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			42 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			42 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| // Copyright 2015 The etcd Authors
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| //
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| // Licensed under the Apache License, Version 2.0 (the "License");
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| // you may not use this file except in compliance with the License.
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| // You may obtain a copy of the License at
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| //
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| //     http://www.apache.org/licenses/LICENSE-2.0
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| //
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| // Unless required by applicable law or agreed to in writing, software
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| // distributed under the License is distributed on an "AS IS" BASIS,
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| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| // See the License for the specific language governing permissions and
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| // limitations under the License.
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| 
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| package fileutil
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| 
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| import (
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| 	"os"
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| 	"syscall"
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| 	"unsafe"
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| )
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| 
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| func preallocExtend(f *os.File, sizeInBytes int64) error {
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| 	if err := preallocFixed(f, sizeInBytes); err != nil {
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| 		return err
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| 	}
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| 	return preallocExtendTrunc(f, sizeInBytes)
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| }
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| 
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| func preallocFixed(f *os.File, sizeInBytes int64) error {
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| 	fstore := &syscall.Fstore_t{
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| 		Flags:   syscall.F_ALLOCATEALL,
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| 		Posmode: syscall.F_PEOFPOSMODE,
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| 		Length:  sizeInBytes}
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| 	p := unsafe.Pointer(fstore)
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| 	_, _, errno := syscall.Syscall(syscall.SYS_FCNTL, f.Fd(), uintptr(syscall.F_PREALLOCATE), uintptr(p))
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| 	if errno == 0 || errno == syscall.ENOTSUP {
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| 		return nil
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| 	}
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| 	return errno
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| }
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