mirror of
https://github.com/luxfi/zapdb.git
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Dominic Della ValleandIbrahim Jarif
bd676a2394
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).
(cherry picked from commit b21308673c)
56 lines
1.5 KiB
Go
56 lines
1.5 KiB
Go
/*
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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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"os"
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"syscall"
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"unsafe"
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"golang.org/x/sys/unix"
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)
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// Mmap uses the mmap system call to memory-map a file. If writable is true,
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// memory protection of the pages is set so that they may be written to as well.
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func mmap(fd *os.File, writable bool, size int64) ([]byte, error) {
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mtype := unix.PROT_READ
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if writable {
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mtype |= unix.PROT_WRITE
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}
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return unix.Mmap(int(fd.Fd()), 0, int(size), mtype, unix.MAP_SHARED)
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}
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// Munmap unmaps a previously mapped slice.
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func munmap(b []byte) error {
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return unix.Munmap(b)
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}
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// This is required because the unix package does not support the madvise system call on OS X.
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func madvise(b []byte, readahead bool) error {
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advice := unix.MADV_NORMAL
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if !readahead {
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advice = unix.MADV_RANDOM
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}
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_, _, e1 := syscall.Syscall(syscall.SYS_MADVISE, uintptr(unsafe.Pointer(&b[0])),
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uintptr(len(b)), uintptr(advice))
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if e1 != 0 {
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return e1
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}
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return nil
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}
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