github.com/qiniu/go-sdk/v7@v7.27.0/internal/hostprovider/host_provider.go (about)

     1  package hostprovider
     2  
     3  import (
     4  	"errors"
     5  	"time"
     6  
     7  	"github.com/qiniu/go-sdk/v7/internal/freezer"
     8  )
     9  
    10  var (
    11  	ErrNoHostFound    = errors.New("no host found")
    12  	ErrAllHostsFrozen = errors.New("all hosts are frozen")
    13  )
    14  
    15  type (
    16  	HostProvider interface {
    17  		Provider() (string, error)
    18  		Freeze(host string, cause error, duration time.Duration) error
    19  	}
    20  
    21  	arrayHostProvider struct {
    22  		hosts         []string
    23  		freezer       freezer.Freezer
    24  		lastFreezeErr error
    25  	}
    26  )
    27  
    28  func NewWithHosts(hosts []string) HostProvider {
    29  	return &arrayHostProvider{
    30  		hosts:   hosts,
    31  		freezer: freezer.New(),
    32  	}
    33  }
    34  
    35  func (a *arrayHostProvider) Provider() (string, error) {
    36  	if len(a.hosts) == 0 {
    37  		return "", ErrNoHostFound
    38  	}
    39  
    40  	for _, host := range a.hosts {
    41  		if a.freezer.Available(host) {
    42  			return host, nil
    43  		}
    44  	}
    45  
    46  	if a.lastFreezeErr != nil {
    47  		return "", a.lastFreezeErr
    48  	} else {
    49  		return "", ErrAllHostsFrozen
    50  	}
    51  }
    52  
    53  func (a *arrayHostProvider) Freeze(host string, cause error, duration time.Duration) error {
    54  	if duration <= 0 {
    55  		return nil
    56  	}
    57  
    58  	a.lastFreezeErr = cause
    59  	return a.freezer.Freeze(host, duration)
    60  }