Type-Unsafe Pointers
1. NO reference only pointer type 没有引用类型；使用指针作复合数据 特殊的指针:
No care pointer cycleLife garbage collector;
limit the usage of pointer: No pointer convert; No pointer arithmetic use unsafe.Pointer
unsafe.Pointer 1 2 3 package unsafe type ArbitraryType int //表示任何类型 type Pointer *ArbitraryType //表示任何类型的指针
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Map实现原理分析
深度解密Go语言之 map
由浅到深，入门Go语言Map实现原理 golang map底层实现
哈希表
现在面试都这么直接的嘛？(golang map)
the core to design a map:
how to get hash value: hash funcitonn how to handle collision. how to rehash: grow, hash function what: 将输入数据经过一系列计算， 输出固定长度的数据
types:
加密: 低碰撞，难复原 非加密 why md5 is cryptographic:
one-way funciton collision-resistant, hash function excample
myhash:
1 2 3 4 5 6 7 func myHash(data []byte) uint32 { var hash uint32 for _, b := range data { hash = hash*13 + uint32(b) } return hash } djb:
What’s the difference between passing by reference vs. passing by value?
go中的引用类型； 引用类型；
存储的是变量的引用(指针); 不需要显式的取地址；解引用; 目标: 共享变量，而不需要显示使用指针;
1 2 3 let a = {value:100}; b = a; b.value = 200; 引用类型实现 c++方式; 指针的语法糖；
1 2 3 int i=5; int &ri=i; ri=8 1 2 3 int i = 5; int const *ri = &i; *ri=8 map, chan, slice 是不是引用类型? 可以认为是引用类型； 从结果看: 虽然实现有差异，但是都让我们不用操作指针而共享变量；
pass by value; pass by reference: 实参和形参是同一个变量； pass by value: 实参是实参的拷贝；
被知乎大佬嘲讽后的一个月，我重新研究了一下内联函数
overview 生成抽象语法树 类型检查； 根据抽象语法树生成目标代码 内联优化 直接展开函数，从而减少函数调用的开销；
parese tree; command; -gcflags -m: print optimization decisions; -l: disable inline;
切片的容量是怎样增长的 | Go 程序员面试笔试宝典
basic operator create:
1 2 3 4 s := []int{1,2,3} s1 := make([]int, 2, 2) fmt.Println(len(s1),cap(s1)) basic operate:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 // append s = append(s,4) // cut s = s[0:1] //range for index,value := range s { .... } copy(slice1, slice2) // max slice lenght=cap s := make([]int, 3,4) s = s[:] // [0,0,0] s = s[:cap(s)] // [0,0,0,0] inert at some Index:
1. about ponter address(取地址): &b
dereference(解引用)；indirection(间接寻址)
一个指针代表对变量的一次引用； 访问指针指向地址: *p=100
引用操作: 赋值给指针
resource-bound: the rate of the task is bound(decided) to resources in other words: it need many that resources. (resources 密集型)
types of bounds:
cpu-bound: cpu speed i/o-bound：i/o speed memory-bound: memory size and memory accessing speed i/o bound:
the type of devices the arhitecture of read/write file do many task such as read/write file,, network
chat app; cpu bound app: do many tasks such as caculations
