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// *****************************************************************************
// * This file is part of the FreeFileSync project. It is distributed under *
// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0 *
// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
// *****************************************************************************
#ifndef DIR_EXIST_ASYNC_H_0817328167343215806734213
#define DIR_EXIST_ASYNC_H_0817328167343215806734213
#include <zen/thread.h>
#include <zen/file_error.h>
#include "process_callback.h"
#include "../afs/abstract.h"
namespace fff
{
const int DEFAULT_FOLDER_ACCESS_TIME_OUT_SEC = 20; //consider CD-ROM insert or hard disk spin up time from sleep
namespace
{
//directory existence checking may hang for non-existent network drives => run asynchronously and update UI!
//- check existence of all directories in parallel! (avoid adding up search times if multiple network drives are not reachable)
//- add reasonable time-out time!
struct FolderStatus
{
std::set<AbstractPath> existing;
std::set<AbstractPath> notExisting;
std::map<AbstractPath, zen::FileError> failedChecks;
};
FolderStatus getFolderStatusNonBlocking(const std::set<AbstractPath>& folderPaths,
bool allowUserInteraction, PhaseCallback& procCallback /*throw X*/)
{
using namespace zen;
//aggregate folder paths that are on the same root device: see parallel_scan.h
std::map<AfsDevice, std::set<AbstractPath>> perDevicePaths;
for (const AbstractPath& folderPath : folderPaths)
if (!AFS::isNullPath(folderPath)) //skip empty folders
perDevicePaths[folderPath.afsDevice].insert(folderPath);
std::vector<std::pair<AbstractPath, std::future<bool>>> futureDetails;
std::vector<ThreadGroup<std::packaged_task<bool()>>> perDeviceThreads;
for (const auto& [afsDevice, deviceFolderPaths] : perDevicePaths)
{
perDeviceThreads.emplace_back(1, Zstr("DirExist: ") + utfTo<Zstring>(AFS::getDisplayPath(AbstractPath(afsDevice, AfsPath()))));
auto& threadGroup = perDeviceThreads.back();
threadGroup.detach(); //don't wait on threads hanging longer than "folderAccessTimeout"
//1. login to network share, connect with Google Drive, etc.
std::shared_future<void> ftAuth = runAsync([afsDevice /*clang bug*/= afsDevice, allowUserInteraction]
{ AFS::authenticateAccess(afsDevice, allowUserInteraction); /*throw FileError*/ });
for (const AbstractPath& folderPath : deviceFolderPaths)
{
std::packaged_task<bool()> pt([folderPath, ftAuth]
{
ftAuth.get(); //throw FileError
/* 2. check dir existence:
CAVEAT: the case-sensitive semantics of AFS::itemStillExists() do not fit here!
BUT: its implementation happens to be okay for our use:
Assume we have a case-insensitive path match:
=> AFS::itemStillExists() first checks AFS::getItemType()
=> either succeeds (fine) or fails because of 1. not existing or 2. access error
=> if the subsequent case-sensitive folder search also doesn't find the folder: only a problem in case 2
=> FFS tries to create the folder during sync and fails with I. access error (fine) or II. already existing (obscures the previous "access error") */
return static_cast<bool>(AFS::itemStillExists(folderPath)); //throw FileError
//consider ItemType::file a failure instead? Meanwhile: return "false" IFF nothing (of any type) exists
});
auto ftIsExisting = pt.get_future();
threadGroup.run(std::move(pt));
futureDetails.emplace_back(folderPath, std::move(ftIsExisting));
}
}
//don't wait (almost) endlessly like Win32 would on non-existing network shares:
const auto startTime = std::chrono::steady_clock::now();
FolderStatus output;
for (auto& [folderPath, ftIsExisting] : futureDetails)
{
const std::wstring& displayPathFmt = fmtPath(AFS::getDisplayPath(folderPath));
procCallback.updateStatus(replaceCpy(_("Searching for folder %x..."), L"%x", displayPathFmt)); //throw X
int deviceTimeOutSec = AFS::getAccessTimeout(folderPath); //0 if no timeout in force
if (deviceTimeOutSec <= 0)
deviceTimeOutSec = DEFAULT_FOLDER_ACCESS_TIME_OUT_SEC;
const auto timeoutTime = startTime + std::chrono::seconds(deviceTimeOutSec);
while (std::chrono::steady_clock::now() < timeoutTime &&
ftIsExisting.wait_for(UI_UPDATE_INTERVAL / 2) == std::future_status::timeout)
procCallback.requestUiUpdate(); //throw X
if (!isReady(ftIsExisting))
output.failedChecks.emplace(folderPath, FileError(replaceCpy(_("Timeout while searching for folder %x."), L"%x", displayPathFmt) +
L" [" + _P("1 sec", "%x sec", deviceTimeOutSec) + L']'));
else
try
{
//call future::get() only *once*! otherwise: undefined behavior!
if (ftIsExisting.get()) //throw FileError
output.existing.emplace(folderPath);
else
output.notExisting.insert(folderPath);
}
catch (const FileError& e) { output.failedChecks.emplace(folderPath, e); }
}
return output;
}
}
}
#endif //DIR_EXIST_ASYNC_H_0817328167343215806734213
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