Mercurial > hg > easyhg
view src/fswatcher.cpp @ 559:95877ad67d3e
Merge from branch "find"
author | Chris Cannam |
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date | Mon, 27 Feb 2012 17:08:47 +0000 |
parents | 7829da6abe97 |
children | 533519ebc0cb |
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ /* EasyMercurial Based on hgExplorer by Jari Korhonen Copyright (c) 2010 Jari Korhonen Copyright (c) 2011 Chris Cannam Copyright (c) 2011 Queen Mary, University of London This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. See the file COPYING included with this distribution for more information. */ #include "fswatcher.h" #include "debug.h" #include <QMutexLocker> #include <QDir> #include <deque> #define DEBUG_FSWATCHER 1 /* * Watching the filesystem is trickier than it seems at first glance. * * We ideally should watch every directory, and every file that is * tracked by Hg. If a new file is created in a directory, then we * need to respond in order to show it as a potential candidate to be * added. * * Complicating matters though is that Hg itself might modify the * filesystem. This can happen even in "read-only" operations: for * example, hg stat creates files called hg-checklink and hg-checkexec * to test properties of the filesystem. So we need to know to ignore * those files; unfortunately, when watching a directory (which is how * we find out about the creation of new files) we are notified only * that the directory has changed -- we aren't told what changed. * * This means that, when a directory changes, we need to rescan the * directory to learn whether the set of files in it _excluding_ files * matching our ignore patterns differs from the previous scan, and * ignore the change if it doesn't. */ FsWatcher::FsWatcher() : m_lastToken(0), m_lastCounter(0) { connect(&m_watcher, SIGNAL(directoryChanged(QString)), this, SLOT(fsDirectoryChanged(QString))); connect(&m_watcher, SIGNAL(fileChanged(QString)), this, SLOT(fsFileChanged(QString))); } FsWatcher::~FsWatcher() { } void FsWatcher::setWorkDirPath(QString path) { QMutexLocker locker(&m_mutex); if (m_workDirPath == path) return; m_watcher.removePaths(m_watcher.directories()); m_watcher.removePaths(m_watcher.files()); m_workDirPath = path; addWorkDirectory(path); debugPrint(); } void FsWatcher::setTrackedFilePaths(QStringList paths) { QMutexLocker locker(&m_mutex); QSet<QString> alreadyWatched = QSet<QString>::fromList(m_watcher.files()); foreach (QString path, paths) { path = m_workDirPath + QDir::separator() + path; if (!alreadyWatched.contains(path)) { m_watcher.addPath(path); } else { alreadyWatched.remove(path); } } // Remove the remaining paths, those that were being watched // before but that are not in the list we were given foreach (QString path, alreadyWatched) { m_watcher.removePath(path); } debugPrint(); } void FsWatcher::addWorkDirectory(QString path) { // QFileSystemWatcher will refuse to add a file or directory to // its watch list that it is already watching -- fine -- but it // prints a warning when this happens, which we wouldn't want. So // we'll check for duplicates ourselves. QSet<QString> alreadyWatched = QSet<QString>::fromList(m_watcher.directories()); std::deque<QString> pending; pending.push_back(path); while (!pending.empty()) { QString path = pending.front(); pending.pop_front(); if (!alreadyWatched.contains(path)) { m_watcher.addPath(path); m_dirContents[path] = scanDirectory(path); } QDir d(path); if (d.exists()) { d.setFilter(QDir::Dirs | QDir::NoDotAndDotDot | QDir::Readable | QDir::NoSymLinks); foreach (QString entry, d.entryList()) { if (entry.startsWith('.')) continue; QString entryPath = d.absoluteFilePath(entry); pending.push_back(entryPath); } } } } void FsWatcher::setIgnoredFilePrefixes(QStringList prefixes) { QMutexLocker locker(&m_mutex); m_ignoredPrefixes = prefixes; } void FsWatcher::setIgnoredFileSuffixes(QStringList suffixes) { QMutexLocker locker(&m_mutex); m_ignoredSuffixes = suffixes; } int FsWatcher::getNewToken() { QMutexLocker locker(&m_mutex); int token = ++m_lastToken; m_tokenMap[token] = m_lastCounter; return token; } QSet<QString> FsWatcher::getChangedPaths(int token) { QMutexLocker locker(&m_mutex); size_t lastUpdatedAt = m_tokenMap[token]; QSet<QString> changed; for (QHash<QString, size_t>::const_iterator i = m_changes.begin(); i != m_changes.end(); ++i) { if (i.value() > lastUpdatedAt) { changed.insert(i.key()); } } m_tokenMap[token] = m_lastCounter; return changed; } void FsWatcher::fsDirectoryChanged(QString path) { { QMutexLocker locker(&m_mutex); if (shouldIgnore(path)) return; QSet<QString> files = scanDirectory(path); if (files == m_dirContents[path]) { #ifdef DEBUG_FSWATCHER std::cerr << "FsWatcher: Directory " << path << " has changed, but not in a way that we are monitoring" << std::endl; #endif return; } else { #ifdef DEBUG_FSWATCHER std::cerr << "FsWatcher: Directory " << path << " has changed" << std::endl; #endif m_dirContents[path] = files; } size_t counter = ++m_lastCounter; m_changes[path] = counter; } emit changed(); } void FsWatcher::fsFileChanged(QString path) { { QMutexLocker locker(&m_mutex); // We don't check whether the file matches an ignore pattern, // because we are only notified for file changes if we are // watching the file explicitly, i.e. the file is in the // tracked file paths list. So we never want to ignore them std::cerr << "FsWatcher: Tracked file " << path << " has changed" << std::endl; size_t counter = ++m_lastCounter; m_changes[path] = counter; } emit changed(); } bool FsWatcher::shouldIgnore(QString path) { QFileInfo fi(path); QString fn(fi.fileName()); foreach (QString pfx, m_ignoredPrefixes) { if (fn.startsWith(pfx)) { std::cerr << "(ignoring: " << path << ")" << std::endl; return true; } } foreach (QString sfx, m_ignoredSuffixes) { if (fn.endsWith(sfx)) { std::cerr << "(ignoring: " << path << ")" << std::endl; return true; } } return false; } QSet<QString> FsWatcher::scanDirectory(QString path) { QSet<QString> files; QDir d(path); if (d.exists()) { d.setFilter(QDir::Files | QDir::NoDotAndDotDot | QDir::Readable | QDir::NoSymLinks); foreach (QString entry, d.entryList()) { if (entry.startsWith('.')) continue; if (shouldIgnore(entry)) continue; files.insert(entry); } } // std::cerr << "scanDirectory:" << std::endl; // foreach (QString f, files) std::cerr << f << std::endl; return files; } void FsWatcher::debugPrint() { #ifdef DEBUG_FSWATCHER std::cerr << "FsWatcher: Now watching " << m_watcher.directories().size() << " directories and " << m_watcher.files().size() << " files" << std::endl; #endif }