Remove select() usage

This commit is contained in:
Igor Nikonov 2023-12-04 09:33:34 +00:00
parent adbc819a09
commit 73ff984755
7 changed files with 3 additions and 860 deletions

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@ -30,7 +30,6 @@ int __gai_sigqueue(int sig, const union sigval val, pid_t caller_pid)
}
#include <sys/select.h>
#include <stdlib.h>
#include <features.h>

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@ -55,7 +55,6 @@ set (SRCS
src/DigestStream.cpp
src/DirectoryIterator.cpp
src/DirectoryIteratorStrategy.cpp
src/DirectoryWatcher.cpp
src/Environment.cpp
src/Error.cpp
src/ErrorHandler.cpp

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@ -1,228 +0,0 @@
//
// DirectoryWatcher.h
//
// Library: Foundation
// Package: Filesystem
// Module: DirectoryWatcher
//
// Definition of the DirectoryWatcher class.
//
// Copyright (c) 2012, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_DirectoryWatcher_INCLUDED
#define Foundation_DirectoryWatcher_INCLUDED
#include "Poco/Foundation.h"
#ifndef POCO_NO_INOTIFY
# include "Poco/AtomicCounter.h"
# include "Poco/BasicEvent.h"
# include "Poco/File.h"
# include "Poco/Runnable.h"
# include "Poco/Thread.h"
namespace Poco
{
class DirectoryWatcherStrategy;
class Foundation_API DirectoryWatcher : protected Runnable
/// This class is used to get notifications about changes
/// to the filesystem, more specifically, to a specific
/// directory. Changes to a directory are reported via
/// events.
///
/// A thread will be created that watches the specified
/// directory for changes. Events are reported in the context
/// of this thread.
///
/// Note that changes to files in subdirectories of the watched
/// directory are not reported. Separate DirectoryWatcher objects
/// must be created for these directories if they should be watched.
///
/// Changes to file attributes are not reported.
///
/// On Windows, this class is implemented using FindFirstChangeNotification()/FindNextChangeNotification().
/// On Linux, this class is implemented using inotify.
/// On FreeBSD and Darwin (Mac OS X, iOS), this class uses kevent/kqueue.
/// On all other platforms, the watched directory is periodically scanned
/// for changes. This can negatively affect performance if done too often.
/// Therefore, the interval in which scans are done can be specified in
/// the constructor. Note that periodic scanning will also be done on FreeBSD
/// and Darwin if events for changes to files (DW_ITEM_MODIFIED) are enabled.
///
/// DW_ITEM_MOVED_FROM and DW_ITEM_MOVED_TO events will only be reported
/// on Linux. On other platforms, a file rename or move operation
/// will be reported via a DW_ITEM_REMOVED and a DW_ITEM_ADDED event.
/// The order of these two events is not defined.
///
/// An event mask can be specified to enable only certain events.
{
public:
enum DirectoryEventType
{
DW_ITEM_ADDED = 1,
/// A new item has been created and added to the directory.
DW_ITEM_REMOVED = 2,
/// An item has been removed from the directory.
DW_ITEM_MODIFIED = 4,
/// An item has been modified.
DW_ITEM_MOVED_FROM = 8,
/// An item has been renamed or moved. This event delivers the old name.
DW_ITEM_MOVED_TO = 16
/// An item has been renamed or moved. This event delivers the new name.
};
enum DirectoryEventMask
{
DW_FILTER_ENABLE_ALL = 31,
/// Enables all event types.
DW_FILTER_DISABLE_ALL = 0
/// Disables all event types.
};
enum
{
DW_DEFAULT_SCAN_INTERVAL = 5 /// Default scan interval for platforms that don't provide a native notification mechanism.
};
struct DirectoryEvent
{
DirectoryEvent(const File & f, DirectoryEventType ev) : item(f), event(ev) { }
const File & item; /// The directory or file that has been changed.
DirectoryEventType event; /// The kind of event.
};
BasicEvent<const DirectoryEvent> itemAdded;
/// Fired when a file or directory has been created or added to the directory.
BasicEvent<const DirectoryEvent> itemRemoved;
/// Fired when a file or directory has been removed from the directory.
BasicEvent<const DirectoryEvent> itemModified;
/// Fired when a file or directory has been modified.
BasicEvent<const DirectoryEvent> itemMovedFrom;
/// Fired when a file or directory has been renamed. This event delivers the old name.
BasicEvent<const DirectoryEvent> itemMovedTo;
/// Fired when a file or directory has been moved. This event delivers the new name.
BasicEvent<const Exception> scanError;
/// Fired when an error occurs while scanning for changes.
DirectoryWatcher(const std::string & path, int eventMask = DW_FILTER_ENABLE_ALL, int scanInterval = DW_DEFAULT_SCAN_INTERVAL);
/// Creates a DirectoryWatcher for the directory given in path.
/// To enable only specific events, an eventMask can be specified by
/// OR-ing the desired event IDs (e.g., DW_ITEM_ADDED | DW_ITEM_MODIFIED).
/// On platforms where no native filesystem notifications are available,
/// scanInterval specifies the interval in seconds between scans
/// of the directory.
DirectoryWatcher(const File & directory, int eventMask = DW_FILTER_ENABLE_ALL, int scanInterval = DW_DEFAULT_SCAN_INTERVAL);
/// Creates a DirectoryWatcher for the specified directory
/// To enable only specific events, an eventMask can be specified by
/// OR-ing the desired event IDs (e.g., DW_ITEM_ADDED | DW_ITEM_MODIFIED).
/// On platforms where no native filesystem notifications are available,
/// scanInterval specifies the interval in seconds between scans
/// of the directory.
~DirectoryWatcher();
/// Destroys the DirectoryWatcher.
void suspendEvents();
/// Suspends sending of events. Can be called multiple times, but every
/// call to suspendEvent() must be matched by a call to resumeEvents().
void resumeEvents();
/// Resumes events, after they have been suspended with a call to suspendEvents().
bool eventsSuspended() const;
/// Returns true iff events are suspended.
int eventMask() const;
/// Returns the value of the eventMask passed to the constructor.
int scanInterval() const;
/// Returns the scan interval in seconds.
const File & directory() const;
/// Returns the directory being watched.
bool supportsMoveEvents() const;
/// Returns true iff the platform supports DW_ITEM_MOVED_FROM/itemMovedFrom and
/// DW_ITEM_MOVED_TO/itemMovedTo events.
protected:
void init();
void stop();
void run();
private:
DirectoryWatcher();
DirectoryWatcher(const DirectoryWatcher &);
DirectoryWatcher & operator=(const DirectoryWatcher &);
Thread _thread;
File _directory;
int _eventMask;
AtomicCounter _eventsSuspended;
int _scanInterval;
DirectoryWatcherStrategy * _pStrategy;
};
//
// inlines
//
inline bool DirectoryWatcher::eventsSuspended() const
{
return _eventsSuspended.value() > 0;
}
inline int DirectoryWatcher::eventMask() const
{
return _eventMask;
}
inline int DirectoryWatcher::scanInterval() const
{
return _scanInterval;
}
inline const File & DirectoryWatcher::directory() const
{
return _directory;
}
} // namespace Poco
#endif // POCO_NO_INOTIFY
#endif // Foundation_DirectoryWatcher_INCLUDED

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@ -1,602 +0,0 @@
//
// DirectoryWatcher.cpp
//
// Library: Foundation
// Package: Filesystem
// Module: DirectoryWatcher
//
// Copyright (c) 2012, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#include "Poco/DirectoryWatcher.h"
#ifndef POCO_NO_INOTIFY
#include "Poco/Path.h"
#include "Poco/Glob.h"
#include "Poco/DirectoryIterator.h"
#include "Poco/Event.h"
#include "Poco/Exception.h"
#include "Poco/Buffer.h"
#if POCO_OS == POCO_OS_LINUX || POCO_OS == POCO_OS_ANDROID
#include <sys/inotify.h>
#include <sys/select.h>
#include <unistd.h>
#elif POCO_OS == POCO_OS_MAC_OS_X || POCO_OS == POCO_OS_FREE_BSD
#include <fcntl.h>
#include <sys/types.h>
#include <sys/event.h>
#include <sys/time.h>
#include <unistd.h>
#if (POCO_OS == POCO_OS_FREE_BSD) && !defined(O_EVTONLY)
#define O_EVTONLY 0x8000
#endif
#endif
#include <algorithm>
#include <atomic>
#include <map>
namespace Poco {
class DirectoryWatcherStrategy
{
public:
DirectoryWatcherStrategy(DirectoryWatcher& owner):
_owner(owner)
{
}
virtual ~DirectoryWatcherStrategy()
{
}
DirectoryWatcher& owner()
{
return _owner;
}
virtual void run() = 0;
virtual void stop() = 0;
virtual bool supportsMoveEvents() const = 0;
protected:
struct ItemInfo
{
ItemInfo():
size(0)
{
}
ItemInfo(const ItemInfo& other):
path(other.path),
size(other.size),
lastModified(other.lastModified)
{
}
explicit ItemInfo(const File& f):
path(f.path()),
size(f.isFile() ? f.getSize() : 0),
lastModified(f.getLastModified())
{
}
std::string path;
File::FileSize size;
Timestamp lastModified;
};
typedef std::map<std::string, ItemInfo> ItemInfoMap;
void scan(ItemInfoMap& entries)
{
DirectoryIterator it(owner().directory());
DirectoryIterator end;
while (it != end)
{
entries[it.path().getFileName()] = ItemInfo(*it);
++it;
}
}
void compare(ItemInfoMap& oldEntries, ItemInfoMap& newEntries)
{
for (ItemInfoMap::iterator itn = newEntries.begin(); itn != newEntries.end(); ++itn)
{
ItemInfoMap::iterator ito = oldEntries.find(itn->first);
if (ito != oldEntries.end())
{
if ((owner().eventMask() & DirectoryWatcher::DW_ITEM_MODIFIED) && !owner().eventsSuspended())
{
if (itn->second.size != ito->second.size || itn->second.lastModified != ito->second.lastModified)
{
Poco::File f(itn->second.path);
DirectoryWatcher::DirectoryEvent ev(f, DirectoryWatcher::DW_ITEM_MODIFIED);
owner().itemModified(&owner(), ev);
}
}
oldEntries.erase(ito);
}
else if ((owner().eventMask() & DirectoryWatcher::DW_ITEM_ADDED) && !owner().eventsSuspended())
{
Poco::File f(itn->second.path);
DirectoryWatcher::DirectoryEvent ev(f, DirectoryWatcher::DW_ITEM_ADDED);
owner().itemAdded(&owner(), ev);
}
}
if ((owner().eventMask() & DirectoryWatcher::DW_ITEM_REMOVED) && !owner().eventsSuspended())
{
for (ItemInfoMap::iterator it = oldEntries.begin(); it != oldEntries.end(); ++it)
{
Poco::File f(it->second.path);
DirectoryWatcher::DirectoryEvent ev(f, DirectoryWatcher::DW_ITEM_REMOVED);
owner().itemRemoved(&owner(), ev);
}
}
}
private:
DirectoryWatcherStrategy();
DirectoryWatcherStrategy(const DirectoryWatcherStrategy&);
DirectoryWatcherStrategy& operator = (const DirectoryWatcherStrategy&);
DirectoryWatcher& _owner;
};
#if POCO_OS == POCO_OS_WINDOWS_NT
class WindowsDirectoryWatcherStrategy: public DirectoryWatcherStrategy
{
public:
WindowsDirectoryWatcherStrategy(DirectoryWatcher& owner):
DirectoryWatcherStrategy(owner)
{
_hStopped = CreateEventW(NULL, FALSE, FALSE, NULL);
if (!_hStopped)
throw SystemException("cannot create event");
}
~WindowsDirectoryWatcherStrategy()
{
CloseHandle(_hStopped);
}
void run()
{
ItemInfoMap entries;
scan(entries);
DWORD filter = FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
if (owner().eventMask() & DirectoryWatcher::DW_ITEM_MODIFIED)
filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
std::string path(owner().directory().path());
HANDLE hChange = FindFirstChangeNotificationA(path.c_str(), FALSE, filter);
if (hChange == INVALID_HANDLE_VALUE)
{
try
{
FileImpl::handleLastErrorImpl(path);
}
catch (Poco::Exception& exc)
{
owner().scanError(&owner(), exc);
}
return;
}
bool stopped = false;
while (!stopped)
{
try
{
HANDLE h[2];
h[0] = _hStopped;
h[1] = hChange;
switch (WaitForMultipleObjects(2, h, FALSE, INFINITE))
{
case WAIT_OBJECT_0:
stopped = true;
break;
case WAIT_OBJECT_0 + 1:
{
ItemInfoMap newEntries;
scan(newEntries);
compare(entries, newEntries);
std::swap(entries, newEntries);
if (FindNextChangeNotification(hChange) == FALSE)
{
FileImpl::handleLastErrorImpl(path);
}
}
break;
default:
throw SystemException("failed to wait for directory changes");
}
}
catch (Poco::Exception& exc)
{
owner().scanError(&owner(), exc);
}
}
FindCloseChangeNotification(hChange);
}
void stop()
{
SetEvent(_hStopped);
}
bool supportsMoveEvents() const
{
return false;
}
private:
HANDLE _hStopped;
};
#elif POCO_OS == POCO_OS_LINUX || POCO_OS == POCO_OS_ANDROID
class LinuxDirectoryWatcherStrategy: public DirectoryWatcherStrategy
{
public:
LinuxDirectoryWatcherStrategy(DirectoryWatcher& owner):
DirectoryWatcherStrategy(owner),
_fd(-1),
_stopped(false)
{
_fd = inotify_init();
if (_fd == -1) throw Poco::IOException("cannot initialize inotify", errno);
}
~LinuxDirectoryWatcherStrategy()
{
close(_fd);
}
void run()
{
int mask = 0;
if (owner().eventMask() & DirectoryWatcher::DW_ITEM_ADDED)
mask |= IN_CREATE;
if (owner().eventMask() & DirectoryWatcher::DW_ITEM_REMOVED)
mask |= IN_DELETE;
if (owner().eventMask() & DirectoryWatcher::DW_ITEM_MODIFIED)
mask |= IN_MODIFY;
if (owner().eventMask() & DirectoryWatcher::DW_ITEM_MOVED_FROM)
mask |= IN_MOVED_FROM;
if (owner().eventMask() & DirectoryWatcher::DW_ITEM_MOVED_TO)
mask |= IN_MOVED_TO;
int wd = inotify_add_watch(_fd, owner().directory().path().c_str(), mask);
if (wd == -1)
{
try
{
FileImpl::handleLastErrorImpl(owner().directory().path());
}
catch (Poco::Exception& exc)
{
owner().scanError(&owner(), exc);
}
}
Poco::Buffer<char> buffer(4096);
while (!_stopped.load(std::memory_order_relaxed))
{
fd_set fds;
FD_ZERO(&fds);
FD_SET(_fd, &fds);
struct timeval tv;
tv.tv_sec = 0;
tv.tv_usec = 200000;
if (select(_fd + 1, &fds, NULL, NULL, &tv) == 1)
{
int n = read(_fd, buffer.begin(), buffer.size());
int i = 0;
if (n > 0)
{
while (n > 0)
{
struct inotify_event* event = reinterpret_cast<struct inotify_event*>(buffer.begin() + i);
if (event->len > 0)
{
if (!owner().eventsSuspended())
{
Poco::Path p(owner().directory().path());
p.makeDirectory();
p.setFileName(event->name);
Poco::File f(p.toString());
if ((event->mask & IN_CREATE) && (owner().eventMask() & DirectoryWatcher::DW_ITEM_ADDED))
{
DirectoryWatcher::DirectoryEvent ev(f, DirectoryWatcher::DW_ITEM_ADDED);
owner().itemAdded(&owner(), ev);
}
if ((event->mask & IN_DELETE) && (owner().eventMask() & DirectoryWatcher::DW_ITEM_REMOVED))
{
DirectoryWatcher::DirectoryEvent ev(f, DirectoryWatcher::DW_ITEM_REMOVED);
owner().itemRemoved(&owner(), ev);
}
if ((event->mask & IN_MODIFY) && (owner().eventMask() & DirectoryWatcher::DW_ITEM_MODIFIED))
{
DirectoryWatcher::DirectoryEvent ev(f, DirectoryWatcher::DW_ITEM_MODIFIED);
owner().itemModified(&owner(), ev);
}
if ((event->mask & IN_MOVED_FROM) && (owner().eventMask() & DirectoryWatcher::DW_ITEM_MOVED_FROM))
{
DirectoryWatcher::DirectoryEvent ev(f, DirectoryWatcher::DW_ITEM_MOVED_FROM);
owner().itemMovedFrom(&owner(), ev);
}
if ((event->mask & IN_MOVED_TO) && (owner().eventMask() & DirectoryWatcher::DW_ITEM_MOVED_TO))
{
DirectoryWatcher::DirectoryEvent ev(f, DirectoryWatcher::DW_ITEM_MOVED_TO);
owner().itemMovedTo(&owner(), ev);
}
}
}
i += sizeof(inotify_event) + event->len;
n -= sizeof(inotify_event) + event->len;
}
}
}
}
}
void stop()
{
_stopped.store(true, std::memory_order_relaxed);
}
bool supportsMoveEvents() const
{
return true;
}
private:
int _fd;
std::atomic<bool> _stopped;
};
#elif POCO_OS == POCO_OS_MAC_OS_X || POCO_OS == POCO_OS_FREE_BSD
class BSDDirectoryWatcherStrategy: public DirectoryWatcherStrategy
{
public:
BSDDirectoryWatcherStrategy(DirectoryWatcher& owner):
DirectoryWatcherStrategy(owner),
_queueFD(-1),
_dirFD(-1),
_stopped(false)
{
_dirFD = open(owner.directory().path().c_str(), O_EVTONLY);
if (_dirFD < 0) throw Poco::FileNotFoundException(owner.directory().path());
_queueFD = kqueue();
if (_queueFD < 0)
{
close(_dirFD);
throw Poco::SystemException("Cannot create kqueue", errno);
}
}
~BSDDirectoryWatcherStrategy()
{
close(_dirFD);
close(_queueFD);
}
void run()
{
Poco::Timestamp lastScan;
ItemInfoMap entries;
scan(entries);
while (!_stopped.load(std::memory_order_relaxed))
{
struct timespec timeout;
timeout.tv_sec = 0;
timeout.tv_nsec = 200000000;
unsigned eventFilter = NOTE_WRITE;
struct kevent event;
struct kevent eventData;
EV_SET(&event, _dirFD, EVFILT_VNODE, EV_ADD | EV_CLEAR, eventFilter, 0, 0);
int nEvents = kevent(_queueFD, &event, 1, &eventData, 1, &timeout);
if (nEvents < 0 || eventData.flags == EV_ERROR)
{
try
{
FileImpl::handleLastErrorImpl(owner().directory().path());
}
catch (Poco::Exception& exc)
{
owner().scanError(&owner(), exc);
}
}
else if (nEvents > 0 || ((owner().eventMask() & DirectoryWatcher::DW_ITEM_MODIFIED) && lastScan.isElapsed(owner().scanInterval()*1000000)))
{
ItemInfoMap newEntries;
scan(newEntries);
compare(entries, newEntries);
std::swap(entries, newEntries);
lastScan.update();
}
}
}
void stop()
{
_stopped.store(true, std::memory_order_relaxed);
}
bool supportsMoveEvents() const
{
return false;
}
private:
int _queueFD;
int _dirFD;
std::atomic<bool> _stopped;
};
#else
class PollingDirectoryWatcherStrategy: public DirectoryWatcherStrategy
{
public:
PollingDirectoryWatcherStrategy(DirectoryWatcher& owner):
DirectoryWatcherStrategy(owner)
{
}
~PollingDirectoryWatcherStrategy()
{
}
void run()
{
ItemInfoMap entries;
scan(entries);
while (!_stopped.tryWait(1000*owner().scanInterval()))
{
try
{
ItemInfoMap newEntries;
scan(newEntries);
compare(entries, newEntries);
std::swap(entries, newEntries);
}
catch (Poco::Exception& exc)
{
owner().scanError(&owner(), exc);
}
}
}
void stop()
{
_stopped.set();
}
bool supportsMoveEvents() const
{
return false;
}
private:
Poco::Event _stopped;
};
#endif
DirectoryWatcher::DirectoryWatcher(const std::string& path, int eventMask, int scanInterval):
_directory(path),
_eventMask(eventMask),
_scanInterval(scanInterval)
{
init();
}
DirectoryWatcher::DirectoryWatcher(const Poco::File& directory, int eventMask, int scanInterval):
_directory(directory),
_eventMask(eventMask),
_scanInterval(scanInterval)
{
init();
}
DirectoryWatcher::~DirectoryWatcher()
{
try
{
stop();
delete _pStrategy;
}
catch (...)
{
poco_unexpected();
}
}
void DirectoryWatcher::suspendEvents()
{
poco_assert (_eventsSuspended > 0);
_eventsSuspended--;
}
void DirectoryWatcher::resumeEvents()
{
_eventsSuspended++;
}
void DirectoryWatcher::init()
{
if (!_directory.exists())
throw Poco::FileNotFoundException(_directory.path());
if (!_directory.isDirectory())
throw Poco::InvalidArgumentException("not a directory", _directory.path());
#if POCO_OS == POCO_OS_WINDOWS_NT
_pStrategy = new WindowsDirectoryWatcherStrategy(*this);
#elif POCO_OS == POCO_OS_LINUX || POCO_OS == POCO_OS_ANDROID
_pStrategy = new LinuxDirectoryWatcherStrategy(*this);
#elif POCO_OS == POCO_OS_MAC_OS_X || POCO_OS == POCO_OS_FREE_BSD
_pStrategy = new BSDDirectoryWatcherStrategy(*this);
#else
_pStrategy = new PollingDirectoryWatcherStrategy(*this);
#endif
_thread.start(*this);
}
void DirectoryWatcher::run()
{
_pStrategy->run();
}
void DirectoryWatcher::stop()
{
_pStrategy->stop();
_thread.join();
}
bool DirectoryWatcher::supportsMoveEvents() const
{
return _pStrategy->supportsMoveEvents();
}
} // namespace Poco
#endif // POCO_NO_INOTIFY

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@ -7,7 +7,7 @@
#include <cassert>
#include <cstring>
#include <unistd.h>
#include <sys/select.h>
#include <sys/poll.h>
#include <sys/time.h>
#include <sys/types.h>
@ -27,11 +27,8 @@ void trim(String & s)
/// Allows delaying the start of query execution until the entirety of query is inserted.
bool hasInputData()
{
timeval timeout = {0, 0};
fd_set fds{};
FD_ZERO(&fds);
FD_SET(STDIN_FILENO, &fds);
return select(1, &fds, nullptr, nullptr, &timeout) == 1;
pollfd fd{STDIN_FILENO, POLLIN, 0};
return poll(&fd, 1, 0) == 1;
}
struct NoCaseCompare

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@ -249,24 +249,6 @@ void ReadBufferFromFileDescriptor::rewind()
file_offset_of_buffer_end = 0;
}
/// Assuming file descriptor supports 'select', check that we have data to read or wait until timeout.
bool ReadBufferFromFileDescriptor::poll(size_t timeout_microseconds) const
{
fd_set fds;
FD_ZERO(&fds);
FD_SET(fd, &fds);
timeval timeout = { time_t(timeout_microseconds / 1000000), suseconds_t(timeout_microseconds % 1000000) };
int res = select(1, &fds, nullptr, nullptr, &timeout);
if (-1 == res)
throwFromErrno("Cannot select", ErrorCodes::CANNOT_SELECT);
return res > 0;
}
size_t ReadBufferFromFileDescriptor::getFileSize()
{
return getSizeFromFileDescriptor(fd, getFileName());

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@ -75,10 +75,6 @@ public:
size_t readBigAt(char * to, size_t n, size_t offset, const std::function<bool(size_t)> &) override;
bool supportsReadAt() override { return use_pread; }
private:
/// Assuming file descriptor supports 'select', check that we have data to read or wait until timeout.
bool poll(size_t timeout_microseconds) const;
};