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authorDaniel Wilhelm <daniel@wili.li>2014-04-18 17:15:16 +0200
committerDaniel Wilhelm <daniel@wili.li>2014-04-18 17:15:16 +0200
commitbd6336c629841c6db3a6ca53a936d629d34db53b (patch)
tree3721ef997864108df175ce677a8a7d4342a6f1d2 /lib/parallel_scan.cpp
parent4.0 (diff)
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4.1
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diff --git a/lib/parallel_scan.cpp b/lib/parallel_scan.cpp
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+// **************************************************************************
+// * This file is part of the FreeFileSync project. It is distributed under *
+// * GNU General Public License: http://www.gnu.org/licenses/gpl.html *
+// * Copyright (C) 2008-2011 ZenJu (zhnmju123 AT gmx.de) *
+// **************************************************************************
+
+#include "parallel_scan.h"
+#include <boost/detail/atomic_count.hpp>
+#include "db_file.h"
+#include "lock_holder.h"
+#include <zen/file_traverser.h>
+#include <zen/file_error.h>
+#include <wx+/string_conv.h>
+#include <zen/thread.h> //includes <boost/thread.hpp>
+#include <zen/scope_guard.h>
+
+using namespace zen;
+
+
+#ifndef BOOST_HAS_THREADS
+#error just some paranoia check...
+#endif
+
+
+namespace
+{
+/*
+#ifdef FFS_WIN
+
+struct DiskInfo
+{
+ DiskInfo() :
+ driveType(DRIVE_UNKNOWN),
+ diskID(-1) {}
+
+ UINT driveType;
+ int diskID; // -1 if id could not be determined, this one is filled if driveType == DRIVE_FIXED or DRIVE_REMOVABLE;
+};
+
+inline
+bool operator<(const DiskInfo& lhs, const DiskInfo& rhs)
+{
+ if (lhs.driveType != rhs.driveType)
+ return lhs.driveType < rhs.driveType;
+
+ if (lhs.diskID < 0 || rhs.diskID < 0)
+ return false;
+ //consider "same", reason: one volume may be uniquely associated with one disk, while the other volume is associated to the same disk AND another one!
+ //volume <-> disk is 0..N:1..N
+
+ return lhs.diskID < rhs.diskID ;
+}
+
+
+DiskInfo retrieveDiskInfo(const Zstring& pathName)
+{
+ std::vector<wchar_t> volName(std::max(pathName.size(), static_cast<size_t>(10000)));
+
+ DiskInfo output;
+
+ //full pathName need not yet exist!
+ if (!::GetVolumePathName(pathName.c_str(), //__in LPCTSTR lpszFileName,
+ &volName[0], //__out LPTSTR lpszVolumePathName,
+ static_cast<DWORD>(volName.size()))) //__in DWORD cchBufferLength
+ return output;
+
+ const Zstring rootPathName = &volName[0];
+
+ output.driveType = ::GetDriveType(rootPathName.c_str());
+
+ if (output.driveType == DRIVE_NO_ROOT_DIR) //these two should be the same error category
+ output.driveType = DRIVE_UNKNOWN;
+
+ if (output.driveType != DRIVE_FIXED && output.driveType != DRIVE_REMOVABLE)
+ return output; //no reason to get disk ID
+
+ //go and find disk id:
+
+ //format into form: "\\.\C:"
+ Zstring volnameFmt = rootPathName;
+ if (endsWith(volnameFmt, FILE_NAME_SEPARATOR))
+ volnameFmt.resize(volnameFmt.size() - 1);
+ volnameFmt = L"\\\\.\\" + volnameFmt;
+
+ HANDLE hVolume = ::CreateFile(volnameFmt.c_str(),
+ 0,
+ FILE_SHARE_READ | FILE_SHARE_WRITE,
+ 0,
+ OPEN_EXISTING,
+ 0,
+ NULL);
+ if (hVolume == INVALID_HANDLE_VALUE)
+ return output;
+ ZEN_ON_BLOCK_EXIT(::CloseHandle(hVolume));
+
+ std::vector<char> buffer(sizeof(VOLUME_DISK_EXTENTS) + sizeof(DISK_EXTENT)); //reserve buffer for at most one disk! call below will then fail if volume spans multiple disks!
+
+ DWORD bytesReturned = 0;
+ if (!::DeviceIoControl(hVolume, // handle to device
+ IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS, // dwIoControlCode
+ NULL, // lpInBuffer
+ 0, // nInBufferSize
+ &buffer[0], // output buffer
+ static_cast<DWORD>(buffer.size()), // size of output buffer
+ &bytesReturned, // number of bytes returned
+ NULL)) // OVERLAPPED structure
+ return output;
+
+ const VOLUME_DISK_EXTENTS& volDisks = *reinterpret_cast<VOLUME_DISK_EXTENTS*>(&buffer[0]);
+
+ if (volDisks.NumberOfDiskExtents != 1)
+ return output;
+
+ output.diskID = volDisks.Extents[0].DiskNumber;
+
+ return output;
+}
+
+#elif defined FFS_LINUX
+#endif
+*/
+
+/*
+PERF NOTE
+
+--------------------------------------------
+|Testcase: Reading from two different disks|
+--------------------------------------------
+Windows 7:
+ 1st(unbuffered) |2nd (OS buffered)
+ ----------------------------------
+1 Thread: 57s | 8s
+2 Threads: 39s | 7s
+
+--------------------------------------------------
+|Testcase: Reading two directories from same disk|
+--------------------------------------------------
+Windows 7: Windows XP:
+ 1st(unbuffered) |2nd (OS buffered) 1st(unbuffered) |2nd (OS buffered)
+ ---------------------------------- ----------------------------------
+1 Thread: 41s | 13s 1 Thread: 45s | 13s
+2 Threads: 42s | 11s 2 Threads: 38s | 8s
+
+=> Traversing does not take any advantage of file locality so that even multiple threads operating on the same disk impose no performance overhead!
+*/
+
+
+std::vector<std::set<DirectoryKey>> separateByDistinctDisk(const std::set<DirectoryKey>& dirkeys)
+{
+ //see perf note: use one thread per dirkey:
+ typedef std::map<int, std::set<DirectoryKey>> DiskKeyMapping;
+ DiskKeyMapping tmp;
+ int index = 0;
+ std::for_each(dirkeys.begin(), dirkeys.end(),
+ [&](const DirectoryKey& key) { tmp[++index].insert(key); });
+
+ /*
+ //use one thread per physical disk:
+ typedef std::map<DiskInfo, std::set<DirectoryKey>> DiskKeyMapping;
+ DiskKeyMapping tmp;
+ std::for_each(dirkeys.begin(), dirkeys.end(),
+ [&](const DirectoryKey& key) { tmp[retrieveDiskInfo(key.dirnameFull_)].insert(key); });
+ */
+ std::vector<std::set<DirectoryKey>> buckets;
+ std::transform(tmp.begin(), tmp.end(), std::back_inserter(buckets),
+ [&](const DiskKeyMapping::value_type& diskToKey) { return diskToKey.second; });
+ return buckets;
+}
+
+//------------------------------------------------------------------------------------------
+typedef Zbase<wchar_t, StorageRefCountThreadSafe> BasicWString; //thread safe string class for UI texts
+
+
+class AsyncCallback
+{
+public:
+ AsyncCallback() :
+ notifyingThreadID(-1),
+ textScanning(_("Scanning:")),
+ itemsScanned(0),
+ activeWorker(0) {}
+
+ FillBufferCallback::HandleError reportError(const std::wstring& msg) //blocking call: context of worker thread
+ {
+ boost::unique_lock<boost::mutex> dummy(lockErrorMsg);
+ while (!errorMsg.empty() || errorResponse.get())
+ conditionCanReportError.timed_wait(dummy, boost::posix_time::milliseconds(50)); //interruption point!
+
+ errorMsg = BasicWString(msg);
+
+ while (!errorResponse.get())
+ conditionGotResponse.timed_wait(dummy, boost::posix_time::milliseconds(50)); //interruption point!
+
+ FillBufferCallback::HandleError rv = *errorResponse;
+
+ errorMsg.clear();
+ errorResponse.reset();
+
+ //dummy.unlock();
+ conditionCanReportError.notify_one();
+
+ return rv;
+ }
+
+ void processErrors(FillBufferCallback& callback) //context of main thread, call repreatedly
+ {
+ boost::lock_guard<boost::mutex> dummy(lockErrorMsg);
+ if (!errorMsg.empty() && !errorResponse.get())
+ {
+ FillBufferCallback::HandleError rv = callback.reportError(cvrtString<std::wstring>(errorMsg)); //throw!
+ errorResponse.reset(new FillBufferCallback::HandleError(rv));
+
+ //dummy.unlock();
+ conditionGotResponse.notify_one();
+ }
+ }
+
+ void setNotifyingThread(int threadID) { notifyingThreadID = threadID; } //context of main thread
+
+ void reportCurrentFile(const Zstring& filename, int threadID) //context of worker thread
+ {
+ if (threadID != notifyingThreadID) return; //only one thread may report status
+
+ boost::lock_guard<boost::mutex> dummy(lockCurrentStatus);
+ currentFile = filename;
+ currentStatus.clear();
+ }
+
+ void reportCurrentStatus(const std::wstring& status, int threadID) //context of worker thread
+ {
+ if (threadID != notifyingThreadID) return; //only one thread may report status
+
+ boost::lock_guard<boost::mutex> dummy(lockCurrentStatus);
+ currentFile.clear();
+ currentStatus = BasicWString(status); //we cannot assume std::wstring to be thread safe (yet)!
+ }
+
+ std::wstring getCurrentStatus() //context of main thread, call repreatedly
+ {
+ std::wstring filename;
+ std::wstring statusMsg;
+ {
+ boost::lock_guard<boost::mutex> dummy(lockCurrentStatus);
+ if (!currentFile.empty())
+ filename = utf8CvrtTo<std::wstring>(currentFile);
+ else if (!currentStatus.empty())
+ statusMsg = cvrtString<std::wstring>(currentStatus);
+ }
+
+ if (!filename.empty())
+ {
+ std::wstring statusText = cvrtString<std::wstring>(textScanning);
+ const long activeCount = activeWorker;
+ if (activeCount >= 2)
+ {
+ statusText += L" " + _P("[1 Thread]", "[%x Threads]", activeCount);
+ replace(statusText, L"%x", toString<std::wstring>(activeCount));
+ }
+ statusText += std::wstring(L" \n") + L'\"' + filename + L'\"';
+ return statusText;
+ }
+ else
+ return statusMsg;
+ }
+
+ void incItemsScanned() { ++itemsScanned; }
+ long getItemsScanned() const { return itemsScanned; }
+
+ void incActiveWorker() { ++activeWorker; }
+ void decActiveWorker() { --activeWorker; }
+ long getActiveWorker() const { return activeWorker; }
+
+private:
+ //---- error handling ----
+ boost::mutex lockErrorMsg;
+ boost::condition_variable conditionCanReportError;
+ boost::condition_variable conditionGotResponse;
+ BasicWString errorMsg;
+ std::unique_ptr<FillBufferCallback::HandleError> errorResponse;
+
+ //---- status updates ----
+ volatile int notifyingThreadID; //theoretically racy, but there is nothing that could go wrong...
+ //CAVEAT: do NOT use boost::thread::id as long as this showstopper exists: https://svn.boost.org/trac/boost/ticket/5754
+ boost::mutex lockCurrentStatus; //use a different lock for current file: continue traversing while some thread may process an error
+ Zstring currentFile; //only one of these two is filled at a time!
+ BasicWString currentStatus; //
+
+ const BasicWString textScanning; //this one is (currently) not shared and could be made a std::wstring, but we stay consistent and use thread-safe variables in this class only!
+
+ //---- status updates II (lock free) ----
+ boost::detail::atomic_count itemsScanned;
+ boost::detail::atomic_count activeWorker;
+};
+//-------------------------------------------------------------------------------------------------
+
+class DirCallback;
+
+struct TraverserShared
+{
+public:
+ TraverserShared(int threadID,
+ SymLinkHandling handleSymlinks,
+ const HardFilter::FilterRef& filter,
+ std::set<Zstring>& failedReads,
+ AsyncCallback& acb) :
+ handleSymlinks_(handleSymlinks),
+ filterInstance(filter),
+ failedReads_(failedReads),
+ acb_(acb),
+ threadID_(threadID) {}
+
+ typedef std::shared_ptr<DirCallback> CallbackPointer;
+ std::vector<CallbackPointer> callBackBox; //collection of callback pointers to handle ownership
+
+ const SymLinkHandling handleSymlinks_;
+ const HardFilter::FilterRef filterInstance; //always bound!
+
+ std::set<Zstring>& failedReads_; //relative postfixed names of directories that could not be read (empty for root)
+
+ AsyncCallback& acb_;
+ int threadID_;
+};
+
+
+class DirCallback : public zen::TraverseCallback
+{
+public:
+ DirCallback(TraverserShared& config,
+ const Zstring& relNameParentPf, //postfixed with FILE_NAME_SEPARATOR!
+ DirContainer& output) :
+ cfg(config),
+ relNameParentPf_(relNameParentPf),
+ output_(output) {}
+
+ virtual void onFile (const Zchar* shortName, const Zstring& fullName, const FileInfo& details);
+ virtual void onSymlink(const Zchar* shortName, const Zstring& fullName, const SymlinkInfo& details);
+ virtual ReturnValDir onDir (const Zchar* shortName, const Zstring& fullName);
+ virtual HandleError onError (const std::wstring& errorText);
+
+private:
+ TraverserShared& cfg;
+ const Zstring relNameParentPf_;
+ DirContainer& output_;
+};
+
+
+void DirCallback::onFile(const Zchar* shortName, const Zstring& fullName, const FileInfo& details)
+{
+ boost::this_thread::interruption_point();
+
+ const Zstring fileNameShort = shortName;
+
+ //do not list the database file(s) sync.ffs_db, sync.x64.ffs_db, etc. or lock files
+ if (endsWith(fileNameShort, SYNC_DB_FILE_ENDING) ||
+ endsWith(fileNameShort, LOCK_FILE_ENDING))
+ return;
+
+ //update status information no matter whether object is excluded or not!
+ cfg.acb_.reportCurrentFile(fullName, cfg.threadID_);
+
+ //------------------------------------------------------------------------------------
+ //apply filter before processing (use relative name!)
+ if (!cfg.filterInstance->passFileFilter(relNameParentPf_ + fileNameShort))
+ return;
+
+ // std::string fileId = details.fileSize >= 1024 * 1024U ?
+ // util::retrieveFileID(fullName) :
+ // std::string();
+ /*
+ Perf test Windows 7, SSD, 350k files, 50k dirs, files > 1MB: 7000
+ regular: 6.9s
+ ID per file: 43.9s
+ ID per file > 1MB: 7.2s
+ ID per dir: 8.4s
+
+ Linux: retrieveFileID takes about 50% longer in VM! (avoidable because of redundant stat() call!)
+ */
+
+ output_.addSubFile(fileNameShort, FileDescriptor(details.lastWriteTimeRaw, details.fileSize));
+
+ cfg.acb_.incItemsScanned(); //add 1 element to the progress indicator
+}
+
+
+void DirCallback::onSymlink(const Zchar* shortName, const Zstring& fullName, const SymlinkInfo& details)
+{
+ boost::this_thread::interruption_point();
+
+ if (cfg.handleSymlinks_ == SYMLINK_IGNORE)
+ return;
+
+ //update status information no matter whether object is excluded or not!
+ cfg.acb_.reportCurrentFile(fullName, cfg.threadID_);
+
+ //------------------------------------------------------------------------------------
+ const Zstring& relName = relNameParentPf_ + shortName;
+
+ //apply filter before processing (use relative name!)
+ if (!cfg.filterInstance->passFileFilter(relName)) //always use file filter: Link type may not be "stable" on Linux!
+ return;
+
+ output_.addSubLink(shortName, LinkDescriptor(details.lastWriteTimeRaw, details.targetPath, details.dirLink ? LinkDescriptor::TYPE_DIR : LinkDescriptor::TYPE_FILE));
+
+ cfg.acb_.incItemsScanned(); //add 1 element to the progress indicator
+}
+
+
+TraverseCallback::ReturnValDir DirCallback::onDir(const Zchar* shortName, const Zstring& fullName)
+{
+ boost::this_thread::interruption_point();
+
+ //update status information no matter whether object is excluded or not!
+ cfg.acb_.reportCurrentFile(fullName, cfg.threadID_);
+
+ //------------------------------------------------------------------------------------
+ const Zstring& relName = relNameParentPf_ + shortName;
+
+ //apply filter before processing (use relative name!)
+ bool subObjMightMatch = true;
+ const bool passFilter = cfg.filterInstance->passDirFilter(relName, &subObjMightMatch);
+ if (!passFilter && !subObjMightMatch)
+ return Int2Type<ReturnValDir::TRAVERSING_DIR_IGNORE>(); //do NOT traverse subdirs
+ //else: attention! ensure directory filtering is applied later to exclude actually filtered directories
+
+ DirContainer& subDir = output_.addSubDir(shortName);
+ if (passFilter)
+ cfg.acb_.incItemsScanned(); //add 1 element to the progress indicator
+
+ TraverserShared::CallbackPointer subDirCallback = std::make_shared<DirCallback>(cfg, relName + FILE_NAME_SEPARATOR, subDir);
+ cfg.callBackBox.push_back(subDirCallback); //handle lifetime
+ return ReturnValDir(Int2Type<ReturnValDir::TRAVERSING_DIR_CONTINUE>(), *subDirCallback);
+}
+
+
+DirCallback::HandleError DirCallback::onError(const std::wstring& errorText)
+{
+ switch (cfg.acb_.reportError(errorText))
+ {
+ case FillBufferCallback::TRAV_ERROR_IGNORE:
+ cfg.failedReads_.insert(relNameParentPf_);
+ return TRAV_ERROR_IGNORE;
+
+ case FillBufferCallback::TRAV_ERROR_RETRY:
+ return TRAV_ERROR_RETRY;
+ }
+
+ assert(false);
+ return TRAV_ERROR_IGNORE;
+}
+
+
+#ifdef FFS_WIN
+class DstHackCallbackImpl : public DstHackCallback
+{
+public:
+ DstHackCallbackImpl(AsyncCallback& acb, int threadID) :
+ acb_(acb),
+ threadID_(threadID),
+ textApplyingDstHack(toZ(replaceCpy(_("Encoding extended time information: %x"), L"%x", L"\n\"%x\""))) {}
+
+private:
+ virtual void requestUiRefresh(const Zstring& filename) //applying DST hack imposes significant one-time performance drawback => callback to inform user
+ {
+ const Zstring statusText = replaceCpy(textApplyingDstHack, Zstr("%x"), filename);
+ acb_.reportCurrentStatus(utf8CvrtTo<std::wstring>(statusText), threadID_);
+ }
+
+ AsyncCallback& acb_;
+ int threadID_;
+ const Zstring textApplyingDstHack;
+};
+#endif
+//------------------------------------------------------------------------------------------
+
+
+class WorkerThread
+{
+public:
+ WorkerThread(int threadID,
+ const std::shared_ptr<AsyncCallback>& acb,
+ const std::vector<std::pair<DirectoryKey, DirectoryValue*>>& workload) :
+ threadID_(threadID),
+ acb_(acb),
+ workload_(workload) {}
+
+ void operator()() //thread entry
+ {
+ acb_->incActiveWorker();
+ ZEN_ON_BLOCK_EXIT(acb_->decActiveWorker(););
+
+ std::for_each(workload_.begin(), workload_.end(),
+ [&](std::pair<DirectoryKey, DirectoryValue*>& item)
+ {
+ const Zstring& directoryName = item.first.dirnameFull_;
+ DirectoryValue& dirVal = *item.second;
+
+ acb_->reportCurrentFile(directoryName, threadID_); //just in case first directory access is blocking
+
+ TraverserShared travCfg(threadID_,
+ item.first.handleSymlinks_, //shared by all(!) instances of DirCallback while traversing a folder hierarchy
+ item.first.filter_,
+ dirVal.failedReads,
+ *acb_);
+
+ DirCallback traverser(travCfg,
+ Zstring(),
+ dirVal.dirCont);
+
+ bool followSymlinks = false;
+ switch (item.first.handleSymlinks_)
+ {
+ case SYMLINK_IGNORE:
+ followSymlinks = false; //=> symlinks will be reported via onSymlink() where they are excluded
+ break;
+ case SYMLINK_USE_DIRECTLY:
+ followSymlinks = false;
+ break;
+ case SYMLINK_FOLLOW_LINK:
+ followSymlinks = true;
+ break;
+ }
+
+ DstHackCallback* dstCallbackPtr = NULL;
+#ifdef FFS_WIN
+ DstHackCallbackImpl dstCallback(*acb_, threadID_);
+ dstCallbackPtr = &dstCallback;
+#endif
+
+ //get all files and folders from directoryPostfixed (and subdirectories)
+ traverseFolder(directoryName, followSymlinks, traverser, dstCallbackPtr); //exceptions may be thrown!
+ });
+ }
+
+private:
+ int threadID_;
+ std::shared_ptr<AsyncCallback> acb_;
+ std::vector<std::pair<DirectoryKey, DirectoryValue*>> workload_;
+};
+}
+
+
+void zen::fillBuffer(const std::set<DirectoryKey>& keysToRead, //in
+ std::map<DirectoryKey, DirectoryValue>& buf, //out
+ FillBufferCallback& callback,
+ size_t updateInterval)
+{
+ buf.clear();
+
+ std::vector<std::set<DirectoryKey>> buckets = separateByDistinctDisk(keysToRead); //one bucket per physical device
+
+ std::vector<boost::thread> worker; //note: GCC doesn't allow to construct an array of empty threads since they would be initialized by const boost::thread&
+ worker.reserve(buckets.size());
+
+ zen::ScopeGuard guardWorker = zen::makeGuard([&]()
+ {
+ std::for_each(worker.begin(), worker.end(), std::mem_fun_ref(&boost::thread::interrupt)); //interrupt all at once, then join
+ std::for_each(worker.begin(), worker.end(), std::mem_fun_ref(&boost::thread::join));
+ });
+
+ std::shared_ptr<AsyncCallback> acb = std::make_shared<AsyncCallback>();
+
+ //init worker threads
+ for (auto iter = buckets.begin(); iter != buckets.end(); ++iter)
+ {
+ int threadID = iter - buckets.begin();
+ const std::set<DirectoryKey>& bucket = *iter;
+
+ std::vector<std::pair<DirectoryKey, DirectoryValue*>> workload;
+ std::for_each(bucket.begin(), bucket.end(),
+ [&](const DirectoryKey& key)
+ {
+ auto rv = buf.insert(std::make_pair(key, DirectoryValue()));
+ assert(rv.second);
+ workload.push_back(std::make_pair(key, &rv.first->second));
+ });
+
+ worker.push_back(boost::thread(WorkerThread(threadID, acb, workload)));
+ }
+
+ //wait until done
+ for (auto iter = worker.begin(); iter != worker.end(); ++iter)
+ {
+ boost::thread& wt = *iter;
+ int threadID = iter - worker.begin();
+
+ acb->setNotifyingThread(threadID); //process info messages of first (active) thread only
+
+ do
+ {
+ //update status
+ callback.reportStatus(acb->getCurrentStatus(), acb->getItemsScanned()); //throw!
+
+ //process errors
+ acb->processErrors(callback);
+ }
+ while (!wt.timed_join(boost::posix_time::milliseconds(updateInterval)));
+ }
+
+ guardWorker.dismiss();
+}
bgstack15