blob: 8e6b794cf2e421d63d9113f7a05b92ffe1bf0047 [file] [log] [blame]
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package cache
import (
"context"
"golang.org/x/tools/internal/lsp/source"
"golang.org/x/tools/internal/span"
errors "golang.org/x/xerrors"
)
type overlay struct {
session *session
uri span.URI
text []byte
hash string
version float64
kind source.FileKind
// sameContentOnDisk is true if a file has been saved on disk,
// and therefore does not need to be part of the overlay sent to go/packages.
sameContentOnDisk bool
}
func (o *overlay) FileSystem() source.FileSystem {
return o.session
}
func (o *overlay) Identity() source.FileIdentity {
return source.FileIdentity{
URI: o.uri,
Identifier: o.hash,
Version: o.version,
Kind: o.kind,
}
}
func (o *overlay) Read(ctx context.Context) ([]byte, string, error) {
return o.text, o.hash, nil
}
func (s *session) updateOverlay(ctx context.Context, c source.FileModification) error {
s.overlayMu.Lock()
defer s.overlayMu.Unlock()
o, ok := s.overlays[c.URI]
// Determine the file kind on open, otherwise, assume it has been cached.
var kind source.FileKind
switch c.Action {
case source.Open:
kind = source.DetectLanguage(c.LanguageID, c.URI.Filename())
default:
if !ok {
return errors.Errorf("updateOverlay: modifying unopened overlay %v", c.URI)
}
kind = o.kind
}
if kind == source.UnknownKind {
return errors.Errorf("updateOverlay: unknown file kind for %s", c.URI)
}
// Closing a file just deletes its overlay.
if c.Action == source.Close {
delete(s.overlays, c.URI)
return nil
}
// If the file is on disk, check if its content is the same as the overlay.
text := c.Text
if text == nil {
text = o.text
}
hash := hashContents(text)
var sameContentOnDisk bool
switch c.Action {
case source.Open:
_, h, err := s.cache.GetFile(c.URI, kind).Read(ctx)
sameContentOnDisk = (err == nil && h == hash)
case source.Save:
// Make sure the version and content (if present) is the same.
if o.version != c.Version {
return errors.Errorf("updateOverlay: saving %s at version %v, currently at %v", c.URI, c.Version, o.version)
}
if c.Text != nil && o.hash != hash {
return errors.Errorf("updateOverlay: overlay %s changed on save", c.URI)
}
sameContentOnDisk = true
}
s.overlays[c.URI] = &overlay{
session: s,
uri: c.URI,
version: c.Version,
text: text,
kind: kind,
hash: hash,
sameContentOnDisk: sameContentOnDisk,
}
return nil
}
func (s *session) readOverlay(uri span.URI) *overlay {
s.overlayMu.Lock()
defer s.overlayMu.Unlock()
// We might have the content saved in an overlay.
if overlay, ok := s.overlays[uri]; ok {
return overlay
}
return nil
}
func (s *session) buildOverlay() map[string][]byte {
s.overlayMu.Lock()
defer s.overlayMu.Unlock()
overlays := make(map[string][]byte)
for uri, overlay := range s.overlays {
// TODO(rstambler): Make sure not to send overlays outside of the current view.
if overlay.sameContentOnDisk {
continue
}
overlays[uri.Filename()] = overlay.text
}
return overlays
}