github.com/linapex/ethereum-go-chinese@v0.0.0-20190316121929-f8b7a73c3fa1/eth/downloader/modes.go (about)

     1  
     2  //<developer>
     3  //    <name>linapex 曹一峰</name>
     4  //    <email>linapex@163.com</email>
     5  //    <wx>superexc</wx>
     6  //    <qqgroup>128148617</qqgroup>
     7  //    <url>https://jsq.ink</url>
     8  //    <role>pku engineer</role>
     9  //    <date>2019-03-16 19:16:37</date>
    10  //</624450088206340096>
    11  
    12  
    13  package downloader
    14  
    15  import "fmt"
    16  
    17  //SyncMode表示下载程序的同步模式。
    18  type SyncMode int
    19  
    20  const (
    21  FullSync  SyncMode = iota //从完整块同步整个区块链历史
    22  FastSync                  //快速下载邮件头，仅在链头完全同步
    23  LightSync                 //只下载邮件头，然后终止
    24  )
    25  
    26  func (mode SyncMode) IsValid() bool {
    27  	return mode >= FullSync && mode <= LightSync
    28  }
    29  
    30  //字符串实现字符串接口。
    31  func (mode SyncMode) String() string {
    32  	switch mode {
    33  	case FullSync:
    34  		return "full"
    35  	case FastSync:
    36  		return "fast"
    37  	case LightSync:
    38  		return "light"
    39  	default:
    40  		return "unknown"
    41  	}
    42  }
    43  
    44  func (mode SyncMode) MarshalText() ([]byte, error) {
    45  	switch mode {
    46  	case FullSync:
    47  		return []byte("full"), nil
    48  	case FastSync:
    49  		return []byte("fast"), nil
    50  	case LightSync:
    51  		return []byte("light"), nil
    52  	default:
    53  		return nil, fmt.Errorf("unknown sync mode %d", mode)
    54  	}
    55  }
    56  
    57  func (mode *SyncMode) UnmarshalText(text []byte) error {
    58  	switch string(text) {
    59  	case "full":
    60  		*mode = FullSync
    61  	case "fast":
    62  		*mode = FastSync
    63  	case "light":
    64  		*mode = LightSync
    65  	default:
    66  		return fmt.Errorf(`unknown sync mode %q, want "full", "fast" or "light"`, text)
    67  	}
    68  	return nil
    69  }
    70