Files
tidb/pkg/bindinfo/binding_cache_test.go

135 lines
4.5 KiB
Go

// Copyright 2022 PingCAP, Inc.
//
// 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 bindinfo
import (
"strconv"
"strings"
"testing"
"github.com/pingcap/tidb/pkg/bindinfo/norm"
"github.com/pingcap/tidb/pkg/parser"
"github.com/pingcap/tidb/pkg/sessionctx/variable"
"github.com/pingcap/tidb/pkg/util/hack"
"github.com/stretchr/testify/require"
)
func bindingFuzzyDigest(t *testing.T, b Binding) string {
p := parser.New()
stmt, err := p.ParseOneStmt(b.BindSQL, b.Charset, b.Collation)
require.NoError(t, err)
_, fuzzyDigest := norm.NormalizeStmtForBinding(stmt, norm.WithFuzz(true))
return fuzzyDigest
}
func TestFuzzyBindingCache(t *testing.T) {
fbc := newFuzzyBindingCache(nil).(*fuzzyBindingCache)
b1 := Binding{BindSQL: "SELECT * FROM db1.t1", SQLDigest: "b1"}
fDigest1 := bindingFuzzyDigest(t, b1)
b2 := Binding{BindSQL: "SELECT * FROM db2.t1", SQLDigest: "b2"}
b3 := Binding{BindSQL: "SELECT * FROM db2.t3", SQLDigest: "b3"}
fDigest3 := bindingFuzzyDigest(t, b3)
// add 3 bindings and b1 and b2 have the same fuzzy digest
require.NoError(t, fbc.SetBinding(b1.SQLDigest, []Binding{b1}))
require.NoError(t, fbc.SetBinding(b2.SQLDigest, []Binding{b2}))
require.NoError(t, fbc.SetBinding(b3.SQLDigest, []Binding{b3}))
require.Equal(t, len(fbc.fuzzy2SQLDigests), 2) // b1 and b2 have the same fuzzy digest
require.Equal(t, len(fbc.fuzzy2SQLDigests[fDigest1]), 2)
require.Equal(t, len(fbc.fuzzy2SQLDigests[fDigest3]), 1)
require.Equal(t, len(fbc.sql2FuzzyDigest), 3)
_, ok := fbc.sql2FuzzyDigest[b1.SQLDigest]
require.True(t, ok)
_, ok = fbc.sql2FuzzyDigest[b2.SQLDigest]
require.True(t, ok)
_, ok = fbc.sql2FuzzyDigest[b3.SQLDigest]
require.True(t, ok)
// remove b2
fbc.RemoveBinding(b2.SQLDigest)
require.Equal(t, len(fbc.fuzzy2SQLDigests), 2)
require.Equal(t, len(fbc.fuzzy2SQLDigests[fDigest1]), 1)
require.Equal(t, len(fbc.fuzzy2SQLDigests[fDigest3]), 1)
require.Equal(t, len(fbc.sql2FuzzyDigest), 2)
_, ok = fbc.sql2FuzzyDigest[b1.SQLDigest]
require.True(t, ok)
_, ok = fbc.sql2FuzzyDigest[b2.SQLDigest]
require.False(t, ok) // can't find b2 now
_, ok = fbc.sql2FuzzyDigest[b3.SQLDigest]
require.True(t, ok)
// test deep copy
newCache, err := fbc.Copy()
require.NoError(t, err)
newFBC := newCache.(*fuzzyBindingCache)
newFBC.fuzzy2SQLDigests[fDigest1] = nil
delete(newFBC.sql2FuzzyDigest, b1.SQLDigest)
require.Equal(t, len(fbc.fuzzy2SQLDigests[fDigest1]), 1) // no impact to the original cache
_, ok = fbc.sql2FuzzyDigest[b1.SQLDigest]
require.True(t, ok)
}
func TestBindCache(t *testing.T) {
variable.MemQuotaBindingCache.Store(250)
bindCache := newBindCache().(*bindingCache)
value := make([]Bindings, 3)
key := make([]bindingCacheKey, 3)
var bigKey string
for i := 0; i < 3; i++ {
cacheKey := strings.Repeat(strconv.Itoa(i), 50)
key[i] = bindingCacheKey(hack.Slice(cacheKey))
value[i] = []Binding{{OriginalSQL: cacheKey}}
bigKey += cacheKey
require.Equal(t, int64(116), calcBindCacheKVMem(key[i], value[i]))
}
ok, err := bindCache.set(key[0], value[0])
require.True(t, ok)
require.Nil(t, err)
result := bindCache.get(key[0])
require.NotNil(t, result)
ok, err = bindCache.set(key[1], value[1])
require.True(t, ok)
require.Nil(t, err)
result = bindCache.get(key[1])
require.NotNil(t, result)
ok, err = bindCache.set(key[2], value[2])
require.True(t, ok)
require.NotNil(t, err) // exceed the memory limit
result = bindCache.get(key[2])
require.NotNil(t, result)
// key[0] is not in the cache
result = bindCache.get(key[0])
require.Nil(t, result)
// key[1] is still in the cache
result = bindCache.get(key[1])
require.NotNil(t, result)
bigBindCacheKey := bindingCacheKey(hack.Slice(bigKey))
bigBindCacheValue := []Binding{{OriginalSQL: strings.Repeat("x", 100)}}
require.Equal(t, int64(266), calcBindCacheKVMem(bigBindCacheKey, bigBindCacheValue))
ok, err = bindCache.set(bigBindCacheKey, bigBindCacheValue)
require.False(t, ok) // the key-value pair is too big to be cached
require.NotNil(t, err)
result = bindCache.get(bigBindCacheKey)
require.Nil(t, result)
}