mirror of
https://github.com/facebook/sapling.git
synced 2024-10-10 16:57:49 +03:00
8b9261f2a1
Summary:
Per discussion with bolinfest, this brings Eden in line with clang-format.
This diff was generated with `find . \( -iname '*.cpp' -o -iname '*.h' \) -exec bash -c "yes | arc lint {}" \;`
Reviewed By: bolinfest
Differential Revision: D6232695
fbshipit-source-id: d54942bf1c69b5b0dcd4df629f1f2d5538c9e28c
96 lines
2.9 KiB
C++
96 lines
2.9 KiB
C++
/*
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* Copyright (c) 2016-present, Facebook, Inc.
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* All rights reserved.
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*
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* This source code is licensed under the BSD-style license found in the
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* LICENSE file in the root directory of this source tree. An additional grant
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* of patent rights can be found in the PATENTS file in the same directory.
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*
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*/
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#pragma once
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#include "FileHandleBase.h"
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namespace facebook {
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namespace eden {
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namespace fusell {
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class FileHandle : public FileHandleBase {
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public:
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/**
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* Return true if this file handle uses direct IO
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*/
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virtual bool usesDirectIO() const;
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/**
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* Return true if, at open() time, the kernel can retain cached info.
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*/
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virtual bool preserveCache() const;
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/**
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* Return true if the file is seekable.
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*/
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virtual bool isSeekable() const;
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/**
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* Read data
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*
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* Read should send exactly the number of bytes requested except
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* on EOF or error, otherwise the rest of the data will be
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* substituted with zeroes. An exception to this is when the file
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* has been opened in 'direct_io' mode, in which case the return
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* value of the read system call will reflect the return value of
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* this operation.
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*
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* @param size number of bytes to read
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* @param off offset to read from
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*/
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virtual folly::Future<BufVec> read(size_t size, off_t off) = 0;
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/**
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* Write data
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*
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* Write should return exactly the number of bytes requested
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* except on error. An exception to this is when the file has
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* been opened in 'direct_io' mode, in which case the return value
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* of the write system call will reflect the return value of this
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* operation.
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*/
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virtual folly::Future<size_t> write(BufVec&& buf, off_t off) = 0;
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virtual folly::Future<size_t> write(folly::StringPiece data, off_t off) = 0;
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/**
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* Flush method
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*
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* This is called on each close() of the opened file.
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*
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* Since file descriptors can be duplicated (dup, dup2, fork), for
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* one open call there may be many flush calls.
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*
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* Filesystems shouldn't assume that flush will always be called
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* after some writes, or that if will be called at all.
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*
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* NOTE: the name of the method is misleading, since (unlike
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* fsync) the filesystem is not forced to flush pending writes.
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* One reason to flush data, is if the filesystem wants to return
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* write errors.
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*
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* If the filesystem supports file locking operations (setlk,
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* getlk) it should remove all locks belonging to 'lock_owner'.
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*/
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virtual folly::Future<folly::Unit> flush(uint64_t lock_owner) = 0;
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/**
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* Synchronize file contents
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*
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* If the datasync parameter is non-zero, then only the user data
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* should be flushed, not the meta data.
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*
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* @param datasync flag indicating if only data should be flushed
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* @param fi file information
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*/
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virtual folly::Future<folly::Unit> fsync(bool datasync) = 0;
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};
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} // namespace fusell
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} // namespace eden
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} // namespace facebook
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