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go/internal/lsp/source/file.go
Ian Cottrell d0600fd9f1 internal/lsp: make source independent of protocol
I realized this was a mistake, we should try to keep the source
directory independent of the LSP protocol itself, and adapt in
the outer layer.
This will keep us honest about capabilities, let us add the
caching and conversion layers easily, and also allow for a future
where we expose the source directory as a supported API for other
tools.
The outer lsp package then becomes the adapter from the core
features to the specifics of the LSP protocol.

Change-Id: I68fd089f1b9f2fd38decc1cbc13c6f0f86157b94
Reviewed-on: https://go-review.googlesource.com/c/148157
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
2018-11-07 18:42:35 +00:00

124 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 source
import (
"fmt"
"go/ast"
"go/token"
"golang.org/x/tools/go/packages"
"io/ioutil"
)
// File holds all the information we know about a file.
type File struct {
URI URI
view *View
active bool
content []byte
ast *ast.File
token *token.File
pkg *packages.Package
}
// Range represents a start and end position.
// Because Range is based purely on two token.Pos entries, it is not self
// contained. You need access to a token.FileSet to regain the file
// information.
type Range struct {
Start token.Pos
End token.Pos
}
// 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) 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
}