go/internal/lsp/cache/file.go
Rebecca Stambler 00c44ba9c1 internal/lsp: add cache for type information
This change adds an additional cache for type information, which here is
just a *packages.Package for each package. The metadata cache maintains
the import graph, which allows us to easily determine when a package X
(and therefore any other package that imports X) should be invalidated.

Additionally, rather than performing content changes as they happen, we
queue up content changes and apply them the next time that any type
information is requested.

Updates golang/go#30309

Change-Id: Iaf569f641f84ce69b0c0d5bdabbaa85635eeb8bf
Reviewed-on: https://go-review.googlesource.com/c/tools/+/165438
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
2019-03-08 17:45:44 +00:00

114 lines
2.4 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 (
"context"
"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
meta *metadata
imports []*ast.ImportSpec
}
// GetContent returns the contents of the file, reading it from file system if needed.
func (f *File) GetContent(ctx context.Context) []byte {
f.view.mu.Lock()
defer f.view.mu.Unlock()
if ctx.Err() == nil {
f.read(ctx)
}
return f.content
}
func (f *File) GetFileSet(ctx context.Context) *token.FileSet {
return f.view.Config.Fset
}
func (f *File) GetToken(ctx context.Context) *token.File {
f.view.mu.Lock()
defer f.view.mu.Unlock()
if f.token == nil || len(f.view.contentChanges) > 0 {
if err := f.view.parse(ctx, f.URI); err != nil {
return nil
}
}
return f.token
}
func (f *File) GetAST(ctx context.Context) *ast.File {
f.view.mu.Lock()
defer f.view.mu.Unlock()
if f.ast == nil || len(f.view.contentChanges) > 0 {
if err := f.view.parse(ctx, f.URI); err != nil {
return nil
}
}
return f.ast
}
func (f *File) GetPackage(ctx context.Context) *packages.Package {
f.view.mu.Lock()
defer f.view.mu.Unlock()
if f.pkg == nil || len(f.view.contentChanges) > 0 {
if err := f.view.parse(ctx, f.URI); err != nil {
return nil
}
}
return f.pkg
}
// read is the internal part of GetContent. It assumes that the caller is
// holding the mutex of the file's view.
func (f *File) read(ctx context.Context) {
if f.content != nil {
if len(f.view.contentChanges) == 0 {
return
}
f.view.mcache.mu.Lock()
err := f.view.applyContentChanges(ctx)
f.view.mcache.mu.Unlock()
if err == nil {
return
}
}
// We don't know the content yet, so read it.
filename, err := f.URI.Filename()
if err != nil {
return
}
content, err := ioutil.ReadFile(filename)
if err != nil {
return
}
f.content = content
}
// isPopulated returns true if all of the computed fields of the file are set.
func (f *File) isPopulated() bool {
return f.ast != nil && f.token != nil && f.pkg != nil && f.meta != nil && f.imports != nil
}