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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/Memory.h>
#include <Kernel/FileSystem/Inode.h>
#include <Kernel/FileSystem/InodeWatcher.h>
namespace Kernel {
NonnullRefPtr<InodeWatcher> InodeWatcher::create(Inode& inode)
{
return adopt(*new InodeWatcher(inode));
}
InodeWatcher::InodeWatcher(Inode& inode)
: m_inode(inode)
{
inode.register_watcher({}, *this);
}
InodeWatcher::~InodeWatcher()
{
if (auto inode = m_inode.strong_ref())
inode->unregister_watcher({}, *this);
}
bool InodeWatcher::can_read(const FileDescription&, size_t) const
{
return !m_queue.is_empty() || !m_inode;
}
bool InodeWatcher::can_write(const FileDescription&, size_t) const
{
return true;
}
KResultOr<size_t> InodeWatcher::read(FileDescription&, size_t, UserOrKernelBuffer& buffer, size_t buffer_size)
{
LOCKER(m_lock);
ASSERT(!m_queue.is_empty() || !m_inode);
if (!m_inode)
return 0;
auto event = m_queue.dequeue();
if (buffer_size < sizeof(InodeWatcherEvent))
return buffer_size;
size_t bytes_to_write = min(buffer_size, sizeof(event));
ssize_t nwritten = buffer.write_buffered<sizeof(event)>(bytes_to_write, [&](u8* data, size_t data_bytes) {
memcpy(data, &event, bytes_to_write);
return (ssize_t)data_bytes;
});
if (nwritten < 0)
return KResult((ErrnoCode)-nwritten);
evaluate_block_conditions();
return bytes_to_write;
}
KResultOr<size_t> InodeWatcher::write(FileDescription&, size_t, const UserOrKernelBuffer&, size_t)
{
return EIO;
}
String InodeWatcher::absolute_path(const FileDescription&) const
{
if (auto inode = m_inode.strong_ref())
return String::formatted("InodeWatcher:{}", inode->identifier().to_string());
return "InodeWatcher:(gone)";
}
void InodeWatcher::notify_inode_event(Badge<Inode>, InodeWatcherEvent::Type event_type)
{
LOCKER(m_lock);
m_queue.enqueue({ event_type });
evaluate_block_conditions();
}
void InodeWatcher::notify_child_added(Badge<Inode>, const InodeIdentifier& child_id)
{
LOCKER(m_lock);
m_queue.enqueue({ InodeWatcherEvent::Type::ChildAdded, child_id.index().value() });
evaluate_block_conditions();
}
void InodeWatcher::notify_child_removed(Badge<Inode>, const InodeIdentifier& child_id)
{
LOCKER(m_lock);
m_queue.enqueue({ InodeWatcherEvent::Type::ChildRemoved, child_id.index().value() });
evaluate_block_conditions();
}
}
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