libreoffice-online/loolwsd/Util.hpp
Tor Lillqvist 86bd8426d0 More work on disk space monitoring
Monitor the disk space on important file systems: The ones where
cached tiles are stored and where the chroot jails are created. Those
might be the same file system of course, the code checks and doesn't
do needless work.

The check is done whenever a new loolkit process is taken into use and
a new chroot jail it constructed, and whenever a new client session
connects to a document. We don't check more often than once a minute,
though.

Still need to add code to guard against running out of diska space
when saving documents back to where they were opened from. For that
presumably need to enhance the Storage abstraction.
2016-09-29 17:54:40 +03:00

277 lines
8.5 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
#ifndef INCLUDED_UTIL_HPP
#define INCLUDED_UTIL_HPP
#include <atomic>
#include <cassert>
#include <functional>
#include <memory>
#include <regex>
#include <set>
#include <sstream>
#include <string>
#include <Poco/File.h>
#include <Poco/Net/WebSocket.h>
#include <Poco/Path.h>
#include <Poco/Process.h>
#include <Poco/RegularExpression.h>
#define LOK_USE_UNSTABLE_API
#include <LibreOfficeKit/LibreOfficeKitEnums.h>
/// Flag to stop pump loops.
extern std::atomic<bool> TerminationFlag;
namespace Util
{
namespace rng
{
void reseed();
unsigned getNext();
}
/// Encode an integral ID into a string, with padding support.
std::string encodeId(const unsigned number, const int padding = 5);
/// Decode an integral ID from a string.
unsigned decodeId(const std::string& str);
/// Creates a randomly name directory within path and returns the name.
std::string createRandomDir(const std::string& path);
bool windowingAvailable();
// Save data to a file (overwriting an existing file if necessary) with checks for errors. Write
// to a temporary file in the same directory that is then atomically renamed to the desired name
// if everything goes well. In case of any error, both the destination file (if it already
// exists) and the temporary file (if was created, or existed already) are removed. Return true
// if everything succeeded.
bool saveDataToFileSafely(std::string fileName, const char *data, size_t size);
// We work around some of the mess of using the same sources both on the server side and in unit
// tests with conditional compilation based on BUILDING_TESTS.
#ifndef BUILDING_TESTS
// Send a 'error:' message with the specified cmd and kind parameters to all connected
// clients. This function can be called either in loolwsd or loolkit processes, even if only
// loolwsd obviously has contact with the actual clients; in loolkit it will be forwarded to
// loolwsd for redistribution. (This function must be implemented separately in each program
// that uses it, it is not in Util.cpp.)
void alertAllUsers(const std::string& cmd, const std::string& kind);
#else
// No-op implementation in the test programs
inline void alertAllUsers(const std::string&, const std::string&)
{
}
#endif
// Check disk space on a list of file systems. The list is initially empty, and each call to the
// function with a non-empty 'path' adds the file system that path is located on to the list, if
// not already there. If the free space on any of the file systems in question is below 5%, call
// 'alertAllUsers("internal", "diskfull")'. The check will be made no more often than once a
// minute.
void checkDiskSpace(const std::string& path);
/// Assert that a lock is already taken.
template <typename T>
void assertIsLocked(T& lock)
{
assert(!lock.try_lock());
}
/// Safely remove a file or directory.
/// Supresses exception when the file is already removed.
/// This can happen when there is a race (unavoidable) or when
/// we don't care to check before we remove (when no race exists).
inline
void removeFile(const std::string& path, const bool recursive = false)
{
try
{
Poco::File(path).remove(recursive);
}
catch (const std::exception&)
{
// Already removed or we don't care about failures.
}
}
inline
void removeFile(const Poco::Path& path, const bool recursive = false)
{
removeFile(path.toString(), recursive);
}
/// Make a temp copy of a file.
/// Primarily used by tests to avoid tainting the originals.
/// srcDir shouldn't end with '/' and srcFilename shouldn't contain '/'.
/// Returns the created file path.
std::string getTempFilePath(const std::string& srcDir, const std::string& srcFilename);
/// Returns the name of the signal.
const char *signalName(int signo);
/// Trap signals to cleanup and exit the process gracefully.
void setTerminationSignals();
void setFatalSignals();
void requestTermination(const Poco::Process::PID& pid);
int getMemoryUsage(const Poco::Process::PID nPid);
std::string replace(const std::string& s, const std::string& a, const std::string& b);
std::string formatLinesForLog(const std::string& s);
void setThreadName(const std::string& s);
/// Get version information
void getVersionInfo(std::string& version, std::string& hash);
/// Return a string that is unique across processes and calls.
std::string UniqueId();
/// Given one or more patterns to allow, and one or more to deny,
/// the match member will return true if, and only if, the subject
/// matches the allowed list, but not the deny.
/// By default, everything is denied.
class RegexListMatcher
{
public:
RegexListMatcher() :
_allowByDefault(false)
{
}
RegexListMatcher(const bool allowByDefault) :
_allowByDefault(allowByDefault)
{
}
RegexListMatcher(std::initializer_list<std::string> allowed) :
_allowByDefault(false),
_allowed(allowed)
{
}
RegexListMatcher(std::initializer_list<std::string> allowed,
std::initializer_list<std::string> denied) :
_allowByDefault(false),
_allowed(allowed),
_denied(denied)
{
}
RegexListMatcher(const bool allowByDefault,
std::initializer_list<std::string> denied) :
_allowByDefault(allowByDefault),
_denied(denied)
{
}
void allow(const std::string& pattern) { _allowed.insert(pattern); }
void deny(const std::string& pattern)
{
_allowed.erase(pattern);
_denied.insert(pattern);
}
void clear()
{
_allowed.clear();
_denied.clear();
}
bool match(const std::string& subject) const
{
return (_allowByDefault || match(_allowed, subject)) &&
!match(_denied, subject);
}
private:
bool match(const std::set<std::string>& set, const std::string& subject) const
{
if (set.find(subject) != set.end())
{
return true;
}
// Not a perfect match, try regex.
for (const auto& value : set)
{
try
{
// Not performance critical to warrant caching.
Poco::RegularExpression re(value, Poco::RegularExpression::RE_CASELESS);
Poco::RegularExpression::Match reMatch;
// Must be a full match.
if (re.match(subject, reMatch) && reMatch.offset == 0 && reMatch.length == subject.size())
{
return true;
}
}
catch (const std::exception& exc)
{
// Nothing to do; skip.
}
}
return false;
}
private:
const bool _allowByDefault;
std::set<std::string> _allowed;
std::set<std::string> _denied;
};
/// A logical constant that is allowed to initialize
/// exactly once and checks usage before initialization.
template<typename T>
class RuntimeConstant
{
T _value;
std::atomic<bool> _initialized;
public:
RuntimeConstant()
: _value()
, _initialized(false)
{
}
/// Use a compile-time const instead.
RuntimeConstant(const T& value) = delete;
const T& get()
{
if (_initialized)
{
return _value;
}
throw std::runtime_error("RuntimeConstant instance read before being initialized.");
}
void set(const T& value)
{
assert(!_initialized);
_initialized = true;
_value = value;
}
};
} // end namespace Util
#endif
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */