github.com/zhongdalu/gf@v1.0.0/g/container/gtype/float64.go (about)

     1  // Copyright 2018 gf Author(https://github.com/zhongdalu/gf). All Rights Reserved.
     2  //
     3  // This Source Code Form is subject to the terms of the MIT License.
     4  // If a copy of the MIT was not distributed with this file,
     5  // You can obtain one at https://github.com/zhongdalu/gf.
     6  
     7  package gtype
     8  
     9  import (
    10  	"math"
    11  	"sync/atomic"
    12  	"unsafe"
    13  )
    14  
    15  type Float64 struct {
    16  	value uint64
    17  }
    18  
    19  // NewFloat64 returns a concurrent-safe object for float64 type,
    20  // with given initial value <value>.
    21  func NewFloat64(value ...float64) *Float64 {
    22  	if len(value) > 0 {
    23  		return &Float64{
    24  			value: math.Float64bits(value[0]),
    25  		}
    26  	}
    27  	return &Float64{}
    28  }
    29  
    30  // Clone clones and returns a new concurrent-safe object for float64 type.
    31  func (v *Float64) Clone() *Float64 {
    32  	return NewFloat64(v.Val())
    33  }
    34  
    35  // Set atomically stores <value> into t.value and returns the previous value of t.value.
    36  func (v *Float64) Set(value float64) (old float64) {
    37  	return math.Float64frombits(atomic.SwapUint64(&v.value, math.Float64bits(value)))
    38  }
    39  
    40  // Val atomically loads t.value.
    41  func (v *Float64) Val() float64 {
    42  	return math.Float64frombits(atomic.LoadUint64(&v.value))
    43  }
    44  
    45  // Add atomically adds <delta> to t.value and returns the new value.
    46  func (v *Float64) Add(delta float64) (new float64) {
    47  	for {
    48  		old := math.Float64frombits(v.value)
    49  		new = old + delta
    50  		if atomic.CompareAndSwapUint64(
    51  			(*uint64)(unsafe.Pointer(&v.value)),
    52  			math.Float64bits(old),
    53  			math.Float64bits(new),
    54  		) {
    55  			break
    56  		}
    57  	}
    58  	return
    59  }
    60  
    61  // Cas executes the compare-and-swap operation for value.
    62  func (v *Float64) Cas(old, new float64) bool {
    63  	return atomic.CompareAndSwapUint64(&v.value, uint64(old), uint64(new))
    64  }