github.com/cloudwego/localsession@v0.0.2/example_test.go (about)

     1  // Copyright 2023 CloudWeGo Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package localsession
    16  
    17  import (
    18  	"context"
    19  	"runtime/pprof"
    20  	"sync"
    21  	"time"
    22  )
    23  
    24  func ASSERT(v bool) {
    25  	if !v {
    26  		panic("not true!")
    27  	}
    28  }
    29  
    30  func GetCurSession() Session {
    31  	s, ok := CurSession()
    32  	if !ok {
    33  		panic("can't get current session!")
    34  	}
    35  	return s
    36  }
    37  
    38  func ExampleSessionCtx_EnableImplicitlyTransmitAsync() {
    39  	// EnableImplicitlyTransmitAsync must be true
    40  	InitDefaultManager(ManagerOptions{
    41  		ShardNumber:                   10,
    42  		EnableImplicitlyTransmitAsync: true,
    43  		GCInterval:                    time.Hour,
    44  	})
    45  
    46  	// WARNING: pprof.Do() must be called before BindSession(),
    47  	// otherwise transparently transmitting session will be dysfunctional
    48  	labels := pprof.Labels("c", "d")
    49  	pprof.Do(context.Background(), labels, func(ctx context.Context) {})
    50  
    51  	s := NewSessionMap(map[interface{}]interface{}{
    52  		"a": "b",
    53  	})
    54  	BindSession(s)
    55  
    56  	// WARNING: pprof.Do() must be called before BindSession(),
    57  	// otherwise transparently transmitting session will be dysfunctional
    58  	// labels := pprof.Labels("c", "d")
    59  	// pprof.Do(context.Background(), labels, func(ctx context.Context){})
    60  
    61  	wg := sync.WaitGroup{}
    62  	wg.Add(3)
    63  	go func() {
    64  		defer wg.Done()
    65  		ASSERT("b" == mustCurSession().Get("a"))
    66  
    67  		go func() {
    68  			defer wg.Done()
    69  			ASSERT("b" == mustCurSession().Get("a"))
    70  		}()
    71  
    72  		ASSERT("b" == mustCurSession().Get("a"))
    73  		UnbindSession()
    74  		ASSERT(nil == mustCurSession())
    75  
    76  		go func() {
    77  			defer wg.Done()
    78  			ASSERT(nil == mustCurSession())
    79  		}()
    80  
    81  	}()
    82  	wg.Wait()
    83  }
    84  
    85  func ExampleSessionCtx() {
    86  	// initialize default manager first
    87  	InitDefaultManager(DefaultManagerOptions())
    88  
    89  	var ctx = context.Background()
    90  	var key, v = "a", "b"
    91  	var key2, v2 = "c", "d"
    92  	var sig = make(chan struct{})
    93  	var sig2 = make(chan struct{})
    94  
    95  	// initialize new session with context
    96  	var session = NewSessionCtx(ctx) // implementation...
    97  
    98  	// set specific key-value and update session
    99  	start := session.WithValue(key, v)
   100  
   101  	// set current session
   102  	BindSession(start)
   103  
   104  	// pass to new goroutine...
   105  	Go(func() {
   106  		// read specific key under current session
   107  		val := GetCurSession().Get(key) // val exists
   108  		ASSERT(val == v)
   109  		// doSomething....
   110  
   111  		// set specific key-value under current session
   112  		// NOTICE: current session won't change here
   113  		next := GetCurSession().WithValue(key2, v2)
   114  		val2 := GetCurSession().Get(key2) // val2 == nil
   115  		ASSERT(val2 == nil)
   116  
   117  		// pass both parent session and new session to sub goroutine
   118  		GoSession(next, func() {
   119  			// read specific key under current session
   120  			val := GetCurSession().Get(key) // val exists
   121  			ASSERT(val == v)
   122  
   123  			val2 := GetCurSession().Get(key2) // val2 exists
   124  			ASSERT(val2 == v2)
   125  			// doSomething....
   126  
   127  			sig2 <- struct{}{}
   128  
   129  			<-sig
   130  			ASSERT(GetCurSession().IsValid() == false) // current session is invalid
   131  
   132  			println("g2 done")
   133  			sig2 <- struct{}{}
   134  		})
   135  
   136  		Go(func() {
   137  			// read specific key under current session
   138  			val := GetCurSession().Get(key) // val exists
   139  			ASSERT(v == val)
   140  
   141  			val2 := GetCurSession().Get(key2) // val2 == nil
   142  			ASSERT(val2 == nil)
   143  			// doSomething....
   144  
   145  			sig2 <- struct{}{}
   146  
   147  			<-sig
   148  			ASSERT(GetCurSession().IsValid() == false) // current session is invalid
   149  
   150  			println("g3 done")
   151  			sig2 <- struct{}{}
   152  		})
   153  
   154  		BindSession(next)
   155  		val2 = GetCurSession().Get(key2) // val2 exists
   156  		ASSERT(v2 == val2)
   157  
   158  		sig2 <- struct{}{}
   159  
   160  		<-sig
   161  		ASSERT(next.IsValid() == false) // next is invalid
   162  
   163  		println("g1 done")
   164  		sig2 <- struct{}{}
   165  	})
   166  
   167  	<-sig2
   168  	<-sig2
   169  	<-sig2
   170  
   171  	val2 := GetCurSession().Get(key2) // val2 == nil
   172  	ASSERT(val2 == nil)
   173  
   174  	// initiatively ends the session，
   175  	// then all the inherited session (including next) will be disabled
   176  	session.Disable()
   177  	close(sig)
   178  
   179  	ASSERT(start.IsValid() == false) // start is invalid
   180  
   181  	<-sig2
   182  	<-sig2
   183  	<-sig2
   184  	println("g0 done")
   185  
   186  	UnbindSession()
   187  }