)
@@ -77,6 +83,7 @@ func (s *DocumentStore) Get(ctx context.Context, collection string, id storage.D
 		document = storage.Document(data)
 
 		document[storage.DocumentAttrID] = id
+		document[storage.DocumentAttrRevision] = revision
 		document[storage.DocumentAttrCreatedAt] = createdAt
 		document[storage.DocumentAttrUpdatedAt] = updatedAt
 
@@ -119,7 +126,7 @@ func (s *DocumentStore) Query(ctx context.Context, collection string, filter *fi
 		}
 
 		query := `
-		SELECT id, data, created_at, updated_at 
+		SELECT id, revision, data, created_at, updated_at 
 		FROM documents 
 		WHERE collection = $1 AND (` + criteria + `)
 		`
@@ -171,17 +178,19 @@ func (s *DocumentStore) Query(ctx context.Context, collection string, filter *fi
 		for rows.Next() {
 			var (
 				id        storage.DocumentID
+				revision  int
 				createdAt time.Time
 				updatedAt time.Time
 				data      JSONMap
 			)
 
-			if err := rows.Scan(&id, &data, &createdAt, &updatedAt); err != nil {
+			if err := rows.Scan(&id, &revision, &data, &createdAt, &updatedAt); err != nil {
 				return errors.WithStack(err)
 			}
 
 			document := storage.Document(data)
 			document[storage.DocumentAttrID] = id
+			document[storage.DocumentAttrRevision] = revision
 			document[storage.DocumentAttrCreatedAt] = createdAt
 			document[storage.DocumentAttrUpdatedAt] = updatedAt
 
@@ -206,22 +215,16 @@ func (s *DocumentStore) Upsert(ctx context.Context, collection string, document
 	var upsertedDocument storage.Document
 
 	err := s.withTx(ctx, func(tx *sql.Tx) error {
-		query := `
-		INSERT INTO documents (id, collection, data, created_at, updated_at) 
-		VALUES($1, $2, $3, $4, $4)
-		ON CONFLICT (id, collection) DO UPDATE SET
-			data = $3, updated_at = $4
-		RETURNING "id", "data", "created_at", "updated_at"
-		`
-
-		now := time.Now().UTC()
-
 		id, exists := document.ID()
 		if !exists || id == "" {
 			id = storage.NewDocumentID()
 		}
 
-		args := []any{id, collection, JSONMap(document), now, now}
+		query := `
+			SELECT revision FROM documents WHERE id = $1
+		`
+
+		args := []any{id}
 
 		logger.Debug(
 			ctx, "executing query",
@@ -231,14 +234,44 @@ func (s *DocumentStore) Upsert(ctx context.Context, collection string, document
 
 		row := tx.QueryRowContext(ctx, query, args...)
 
+		var storedRevision int
+
+		if err := row.Scan(&storedRevision); err != nil && !errors.Is(err, sql.ErrNoRows) {
+			return errors.WithStack(err)
+		}
+
+		revision, found := document.Revision()
+		if found && storedRevision != revision {
+			return errors.Wrapf(storage.ErrDocumentRevisionConflict, "document revision '%d' does not match stored '%d'", revision, storedRevision)
+		}
+
+		query = `
+		INSERT INTO documents (id, collection, data, created_at, updated_at) 
+		VALUES($1, $2, $3, $4, $4)
+		ON CONFLICT (id, collection) DO UPDATE SET
+			data = $3, updated_at = $4, revision = revision + 1
+		RETURNING "id", "revision", "data", "created_at", "updated_at"
+		`
+
+		now := time.Now().UTC()
+
+		args = []any{id, collection, JSONMap(document), now, now}
+
+		logger.Debug(
+			ctx, "executing query",
+			logger.F("query", query),
+			logger.F("args", args),
+		)
+
+		row = tx.QueryRowContext(ctx, query, args...)
+
 		var (
 			createdAt time.Time
 			updatedAt time.Time
 			data      JSONMap
 		)
 
-		err := row.Scan(&id, &data, &createdAt, &updatedAt)
+		if err := row.Scan(&id, &revision, &data, &createdAt, &updatedAt); err != nil {
-		if err != nil {
 			return errors.WithStack(err)
 		}
 
@@ -249,6 +282,7 @@ func (s *DocumentStore) Upsert(ctx context.Context, collection string, document
 		upsertedDocument = storage.Document(data)
 
 		upsertedDocument[storage.DocumentAttrID] = id
+		upsertedDocument[storage.DocumentAttrRevision] = revision
 		upsertedDocument[storage.DocumentAttrCreatedAt] = createdAt
 		upsertedDocument[storage.DocumentAttrUpdatedAt] = updatedAt
 
@@ -276,29 +310,13 @@ func (s *DocumentStore) withTx(ctx context.Context, fn func(tx *sql.Tx) error) e
 	return nil
 }
 
-func ensureDocumentTables(ctx context.Context, db *sql.DB) error {
+func migrateSchema(ctx context.Context, db *sql.DB) error {
 	err := WithTx(ctx, db, func(tx *sql.Tx) error {
-		query := `
+		for _, migr := range documentStoreMigrations {
-			CREATE TABLE IF NOT EXISTS documents (
+			if err := migr(ctx, tx); err != nil {
-				id TEXT PRIMARY KEY,
-				collection TEXT NOT NULL,
-				data TEXT,
-				created_at TIMESTAMP NOT NULL,
-				updated_at TIMESTAMP NOT NULL,
-				UNIQUE(id, collection) ON CONFLICT REPLACE
-			);
-		`
-		if _, err := tx.ExecContext(ctx, query); err != nil {
 				return errors.WithStack(err)
 			}
-
-		query = `
-			CREATE INDEX IF NOT EXISTS collection_idx ON documents (collection);
-		`
-		if _, err := tx.ExecContext(ctx, query); err != nil {
-			return errors.WithStack(err)
 		}
-
 		return nil
 	})
 	if err != nil {
@@ -344,7 +362,7 @@ func withLimitOffsetClause(query string, args []any, limit int, offset int) (str
 }
 
 func NewDocumentStore(path string) *DocumentStore {
-	getDB := NewGetDBFunc(path, ensureDocumentTables)
+	getDB := NewGetDBFunc(path, migrateSchema)
 
 	return &DocumentStore{
 		getDB: getDB,
@@ -352,7 +370,7 @@ func NewDocumentStore(path string) *DocumentStore {
 }
 
 func NewDocumentStoreWithDB(db *sql.DB) *DocumentStore {
-	getDB := NewGetDBFuncFromDB(db, ensureDocumentTables)
+	getDB := NewGetDBFuncFromDB(db, migrateSchema)
 
 	return &DocumentStore{
 		getDB: getDB,

pkg/storage/driver/sqlite/document_store.sql

@@ -0,0 +1,16 @@
+CREATE TABLE IF NOT EXISTS documents (
+    id TEXT PRIMARY KEY,
+    collection TEXT NOT NULL,
+    data TEXT,
+    created_at TIMESTAMP NOT NULL,
+    updated_at TIMESTAMP NOT NULL,
+    UNIQUE(id, collection) ON CONFLICT REPLACE
+);
+
+---
+
+CREATE INDEX IF NOT EXISTS collection_idx ON documents (collection);
+
+---
+
+ALTER TABLE documents ADD COLUMN revision INTEGER DEFAULT 0;

pkg/storage/driver/sqlite/document_store_migrations.go

@@ -0,0 +1,98 @@
+package sqlite
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/pkg/errors"
+	"gitlab.com/wpetit/goweb/logger"
+)
+
+type MigrateFunc func(ctx context.Context, tx *sql.Tx) error
+
+var documentStoreMigrations = []MigrateFunc{
+	documentStoreMigrationBaseSchema,
+	documentStoreMigrationAddIDIndex,
+	documentStoreMigrationAddRevisionColumn,
+}
+
+func documentStoreMigrationBaseSchema(ctx context.Context, tx *sql.Tx) error {
+	query := `
+		CREATE TABLE IF NOT EXISTS documents (
+			id TEXT PRIMARY KEY,
+			collection TEXT NOT NULL,
+			data TEXT,
+			created_at TIMESTAMP NOT NULL,
+			updated_at TIMESTAMP NOT NULL,
+			UNIQUE(id, collection) ON CONFLICT REPLACE
+		);
+	`
+
+	if _, err := tx.ExecContext(ctx, query); err != nil {
+		return errors.WithStack(err)
+	}
+
+	return nil
+}
+
+func documentStoreMigrationAddIDIndex(ctx context.Context, tx *sql.Tx) error {
+	query := `
+		CREATE INDEX IF NOT EXISTS collection_idx ON documents (collection);
+	`
+
+	if _, err := tx.ExecContext(ctx, query); err != nil {
+		return errors.WithStack(err)
+	}
+
+	return nil
+}
+
+func documentStoreMigrationAddRevisionColumn(ctx context.Context, tx *sql.Tx) error {
+	query := `PRAGMA table_info(documents)`
+
+	rows, err := tx.QueryContext(ctx, query)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	defer func() {
+		if err := rows.Close(); err != nil {
+			logger.Error(ctx, "could not close rows", logger.CapturedE(errors.WithStack(err)))
+		}
+	}()
+
+	var hasRevisionColumn bool
+
+	for rows.Next() {
+		var (
+			id           int
+			name         string
+			dataType     string
+			nullable     int
+			defaultValue any
+			primaryKey   int
+		)
+
+		if err := rows.Scan(&id, &name, &dataType, &nullable, &defaultValue, &primaryKey); err != nil {
+			return errors.WithStack(err)
+		}
+
+		if name == "revision" {
+			hasRevisionColumn = true
+			break
+		}
+	}
+
+	if err := rows.Err(); err != nil {
+		return errors.WithStack(err)
+	}
+
+	if !hasRevisionColumn {
+		query = `ALTER TABLE documents ADD COLUMN revision INTEGER DEFAULT 0`
+		if _, err := tx.ExecContext(ctx, query); err != nil {
+			return errors.WithStack(err)
+		}
+	}
+
+	return nil
+}

pkg/storage/driver/sqlite/document_store_test.go

@@ -22,7 +22,7 @@ func TestDocumentStore(t *testing.T) {
 		t.Fatalf("%+v", errors.WithStack(err))
 	}
 
-	dsn := fmt.Sprintf("%s?_pragma=foreign_keys(1)&_pragma=busy_timeout=%d", file, (60 * time.Second).Milliseconds())
+	dsn := fmt.Sprintf("%s?_pragma=foreign_keys(1)&_pragma=busy_timeout=%d&_pragma=journal_mode=wal", file, (60 * time.Second).Milliseconds())
 	store := NewDocumentStore(dsn)
 
 	testsuite.TestDocumentStore(context.Background(), t, store)

pkg/storage/driver/sqlite/share_store_test.go

@@ -26,7 +26,7 @@ func newTestStore(testName string) (share.Store, error) {
 		return nil, errors.WithStack(err)
 	}
 
-	dsn := fmt.Sprintf("%s?_pragma=foreign_keys(1)&_pragma=busy_timeout=%d", file, (60 * time.Second).Milliseconds())
+	dsn := fmt.Sprintf("%s?_pragma=foreign_keys(1)&_pragma=busy_timeout=%d&_pragma=journal_mode=wal", file, (60 * time.Second).Milliseconds())
 	store := NewShareStore(dsn)
 
 	return store, nil

pkg/storage/testsuite/document_store_ops.go

@@ -185,8 +185,13 @@ var documentStoreOpsTestCases = []documentStoreOpsTestCase{
 				return errors.Errorf("upsertedDoc[\"attr1\"]: expected '%v', got '%v'", e, g)
 			}
 
+			upsertedDocRevision, _ := upsertedDoc.Revision()
+			if e, g := 0, upsertedDocRevision; e != g {
+				return errors.Errorf("upsertedDoc.Revision(): expected '%v', got '%v'", e, g)
+			}
+
 			// Check that document does not have unexpected properties
-			if e, g := 4, len(upsertedDoc); e != g {
+			if e, g := 5, len(upsertedDoc); e != g {
 				return errors.Errorf("len(upsertedDoc): expected '%v', got '%v'", e, g)
 			}
 
@@ -217,6 +222,11 @@ var documentStoreOpsTestCases = []documentStoreOpsTestCase{
 				return errors.New("upsertedDoc2.UpdatedAt() should have been different than upsertedDoc.UpdatedAt()")
 			}
 
+			upsertedDoc2Revision, _ := upsertedDoc2.Revision()
+			if e, g := 1, upsertedDoc2Revision; e != g {
+				return errors.Errorf("upsertedDoc.Revision(): expected '%v', got '%v'", e, g)
+			}
+
 			// Verify that there is no additional created document in the collection
 
 			results, err := store.Query(ctx, collection, nil)
@@ -228,6 +238,11 @@ var documentStoreOpsTestCases = []documentStoreOpsTestCase{
 				return errors.Errorf("len(results): expected '%v', got '%v'", e, g)
 			}
 
+			firstResultRevision, _ := results[0].Revision()
+			if e, g := 1, firstResultRevision; e != g {
+				return errors.Errorf("results[0].Revision(): expected '%v', got '%v'", e, g)
+			}
+
 			return nil
 		},
 	},
@@ -437,7 +452,6 @@ func testDocumentStoreOps(ctx context.Context, t *testing.T, store storage.Docum
 	for _, tc := range documentStoreOpsTestCases {
 		func(tc documentStoreOpsTestCase) {
 			t.Run(tc.Name, func(t *testing.T) {
-				t.Parallel()
 				if err := tc.Run(ctx, store); err != nil {
 					t.Errorf("%+v", errors.WithStack(err))
 				}