*: add encode SQL digest function (pingcap#43194)

close pingcap#43193

executor/cluster_table_test.go

@@ -392,6 +392,32 @@ func TestFunctionDecodeSQLDigestsPrivilege(t *testing.T) {
 	tk.MustExec("select tidb_decode_sql_digests('[\"aa\"]')")
 }
 
+func TestFunctionEncodeSQLDigest(t *testing.T) {
+	store, dom := testkit.CreateMockStoreAndDomain(t)
+	srv := createRPCServer(t, dom)
+	defer srv.Stop()
+
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	require.NoError(t, tk.Session().Auth(&auth.UserIdentity{Username: "root", Hostname: "%"}, nil, nil, nil))
+	tk.MustExec("drop table if exists test_func_encode_sql_digest")
+	tk.MustExec("create table test_func_encode_sql_digest(id int primary key, v int)")
+
+	q1 := "begin"
+	digest1 := parser.DigestHash(q1)
+	q2 := "select @@tidb_current_ts"
+	digest2 := parser.DigestHash(q2)
+	q3 := "select id, v from test_func_decode_sql_digests where id = 1 for update"
+	digest3 := parser.DigestHash(q3)
+
+	tk.MustQuery(fmt.Sprintf("select tidb_encode_sql_digest(\"%s\")", q1)).Check(testkit.Rows(digest1.String()))
+	tk.MustQuery(fmt.Sprintf("select tidb_encode_sql_digest(\"%s\")", q2)).Check(testkit.Rows(digest2.String()))
+	tk.MustQuery(fmt.Sprintf("select tidb_encode_sql_digest(\"%s\")", q3)).Check(testkit.Rows(digest3.String()))
+
+	tk.MustQuery("select tidb_encode_sql_digest(null)").Check(testkit.Rows("<nil>"))
+	tk.MustGetErrCode("select tidb_encode_sql_digest()", 1582)
+}
+
 func prepareLogs(t *testing.T, logData []string, fileNames []string) {
 	for i, log := range logData {
 		f, err := os.OpenFile(fileNames[i], os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)

executor/test/showtest/show_test.go

@@ -1524,7 +1524,7 @@ func TestShowBuiltin(t *testing.T) {
 	res := tk.MustQuery("show builtins;")
 	require.NotNil(t, res)
 	rows := res.Rows()
-	const builtinFuncNum = 288
+	const builtinFuncNum = 289
 	require.Equal(t, builtinFuncNum, len(rows))
 	require.Equal(t, rows[0][0].(string), "abs")
 	require.Equal(t, rows[builtinFuncNum-1][0].(string), "yearweek")

expression/builtin.go

@@ -903,6 +903,7 @@ var funcs = map[string]functionClass{
 	ast.TiDBDecodePlan:       &tidbDecodePlanFunctionClass{baseFunctionClass{ast.TiDBDecodePlan, 1, 1}},
 	ast.TiDBDecodeBinaryPlan: &tidbDecodePlanFunctionClass{baseFunctionClass{ast.TiDBDecodeBinaryPlan, 1, 1}},
 	ast.TiDBDecodeSQLDigests: &tidbDecodeSQLDigestsFunctionClass{baseFunctionClass{ast.TiDBDecodeSQLDigests, 1, 2}},
+	ast.TiDBEncodeSQLDigest:  &tidbEncodeSQLDigestFunctionClass{baseFunctionClass{ast.TiDBEncodeSQLDigest, 1, 1}},
 
 	// TiDB Sequence function.
 	ast.NextVal: &nextValFunctionClass{baseFunctionClass{ast.NextVal, 1, 1}},

expression/builtin_info.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/pingcap/errors"
+	"github.com/pingcap/tidb/parser"
 	"github.com/pingcap/tidb/parser/ast"
 	"github.com/pingcap/tidb/parser/model"
 	"github.com/pingcap/tidb/parser/mysql"
@@ -964,6 +965,45 @@ func (b *builtinTiDBDecodeSQLDigestsSig) evalString(row chunk.Row) (string, bool
 	return string(resultStr), false, nil
 }
 
+type tidbEncodeSQLDigestFunctionClass struct {
+	baseFunctionClass
+}
+
+func (c *tidbEncodeSQLDigestFunctionClass) getFunction(ctx sessionctx.Context, args []Expression) (builtinFunc, error) {
+	if err := c.verifyArgs(args); err != nil {
+		return nil, err
+	}
+
+	argTps := []types.EvalType{types.ETString}
+	bf, err := newBaseBuiltinFuncWithTp(ctx, c.funcName, args, types.ETString, argTps...)
+	if err != nil {
+		return nil, err
+	}
+	sig := &builtinTiDBEncodeSQLDigestSig{bf}
+	return sig, nil
+}
+
+type builtinTiDBEncodeSQLDigestSig struct {
+	baseBuiltinFunc
+}
+
+func (b *builtinTiDBEncodeSQLDigestSig) Clone() builtinFunc {
+	newSig := &builtinTiDBEncodeSQLDigestSig{}
+	newSig.cloneFrom(&b.baseBuiltinFunc)
+	return newSig
+}
+
+func (b *builtinTiDBEncodeSQLDigestSig) evalString(row chunk.Row) (string, bool, error) {
+	orgSQLStr, isNull, err := b.getArgs()[0].EvalString(b.ctx, row)
+	if err != nil {
+		return "", true, err
+	}
+	if isNull {
+		return "", true, nil
+	}
+	return parser.DigestHash(orgSQLStr).String(), false, nil
+}
+
 type tidbDecodePlanFunctionClass struct {
 	baseFunctionClass
 }

parser/ast/functions.go

@@ -265,6 +265,7 @@ const (
 	TiDBDecodePlan       = "tidb_decode_plan"
 	TiDBDecodeBinaryPlan = "tidb_decode_binary_plan"
 	TiDBDecodeSQLDigests = "tidb_decode_sql_digests"
+	TiDBEncodeSQLDigest  = "tidb_encode_sql_digest"
 	FormatBytes          = "format_bytes"
 	FormatNanoTime       = "format_nano_time"
 	CurrentResourceGroup = "current_resource_group"