func TestPcacherSimple(t *testing.T) {
pc := pcacher.Create("/tmp/pcacher_simple_test.db", pcacher.PAGE_SIZE*50)
for i := 0; i < 100; i++ {
tmp := make([]byte, pcacher.PAGE_SIZE)
pgno := pc.NewPage(tmp)
pg, err := pc.GetPage(pgno)
if err != nil {
utils.Fatal(err)
}
pg.Dirty()
pg.Data()[0] = byte(i)
pg.Release()
}
pc.Close()
pc = pcacher.Open("/tmp/pcacher_simple_test.db", pcacher.PAGE_SIZE*50)
for i := 1; i <= 100; i++ {
pg, err := pc.GetPage(pcacher.Pgno(i))
if err != nil {
utils.Fatal(err)
}
if pg.Data()[0] != byte(i-1) {
utils.Fatal(err)
}
pg.Release()
}
pc.Close()
}
func TestPcacherMultiSimple(t *testing.T) {
pc := pcacher.Create("/tmp/pcacher_multisimple_test.db", pcacher.PAGE_SIZE*50)
var noPages uint32
wg := sync.WaitGroup{}
noWorkers := 200
wg.Add(noWorkers)
worker := func(id int) {
for i := 0; i < 80; i++ {
op := rand.Int() % 20
if op == 0 { // New Page
data := utils.RandBytes(pcacher.PAGE_SIZE)
pgno := pc.NewPage(data)
pg, err := pc.GetPage(pgno)
if err != nil {
if err == cacher.ErrCacheFull {
continue
}
utils.Fatal(err)
}
atomic.AddUint32(&noPages, 1)
pg.Release()
} else if op < 20 { // Read
mod := atomic.LoadUint32(&noPages)
if mod == 0 {
continue
}
pgno := pcacher.Pgno((rand.Uint32() % mod) + 1)
pg, err := pc.GetPage(pgno)
if err != nil {
if err == cacher.ErrCacheFull {
continue
}
utils.Fatal(err)
}
pg.Release()
}
}
wg.Done()
}
for i := 0; i < noWorkers; i++ {
go worker(i)
}
wg.Wait()
}
// get 根据pgno从DB文件中读取页的内容, 并包裹成一页返回.
// get必须能够支持并发.
func (p *pcacher) getForCacher(uid utils.UUID) (interface{}, error) {
pgno := UUID2Pgno(uid)
offset := pageOffset(pgno)
buf := make([]byte, PAGE_SIZE)
p.fileLock.Lock()
_, err := p.file.ReadAt(buf, offset)
if err != nil {
utils.Fatal(uid, " Read: ", pgno, ", ", offset, " ", err) // 如果DB文件出了问题, 则应该立即停止
}
p.fileLock.Unlock()
pg := NewPage(pgno, buf, p)
return pg, nil
}
func TestPcacherMulti(t *testing.T) {
pc := pcacher.Create("/tmp/pcacher_multi_test.db", pcacher.PAGE_SIZE*10)
mpc := pcacher.NewMock()
lockNew := sync.Mutex{}
var noPages uint32
wg := sync.WaitGroup{}
noWorkers := 30
wg.Add(noWorkers)
worker := func(id int) {
for i := 0; i < 1000; i++ {
op := rand.Int() % 20
if op == 0 { // New Page
data := utils.RandBytes(pcacher.PAGE_SIZE)
lockNew.Lock() // 为了让pc和mpc同步更新, 多个线程同时new, 页号可能会出错.
pc.NewPage(data)
mpc.NewPage(data)
lockNew.Unlock()
atomic.AddUint32(&noPages, 1)
} else if op < 10 { // Check
mod := atomic.LoadUint32(&noPages)
if mod == 0 {
continue
}
pgno := pcacher.Pgno((rand.Uint32() % mod) + 1)
pg, err := pc.GetPage(pgno)
if err != nil {
if err == cacher.ErrCacheFull {
continue
}
utils.Fatal(err)
}
mpg, _ := mpc.GetPage(pgno)
pg.Lock()
if bytes.Compare(mpg.Data(), pg.Data()) != 0 {
utils.Fatal("error")
}
pg.Unlock()
pg.Release()
} else { // Update
mod := atomic.LoadUint32(&noPages)
if mod == 0 {
continue
}
pgno := pcacher.Pgno((rand.Uint32() % mod) + 1)
pg, err := pc.GetPage(pgno)
if err != nil {
if err == cacher.ErrCacheFull {
continue
}
utils.Fatal(err)
}
mpg, _ := mpc.GetPage(pgno)
newData := utils.RandBytes(pcacher.PAGE_SIZE)
pg.Lock()
mpg.Dirty()
copy(mpg.Data(), newData)
pg.Dirty()
copy(pg.Data(), newData)
pg.Unlock()
pg.Release()
}
}
wg.Done()
}
for i := 0; i < noWorkers; i++ {
go worker(i)
}
wg.Wait()
}