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// Copyright (c) 2017 Couchbase, Inc.
//
// 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.
// +build !nommap
package vellum
import (
"os"
mmap "github.com/edsrzf/mmap-go"
)
type mmapWrapper struct {
f *os.File
mm mmap.MMap
}
func (m *mmapWrapper) Close() (err error) {
if m.mm != nil {
err = m.mm.Unmap()
}
// try to close file even if unmap failed
if m.f != nil {
err2 := m.f.Close()
if err == nil {
// try to return first error
err = err2
}
}
return
}
func open(path string) (*FST, error) {
f, err := os.Open(path)
if err != nil {
return nil, err
}
mm, err := mmap.Map(f, mmap.RDONLY, 0)
if err != nil {
// mmap failed, try to close the file
_ = f.Close()
return nil, err
}
return new(mm, &mmapWrapper{
f: f,
mm: mm,
})
}
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