2022年1月12日

.idea/workspace.xml

@@ -34,8 +34,6 @@
       <change afterPath="$PROJECT_DIR$/nonrepeating/c.out" afterDir="false" />
       <change afterPath="$PROJECT_DIR$/nonrepeating/cpu.out" afterDir="false" />
       <change afterPath="$PROJECT_DIR$/queue/queue_test.go" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/misc.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/misc.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/errhandling/filelistingserver/filelisting/filelist.go" beforeDir="false" afterPath="$PROJECT_DIR$/errhandling/filelistingserver/filelisting/filelist.go" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/errhandling/filelistingserver/web.go" beforeDir="false" afterPath="$PROJECT_DIR$/errhandling/filelistingserver/web.go" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/go.mod" beforeDir="false" afterPath="$PROJECT_DIR$/go.mod" afterDir="false" />
@@ -254,6 +252,7 @@
       <workItem from="1657814506188" duration="1509000" />
       <workItem from="1657816118798" duration="314000" />
       <workItem from="1658072272414" duration="533000" />
+      <workItem from="1659928006697" duration="288000" />
     </task>
     <task id="LOCAL-00001" summary="2021年12月5日">
       <created>1638720681912</created>
@@ -353,7 +352,14 @@
       <option name="project" value="LOCAL" />
       <updated>1642004021802</updated>
     </task>
-    <option name="localTasksCounter" value="15" />
+    <task id="LOCAL-00015" summary="2022年1月12日">
+      <created>1659928168332</created>
+      <option name="number" value="00015" />
+      <option name="presentableId" value="LOCAL-00015" />
+      <option name="project" value="LOCAL" />
+      <updated>1659928168333</updated>
+    </task>
+    <option name="localTasksCounter" value="16" />
     <servers />
   </component>
   <component name="TypeScriptGeneratedFilesManager">

basic/c.out

+mode: set
+learngo/basic/basic.go:23.26,28.2 3 0
+learngo/basic/basic.go:30.29,34.2 3 0
+learngo/basic/basic.go:36.30,39.2 2 0
+learngo/basic/basic.go:41.24,48.2 2 0
+learngo/basic/basic.go:49.14,52.2 2 0
+learngo/basic/basic.go:55.17,58.2 2 0
+learngo/basic/basic.go:59.33,63.2 3 1
+learngo/basic/basic.go:66.15,77.2 4 0
+learngo/basic/basic.go:80.14,104.2 5 0
+learngo/basic/basic.go:106.13,116.2 9 0

crawler/main.go

+package main
+
+import (
+	"bufio"
+	"fmt"
+	"golang.org/x/net/html/charset"
+	"golang.org/x/text/encoding"
+	"golang.org/x/text/transform"
+	"io"
+	"io/ioutil"
+	"net/http"
+)
+
+func main() {
+
+	resp, err := http.Get("https://www.zhenai.com/zhenghun")
+
+	if err != nil {
+		panic(err)
+	}
+
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		fmt.Println(" Error: status code ", resp.StatusCode)
+		return
+	}
+	// 自动发现见面编码
+	e := determineEncoding(resp.Body)
+	// 把内容以GBK编码读取
+	utf8Reader := transform.NewReader(resp.Body, e.NewDecoder())
+
+	all, err := ioutil.ReadAll(utf8Reader)
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Printf("%s\n", all)
+
+}
+
+func determineEncoding(r io.Reader) encoding.Encoding {
+
+	bytes, err := bufio.NewReader(r).Peek(1024)
+	if err != nil {
+		panic(err)
+	}
+	e, _, _ := charset.DetermineEncoding(
+		bytes,
+		"",
+	)
+	return e
+}

errhandling/filelistingserver/errwrapper_test.go

+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func errPanic(writer http.ResponseWriter, request *http.Request) error {
+	fmt.Println(" this is an panic testing .....")
+	panic(6789)
+	//return nil
+}
+
+func errUserErr(writer http.ResponseWriter, request *http.Request) error {
+	//panic(6789)
+	fmt.Println(" this is an testing .....")
+	return testingUserError("user error")
+}
+
+type testingUserError string
+
+func (e testingUserError) Error() string {
+	return e.Message()
+}
+
+func (e testingUserError) Message() string {
+	return string(e)
+}
+
+var tests = []struct {
+	h       appHandler
+	code    int
+	message string
+}{
+	//	{errPanic,500,"Internal Server Error"},
+	{errUserErr, 400, "user error"},
+}
+
+func TestErrWrapper(t *testing.T) {
+
+	for _, tt := range tests {
+		f := errWrapper(tt.h)
+
+		response := httptest.NewRecorder()
+		request := httptest.NewRequest(http.MethodGet, "http:/www.baidu.com", bytes.NewBufferString("this is custome str "))
+		f(response, request)
+		b, _ := ioutil.ReadAll(response.Body)
+		body := strings.Trim(string(b), "\n")
+		if response.Code != tt.code || body != tt.message {
+			t.Errorf(" expect (%d ,%s) ; got (%d ,%s)", tt.code, tt.message, response.Code, body)
+
+		}
+
+	}
+
+}

errhandling/filelistingserver/filelisting/filelist.go

 package filelisting
 
 import (
+	"fmt"
 	"io/ioutil"
 	"net/http"
 	"os"
@@ -21,6 +22,7 @@ func (e userError) Message() string {
 
 func FileList(writer http.ResponseWriter, request *http.Request) error {
 
+	fmt.Println(" this is FileList func   ")
 	if strings.Index(request.URL.Path, prefix) != 0 {
 		//return  errors.New(" path must start  with "+prefix)
 		return userError(" path must start  with " + prefix)

errhandling/filelistingserver/web.go

 package main
 
 import (
+	"fmt"
 	"learngo/errhandling/filelistingserver/filelisting"
 	"log"
-
 	"net/http"
+	_ "net/http/pprof"
 	"os"
 )
 
@@ -13,8 +14,15 @@ type appHandler func(writer http.ResponseWriter, request *http.Request) error
 
 func errWrapper(handler appHandler) func(writer http.ResponseWriter, request *http.Request) {
 
+	fmt.Println(" this is errWrapper func   ")
+
 	return func(writer http.ResponseWriter, request *http.Request) {
+		fmt.Println(" this is return  func   ")
+		// recover  仅在defer 调用中使用
+		// 获取 panice 的值
+		// 如果无法处理时，可以重新 panic
 		defer func() {
+
 			if r := recover(); r != nil {
 				log.Printf("panic : %v", r)
 				http.Error(writer, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)

errhandling/recover/recover.go

+package main
+
+import (
+	"fmt"
+)
+
+func tryRecover() {
+
+	defer func() {
+		r := recover()
+		if err, ok := r.(error); ok {
+			fmt.Println(" Error occurrend : ", err)
+		} else {
+			panic(r)
+		}
+	}()
+
+	// panic( errors.New("this is an error !"))
+	b := 0
+	a := 199 / b
+	fmt.Println(a)
+
+}
+
+func main() {
+	tryRecover()
+}

fib.txt

+daf
+ad
+fa
+df
+af
+w
+ef
+wef
+wf
\ No newline at end of file

go.mod

 module learngo
 
 go 1.15
+
+require (
+	golang.org/x/net v0.0.0-20211015210444-4f30a5c0130f
+	golang.org/x/text v0.3.7
+	golang.org/x/tools v0.1.9 // indirect
+)

go.sum

+github.com/yuin/goldmark v1.4.1 h1:/vn0k+RBvwlxEmP5E7SZMqNxPhfMVFEJiykr15/0XKM=
+github.com/yuin/goldmark v1.4.1/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/mod v0.5.1 h1:OJxoQ/rynoF0dcCdI7cLPktw/hR2cueqYfjm43oqK38=
+golang.org/x/mod v0.5.1/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20211015210444-4f30a5c0130f h1:OfiFi4JbukWwe3lzw+xunroH1mnC1e2Gy5cxNJApiSY=
+golang.org/x/net v0.0.0-20211015210444-4f30a5c0130f/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20211019181941-9d821ace8654 h1:id054HUawV2/6IGm2IV8KZQjqtwAOo2CYlOToYqa0d0=
+golang.org/x/sys v0.0.0-20211019181941-9d821ace8654/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.9 h1:j9KsMiaP1c3B0OTQGth0/k+miLGTgLsAFUCrF2vLcF8=
+golang.org/x/tools v0.1.9/go.mod h1:nABZi5QlRsZVlzPpHl034qft6wpY4eDcsTt5AaioBiU=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

goroutine/goroutine.go

+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+//  协程 coroutine
+// 轻量级"线程"
+// 非抢占式多任务处理，邮协程主动交出控制权
+//编译器/解释器/虚拟机层面的多任务
+//多个协程可能在一个或多个线程上运行，它是有调度器决定的
+
+// 切换控制权点：I/O ，select ,channel 等待锁，调用函数 runtime.Gosched()
+
+func main() {
+	//var a [10]int
+	for i := 0; i < 1000; i++ {
+
+		go func(i int) {
+			for {
+				fmt.Printf("Hello form gorountine %d\n ", i) // 这个是一个io ，io 会进行切换 交出控制权
+				//a[i]++
+				//runtime.Gosched()// 手动交出控制权
+			}
+		}(i)
+
+	}
+	time.Sleep(time.Minute)
+}

http/client.go

+package main
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httputil"
+)
+
+func main() {
+
+	request, err := http.NewRequest(http.MethodGet, "http://www.imooc.com", nil)
+
+	request.Header.Add("User-Agent", "Mozilla/5.0 (iPhone; CPU iPhone OS 13_2_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.3 Mobile/15E148 Safari/604.1")
+
+	clent := http.Client{CheckRedirect: func(req *http.Request, via []*http.Request) error {
+		fmt.Println("Redirect :", req)
+		return nil
+	}}
+	resp, err := clent.Do(request)
+	//resp ,err := http.DefaultClient.Do(request)
+	//resp ,err := http.Get("http://www.imooc.com")
+	if err != nil {
+		panic(err)
+	}
+
+	defer resp.Body.Close()
+	s, err := httputil.DumpResponse(resp, true)
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Printf(" %s\n", s)
+}

maze/maze.go

+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func readMaze(filename string) [][]int {
+	file, err := os.Open(filename)
+	if err != nil {
+		panic(err)
+	}
+	var row, col, z int
+	fmt.Fscanf(file, "%d %d %d", &row, &col, &z)
+
+	fmt.Printf("%d , %d, %d ", row, col, z)
+	fmt.Println()
+	// [][]int ,第一个方括号是一个slice ,第二个方括号是slice 里的元素
+	maze := make([][]int, row)
+	for i := range maze {
+		//每一行 多少列
+		maze[i] = make([]int, col)
+		for j := range maze[i] {
+			fmt.Fscanf(file, "%d", &maze[i][j])
+		}
+	}
+	return maze
+}
+
+// 当前点位
+type point struct {
+	x, y int
+}
+
+var dirs = [4]point{
+	{-1, 0}, {0, -1}, {1, 0}, {0, 1},
+}
+
+//计算下一个点
+func (p point) add(r point) point {
+	return point{p.x + r.x, p.y + r.y}
+}
+
+// 检查当前点是否越界
+func (p point) at(grid [][]int) (int, bool) {
+
+	if p.x < 0 || p.x >= len(grid) {
+		return 0, false
+	}
+
+	if p.y < 0 || p.y >= len(grid[p.x]) {
+		return 0, false
+	}
+	return grid[p.x][p.y], true
+}
+
+func walk(maze [][]int, start, end point) [][]int {
+	steps := make([][]int, len(maze))
+	for i := range steps {
+		steps[i] = make([]int, len(maze[i]))
+	}
+	//起点加入队列
+	Q := []point{start}
+
+	for len(Q) > 0 {
+		cur := Q[0]
+		Q = Q[1:]
+
+		if cur == end {
+			break
+		}
+
+		for _, dir := range dirs {
+			next := cur.add(dir)
+			// 验证当前点位在迷宫中是否可以继续走
+			val, ok := next.at(maze)
+			if !ok || val == 1 {
+				continue
+			}
+			//验证当前点是否已经走过
+			val, ok = next.at(steps)
+			if !ok || val != 0 {
+				continue
+			}
+			//当前点与原点一致时
+			if next == start {
+				continue
+			}
+
+			curSteps, _ := cur.at(steps)
+			steps[next.x][next.y] = curSteps + 1
+
+			Q = append(Q, next)
+
+		}
+	}
+	return steps
+
+}
+
+func main() {
+	maze := readMaze("maze/maze.in")
+	/*for _,row := range maze {
+		for _, val := range  row {
+			fmt.Printf(" %3d", val)
+
+		}
+		fmt.Println()
+	}*/
+	steps := walk(maze, point{0, 0}, point{len(maze) - 1, len(maze[0]) - 1})
+
+	for _, row := range steps {
+		for _, val := range row {
+			fmt.Printf("%3d", val)
+		}
+		fmt.Println()
+	}
+}

maze/maze.in

+6 8 0
+0 1 0 0 0 1 0 0
+0 0 0 1 0 1 0 0
+0 1 0 1 0 0 1 0
+1 1 1 0 0 1 0 0
+0 1 0 0 1 1 0 1
+0 1 0 0 0 0 0 0

nonrepeating/c.out

+mode: set
+learngo/nonrepeating/nonrepeating.go:5.47,10.31 4 1
+learngo/nonrepeating/nonrepeating.go:20.2,20.34 1 1
+learngo/nonrepeating/nonrepeating.go:23.2,25.18 2 1
+learngo/nonrepeating/nonrepeating.go:10.31,11.59 1 1
+learngo/nonrepeating/nonrepeating.go:14.3,14.28 1 1
+learngo/nonrepeating/nonrepeating.go:17.3,17.24 1 1
+learngo/nonrepeating/nonrepeating.go:11.59,13.4 1 1
+learngo/nonrepeating/nonrepeating.go:14.28,16.4 1 1
+learngo/nonrepeating/nonrepeating.go:20.34,22.3 1 1
+learngo/nonrepeating/nonrepeating.go:28.13,31.2 2 0

queue/entry/main.go

-package main
+package queue
 
 import (
 	"fmt"

queue/queue.go

@@ -3,14 +3,19 @@ package queue
 // 定义别名
 type Queue []interface{}
 
+//  push
 func (q *Queue) Push(v interface{}) {
 	*q = append(*q, v)
 }
+
+// pop
 func (q *Queue) Pop() interface{} {
 	head := (*q)[0]
 	*q = (*q)[1:]
 	return head
 }
+
+// is Empty
 func (q *Queue) IsEmpty() bool {
 	return len(*q) == 0
 }

queue/queue_test.go

+package queue
+
+import "fmt"
+
+func ExampleQueue_Pop() {
+
+	q := Queue{1}
+	q.Push(2)
+	q.Push(3)
+	q.Push(3)
+
+	fmt.Println(q.Pop())
+	fmt.Println(q.Pop())
+	fmt.Println(q.IsEmpty())
+	fmt.Println(q.Pop())
+	fmt.Println(q.IsEmpty())
+
+	// Output:
+	//1
+	//2
+	//false
+	//3
+	//false
+}