gmap

该模块包含多个数据结构的map容器：HashMap、TreeMap和ListMap。

使用场景：

任何map/哈希表/关联数组使用场景，尤其是并发安全场景中。

使用方式：

接口文档：

https://godoc.org/github.com/gogf/gf/container/gmap

m := gmap.New(true)

不仅仅是gmap模块，gf框架的其他并发安全数据结构也支持并发安全特性开关。

package main
import (
    "fmt"
    "github.com/gogf/gf/container/gmap"
)
func main() {
    // 创建一个默认的gmap对象，
    // 默认情况下该gmap对象不支持并发安全特性，
    // 初始化时可以给定true参数开启并发安全特性。
    m := gmap.New()
    // 设置键值对
    for i := 0; i < 10; i++ {
        m.Set(i, i)
    }
    // 查询大小
    fmt.Println(m.Size())
    // 批量设置键值对(不同的数据类型对象参数不同)
    m.Sets(map[interface{}]interface{}{
        10 : 10,
        11 : 11,
    })
    fmt.Println(m.Size())
    // 查询是否存在
    fmt.Println(m.Contains(1))
    // 查询键值
    fmt.Println(m.Get(1))
    // 删除数据项
    m.Remove(9)
    fmt.Println(m.Size())
    // 批量删除
    m.Removes([]interface{}{10, 11})
    fmt.Println(m.Size())
    // 当前键名列表(随机排序)
    fmt.Println(m.Keys())
    // 当前键值列表(随机排序)
    fmt.Println(m.Values())
    // 查询键名，当键值不存在时，写入给定的默认值
    fmt.Println(m.GetOrSet(100, 100))
    // 删除键值对，并返回对应的键值
    fmt.Println(m.Remove(100))
    // 遍历map
    m.Iterator(func(k interface{}, v interface{}) bool {
        fmt.Printf("%v:%v ", k, v)
        return true
    })
    // 自定义写锁操作
    m.LockFunc(func(m map[interface{}]interface{}) {
        m[99] = 99
    })
    // 自定义读锁操作
    m.RLockFunc(func(m map[interface{}]interface{}) {
        fmt.Println(m[99])
    })
    // 清空map
    m.Clear()
    // 判断map是否为空
    fmt.Println(m.IsEmpty())
}

执行后，输出结果为：

10
12
true
1
11
[0 1 2 4 6 7 3 5 8]
[3 5 8 0 1 2 4 6 7]
100
100
true

有序遍历

我们来看一下三种不同类型map的有序性遍历示例。

package main
import (
    "fmt"
    "github.com/gogf/gf/frame/g"
    "github.com/gogf/gf/container/gmap"
    "github.com/gogf/gf/util/gutil"
)
func main() {
    array   := g.Slice{2, 3, 1, 5, 4, 6, 8, 7, 9}
    hashMap := gmap.New(true)
    listMap := gmap.NewListMap(true)
    treeMap := gmap.NewTreeMap(gutil.ComparatorInt, true)
    for _, v := range array {
        hashMap.Set(v, v)
    }
    for _, v := range array {
        listMap.Set(v, v)
    }
    for _, v := range array {
        treeMap.Set(v, v)
    }
    fmt.Println("HashMap   Keys:", hashMap.Keys())
    fmt.Println("HashMap Values:", hashMap.Values())
    fmt.Println("ListMap   Keys:", listMap.Keys())
    fmt.Println("ListMap Values:", listMap.Values())
    fmt.Println("TreeMap   Keys:", treeMap.Keys())
    fmt.Println("TreeMap Values:", treeMap.Values())
}

执行后，输出结果为：

HashMap   Keys: [4 6 8 7 9 2 3 1 5]
HashMap Values: [6 8 4 3 1 5 7 9 2]
ListMap   Keys: [2 3 1 5 4 6 8 7 9]
ListMap Values: [2 3 1 5 4 6 8 7 9]
TreeMap   Keys: [1 2 3 4 5 6 7 8 9]
TreeMap Values: [1 2 3 4 5 6 7 8 9]

`FilterEmpty/FilterNil`空值过滤

`Flip`键值对反转

package main
import (
    "fmt"
    "github.com/gogf/gf/container/gmap"
    "github.com/gogf/gf/frame/g"
)
func main() {
    var m gmap.Map
    m.Sets(g.MapAnyAny{
        "k1": "v1",
        "k2": "v2",
    })
    m.Flip()
    fmt.Println(m.Map())
    // May Output:
    // map[v1:k1 v2:k2]
}

package main
import (
    "fmt"
    "github.com/gogf/gf/container/gmap"
    "github.com/gogf/gf/frame/g"
)
func main() {
    var m gmap.Map
    m.Sets(g.MapAnyAny{
        "k1": "v1",
        "k2": "v2",
        "k3": "v3",
        "k4": "v4",
    })
    fmt.Println(m.Keys())
    fmt.Println(m.Values())
    // May Output:
    // [k1 k2 k3 k4]
    // [v2 v3 v4 v1]
}

`Pop/Pops`随机出栈

package main
import (
    "fmt"
    "github.com/gogf/gf/container/gmap"
    "github.com/gogf/gf/frame/g"
)
func main() {
    var m gmap.Map
    m.Sets(g.MapAnyAny{
        "k1": "v1",
        "k2": "v2",
        "k3": "v3",
        "k4": "v4",
    })
    fmt.Println(m.Pop())
    fmt.Println(m.Pops(2))
    fmt.Println(m.Size())
    // map[k2:v2 k4:v4]
    // 1
}

`SetIfNotExist*`判断性写入

判断性写入是指当指定的键名不存在时则写入并且方法返回true，否则忽略吸入并且方法返回false。相关方法如下：

SetIfNotExist
SetIfNotExistFunc
SetIfNotExistFuncLock

方法具体描述请查看接口文档或源码注释。

package main
import (
    "fmt"
    "github.com/gogf/gf/container/gmap"
)
func main() {
    var m gmap.Map
    fmt.Println(m.SetIfNotExist("k1", "v1"))
    fmt.Println(m.SetIfNotExist("k1", "v1"))
    fmt.Println(m.Map())
    // Output:
    // true
    // false
    // map[k1:v1]
}

`Merge`哈希表合并

package main
import (
    "fmt"
    "github.com/gogf/gf/container/gmap"
)
func main() {
    var m1, m2 gmap.Map
    m1.Set("key1", "val1")
    m2.Set("key2", "val2")
    m1.Merge(&m2)
    fmt.Println(m1.Map())
    // May Output:
    // map[key1:val1 key2:val2]
}

gmap模块下的所有容器类型均实现了标准库json数据格式的序列化/反序列化接口。

执行后，输出结果：
```
 {"name":"john","score":100}
```

Unmarshal

 package main
 import (
     "encoding/json"
     "fmt"
     "github.com/gogf/gf/container/gmap"
 )
 func main() {
     m := gmap.Map{}
     s := []byte(`{"name":"john","score":100}`)
     json.Unmarshal(s, &m)
     fmt.Println(m.Map())
 }

执行后，输出结果：

 map[name:john score:100]

并发安全

https://github.com/gogf/gf/blob/master/container/gmap/gmap_z_bench_safe_test.go

goos: linux
goarch: amd64
Benchmark_IntIntMap_Set-4               10000000               202 ns/op              15 B/op          0 allocs/op
Benchmark_IntAnyMap_Set-4               10000000               262 ns/op              29 B/op          1 allocs/op
Benchmark_IntStrMap_Set-4               10000000               241 ns/op              22 B/op          0 allocs/op
Benchmark_AnyAnyMap_Set-4                5000000               359 ns/op              40 B/op          2 allocs/op
Benchmark_StrIntMap_Set-4                5000000               305 ns/op              26 B/op          1 allocs/op
Benchmark_StrAnyMap_Set-4                5000000               354 ns/op              40 B/op          2 allocs/op
Benchmark_StrStrMap_Set-4                5000000               338 ns/op              32 B/op          1 allocs/op
Benchmark_IntIntMap_Get-4               20000000              86.6 ns/op               0 B/op          0 allocs/op
Benchmark_IntAnyMap_Get-4               30000000              69.7 ns/op               0 B/op          0 allocs/op
Benchmark_IntStrMap_Get-4               30000000              69.6 ns/op               0 B/op          0 allocs/op
Benchmark_AnyAnyMap_Get-4               20000000              74.4 ns/op               0 B/op          0 allocs/op
Benchmark_StrIntMap_Get-4               20000000               116 ns/op               7 B/op          0 allocs/op
Benchmark_StrAnyMap_Get-4               20000000              92.3 ns/op               7 B/op          0 allocs/op
Benchmark_StrStrMap_Get-4               20000000              91.9 ns/op               7 B/op          0 allocs/op

非并发安全

https://github.com/gogf/gf/blob/master/container/gmap/gmap_z_bench_unsafe_test.go

goos: linux
goarch: amd64
Benchmark_Unsafe_IntIntMap_Set-4        10000000               318 ns/op              62 B/op          0 allocs/op
Benchmark_Unsafe_IntAnyMap_Set-4         5000000               282 ns/op              57 B/op          1 allocs/op
Benchmark_Unsafe_IntStrMap_Set-4         5000000               332 ns/op              82 B/op          1 allocs/op
Benchmark_Unsafe_AnyAnyMap_Set-4         3000000               471 ns/op              73 B/op          2 allocs/op
Benchmark_Unsafe_StrIntMap_Set-4         5000000               429 ns/op              82 B/op          1 allocs/op
Benchmark_Unsafe_StrAnyMap_Set-4         3000000               424 ns/op              73 B/op          2 allocs/op
Benchmark_Unsafe_StrStrMap_Set-4         2000000               515 ns/op              96 B/op          2 allocs/op
Benchmark_Unsafe_IntIntMap_Get-4        10000000               133 ns/op               0 B/op          0 allocs/op
Benchmark_Unsafe_IntAnyMap_Get-4        20000000               134 ns/op               0 B/op          0 allocs/op
Benchmark_Unsafe_IntStrMap_Get-4        10000000               126 ns/op               0 B/op          0 allocs/op
Benchmark_Unsafe_AnyAnyMap_Get-4        10000000               166 ns/op               0 B/op          0 allocs/op
Benchmark_Unsafe_StrIntMap_Get-4         5000000               246 ns/op               7 B/op          0 allocs/op
Benchmark_Unsafe_StrAnyMap_Get-4        10000000               238 ns/op               7 B/op          0 allocs/op
Benchmark_Unsafe_StrStrMap_Get-4         5000000               229 ns/op               7 B/op          0 allocs/op

不同类型map性能

https://github.com/gogf/gf/blob/master/container/gmap/gmap_z_bench_maps_test.go

go语言从1.9版本开始引入了并发安全的sync.Map，但gmap比较于标准库的sync.Map性能更加优异，并且功能更加丰富。

goos: linux
goarch: amd64
Benchmark_GMapSet-4                     10000000               209 ns/op              15 B/op          0 allocs/op
Benchmark_SyncMapSet-4                   3000000               451 ns/op              67 B/op          3 allocs/op
Benchmark_GMapGet-4                     30000000              66.4 ns/op               0 B/op          0 allocs/op
Benchmark_SyncMapGet-4                  30000000              36.0 ns/op               0 B/op          0 allocs/op
Benchmark_GMapRemove-4                  10000000               207 ns/op               0 B/op          0 allocs/op

gmap (哈希表)

gmap

有序遍历

FilterEmpty/FilterNil空值过滤

Flip键值对反转

Pop/Pops随机出栈

SetIfNotExist*判断性写入

Merge哈希表合并