mirror of
https://github.com/luxfi/zapdb.git
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Dominic Della ValleandIbrahim Jarif
b21308673c
Using the unix package by default for other systems instead of syscall. This way when systems get added to unix, they will work without change. And the special case is restricted only to darwin builds. I encountered problems building on Solaris prior to this patch: github.com/dgraph-io/badger/y/mmap_unix.go:57:30: undefined: syscall.SYS_MADVISE But unix.Madvise works fine on that platform (and others).
92 lines
2.3 KiB
Go
92 lines
2.3 KiB
Go
// +build windows
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/*
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* Copyright 2019 Dgraph Labs, Inc. and Contributors
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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 y
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import (
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"fmt"
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"os"
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"syscall"
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"unsafe"
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)
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func mmap(fd *os.File, write bool, size int64) ([]byte, error) {
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protect := syscall.PAGE_READONLY
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access := syscall.FILE_MAP_READ
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if write {
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protect = syscall.PAGE_READWRITE
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access = syscall.FILE_MAP_WRITE
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}
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fi, err := fd.Stat()
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if err != nil {
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return nil, err
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}
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// In windows, we cannot mmap a file more than it's actual size.
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// So truncate the file to the size of the mmap.
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if fi.Size() < size {
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if err := fd.Truncate(size); err != nil {
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return nil, fmt.Errorf("truncate: %s", err)
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}
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}
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// Open a file mapping handle.
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sizelo := uint32(size >> 32)
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sizehi := uint32(size) & 0xffffffff
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handler, err := syscall.CreateFileMapping(syscall.Handle(fd.Fd()), nil,
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uint32(protect), sizelo, sizehi, nil)
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if err != nil {
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return nil, os.NewSyscallError("CreateFileMapping", err)
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}
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// Create the memory map.
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addr, err := syscall.MapViewOfFile(handler, uint32(access), 0, 0, uintptr(size))
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if addr == 0 {
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return nil, os.NewSyscallError("MapViewOfFile", err)
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}
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// Close mapping handle.
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if err := syscall.CloseHandle(syscall.Handle(handler)); err != nil {
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return nil, os.NewSyscallError("CloseHandle", err)
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}
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// Slice memory layout
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// Copied this snippet from golang/sys package
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var sl = struct {
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addr uintptr
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len int
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cap int
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}{addr, int(size), int(size)}
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// Use unsafe to turn sl into a []byte.
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data := *(*[]byte)(unsafe.Pointer(&sl))
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return data, nil
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}
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func munmap(b []byte) error {
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return syscall.UnmapViewOfFile(uintptr(unsafe.Pointer(&b[0])))
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}
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func madvise(b []byte, readahead bool) error {
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// Do Nothing. We don’t care about this setting on Windows
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return nil
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}
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