github.com/clem109/go-ethereum@v1.8.3-0.20180316121352-fe6cf00f480a/eth/downloader/modes.go (about)

     1  // Copyright 2015 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package downloader
    18  
    19  import "fmt"
    20  
    21  // SyncMode represents the synchronisation mode of the downloader.
    22  type SyncMode int
    23  
    24  const (
    25  	FullSync  SyncMode = iota // Synchronise the entire blockchain history from full blocks
    26  	FastSync                  // Quickly download the headers, full sync only at the chain head
    27  	LightSync                 // Download only the headers and terminate afterwards
    28  )
    29  
    30  func (mode SyncMode) IsValid() bool {
    31  	return mode >= FullSync && mode <= LightSync
    32  }
    33  
    34  // String implements the stringer interface.
    35  func (mode SyncMode) String() string {
    36  	switch mode {
    37  	case FullSync:
    38  		return "full"
    39  	case FastSync:
    40  		return "fast"
    41  	case LightSync:
    42  		return "light"
    43  	default:
    44  		return "unknown"
    45  	}
    46  }
    47  
    48  func (mode SyncMode) MarshalText() ([]byte, error) {
    49  	switch mode {
    50  	case FullSync:
    51  		return []byte("full"), nil
    52  	case FastSync:
    53  		return []byte("fast"), nil
    54  	case LightSync:
    55  		return []byte("light"), nil
    56  	default:
    57  		return nil, fmt.Errorf("unknown sync mode %d", mode)
    58  	}
    59  }
    60  
    61  func (mode *SyncMode) UnmarshalText(text []byte) error {
    62  	switch string(text) {
    63  	case "full":
    64  		*mode = FullSync
    65  	case "fast":
    66  		*mode = FastSync
    67  	case "light":
    68  		*mode = LightSync
    69  	default:
    70  		return fmt.Errorf(`unknown sync mode %q, want "full", "fast" or "light"`, text)
    71  	}
    72  	return nil
    73  }