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go/internal/lsp/cache/file.go
Rebecca Stambler 3576414c54 internal/lsp: refactor source package to use an interface
This change separates a cache package out of the
golang.org/x/tools/internal/lsp/source package. The source package now
uses an interface instead a File struct, which will allow it be reused
more easily. The cache package contains the View and File structs now.

Change-Id: Ia2114e9dafc5214c8b21bceba3adae1c36b9799d
Reviewed-on: https://go-review.googlesource.com/c/152798
Reviewed-by: Ian Cottrell <iancottrell@google.com>
2018-12-05 22:49:35 +00:00

127 lines
2.8 KiB
Go

// Copyright 2018 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 (
"fmt"
"go/ast"
"go/token"
"io/ioutil"
"golang.org/x/tools/go/packages"
"golang.org/x/tools/internal/lsp/source"
)
// File holds all the information we know about a file.
type File struct {
URI source.URI
view *View
active bool
content []byte
ast *ast.File
token *token.File
pkg *packages.Package
}
// SetContent sets the overlay contents for a file.
// Setting it to nil will revert it to the on disk contents, and remove it
// from the active set.
func (f *File) SetContent(content []byte) {
f.view.mu.Lock()
defer f.view.mu.Unlock()
f.content = content
// the ast and token fields are invalid
f.ast = nil
f.token = nil
f.pkg = nil
// and we might need to update the overlay
switch {
case f.active && content == nil:
// we were active, and want to forget the content
f.active = false
if filename, err := f.URI.Filename(); err == nil {
delete(f.view.Config.Overlay, filename)
}
f.content = nil
case content != nil:
// an active overlay, update the map
f.active = true
if filename, err := f.URI.Filename(); err == nil {
f.view.Config.Overlay[filename] = f.content
}
}
}
// Read returns the contents of the file, reading it from file system if needed.
func (f *File) Read() ([]byte, error) {
f.view.mu.Lock()
defer f.view.mu.Unlock()
return f.read()
}
func (f *File) GetFileSet() (*token.FileSet, error) {
if f.view.Config == nil {
return nil, fmt.Errorf("no config for file view")
}
if f.view.Config.Fset == nil {
return nil, fmt.Errorf("no fileset for file view config")
}
return f.view.Config.Fset, nil
}
func (f *File) GetToken() (*token.File, error) {
f.view.mu.Lock()
defer f.view.mu.Unlock()
if f.token == nil {
if err := f.view.parse(f.URI); err != nil {
return nil, err
}
if f.token == nil {
return nil, fmt.Errorf("failed to find or parse %v", f.URI)
}
}
return f.token, nil
}
func (f *File) GetAST() (*ast.File, error) {
f.view.mu.Lock()
defer f.view.mu.Unlock()
if f.ast == nil {
if err := f.view.parse(f.URI); err != nil {
return nil, err
}
}
return f.ast, nil
}
func (f *File) GetPackage() (*packages.Package, error) {
f.view.mu.Lock()
defer f.view.mu.Unlock()
if f.pkg == nil {
if err := f.view.parse(f.URI); err != nil {
return nil, err
}
}
return f.pkg, nil
}
// read is the internal part of Read that presumes the lock is already held
func (f *File) read() ([]byte, error) {
if f.content != nil {
return f.content, nil
}
// we don't know the content yet, so read it
filename, err := f.URI.Filename()
if err != nil {
return nil, err
}
content, err := ioutil.ReadFile(filename)
if err != nil {
return nil, err
}
f.content = content
return f.content, nil
}