Merge pull request #3227 from dolthub/elian/9857

dolthub/dolt#9857: Add UUID_SHORT() support

Author: elianddb

enginetest/queries/script_queries.go

@@ -121,6 +121,68 @@ type ScriptTestAssertion struct {
 // Unlike other engine tests, ScriptTests must be self-contained. No other tables are created outside the definition of
 // the tests.
 var ScriptTests = []ScriptTest{
+	{
+		// https://github.com/dolthub/dolt/issues/9857
+		Name:        "UUID_SHORT() function returns 64-bit unsigned integers with proper construction",
+		Dialect:     "mysql",
+		SetUpScript: []string{},
+		Assertions: []ScriptTestAssertion{
+			{
+				Query: "SELECT UUID_SHORT() > 0",
+				Expected: []sql.Row{
+					{true}, // Should return positive values
+				},
+			},
+			{
+				Query: "SELECT UUID_SHORT() != UUID_SHORT()",
+				Expected: []sql.Row{
+					{true}, // Should return different values on each call
+				},
+			},
+			{
+				Query: "SELECT UUID_SHORT() + 0 > 0",
+				Expected: []sql.Row{
+					{true}, // Should work in arithmetic expressions
+				},
+			},
+			{
+				Query: "SELECT CAST(UUID_SHORT() AS CHAR) != ''",
+				Expected: []sql.Row{
+					{true}, // Should cast to non-empty string
+				},
+			},
+			{
+				Query: "SELECT UUID_SHORT() BETWEEN 1 AND 18446744073709551615",
+				Expected: []sql.Row{
+					{true}, // Should be within uint64 range
+				},
+			},
+			{
+				Query: "SELECT (UUID_SHORT() & 0xFF00000000000000) >> 56 BETWEEN 0 AND 255",
+				Expected: []sql.Row{
+					{true}, // Server ID should be 0-255
+				},
+			},
+			{
+				Query: "SET @@global.server_id = 253",
+				Expected: []sql.Row{
+					{types.NewOkResult(0)},
+				},
+			},
+			{
+				Query: "SELECT (UUID_SHORT() & 0xFF00000000000000) >> 56 BETWEEN 0 AND 255",
+				Expected: []sql.Row{
+					{true}, // server time won't let us pin this down further
+				},
+			},
+			{
+				Query: "SET @@global.server_id = 1",
+				Expected: []sql.Row{
+					{types.NewOkResult(0)},
+				},
+			},
+		},
+	},
 	{
 		// https://github.com/dolthub/go-mysql-server/issues/3216
 		Name: "UNION ALL with BLOB columns",

sql/expression/function/registry.go

@@ -318,6 +318,7 @@ var BuiltIns = []sql.Function{
 	sql.NewFunction0("user", NewUser),
 	sql.FunctionN{Name: "utc_timestamp", Fn: NewUTCTimestamp},
 	sql.Function0{Name: "uuid", Fn: NewUUIDFunc},
+	sql.Function0{Name: "uuid_short", Fn: NewUUIDShortFunc},
 	sql.FunctionN{Name: "uuid_to_bin", Fn: NewUUIDToBin},
 	sql.FunctionN{Name: "week", Fn: NewWeek},
 	sql.Function1{Name: "values", Fn: NewValues},

sql/expression/function/uuid.go

@@ -16,13 +16,21 @@ package function
 
 import (
 	"fmt"
+	"sync"
 
 	"github.com/dolthub/vitess/go/sqltypes"
 	"github.com/dolthub/vitess/go/vt/proto/query"
 	"github.com/google/uuid"
 
 	"github.com/dolthub/go-mysql-server/sql"
 	"github.com/dolthub/go-mysql-server/sql/types"
+	"github.com/dolthub/go-mysql-server/sql/variables"
+)
+
+// Global state for UUID_SHORT function
+var (
+	uuidShortMu      sync.Mutex
+	uuidShortCounter uint64
 )
 
 // UUID()
@@ -528,3 +536,101 @@ func (bu BinToUUID) Children() []sql.Expression {
 func (bu BinToUUID) IsNullable() bool {
 	return false
 }
+
+// UUID_SHORT()
+//
+// Returns a "short" universal identifier as a 64-bit unsigned integer. Values returned by UUID_SHORT() differ from the
+// string-format 128-bit identifiers returned by the UUID() function and have different uniqueness properties. The value
+// of UUID_SHORT() is guaranteed to be unique if the following conditions hold:
+//
+// The server_id value of the current server is between 0 and 255 and is unique among your set of source and replica servers
+//
+// The UUID_SHORT() return value is constructed this way:
+//   (server_id & 255) << 56
+// + (server_startup_time_in_seconds << 24)
+// + incremented_variable++;
+//
+// Note: UUID_SHORT() does not work with statement-based replication.
+// https://dev.mysql.com/doc/refman/8.4/en/miscellaneous-functions.html#function_uuid-short
+
+type UUIDShortFunc struct{}
+
+var _ sql.FunctionExpression = &UUIDShortFunc{}
+var _ sql.CollationCoercible = &UUIDShortFunc{}
+
+func NewUUIDShortFunc() sql.Expression {
+	return &UUIDShortFunc{}
+}
+
+// Description returns a human-readable description of the UUID_SHORT function.
+func (u *UUIDShortFunc) Description() string {
+	return "returns a short universal identifier as a 64-bit unsigned integer."
+}
+
+// String returns a string representation of the UUID_SHORT function call.
+func (u *UUIDShortFunc) String() string {
+	return "UUID_SHORT()"
+}
+
+// Type returns the data type of the UUID_SHORT function result (Uint64).
+func (u *UUIDShortFunc) Type() sql.Type {
+	return types.Uint64
+}
+
+// CollationCoercibility implements the interface sql.CollationCoercible.
+func (u *UUIDShortFunc) CollationCoercibility(ctx *sql.Context) (collation sql.CollationID, coercibility byte) {
+	return sql.Collation_binary, 5
+}
+
+// Eval generates a 64-bit UUID_SHORT value using server_id, startup time, and counter.
+func (u *UUIDShortFunc) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
+	uuidShortMu.Lock()
+	defer uuidShortMu.Unlock()
+
+	uuidShortCounter++
+
+	serverID := uint64(1) // Default fallback
+	if _, val, ok := sql.SystemVariables.GetGlobal("server_id"); ok {
+		if serverIDVal, ok := val.(uint32); ok {
+			serverID = uint64(serverIDVal)
+		}
+	}
+
+	// Construct the UUID_SHORT value according to MySQL specification:
+	result := ((serverID & 255) << 56) + (uint64(variables.ServerStartUpTime.Unix()) << 24) + uuidShortCounter
+	return result, nil
+}
+
+// WithChildren returns a new UUID_SHORT function with the given children (must be empty).
+func (u *UUIDShortFunc) WithChildren(children ...sql.Expression) (sql.Expression, error) {
+	if len(children) != 0 {
+		return nil, sql.ErrInvalidChildrenNumber.New(u, len(children), 0)
+	}
+
+	return &UUIDShortFunc{}, nil
+}
+
+// FunctionName returns the name of the UUID_SHORT function.
+func (u *UUIDShortFunc) FunctionName() string {
+	return "UUID_SHORT"
+}
+
+// Resolved returns true since UUID_SHORT has no dependencies to resolve.
+func (u *UUIDShortFunc) Resolved() bool {
+	return true
+}
+
+// Children returns the children expressions of this expression.
+func (u *UUIDShortFunc) Children() []sql.Expression {
+	return nil
+}
+
+// IsNullable returns false since UUID_SHORT always returns a value.
+func (u *UUIDShortFunc) IsNullable() bool {
+	return false
+}
+
+// IsNonDeterministic returns true since UUID_SHORT generates different values on each call.
+func (u *UUIDShortFunc) IsNonDeterministic() bool {
+	return true
+}

sql/expression/function/uuid_test.go

@@ -215,3 +215,129 @@ func TestBinToUUIDFailing(t *testing.T) {
 		})
 	}
 }
+
+func TestUUIDShort(t *testing.T) {
+	ctx := sql.NewEmptyContext()
+	uuidShortE := NewUUIDShortFunc()
+
+	// Test that UUID_SHORT returns sequential values
+	result1, err := uuidShortE.Eval(ctx, sql.Row{nil})
+	require.NoError(t, err)
+	require.IsType(t, uint64(0), result1)
+
+	result2, err := uuidShortE.Eval(ctx, sql.Row{nil})
+	require.NoError(t, err)
+	require.IsType(t, uint64(0), result2)
+
+	result3, err := uuidShortE.Eval(ctx, sql.Row{nil})
+	require.NoError(t, err)
+	require.IsType(t, uint64(0), result3)
+
+	// Values should be sequential (incrementing by 1)
+	require.Equal(t, result1.(uint64)+1, result2.(uint64))
+	require.Equal(t, result2.(uint64)+1, result3.(uint64))
+
+	// Test that values are 64-bit unsigned integers
+	require.Greater(t, result1.(uint64), uint64(0))
+	require.Greater(t, result2.(uint64), uint64(0))
+	require.Greater(t, result3.(uint64), uint64(0))
+}
+
+func TestUUIDShortMultipleInstances(t *testing.T) {
+	ctx := sql.NewEmptyContext()
+
+	uuidShort1 := NewUUIDShortFunc()
+	uuidShort2 := NewUUIDShortFunc()
+
+	result1, err := uuidShort1.Eval(ctx, sql.Row{nil})
+	require.NoError(t, err)
+
+	result2, err := uuidShort2.Eval(ctx, sql.Row{nil})
+	require.NoError(t, err)
+
+	// Both should return sequential values from the global counter
+	require.IsType(t, uint64(0), result1)
+	require.IsType(t, uint64(0), result2)
+	require.Greater(t, result1.(uint64), uint64(0))
+	require.Greater(t, result2.(uint64), uint64(0))
+
+	// Values should be sequential (global counter)
+	require.Equal(t, result1.(uint64)+1, result2.(uint64))
+}
+
+func TestUUIDShortWithChildren(t *testing.T) {
+	uuidShortE := NewUUIDShortFunc()
+
+	newExpr, err := uuidShortE.WithChildren()
+	require.NoError(t, err)
+	require.NotNil(t, newExpr)
+
+	_, err = uuidShortE.WithChildren(expression.NewLiteral(1, types.Int64))
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "invalid children number")
+}
+
+func TestUUIDShortProperties(t *testing.T) {
+	uuidShortE := NewUUIDShortFunc().(*UUIDShortFunc)
+
+	require.Equal(t, "UUID_SHORT", uuidShortE.FunctionName())
+	require.Equal(t, "returns a short universal identifier as a 64-bit unsigned integer.", uuidShortE.Description())
+	require.Equal(t, "UUID_SHORT()", uuidShortE.String())
+	require.Equal(t, types.Uint64, uuidShortE.Type())
+	require.True(t, uuidShortE.Resolved())
+	require.False(t, uuidShortE.IsNullable())
+	require.True(t, uuidShortE.IsNonDeterministic())
+	require.Nil(t, uuidShortE.Children())
+}
+
+func TestUUIDShortServerIdIntegration(t *testing.T) {
+	ctx := sql.NewEmptyContext()
+	uuidShortE := NewUUIDShortFunc()
+
+	result1, err := uuidShortE.Eval(ctx, sql.Row{nil})
+	require.NoError(t, err)
+	require.IsType(t, uint64(0), result1)
+
+	serverIDFromResult := (result1.(uint64) & 0xFF00000000000000) >> 56
+	require.Equal(t, uint64(1), serverIDFromResult)
+
+	err = sql.SystemVariables.SetGlobal(ctx, "server_id", uint32(123))
+	require.NoError(t, err)
+
+	result2, err := uuidShortE.Eval(ctx, sql.Row{nil})
+	require.NoError(t, err)
+	require.IsType(t, uint64(0), result2)
+
+	serverIDFromResult2 := (result2.(uint64) & 0xFF00000000000000) >> 56
+	require.Equal(t, uint64(123), serverIDFromResult2)
+
+	err = sql.SystemVariables.SetGlobal(ctx, "server_id", uint32(255))
+	require.NoError(t, err)
+
+	result3, err := uuidShortE.Eval(ctx, sql.Row{nil})
+	require.NoError(t, err)
+	require.IsType(t, uint64(0), result3)
+
+	serverIDFromResult3 := (result3.(uint64) & 0xFF00000000000000) >> 56
+	require.Equal(t, uint64(255), serverIDFromResult3)
+
+	err = sql.SystemVariables.SetGlobal(ctx, "server_id", uint32(256))
+	require.NoError(t, err)
+
+	result4, err := uuidShortE.Eval(ctx, sql.Row{nil})
+	require.NoError(t, err)
+	require.IsType(t, uint64(0), result4)
+
+	serverIDFromResult4 := (result4.(uint64) & 0xFF00000000000000) >> 56
+	require.Equal(t, uint64(0), serverIDFromResult4)
+
+	err = sql.SystemVariables.SetGlobal(ctx, "server_id", uint32(243))
+	require.NoError(t, err)
+
+	result5, err := uuidShortE.Eval(ctx, sql.Row{nil})
+	require.NoError(t, err)
+	require.IsType(t, uint64(0), result5)
+
+	serverIDFromResult5 := (result5.(uint64) & 0xFF00000000000000) >> 56
+	require.Equal(t, uint64(243), serverIDFromResult5)
+}

sql/variables/system_variables.go

@@ -34,8 +34,8 @@ import (
 // There's also this page, which shows that a TON of variables are still missing ):
 // https://dev.mysql.com/doc/refman/8.0/en/server-system-variable-reference.html
 
-// serverStartUpTime is needed by uptime status variable
-var serverStartUpTime = time.Now()
+// ServerStartUpTime is needed by uptime status variable
+var ServerStartUpTime = time.Now()
 
 // globalSystemVariables is the underlying type of SystemVariables.
 type globalSystemVariables struct {
@@ -2934,7 +2934,7 @@ var systemVars = map[string]sql.SystemVariable{
 		Type:              types.NewSystemBoolType("updatable_views_with_limit"),
 		Default:           int8(1),
 		ValueFunction: func() (interface{}, error) {
-			return int(time.Now().Sub(serverStartUpTime).Seconds()), nil
+			return int(time.Now().Sub(ServerStartUpTime).Seconds()), nil
 		},
 	},
 	"use_secondary_engine": &sql.MysqlSystemVariable{