sapling/eden/fs/inodes/InodePtrFwd.h

/*
 * 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

/*
 * This file contains forward declarations of InodePtr and related types
 */

namespace facebook {
namespace eden {

class FileInode;
class InodeBase;
class TreeInode;
class DotEdenInode;

template <typename InodeType>
class InodePtrImpl;

/*
 * Friendly names for the various InodePtr classes.
 */
using DotEdenInodePtr = InodePtrImpl<DotEdenInode>;
using FileInodePtr = InodePtrImpl<FileInode>;
using TreeInodePtr = InodePtrImpl<TreeInode>;
class InodePtr;
} // namespace eden
} // namespace facebook
add new InodePtr classes Summary: This defines our own custom smart pointer type for Inode objects. This will provide us with more control over Inode lifetime, allowing us to decide if we want to unload them immediately when they become unreferenced, or keep them around for a while. This will also allow us to fix some memory management issues around EdenMount destruction. Currently we destroy the EdenMount immediately when it is unmounted. This can cause issues if other parts of the code are still holding references to Inode objects from this EdenMount. Our custom InodePtr class will also allow us to delay destroying the EdenMount until all of its Inodes have been destroyed. This diff adds the new pointer types and updates the code to use them, but does not actually implement destroying unreferenced inodes yet. The logic for that has proven to be slightly subtle; I will split it out into its own separate diff. Reviewed By: wez Differential Revision: D4351072 fbshipit-source-id: 7a9d81cbd226c9662a79a2f2ceda82fe2651f312 2017-01-18 02:01:37 +03:00			`/*`
update license headers in C++ files Summary: Update the copyright & license headers in C++ files to reflect the relicensing to GPLv2 Reviewed By: wez Differential Revision: D15487078 fbshipit-source-id: 19f24c933a64ecad0d3a692d0f8d2a38b4194b1d 2019-06-20 02:58:25 +03:00			`* Copyright (c) Facebook, Inc. and its affiliates.`
add new InodePtr classes Summary: This defines our own custom smart pointer type for Inode objects. This will provide us with more control over Inode lifetime, allowing us to decide if we want to unload them immediately when they become unreferenced, or keep them around for a while. This will also allow us to fix some memory management issues around EdenMount destruction. Currently we destroy the EdenMount immediately when it is unmounted. This can cause issues if other parts of the code are still holding references to Inode objects from this EdenMount. Our custom InodePtr class will also allow us to delay destroying the EdenMount until all of its Inodes have been destroyed. This diff adds the new pointer types and updates the code to use them, but does not actually implement destroying unreferenced inodes yet. The logic for that has proven to be slightly subtle; I will split it out into its own separate diff. Reviewed By: wez Differential Revision: D4351072 fbshipit-source-id: 7a9d81cbd226c9662a79a2f2ceda82fe2651f312 2017-01-18 02:01:37 +03:00			`*`
update license headers in C++ files Summary: Update the copyright & license headers in C++ files to reflect the relicensing to GPLv2 Reviewed By: wez Differential Revision: D15487078 fbshipit-source-id: 19f24c933a64ecad0d3a692d0f8d2a38b4194b1d 2019-06-20 02:58:25 +03:00			`* This software may be used and distributed according to the terms of the`
			`* GNU General Public License version 2.`
add new InodePtr classes Summary: This defines our own custom smart pointer type for Inode objects. This will provide us with more control over Inode lifetime, allowing us to decide if we want to unload them immediately when they become unreferenced, or keep them around for a while. This will also allow us to fix some memory management issues around EdenMount destruction. Currently we destroy the EdenMount immediately when it is unmounted. This can cause issues if other parts of the code are still holding references to Inode objects from this EdenMount. Our custom InodePtr class will also allow us to delay destroying the EdenMount until all of its Inodes have been destroyed. This diff adds the new pointer types and updates the code to use them, but does not actually implement destroying unreferenced inodes yet. The logic for that has proven to be slightly subtle; I will split it out into its own separate diff. Reviewed By: wez Differential Revision: D4351072 fbshipit-source-id: 7a9d81cbd226c9662a79a2f2ceda82fe2651f312 2017-01-18 02:01:37 +03:00			`*/`
Tidy up license headers Reviewed By: chadaustin Differential Revision: D17872966 fbshipit-source-id: cd60a364a2146f0dadbeca693b1d4a5d7c97ff63 2019-10-11 15:26:59 +03:00
add new InodePtr classes Summary: This defines our own custom smart pointer type for Inode objects. This will provide us with more control over Inode lifetime, allowing us to decide if we want to unload them immediately when they become unreferenced, or keep them around for a while. This will also allow us to fix some memory management issues around EdenMount destruction. Currently we destroy the EdenMount immediately when it is unmounted. This can cause issues if other parts of the code are still holding references to Inode objects from this EdenMount. Our custom InodePtr class will also allow us to delay destroying the EdenMount until all of its Inodes have been destroyed. This diff adds the new pointer types and updates the code to use them, but does not actually implement destroying unreferenced inodes yet. The logic for that has proven to be slightly subtle; I will split it out into its own separate diff. Reviewed By: wez Differential Revision: D4351072 fbshipit-source-id: 7a9d81cbd226c9662a79a2f2ceda82fe2651f312 2017-01-18 02:01:37 +03:00			`#pragma once`

			`/*`
			`* This file contains forward declarations of InodePtr and related types`
			`*/`

			`namespace facebook {`
			`namespace eden {`

			`class FileInode;`
			`class InodeBase;`
			`class TreeInode;`
add .eden "magic" dir Summary: It's not really magic because we don't have a virtual directory inode base any more. Instead, we mkdir and populate it at mount time. What is slightly magical about it is that we give it some special powers: * We know the inode number of the eden dir and prevent unlink operations on it or inside it. * The .eden dir is present in the contents of the root inode and will show up when that directory is `readdir`'d * When resolving a child of a TreeInode by name, we know to return the magic `.eden` inode number. This means that it is possible to `stat` and consume the `.eden` directory from any directory inside the eden mount, even though it won't show up in `readdir` for those child dirs. The contents of the `.eden` dir are: * `socket` - a symlink back to the unix domain socket that our thrift server is listening on. This means that it is a simple `readlink(".eden/socket")` operation to discover both whether a directory is part of an eden mount and how to talk to the server. * `root` - a symlink back to the root of this eden mount. This allows using `readlink(".eden/root")` as a simple 1-step operation to find the root of an eden mount, and avoids needing to walk up directory by directory as is the common pattern for locating `.hg` or `.git` dirs. Reviewed By: simpkins Differential Revision: D4637285 fbshipit-source-id: 0eabf98b29144acccef5c83bd367493399dc55bb 2017-03-25 08:52:33 +03:00			`class DotEdenInode;`
add new InodePtr classes Summary: This defines our own custom smart pointer type for Inode objects. This will provide us with more control over Inode lifetime, allowing us to decide if we want to unload them immediately when they become unreferenced, or keep them around for a while. This will also allow us to fix some memory management issues around EdenMount destruction. Currently we destroy the EdenMount immediately when it is unmounted. This can cause issues if other parts of the code are still holding references to Inode objects from this EdenMount. Our custom InodePtr class will also allow us to delay destroying the EdenMount until all of its Inodes have been destroyed. This diff adds the new pointer types and updates the code to use them, but does not actually implement destroying unreferenced inodes yet. The logic for that has proven to be slightly subtle; I will split it out into its own separate diff. Reviewed By: wez Differential Revision: D4351072 fbshipit-source-id: 7a9d81cbd226c9662a79a2f2ceda82fe2651f312 2017-01-18 02:01:37 +03:00
			`template <typename InodeType>`
			`class InodePtrImpl;`

			`/*`
			`* Friendly names for the various InodePtr classes.`
			`*/`
add .eden "magic" dir Summary: It's not really magic because we don't have a virtual directory inode base any more. Instead, we mkdir and populate it at mount time. What is slightly magical about it is that we give it some special powers: * We know the inode number of the eden dir and prevent unlink operations on it or inside it. * The .eden dir is present in the contents of the root inode and will show up when that directory is `readdir`'d * When resolving a child of a TreeInode by name, we know to return the magic `.eden` inode number. This means that it is possible to `stat` and consume the `.eden` directory from any directory inside the eden mount, even though it won't show up in `readdir` for those child dirs. The contents of the `.eden` dir are: * `socket` - a symlink back to the unix domain socket that our thrift server is listening on. This means that it is a simple `readlink(".eden/socket")` operation to discover both whether a directory is part of an eden mount and how to talk to the server. * `root` - a symlink back to the root of this eden mount. This allows using `readlink(".eden/root")` as a simple 1-step operation to find the root of an eden mount, and avoids needing to walk up directory by directory as is the common pattern for locating `.hg` or `.git` dirs. Reviewed By: simpkins Differential Revision: D4637285 fbshipit-source-id: 0eabf98b29144acccef5c83bd367493399dc55bb 2017-03-25 08:52:33 +03:00			`using DotEdenInodePtr = InodePtrImpl<DotEdenInode>;`
add new InodePtr classes Summary: This defines our own custom smart pointer type for Inode objects. This will provide us with more control over Inode lifetime, allowing us to decide if we want to unload them immediately when they become unreferenced, or keep them around for a while. This will also allow us to fix some memory management issues around EdenMount destruction. Currently we destroy the EdenMount immediately when it is unmounted. This can cause issues if other parts of the code are still holding references to Inode objects from this EdenMount. Our custom InodePtr class will also allow us to delay destroying the EdenMount until all of its Inodes have been destroyed. This diff adds the new pointer types and updates the code to use them, but does not actually implement destroying unreferenced inodes yet. The logic for that has proven to be slightly subtle; I will split it out into its own separate diff. Reviewed By: wez Differential Revision: D4351072 fbshipit-source-id: 7a9d81cbd226c9662a79a2f2ceda82fe2651f312 2017-01-18 02:01:37 +03:00			`using FileInodePtr = InodePtrImpl<FileInode>;`
			`using TreeInodePtr = InodePtrImpl<TreeInode>;`
simplify InodePtr classes Summary: This simplifies the InodePtrImpl class by removing support for pointer-to-const Inode objects. We don't currently use pointer-to-const Inode objects, and I don't really anticipate that we will ever need this. The primary motivating factor behind this diff is a recent change in clang that breaks the existing code: clang PR31606 prevents children classes from inheriting template constructor instantiations from their parent which take a reference to the parent class type as the only argument. While this could have been fixed by explicitly defining the necessary constructors in the child class (or simply by overriding newPtrLocked() and newPtrFromExisting() to return the subclass type), dropping support for pointer-to-const allows us to simplify the code and resolve this issue. Reviewed By: wez Differential Revision: D4825526 fbshipit-source-id: 999de352788b13818b7f23788bb34686e193cd5d 2017-04-06 23:08:15 +03:00			`class InodePtr;`
run clang-format across all C++ files 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 2017-11-04 01:58:04 +03:00			`} // namespace eden`
			`} // namespace facebook`