68 lines
1.8 KiB
Go
68 lines
1.8 KiB
Go
// Copyright 2013 The ql Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSES/QL-LICENSE file.
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// Copyright 2015 PingCAP, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package builtin
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import (
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"math"
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"math/rand"
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"github.com/juju/errors"
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"github.com/pingcap/tidb/util/types"
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)
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// see https://dev.mysql.com/doc/refman/5.7/en/mathematical-functions.html
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func builtinAbs(args []interface{}, ctx map[interface{}]interface{}) (v interface{}, err error) {
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switch x := args[0].(type) {
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case nil:
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return nil, nil
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case uint, uint8, uint16, uint32, uint64:
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return x, nil
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case int, int8, int16, int32, int64:
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// we don't need to handle error here, it must be success
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v, _ := types.ToInt64(args[0])
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if v >= 0 {
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return x, nil
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}
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// TODO: handle overflow if x is MinInt64
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return -v, nil
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case *types.DataItem:
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args[0] = x.Data
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return builtinAbs(args, ctx)
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default:
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// we will try to convert other types to float
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// TODO: if time has no precision, it will be a integer
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f, err := types.ToFloat64(args[0])
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return math.Abs(f), errors.Trace(err)
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}
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}
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func builtinRand(args []interface{}, ctx map[interface{}]interface{}) (v interface{}, err error) {
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if len(args) == 1 {
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seed, err := types.ToInt64(args[0])
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if err != nil {
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return nil, errors.Trace(err)
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}
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rand.Seed(seed)
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}
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return rand.Float64(), nil
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}
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