github.com/wangyougui/gf/v2@v2.6.5/net/gsel/gsel_selector_random.go (about)

     1  // Copyright GoFrame Author(https://goframe.org). 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/wangyougui/gf.
     6  
     7  package gsel
     8  
     9  import (
    10  	"context"
    11  	"sync"
    12  
    13  	"github.com/wangyougui/gf/v2/internal/intlog"
    14  	"github.com/wangyougui/gf/v2/util/grand"
    15  )
    16  
    17  type selectorRandom struct {
    18  	mu    sync.RWMutex
    19  	nodes Nodes
    20  }
    21  
    22  func NewSelectorRandom() Selector {
    23  	return &selectorRandom{
    24  		nodes: make([]Node, 0),
    25  	}
    26  }
    27  
    28  func (s *selectorRandom) Update(ctx context.Context, nodes Nodes) error {
    29  	intlog.Printf(ctx, `Update nodes: %s`, nodes.String())
    30  	s.mu.Lock()
    31  	defer s.mu.Unlock()
    32  	s.nodes = nodes
    33  	return nil
    34  }
    35  
    36  func (s *selectorRandom) Pick(ctx context.Context) (node Node, done DoneFunc, err error) {
    37  	s.mu.RLock()
    38  	defer s.mu.RUnlock()
    39  	if len(s.nodes) == 0 {
    40  		return nil, nil, nil
    41  	}
    42  	node = s.nodes[grand.Intn(len(s.nodes))]
    43  	intlog.Printf(ctx, `Picked node: %s`, node.Address())
    44  	return node, nil, nil
    45  }