Merge pull request #876 from go-kivik/sqlitedb2

More progress on sqlite backend

.golangci.toml

@@ -24,13 +24,17 @@ enable = [
     "gocritic",
     "staticcheck",
     "goheader",
+
+    # SQL-related linters
+    "rowserrcheck",
+    "sqlclosecheck",
 ]
 
 [issues]
 exclude-use-default = false
 
 [[issues.exclude-rules]]
-source = "defer .*\\.Close\\(\\)$"
+source = "defer .*\\.(Close|Rollback)\\(\\)$"
 linters = ["errcheck"]
 
 [linters-settings.gci]

x/sqlite/db.go

@@ -0,0 +1,167 @@
+// 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 sqlite
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"net/http"
+
+	"modernc.org/sqlite"
+	sqlite3 "modernc.org/sqlite/lib"
+
+	"github.com/go-kivik/kivik/v4/driver"
+	"github.com/go-kivik/kivik/v4/internal"
+)
+
+type db struct {
+	db   *sql.DB
+	name string
+}
+
+var _ driver.DB = (*db)(nil)
+
+func (db) AllDocs(context.Context, driver.Options) (driver.Rows, error) {
+	return nil, nil
+}
+
+func (db) CreateDoc(context.Context, interface{}, driver.Options) (string, string, error) {
+	return "", "", nil
+}
+
+func (d *db) Put(ctx context.Context, docID string, doc interface{}, options driver.Options) (string, error) {
+	docRev, err := extractRev(doc)
+	if err != nil {
+		return "", err
+	}
+	opts := map[string]interface{}{
+		"new_edits": true,
+	}
+	options.Apply(opts)
+	optsRev, _ := opts["rev"].(string)
+	if optsRev != "" && docRev != "" && optsRev != docRev {
+		return "", &internal.Error{Status: http.StatusBadRequest, Message: "Document rev and option have different values"}
+	}
+	if docRev == "" && optsRev != "" {
+		docRev = optsRev
+	}
+
+	docID, rev, jsonDoc, err := prepareDoc(docID, doc)
+	if err != nil {
+		return "", err
+	}
+
+	if newEdits, _ := opts["new_edits"].(bool); !newEdits {
+		if docRev == "" {
+			return "", &internal.Error{Status: http.StatusBadRequest, Message: "When `new_edits: false`, the document needs `_rev` or `_revisions` specified"}
+		}
+		rev, err := parseRev(docRev)
+		if err != nil {
+			return "", err
+		}
+		var newRev string
+		err = d.db.QueryRowContext(ctx, `
+			INSERT INTO `+d.name+` (id, rev_id, rev, doc)
+			VALUES ($1, $2, $3, $4)
+			RETURNING rev_id || '-' || rev
+		`, docID, rev.id, rev.rev, jsonDoc).Scan(&newRev)
+		var sqliteErr *sqlite.Error
+		if errors.As(err, &sqliteErr) && sqliteErr.Code() == sqlite3.SQLITE_CONSTRAINT_UNIQUE {
+			// In the case of a conflict for new_edits=false, we assume that the
+			// documents are identical, for the sake of idempotency, and return
+			// the current rev, to match CouchDB behavior.
+			return docRev, nil
+		}
+		return newRev, err
+	}
+
+	tx, err := d.db.BeginTx(ctx, nil)
+	if err != nil {
+		return "", err
+	}
+	defer tx.Rollback()
+
+	var curRev string
+	err = tx.QueryRowContext(ctx, `
+		SELECT COALESCE(MAX(rev_id || '-' || rev),'')
+		FROM `+d.name+`
+		WHERE id = $1
+	`, docID).Scan(&curRev)
+	if err != nil && !errors.Is(err, sql.ErrNoRows) {
+		return "", err
+	}
+	if curRev != docRev {
+		return "", &internal.Error{Status: http.StatusConflict, Message: "conflict"}
+	}
+	var newRev string
+	err = tx.QueryRowContext(ctx, `
+		INSERT INTO `+d.name+` (id, rev_id, rev, doc)
+		SELECT $1, COALESCE(MAX(rev_id),0) + 1, $2, $3
+		FROM `+d.name+`
+		WHERE id = $1
+		RETURNING rev_id || '-' || rev
+	`, docID, rev, jsonDoc).Scan(&newRev)
+	if err != nil {
+		return "", err
+	}
+	return newRev, tx.Commit()
+}
+
+func (db) Get(context.Context, string, driver.Options) (*driver.Document, error) {
+	return nil, nil
+}
+
+func (db) Delete(context.Context, string, driver.Options) (string, error) {
+	return "", nil
+}
+
+func (db) Stats(context.Context) (*driver.DBStats, error) {
+	return nil, nil
+}
+
+func (db) Compact(context.Context) error {
+	return nil
+}
+
+func (db) CompactView(context.Context, string) error {
+	return nil
+}
+
+func (db) ViewCleanup(context.Context) error {
+	return nil
+}
+
+func (db) Changes(context.Context, driver.Options) (driver.Changes, error) {
+	return nil, nil
+}
+
+func (db) PutAttachment(context.Context, string, *driver.Attachment, driver.Options) (string, error) {
+	return "", nil
+}
+
+func (db) GetAttachment(context.Context, string, string, driver.Options) (*driver.Attachment, error) {
+	return nil, nil
+}
+
+func (db) DeleteAttachment(context.Context, string, string, driver.Options) (string, error) {
+	return "", nil
+}
+
+func (db) Query(context.Context, string, string, driver.Options) (driver.Rows, error) {
+	return nil, nil
+}
+
+func (db) Close() error {
+	return nil
+}