84 lines
2 KiB
Go
84 lines
2 KiB
Go
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// 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 evaluator
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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/context"
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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 []types.Datum, _ context.Context) (d types.Datum, err error) {
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d = args[0]
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switch d.Kind() {
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case types.KindNull:
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return d, nil
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case types.KindUint64:
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return d, nil
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case types.KindInt64:
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iv := d.GetInt64()
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if iv >= 0 {
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d.SetInt64(iv)
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return d, nil
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}
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d.SetInt64(-iv)
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return d, nil
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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 := d.ToFloat64()
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d.SetFloat64(math.Abs(f))
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return d, errors.Trace(err)
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}
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}
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func builtinRand(args []types.Datum, _ context.Context) (d types.Datum, err error) {
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if len(args) == 1 && args[0].Kind() != types.KindNull {
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seed, err := args[0].ToInt64()
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if err != nil {
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d.SetNull()
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return d, errors.Trace(err)
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}
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rand.Seed(seed)
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}
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d.SetFloat64(rand.Float64())
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return d, nil
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}
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func builtinPow(args []types.Datum, _ context.Context) (d types.Datum, err error) {
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x, err := args[0].ToFloat64()
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if err != nil {
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d.SetNull()
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return d, errors.Trace(err)
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}
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y, err := args[1].ToFloat64()
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if err != nil {
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d.SetNull()
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return d, errors.Trace(err)
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}
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d.SetFloat64(math.Pow(x, y))
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return d, nil
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}
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