github.com/10XDev/rclone@v1.52.3-0.20200626220027-16af9ab76b2a/backend/union/policy/eplfs.go (about)

     1  package policy
     2  
     3  import (
     4  	"context"
     5  	"math"
     6  
     7  	"github.com/rclone/rclone/backend/union/upstream"
     8  	"github.com/rclone/rclone/fs"
     9  )
    10  
    11  func init() {
    12  	registerPolicy("eplfs", &EpLfs{})
    13  }
    14  
    15  // EpLfs stands for existing path, least free space
    16  // Of all the candidates on which the path exists choose the one with the least free space.
    17  type EpLfs struct {
    18  	EpAll
    19  }
    20  
    21  func (p *EpLfs) lfs(upstreams []*upstream.Fs) (*upstream.Fs, error) {
    22  	var minFreeSpace int64 = math.MaxInt64
    23  	var lfsupstream *upstream.Fs
    24  	for _, u := range upstreams {
    25  		space, err := u.GetFreeSpace()
    26  		if err != nil {
    27  			fs.LogPrintf(fs.LogLevelNotice, nil,
    28  				"Free Space is not supported for upstream %s, treating as infinite", u.Name())
    29  		}
    30  		if space < minFreeSpace {
    31  			minFreeSpace = space
    32  			lfsupstream = u
    33  		}
    34  	}
    35  	if lfsupstream == nil {
    36  		return nil, fs.ErrorObjectNotFound
    37  	}
    38  	return lfsupstream, nil
    39  }
    40  
    41  func (p *EpLfs) lfsEntries(entries []upstream.Entry) (upstream.Entry, error) {
    42  	var minFreeSpace int64
    43  	var lfsEntry upstream.Entry
    44  	for _, e := range entries {
    45  		space, err := e.UpstreamFs().GetFreeSpace()
    46  		if err != nil {
    47  			fs.LogPrintf(fs.LogLevelNotice, nil,
    48  				"Free Space is not supported for upstream %s, treating as infinite", e.UpstreamFs().Name())
    49  		}
    50  		if space < minFreeSpace {
    51  			minFreeSpace = space
    52  			lfsEntry = e
    53  		}
    54  	}
    55  	return lfsEntry, nil
    56  }
    57  
    58  // Action category policy, governing the modification of files and directories
    59  func (p *EpLfs) Action(ctx context.Context, upstreams []*upstream.Fs, path string) ([]*upstream.Fs, error) {
    60  	upstreams, err := p.EpAll.Action(ctx, upstreams, path)
    61  	if err != nil {
    62  		return nil, err
    63  	}
    64  	u, err := p.lfs(upstreams)
    65  	return []*upstream.Fs{u}, err
    66  }
    67  
    68  // ActionEntries is ACTION category policy but receiving a set of candidate entries
    69  func (p *EpLfs) ActionEntries(entries ...upstream.Entry) ([]upstream.Entry, error) {
    70  	entries, err := p.EpAll.ActionEntries(entries...)
    71  	if err != nil {
    72  		return nil, err
    73  	}
    74  	e, err := p.lfsEntries(entries)
    75  	return []upstream.Entry{e}, err
    76  }
    77  
    78  // Create category policy, governing the creation of files and directories
    79  func (p *EpLfs) Create(ctx context.Context, upstreams []*upstream.Fs, path string) ([]*upstream.Fs, error) {
    80  	upstreams, err := p.EpAll.Create(ctx, upstreams, path)
    81  	if err != nil {
    82  		return nil, err
    83  	}
    84  	u, err := p.lfs(upstreams)
    85  	return []*upstream.Fs{u}, err
    86  }
    87  
    88  // CreateEntries is CREATE category policy but receiving a set of candidate entries
    89  func (p *EpLfs) CreateEntries(entries ...upstream.Entry) ([]upstream.Entry, error) {
    90  	entries, err := p.EpAll.CreateEntries(entries...)
    91  	if err != nil {
    92  		return nil, err
    93  	}
    94  	e, err := p.lfsEntries(entries)
    95  	return []upstream.Entry{e}, err
    96  }
    97  
    98  // Search category policy, governing the access to files and directories
    99  func (p *EpLfs) Search(ctx context.Context, upstreams []*upstream.Fs, path string) (*upstream.Fs, error) {
   100  	if len(upstreams) == 0 {
   101  		return nil, fs.ErrorObjectNotFound
   102  	}
   103  	upstreams, err := p.epall(ctx, upstreams, path)
   104  	if err != nil {
   105  		return nil, err
   106  	}
   107  	return p.lfs(upstreams)
   108  }
   109  
   110  // SearchEntries is SEARCH category policy but receiving a set of candidate entries
   111  func (p *EpLfs) SearchEntries(entries ...upstream.Entry) (upstream.Entry, error) {
   112  	if len(entries) == 0 {
   113  		return nil, fs.ErrorObjectNotFound
   114  	}
   115  	return p.lfsEntries(entries)
   116  }