mirror of
https://github.com/golang/go
synced 2024-11-19 04:14:45 -07:00
e873952e15
Address a lingering TODO. A FileHandle read should return errors if the file has been modified on disk while in use. Change-Id: I540de9bef575a9ca838f49500665a24b05b4f54c Reviewed-on: https://go-review.googlesource.com/c/tools/+/215981 Run-TryBot: Rebecca Stambler <rstambler@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rohan Challa <rohan@golang.org> Reviewed-by: Heschi Kreinick <heschi@google.com>
74 lines
1.9 KiB
Go
74 lines
1.9 KiB
Go
// Copyright 2019 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package cache
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import (
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"context"
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"io/ioutil"
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"os"
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"golang.org/x/tools/internal/lsp/source"
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"golang.org/x/tools/internal/lsp/telemetry"
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"golang.org/x/tools/internal/span"
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"golang.org/x/tools/internal/telemetry/trace"
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errors "golang.org/x/xerrors"
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)
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// ioLimit limits the number of parallel file reads per process.
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var ioLimit = make(chan struct{}, 128)
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// nativeFileSystem implements FileSystem reading from the normal os file system.
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type nativeFileSystem struct{}
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// nativeFileHandle implements FileHandle for nativeFileSystem
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type nativeFileHandle struct {
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fs *nativeFileSystem
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identity source.FileIdentity
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}
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func (fs *nativeFileSystem) GetFile(uri span.URI) source.FileHandle {
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return &nativeFileHandle{
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fs: fs,
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identity: source.FileIdentity{
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URI: uri,
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Identifier: identifier(uri.Filename()),
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Kind: source.DetectLanguage("", uri.Filename()),
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},
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}
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}
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func (h *nativeFileHandle) FileSystem() source.FileSystem {
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return h.fs
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}
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func (h *nativeFileHandle) Identity() source.FileIdentity {
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return h.identity
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}
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func (h *nativeFileHandle) Read(ctx context.Context) ([]byte, string, error) {
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ctx, done := trace.StartSpan(ctx, "cache.nativeFileHandle.Read", telemetry.File.Of(h.identity.URI.Filename()))
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_ = ctx
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defer done()
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ioLimit <- struct{}{}
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defer func() { <-ioLimit }()
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if id := identifier(h.identity.URI.Filename()); id != h.identity.Identifier {
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return nil, "", errors.Errorf("%s: file has been modified", h.identity.URI.Filename())
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}
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data, err := ioutil.ReadFile(h.identity.URI.Filename())
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if err != nil {
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return nil, "", err
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}
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return data, hashContents(data), nil
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}
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func identifier(filename string) string {
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if fi, err := os.Stat(filename); err == nil {
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return fi.ModTime().String()
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}
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return "DOES NOT EXIST"
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}
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