database-filesystem, demo log tailing in term

models/dbfs/dbfs_test.go

@@ -0,0 +1,154 @@
+// Copyright 2022 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 dbfs
+
+import (
+	"bufio"
+	"io"
+	"os"
+	"testing"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/unittest"
+
+	"github.com/stretchr/testify/assert"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+func changeDefaultFileBlockSize(n int64) (restore func()) {
+	old := defaultFileBlockSize
+	defaultFileBlockSize = n
+	return func() {
+		defaultFileBlockSize = old
+	}
+}
+
+func TestDbfsBasic(t *testing.T) {
+	defer changeDefaultFileBlockSize(4)()
+
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	// test basic write/read
+	f, err := OpenFile(db.DefaultContext, "test.txt", os.O_RDWR|os.O_CREATE)
+	assert.NoError(t, err)
+
+	n, err := f.Write([]byte("0123456789")) // blocks: 0123 4567 89
+	assert.NoError(t, err)
+	assert.EqualValues(t, 10, n)
+
+	_, err = f.Seek(0, io.SeekStart)
+	assert.NoError(t, err)
+
+	buf, err := io.ReadAll(f)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 10, n)
+	assert.EqualValues(t, "0123456789", string(buf))
+
+	// write some new data
+	_, err = f.Seek(1, io.SeekStart)
+	assert.NoError(t, err)
+	_, err = f.Write([]byte("bcdefghi")) // blocks: 0bcd efgh i9
+	assert.NoError(t, err)
+
+	// read from offset
+	buf, err = io.ReadAll(f)
+	assert.NoError(t, err)
+	assert.EqualValues(t, "9", string(buf))
+
+	// read all
+	_, err = f.Seek(0, io.SeekStart)
+	assert.NoError(t, err)
+	buf, err = io.ReadAll(f)
+	assert.NoError(t, err)
+	assert.EqualValues(t, "0bcdefghi9", string(buf))
+
+	// write to new size
+	_, err = f.Seek(-1, io.SeekEnd)
+	assert.NoError(t, err)
+	_, err = f.Write([]byte("JKLMNOP")) // blocks: 0bcd efgh iJKL MNOP
+	assert.NoError(t, err)
+	_, err = f.Seek(0, io.SeekStart)
+	assert.NoError(t, err)
+	buf, err = io.ReadAll(f)
+	assert.NoError(t, err)
+	assert.EqualValues(t, "0bcdefghiJKLMNOP", string(buf))
+
+	// write beyond EOF and fill with zero
+	_, err = f.Seek(5, io.SeekCurrent)
+	assert.NoError(t, err)
+	_, err = f.Write([]byte("xyzu")) // blocks: 0bcd efgh iJKL MNOP 0000 0xyz u
+	assert.NoError(t, err)
+	_, err = f.Seek(0, io.SeekStart)
+	assert.NoError(t, err)
+	buf, err = io.ReadAll(f)
+	assert.NoError(t, err)
+	assert.EqualValues(t, "0bcdefghiJKLMNOP\x00\x00\x00\x00\x00xyzu", string(buf))
+
+	// write to the block with zeros
+	_, err = f.Seek(-6, io.SeekCurrent)
+	assert.NoError(t, err)
+	_, err = f.Write([]byte("ABCD")) // blocks: 0bcd efgh iJKL MNOP 000A BCDz u
+	assert.NoError(t, err)
+	_, err = f.Seek(0, io.SeekStart)
+	assert.NoError(t, err)
+	buf, err = io.ReadAll(f)
+	assert.NoError(t, err)
+	assert.EqualValues(t, "0bcdefghiJKLMNOP\x00\x00\x00ABCDzu", string(buf))
+
+	assert.NoError(t, f.Close())
+
+	// test rename
+	err = Rename(db.DefaultContext, "test.txt", "test2.txt")
+	assert.NoError(t, err)
+
+	_, err = OpenFile(db.DefaultContext, "test.txt", os.O_RDONLY)
+	assert.Error(t, err)
+
+	f, err = OpenFile(db.DefaultContext, "test2.txt", os.O_RDONLY)
+	assert.NoError(t, err)
+	assert.NoError(t, f.Close())
+
+	// test remove
+	err = Remove(db.DefaultContext, "test2.txt")
+	assert.NoError(t, err)
+
+	_, err = OpenFile(db.DefaultContext, "test2.txt", os.O_RDONLY)
+	assert.Error(t, err)
+}
+
+func TestDbfsReadWrite(t *testing.T) {
+	defer changeDefaultFileBlockSize(4)()
+
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	f1, err := OpenFile(db.DefaultContext, "test.log", os.O_RDWR|os.O_CREATE)
+	assert.NoError(t, err)
+	defer f1.Close()
+
+	f2, err := OpenFile(db.DefaultContext, "test.log", os.O_RDONLY)
+	assert.NoError(t, err)
+	defer f2.Close()
+
+	_, err = f1.Write([]byte("line 1\n"))
+	assert.NoError(t, err)
+
+	f2r := bufio.NewReader(f2)
+
+	line, err := f2r.ReadString('\n')
+	assert.NoError(t, err)
+	assert.EqualValues(t, "line 1\n", line)
+	_, err = f2r.ReadString('\n')
+	assert.ErrorIs(t, err, io.EOF)
+
+	_, err = f1.Write([]byte("line 2\n"))
+	assert.NoError(t, err)
+
+	line, err = f2r.ReadString('\n')
+	assert.NoError(t, err)
+	assert.EqualValues(t, "line 2\n", line)
+	_, err = f2r.ReadString('\n')
+	assert.ErrorIs(t, err, io.EOF)
+}