github.com/v2fly/tools@v0.100.0/internal/lsp/cache/keys.go (about)

     1  // Copyright 2020 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package cache
     6  
     7  import (
     8  	"io"
     9  
    10  	"github.com/v2fly/tools/internal/event/label"
    11  )
    12  
    13  var (
    14  	KeyCreateSession   = NewSessionKey("create_session", "A new session was added")
    15  	KeyUpdateSession   = NewSessionKey("update_session", "Updated information about a session")
    16  	KeyShutdownSession = NewSessionKey("shutdown_session", "A session was shut down")
    17  )
    18  
    19  // SessionKey represents an event label key that has a *Session value.
    20  type SessionKey struct {
    21  	name        string
    22  	description string
    23  }
    24  
    25  // NewSessionKey creates a new Key for *Session values.
    26  func NewSessionKey(name, description string) *SessionKey {
    27  	return &SessionKey{name: name, description: description}
    28  }
    29  
    30  func (k *SessionKey) Name() string        { return k.name }
    31  func (k *SessionKey) Description() string { return k.description }
    32  
    33  func (k *SessionKey) Format(w io.Writer, buf []byte, l label.Label) {
    34  	io.WriteString(w, k.From(l).ID())
    35  }
    36  
    37  // Of creates a new Label with this key and the supplied session.
    38  func (k *SessionKey) Of(v *Session) label.Label { return label.OfValue(k, v) }
    39  
    40  // Get can be used to get the session for the key from a label.Map.
    41  func (k *SessionKey) Get(lm label.Map) *Session {
    42  	if t := lm.Find(k); t.Valid() {
    43  		return k.From(t)
    44  	}
    45  	return nil
    46  }
    47  
    48  // From can be used to get the session value from a Label.
    49  func (k *SessionKey) From(t label.Label) *Session {
    50  	err, _ := t.UnpackValue().(*Session)
    51  	return err
    52  }