130 lines
3.4 KiB
C++
130 lines
3.4 KiB
C++
/*
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* Copyright 2022 CM4all GmbH
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* All rights reserved.
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*
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* author: Max Kellermann <mk@cm4all.com>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "InotifyEvent.hxx"
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#include "system/Error.hxx"
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#include "io/UniqueFileDescriptor.hxx"
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#include <array>
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#include <limits.h>
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#include <sys/inotify.h>
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static UniqueFileDescriptor
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CreateInotify()
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{
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int fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK);
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if (fd < 0)
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throw MakeErrno("inotify_init1() failed");
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return UniqueFileDescriptor(fd);
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}
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InotifyEvent::InotifyEvent(EventLoop &event_loop, InotifyHandler &_handler)
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:event(event_loop, BIND_THIS_METHOD(OnInotifyReady),
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CreateInotify().Release()),
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handler(_handler)
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{
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Enable();
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}
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InotifyEvent::~InotifyEvent() noexcept
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{
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Close();
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}
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int
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InotifyEvent::AddWatch(const char *pathname, uint32_t mask)
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{
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int wd = inotify_add_watch(event.GetFileDescriptor().Get(),
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pathname, mask);
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if (wd < 0)
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throw FormatErrno("inotify_add_watch('%s') failed", pathname);
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return wd;
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}
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int
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InotifyEvent::AddModifyWatch(const char *pathname)
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{
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return AddWatch(pathname, IN_MODIFY);
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}
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void
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InotifyEvent::RemoveWatch(int wd) noexcept
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{
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inotify_rm_watch(event.GetFileDescriptor().Get(), wd);
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}
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inline void
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InotifyEvent::OnInotifyReady(unsigned) noexcept
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try {
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std::array<std::byte, 4096> buffer;
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static_assert(sizeof(buffer) >= sizeof(struct inotify_event) + NAME_MAX + 1,
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"inotify buffer too small");
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ssize_t nbytes = event.GetFileDescriptor().Read(buffer.data(),
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buffer.size());
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if (nbytes <= 0) [[unlikely]] {
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if (nbytes == 0)
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throw std::runtime_error{"EOF from inotify"};
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const int e = errno;
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if (e == EAGAIN)
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return;
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throw MakeErrno(e, "Reading inotify failed");
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}
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const std::byte *p = buffer.data(), *const end = p + nbytes;
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while (true) {
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const size_t remaining = end - p;
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const auto &ie = *(const struct inotify_event *)(const void *)p;
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if (remaining < sizeof(ie) ||
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remaining < sizeof(ie) + ie.len)
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break;
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const char *name;
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if (ie.len > 0 && ie.name[ie.len - 1] == 0)
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name = ie.name;
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else
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name = nullptr;
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handler.OnInotify(ie.wd, ie.mask, name);
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p += sizeof(ie) + ie.len;
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}
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} catch (...) {
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Close();
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handler.OnInotifyError(std::current_exception());
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}
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