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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#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&, u64, UserOrKernelBuffer& buffer, size_t buffer_size)
{
LOCKER(m_lock);
VERIFY(!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&, u64, 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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