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go/internal/lsp/cache/external.go
Ian Cottrell 7b212d60a1 internal/event: renaming the main event API functions
event.Log removed
event.Print -> event.Log
event.Record -> event.Metric
event.StartSpan -> event.Start

In order to support this core now exposes the MakeEvent and Export functions.

Change-Id: Ic7550d88dbf400e32c419adbb61d1546c471841e
Reviewed-on: https://go-review.googlesource.com/c/tools/+/229238
Reviewed-by: Robert Findley <rfindley@google.com>
2020-04-23 17:21:36 +00:00

74 lines
1.9 KiB
Go

// 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"
"io/ioutil"
"os"
"golang.org/x/tools/internal/event"
"golang.org/x/tools/internal/lsp/debug/tag"
"golang.org/x/tools/internal/lsp/source"
"golang.org/x/tools/internal/span"
errors "golang.org/x/xerrors"
)
// ioLimit limits the number of parallel file reads per process.
var ioLimit = make(chan struct{}, 128)
// nativeFileSystem implements FileSystem reading from the normal os file system.
type nativeFileSystem struct{}
// nativeFileHandle implements FileHandle for nativeFileSystem
type nativeFileHandle struct {
fs *nativeFileSystem
identity source.FileIdentity
}
func (fs *nativeFileSystem) GetFile(uri span.URI) source.FileHandle {
return &nativeFileHandle{
fs: fs,
identity: source.FileIdentity{
URI: uri,
Identifier: identifier(uri.Filename()),
Kind: source.DetectLanguage("", uri.Filename()),
},
}
}
func (h *nativeFileHandle) FileSystem() source.FileSystem {
return h.fs
}
func (h *nativeFileHandle) Identity() source.FileIdentity {
return h.identity
}
func (h *nativeFileHandle) Read(ctx context.Context) ([]byte, string, error) {
ctx, done := event.Start(ctx, "cache.nativeFileHandle.Read", tag.File.Of(h.identity.URI.Filename()))
_ = ctx
defer done()
ioLimit <- struct{}{}
defer func() { <-ioLimit }()
if id := identifier(h.identity.URI.Filename()); id != h.identity.Identifier {
return nil, "", errors.Errorf("%s: file has been modified", h.identity.URI.Filename())
}
data, err := ioutil.ReadFile(h.identity.URI.Filename())
if err != nil {
return nil, "", err
}
return data, hashContents(data), nil
}
func identifier(filename string) string {
if fi, err := os.Stat(filename); err == nil {
return fi.ModTime().String()
}
return "DOES NOT EXIST"
}