mirror of
https://github.com/facebook/sapling.git
synced 2024-10-10 16:57:49 +03:00
38299c2d3a
Summary: This diff introduces a sqlite based overlay, which stores the directory inode and its entries in the sqlite database. This is similar to FsOverlay but doesn't support all the functionality. Sqlite overlay in this diff is only designed to handles the requirement for Eden on Windows. We did not build sqlite overlay as a virtual class because as of this diff the interface and functionality of this is different from fsOverlay. Reviewed By: simpkins Differential Revision: D20480870 fbshipit-source-id: c87cb2ffd11c6c0c7a10bc8dfaf6164e0e442b2b
105 lines
3.4 KiB
C++
105 lines
3.4 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
|
|
#include <folly/Synchronized.h>
|
|
#include "eden/fs/sqlite/Sqlite.h"
|
|
|
|
#include "eden/fs/inodes/overlay/gen-cpp2/overlay_types.h"
|
|
|
|
namespace facebook {
|
|
namespace eden {
|
|
struct InodeNumber;
|
|
using LockedDbPtr = folly::Synchronized<sqlite3*>::LockedPtr;
|
|
|
|
/**
|
|
* Sqlite overlay stores the directory inode and its entries in the sqlite
|
|
* database. This is similar to FsOverlay but doesn't support all the
|
|
* functionality. This is only used on Windows right now.
|
|
*/
|
|
|
|
class SqliteOverlay {
|
|
public:
|
|
explicit SqliteOverlay(AbsolutePathPiece localDir);
|
|
~SqliteOverlay();
|
|
|
|
/**
|
|
* Initialize the overlay, and load the nextInodeNumber. The "close"
|
|
* method should be used to release these resources and persist the
|
|
* nextInodeNumber.
|
|
*
|
|
* It ignores the value of createIfNonExisting. The Sqlite
|
|
* DB and the tables are created or opened in the contructor and are closed in
|
|
* the destructor.
|
|
*/
|
|
std::optional<InodeNumber> initOverlay(bool createIfNonExisting);
|
|
|
|
/**
|
|
* Gracefully, shutdown the overlay, persisting the overlay's
|
|
* nextInodeNumber.
|
|
*/
|
|
void close(std::optional<InodeNumber> nextInodeNumber);
|
|
|
|
const AbsolutePath& getLocalDir() const {
|
|
return localDir_;
|
|
}
|
|
|
|
/**
|
|
* Was FsOverlay initialized - i.e., is cleanup (close) necessary.
|
|
*/
|
|
bool initialized() const {
|
|
return initialized_;
|
|
}
|
|
|
|
void saveOverlayDir(InodeNumber inodeNumber, const overlay::OverlayDir& odir);
|
|
std::optional<overlay::OverlayDir> loadOverlayDir(InodeNumber inodeNumber);
|
|
void removeOverlayData(InodeNumber inodeNumber);
|
|
bool hasOverlayData(InodeNumber inodeNumber);
|
|
|
|
/**
|
|
* Update the last used Inode number to a new value. This is a stop gap
|
|
* solution for the recovery when Eden doesn't know the last used inode number
|
|
* in case of an unclean shutdown.
|
|
*
|
|
* How it works: The SqliteOverlay allocates a range of inodes and keep
|
|
* assigning the inode numbers from that. Once the allocated inode number is
|
|
* at the end of range it will allocate a new range. To allocate the range it
|
|
* will add the the known value of the last used inode number with the size of
|
|
* range and save that value as the last known Inode number. In case of
|
|
* unclean shutdown we know that last used inode number must be smaller than
|
|
* the Inode number stored in the Sqlite.
|
|
*
|
|
*/
|
|
void updateUsedInodeNumber(uint64_t usedInodeNumber);
|
|
|
|
private:
|
|
std::optional<std::string> load(uint64_t inodeNumber) const;
|
|
bool hasInode(uint64_t inodeNumber) const;
|
|
void save(uint64_t inodeNumber, bool isDirectory, folly::ByteRange value);
|
|
|
|
// APIs to fetch and save the value of next Inode number
|
|
void saveNextInodeNumber(uint64_t inodeNumber);
|
|
std::optional<uint64_t> readNextInodeNumber(LockedDbPtr& db);
|
|
void writeNextInodeNumber(LockedDbPtr& db, uint64_t inodeNumber);
|
|
|
|
// Sqlite db handle
|
|
std::unique_ptr<SqliteDatabase> db_;
|
|
|
|
// Path to the folder containing DB.
|
|
const AbsolutePath localDir_;
|
|
|
|
// Has initOverlay() been called on this.
|
|
bool initialized_ = false;
|
|
|
|
// nextInodeNumber_ is part of a stop gap solution for Windows described
|
|
// above. The writes to this are protected by db_ lock.
|
|
std::atomic<uint64_t> nextInodeNumber_{0};
|
|
}; // namespace eden
|
|
|
|
} // namespace eden
|
|
} // namespace facebook
|