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go/internal/lsp/cache/external.go
Ian Cottrell 156eb2ae29 internal/lsp: split the telemetry library out
This is a straight move of some code with no changes.
It splits the part of the telemetry code that will become a standalone library from the bit that belongs in the lsp.

Change-Id: Icedb6bf1f3711da9251450531729984df6df7787
Reviewed-on: https://go-review.googlesource.com/c/tools/+/190403
Run-TryBot: Ian Cottrell <iancottrell@google.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-08-15 21:28:02 +00:00

69 lines
1.8 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/lsp/source"
"golang.org/x/tools/internal/lsp/telemetry"
"golang.org/x/tools/internal/span"
"golang.org/x/tools/internal/telemetry/trace"
)
// 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 {
version := "DOES NOT EXIST"
if fi, err := os.Stat(uri.Filename()); err == nil {
version = fi.ModTime().String()
}
return &nativeFileHandle{
fs: fs,
identity: source.FileIdentity{
URI: uri,
Version: version,
},
}
}
func (h *nativeFileHandle) FileSystem() source.FileSystem {
return h.fs
}
func (h *nativeFileHandle) Identity() source.FileIdentity {
return h.identity
}
func (h *nativeFileHandle) Kind() source.FileKind {
// TODO: How should we determine the file kind?
return source.Go
}
func (h *nativeFileHandle) Read(ctx context.Context) ([]byte, string, error) {
ctx, done := trace.StartSpan(ctx, "cache.nativeFileHandle.Read", telemetry.File.Of(h.identity.URI.Filename()))
defer done()
ioLimit <- struct{}{}
defer func() { <-ioLimit }()
//TODO: this should fail if the version is not the same as the handle
data, err := ioutil.ReadFile(h.identity.URI.Filename())
if err != nil {
return nil, "", err
}
return data, hashContents(data), nil
}