mirror of https://github.com/prometheus/prometheus
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
73 lines
1.5 KiB
73 lines
1.5 KiB
// Copyright 2018 The Prometheus Authors |
|
// Licensed under the Apache License, Version 2.0 (the "License"); |
|
// you may not use this file except in compliance with the License. |
|
// You may obtain a copy of the License at |
|
// |
|
// http://www.apache.org/licenses/LICENSE-2.0 |
|
// |
|
// Unless required by applicable law or agreed to in writing, software |
|
// distributed under the License is distributed on an "AS IS" BASIS, |
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
|
// See the License for the specific language governing permissions and |
|
// limitations under the License. |
|
|
|
package fileutil |
|
|
|
import ( |
|
"os" |
|
|
|
"github.com/pkg/errors" |
|
) |
|
|
|
type MmapFile struct { |
|
f *os.File |
|
b []byte |
|
} |
|
|
|
func OpenMmapFile(path string) (*MmapFile, error) { |
|
return OpenMmapFileWithSize(path, 0) |
|
} |
|
|
|
func OpenMmapFileWithSize(path string, size int) (mf *MmapFile, retErr error) { |
|
f, err := os.Open(path) |
|
if err != nil { |
|
return nil, errors.Wrap(err, "try lock file") |
|
} |
|
defer func() { |
|
if retErr != nil { |
|
f.Close() |
|
} |
|
}() |
|
if size <= 0 { |
|
info, err := f.Stat() |
|
if err != nil { |
|
return nil, errors.Wrap(err, "stat") |
|
} |
|
size = int(info.Size()) |
|
} |
|
|
|
b, err := mmap(f, size) |
|
if err != nil { |
|
return nil, errors.Wrapf(err, "mmap, size %d", size) |
|
} |
|
|
|
return &MmapFile{f: f, b: b}, nil |
|
} |
|
|
|
func (f *MmapFile) Close() error { |
|
err0 := munmap(f.b) |
|
err1 := f.f.Close() |
|
|
|
if err0 != nil { |
|
return err0 |
|
} |
|
return err1 |
|
} |
|
|
|
func (f *MmapFile) File() *os.File { |
|
return f.f |
|
} |
|
|
|
func (f *MmapFile) Bytes() []byte { |
|
return f.b |
|
}
|
|
|