sapling/eden/fs/nfs/DirList.h
Xavier Deguillard ec5a6ef1f0 nfs: implement the READDIR RPC
Summary:
The NFS readdir turns out to be pretty similar to the FUSE one, with a couple
of differences. For one, it only populates the directory entry name, it also
puts a limit on the total size of the serialized result, including all the
NFS/XDR overhead.

It is not specified if the . and .. entries need to be returned, but since the
NFS spec is usually pretty explicit about these and makes it clear that this is
for the most part a client burden, I didn't add these. I may have to revisit
this later when I get to manually browse a repository.

Since the READDIR RPC doesn't populate any filehandle, the client will have to
issue a LOOKUP RPC for each entries, potentially leading to some
inefficiencies. A future diff will implement the READDIRPLUS to fix these.

Reviewed By: chadaustin

Differential Revision: D26802310

fbshipit-source-id: b821b57021d0c2dca33427975b1acd665173bc5c
2021-03-18 10:08:50 -07:00

53 lines
1.1 KiB
C++

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This software may be used and distributed according to the terms of the
* GNU General Public License version 2.
*/
#pragma once
#ifndef _WIN32
#include "eden/fs/inodes/InodeNumber.h"
#include "eden/fs/nfs/NfsdRpc.h"
namespace facebook::eden {
/**
* Abstraction to only add as many directory entries that can fit into a given
* amount of memory.
*/
class NfsDirList {
public:
explicit NfsDirList(uint32_t count);
NfsDirList(NfsDirList&&) = default;
NfsDirList& operator=(NfsDirList&&) = default;
NfsDirList() = delete;
NfsDirList(const NfsDirList&) = delete;
NfsDirList& operator=(const NfsDirList&) = delete;
/**
* Add an entry. Return true if the entry was successfully added, false
* otherwise.
*/
bool add(folly::StringPiece name, InodeNumber ino, uint64_t offset);
/**
* Move the built list out of the NfsDirList.
*/
XdrList<entry3> extractList() {
return std::move(list_);
}
private:
uint32_t remaining_;
XdrList<entry3> list_{};
};
} // namespace facebook::eden
#endif