nextcloud-desktop/src/mirall/owncloudpropagator.cpp
Olivier Goffart 47f299f0ee Send the last known etag to the server in a If-Match header
That way we avoid race conditions in case the file changed between the
update and the reconcile
2013-10-02 15:57:49 +02:00

732 lines
25 KiB
C++

/*
* Copyright (C) by Olivier Goffart <ogoffart@owncloud.com>
* Copyright (C) by Klaas Freitag <freitag@owncloud.com>
*
* 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.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/
#include "owncloudpropagator.h"
#include "progressdatabase.h"
#include <httpbf.h>
#include <qfile.h>
#include <qdir.h>
#include <qdiriterator.h>
#include <qtemporaryfile.h>
#if QT_VERSION < QT_VERSION_CHECK(5, 0, 0)
#include <qabstractfileengine.h>
#else
#include <qsavefile.h>
#endif
#include <QDebug>
#include <QDateTime>
#include <neon/ne_basic.h>
#include <neon/ne_socket.h>
#include <neon/ne_session.h>
#include <neon/ne_props.h>
#include <neon/ne_auth.h>
#include <neon/ne_dates.h>
#include <neon/ne_compress.h>
#include <neon/ne_redirect.h>
#include <time.h>
// We use some internals of csync:
extern "C" int c_utimes(const char *, const struct timeval *);
extern "C" void csync_win32_set_file_hidden( const char *file, bool h );
namespace Mirall {
/* Helper for QScopedPointer<>, to be used as the deleter.
* QScopePointer will call the right overload of cleanup for the pointer it holds
*/
struct ScopedPointerHelpers {
static inline void cleanup(hbf_transfer_t *pointer) { if (pointer) hbf_free_transfer(pointer); }
static inline void cleanup(ne_request *pointer) { if (pointer) ne_request_destroy(pointer); }
static inline void cleanup(ne_decompress *pointer) { if (pointer) ne_decompress_destroy(pointer); }
// static inline void cleanup(ne_propfind_handler *pointer) { if (pointer) ne_propfind_destroy(pointer); }
};
void OwncloudPropagator::propagate(const SyncFileItem &item)
{
_errorCode = CSYNC_STATUS_OK;
_errorString.clear();
_etag.clear();
_httpStatusCode = 0;
switch(item._instruction) {
case CSYNC_INSTRUCTION_REMOVE:
_instruction = item._dir == SyncFileItem::Down ? localRemove(item) : remoteRemove(item);
break;
case CSYNC_INSTRUCTION_NEW:
if (item._isDirectory) {
_instruction = item._dir == SyncFileItem::Down ? localMkdir(item) : remoteMkdir(item);
break;
} //fall trough
case CSYNC_INSTRUCTION_SYNC:
if (item._isDirectory) {
// Should we set the mtime?
_instruction = CSYNC_INSTRUCTION_UPDATED;
break;
}
_instruction = item._dir == SyncFileItem::Down ? downloadFile(item) : uploadFile(item);
break;
case CSYNC_INSTRUCTION_CONFLICT:
if (item._isDirectory) {
_instruction = CSYNC_INSTRUCTION_UPDATED;
break;
}
_instruction = downloadFile(item, true);
break;
case CSYNC_INSTRUCTION_RENAME:
_instruction = remoteRename(item);
break;
default:
_instruction = item._instruction;
break;
}
SyncFileItem newItem = item;
newItem._instruction = _instruction;
newItem._errorString = _errorString;
newItem._httpCode = _httpStatusCode;
newItem._etag = _etag;
emit completed(newItem, _errorCode);
}
// compare two files with given filename and return true if they have the same content
static bool fileEquals(const QString &fn1, const QString &fn2) {
QFile f1(fn1);
QFile f2(fn2);
if (!f1.open(QIODevice::ReadOnly) || !f2.open(QIODevice::ReadOnly)) {
qDebug() << "fileEquals: Failed to open " << fn1 << "or" << fn2;
return false;
}
if (f1.size() != f2.size()) {
return false;
}
const int BufferSize = 16 * 1024;
char buffer1[BufferSize];
char buffer2[BufferSize];
do {
int r = f1.read(buffer1, BufferSize);
if (f2.read(buffer2, BufferSize) != r) {
// this should normaly not happen: the file are supposed to have the same size.
return false;
}
if (r <= 0) {
return true;
}
if (memcmp(buffer1, buffer2, r) != 0) {
return false;
}
} while (true);
return false;
}
// Code copied from Qt5's QDir::removeRecursively
static bool removeRecursively(const QString &path)
{
bool success = true;
QDirIterator di(path, QDir::AllEntries | QDir::Hidden | QDir::System | QDir::NoDotAndDotDot);
while (di.hasNext()) {
di.next();
const QFileInfo& fi = di.fileInfo();
bool ok;
if (fi.isDir() && !fi.isSymLink())
ok = removeRecursively(di.filePath()); // recursive
else
ok = QFile::remove(di.filePath());
if (!ok)
success = false;
}
if (success)
success = QDir().rmdir(path);
return success;
}
csync_instructions_e OwncloudPropagator::localRemove(const SyncFileItem& item)
{
QString filename = _localDir + item._file;
if (item._isDirectory) {
if (!QDir(filename).exists() || removeRecursively(filename))
return CSYNC_INSTRUCTION_DELETED;
} else {
QFile file(filename);
if (!file.exists() || file.remove())
return CSYNC_INSTRUCTION_DELETED;
_errorString = file.errorString();
}
return CSYNC_INSTRUCTION_NONE; // not ERROR so it is still written to the database
}
csync_instructions_e OwncloudPropagator::localMkdir(const SyncFileItem &item)
{
QDir d;
if (!d.mkpath(_localDir + item._file)) {
_errorString = "could not create directory " + _localDir + item._file;
return CSYNC_INSTRUCTION_ERROR;
}
return CSYNC_INSTRUCTION_UPDATED;
}
csync_instructions_e OwncloudPropagator::remoteRemove(const SyncFileItem &item)
{
bool error = false;
QScopedPointer<char, QScopedPointerPodDeleter> uri(ne_path_escape((_remoteDir + item._file).toUtf8()));
int rc = ne_delete(_session, uri.data());
error = updateErrorFromSession(rc);
if (error) {
return CSYNC_INSTRUCTION_ERROR;
}
return CSYNC_INSTRUCTION_DELETED;
}
csync_instructions_e OwncloudPropagator::remoteMkdir(const SyncFileItem &item)
{
QScopedPointer<char, QScopedPointerPodDeleter> uri(ne_path_escape((_remoteDir + item._file).toUtf8()));
bool error = false;
int rc = ne_mkcol(_session, uri.data());
error = updateErrorFromSession( rc );
if( error ) {
/* Special for mkcol: it returns 405 if the directory already exists.
* Ignre that error */
if (_httpStatusCode != 405) {
return CSYNC_INSTRUCTION_ERROR;
}
}
return CSYNC_INSTRUCTION_UPDATED;
}
csync_instructions_e OwncloudPropagator::uploadFile(const SyncFileItem &item)
{
QFile file(_localDir + item._file);
if (!file.open(QIODevice::ReadOnly)) {
_errorString = file.errorString();
return CSYNC_INSTRUCTION_ERROR;
}
QScopedPointer<char, QScopedPointerPodDeleter> uri(ne_path_escape((_remoteDir + item._file).toUtf8()));
bool finished = true;
int attempts = 0;
/*
* do ten tries to upload the file chunked. Check the file size and mtime
* before submitting a chunk and after having submitted the last one.
* If the file has changed, retry.
*/
do {
Hbf_State state = HBF_SUCCESS;
QScopedPointer<hbf_transfer_t, ScopedPointerHelpers> trans(hbf_init_transfer(uri.data()));
finished = true;
Q_ASSERT(trans);
state = hbf_splitlist(trans.data(), file.handle());
if (const ProgressDatabase::UploadInfo* progressInfo = _progressDb->getUploadInfo(item._file)) {
if (progressInfo->mtime == item._modtime) {
trans->start_id = progressInfo->chunk;
trans->transfer_id = progressInfo->transferid;
}
_progressDb->remove(item._file);
}
ne_set_notifier(_session, notify_status_cb, this);
_lastTime.restart();
_lastProgress = 0;
_chunked_done = 0;
_chunked_total_size = item._size;
_currentFile = item._file;
if( state == HBF_SUCCESS ) {
QByteArray previousEtag;
if (!item._etag.isEmpty() && item._etag != "empty_etag") {
// We add quotes because the owncloud server always add quotes around the etag, and
// csync_owncloud.c's owncloud_file_id always strip the quotes.
previousEtag = '"' + item._etag + '"';
trans->previous_etag = previousEtag.data();
}
_chunked_total_size = trans->stat_size;
qDebug() << "About to upload " << item._file << " (" << previousEtag << item._size << ")";
/* Transfer all the chunks through the HTTP session using PUT. */
state = hbf_transfer( _session, trans.data(), "PUT" );
}
if( trans->modtime_accepted ) {
_etag = QByteArray(hbf_transfer_etag( trans.data() ));
}
/* Handle errors. */
if ( state != HBF_SUCCESS ) {
/* If the source file changed during submission, lets try again */
if( state == HBF_SOURCE_FILE_CHANGE ) {
if( attempts++ < 30 ) { /* FIXME: How often do we want to try? */
finished = false; /* make it try again from scratch. */
qDebug("SOURCE file has changed during upload, retry #%d in two seconds!", attempts);
sleep(2);
}
}
if( finished ) {
_errorString = hbf_error_string(trans.data(), state);
_httpStatusCode = hbf_fail_http_code(trans.data());
if (trans->start_id > 0) {
ProgressDatabase::UploadInfo pi;
pi.chunk = trans->start_id;
pi.transferid = trans->transfer_id;
pi.mtime = item._modtime;
_progressDb->setUploadInfo(item._file, pi);
}
return CSYNC_INSTRUCTION_ERROR;
}
}
} while( !finished );
ne_set_notifier(_session, 0, 0);
if( _etag.isEmpty() ) {
updateMTimeAndETag(uri.data(), item._modtime);
}
return CSYNC_INSTRUCTION_UPDATED;
}
static QByteArray parseEtag(ne_request *req) {
const char *header = ne_get_response_header(req, "etag");
if(header && header [0] == '"' && header[ strlen(header)-1] == '"') {
return QByteArray(header + 1, strlen(header)-2);
} else {
return header;
}
}
void OwncloudPropagator::updateMTimeAndETag(const char* uri, time_t mtime)
{
QByteArray modtime = QByteArray::number(qlonglong(mtime));
ne_propname pname;
pname.nspace = "DAV:";
pname.name = "lastmodified";
ne_proppatch_operation ops[2];
ops[0].name = &pname;
ops[0].type = ne_propset;
ops[0].value = modtime.constData();
ops[1].name = NULL;
int rc = ne_proppatch( _session, uri, ops );
bool error = updateErrorFromSession( rc );
if( error ) {
// FIXME: We could not set the mtime. Error or not?
qDebug() << "PROP-Patching of modified date failed.";
}
// get the etag
QScopedPointer<ne_request, ScopedPointerHelpers> req(ne_request_create(_session, "HEAD", uri));
int neon_stat = ne_request_dispatch(req.data());
if( updateErrorFromSession(neon_stat, req.data()) ) {
// error happend
qDebug() << "Could not issue HEAD request for ETag.";
} else {
_etag = parseEtag(req.data());
}
}
class DownloadContext {
public:
QIODevice *_file;
QScopedPointer<ne_decompress, ScopedPointerHelpers> _decompress;
explicit DownloadContext(QIODevice *file) : _file(file) {}
static int content_reader(void *userdata, const char *buf, size_t len)
{
DownloadContext *writeCtx = static_cast<DownloadContext *>(userdata);
size_t written = 0;
if(buf) {
written = writeCtx->_file->write(buf, len);
if( len != written ) {
qDebug() << "WRN: content_reader wrote wrong num of bytes:" << len << "," << written;
}
return NE_OK;
}
return NE_ERROR;
}
/*
* This hook is called after the response is here from the server, but before
* the response body is parsed. It decides if the response is compressed and
* if it is it installs the compression reader accordingly.
* If the response is not compressed, the normal response body reader is installed.
*/
static void install_content_reader( ne_request *req, void *userdata, const ne_status *status )
{
DownloadContext *writeCtx = static_cast<DownloadContext *>(userdata);
Q_UNUSED(status);
if( !writeCtx ) {
qDebug("Error: install_content_reader called without valid write context!");
return;
}
const char *enc = ne_get_response_header( req, "Content-Encoding" );
qDebug("Content encoding ist <%s> with status %d", enc ? enc : "empty",
status ? status->code : -1 );
if( enc == QLatin1String("gzip") ) {
writeCtx->_decompress.reset(ne_decompress_reader( req, ne_accept_2xx,
content_reader, /* reader callback */
writeCtx )); /* userdata */
} else {
ne_add_response_body_reader( req, ne_accept_2xx,
content_reader,
(void*) writeCtx );
}
}
};
csync_instructions_e OwncloudPropagator::downloadFile(const SyncFileItem &item, bool isConflict)
{
QString tmpFileName;
const ProgressDatabase::DownloadInfo* progressInfo = _progressDb->getDownloadInfo(item._file);
if (progressInfo) {
if (progressInfo->etag != item._etag) {
QFile::remove(_localDir + progressInfo->tmpfile);
} else {
tmpFileName = progressInfo->tmpfile;
}
_progressDb->remove(item._file);
}
if (tmpFileName.isEmpty()) {
tmpFileName = item._file;
//add a dot at the begining of the filename to hide the file.
int slashPos = tmpFileName.lastIndexOf('/');
tmpFileName.insert(slashPos+1, '.');
//add the suffix
tmpFileName += ".~" + QString::number(uint(qrand()), 16);
}
QFile tmpFile(_localDir + tmpFileName);
if (!tmpFile.open(QIODevice::Append)) {
_errorString = tmpFile.errorString();
_errorCode = CSYNC_STATUS_LOCAL_CREATE_ERROR;
return CSYNC_INSTRUCTION_ERROR;
}
csync_win32_set_file_hidden(tmpFileName.toUtf8().constData(), true);
{
ProgressDatabase::DownloadInfo pi;
pi.etag = item._etag;
pi.tmpfile = tmpFileName;
_progressDb->setDownloadInfo(item._file, pi);
_progressDb->save(_localDir);
}
/* actually do the request */
int retry = 0;
QScopedPointer<char, QScopedPointerPodDeleter> uri(ne_path_escape((_remoteDir + item._file).toUtf8()));
DownloadContext writeCtx(&tmpFile);
do {
QScopedPointer<ne_request, ScopedPointerHelpers> req(ne_request_create(_session, "GET", uri.data()));
/* Allow compressed content by setting the header */
ne_add_request_header( req.data(), "Accept-Encoding", "gzip" );
if (tmpFile.size() > 0) {
char brange[64];
ne_snprintf(brange, sizeof brange, "bytes=%lld-", (long long) tmpFile.size());
ne_add_request_header(req.data(), "Range", brange);
ne_add_request_header(req.data(), "Accept-Ranges", "bytes");
qDebug("Retry with range %s", brange);
}
/* hook called before the content is parsed to set the correct reader,
* either the compressed- or uncompressed reader.
*/
ne_hook_post_headers( _session, DownloadContext::install_content_reader, &writeCtx);
ne_set_notifier(_session, notify_status_cb, this);
_lastProgress = 0;
_lastTime.start();
_chunked_done = _chunked_total_size = 0;
_currentFile = item._file;
int neon_stat = ne_request_dispatch(req.data());
if (neon_stat == NE_TIMEOUT && (++retry) < 3) {
continue;
}
/* delete the hook again, otherwise they get chained as they are with the session */
ne_unhook_post_headers( _session, DownloadContext::install_content_reader, &writeCtx );
ne_set_notifier(_session, 0, 0);
_chunked_done = _chunked_total_size = 0;
if( updateErrorFromSession(neon_stat, req.data() ) ) {
qDebug("Error GET: Neon: %d", neon_stat);
if (tmpFile.size() == 0) {
// don't keep the temporary file if it is empty.
tmpFile.close();
tmpFile.remove();
_progressDb->remove(item._file);
}
return CSYNC_INSTRUCTION_ERROR;
}
_etag = parseEtag(req.data());
break;
} while (1);
tmpFile.close();
tmpFile.flush();
//In case of conflict, make a backup of the old file
if (isConflict) {
QString fn = _localDir + item._file;
// compare the files to see if there was an actual conflict.
if (fileEquals(fn, tmpFile.fileName())) {
tmpFile.remove();
_progressDb->remove(item._file);
return CSYNC_INSTRUCTION_UPDATED;
}
QFile f(fn);
// Add _conflict-XXXX before the extention.
int dotLocation = fn.lastIndexOf('.');
// If no extention, add it at the end (take care of cases like foo/.hidden or foo.bar/file)
if (dotLocation <= fn.lastIndexOf('/') + 1) {
dotLocation = fn.size();
}
fn.insert(dotLocation, "_conflict-" + QDateTime::fromTime_t(item._modtime).toString("yyyyMMdd-hhmmss"));
if (!f.rename(fn)) {
//If the rename fails, don't replace it.
_errorString = f.errorString();
return CSYNC_INSTRUCTION_ERROR;
}
}
csync_win32_set_file_hidden(tmpFileName.toUtf8().constData(), false);
#ifndef QT_OS_WIN
bool success;
#if QT_VERSION < QT_VERSION_CHECK(5, 0, 0)
success = tmpFile.fileEngine()->rename(_localDir + item._file);
#else
// We want a rename that also overwite. QFile::rename does not overwite.
// Qt 5.1 has QSaveFile::renameOverwrite we cold use.
// ### FIXME
QString newName(_localDir + item._file);
QFile::remove(newName);
success = tmpFile.rename(newName);
#endif
if (!success) {
_errorString = tmpFile.errorString();
return CSYNC_INSTRUCTION_ERROR;
}
#else //QT_OS_WIN
if (::MoveFileEx((wchar_t*)tmpFile.fileName().utf16(),
(wchar_t*)QString(_localDir + item._file).utf16(),
MOVEFILE_REPLACE_EXISTING) != 0) {
wchar_t *string = 0;
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM,
NULL, ::GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPWSTR)&string, 0, NULL);
_errorString = QString::fromWCharArray(string);
LocalFree((HLOCAL)string);
return CSYNC_INSTRUCTION_ERROR;
}
#endif
_progressDb->remove(item._file);
struct timeval times[2];
times[0].tv_sec = times[1].tv_sec = item._modtime;
times[0].tv_usec = times[1].tv_usec = 0;
c_utimes((_localDir + item._file).toUtf8().data(), times);
return CSYNC_INSTRUCTION_UPDATED;
}
csync_instructions_e OwncloudPropagator::remoteRename(const SyncFileItem &item)
{
if (item._file == item._renameTarget)
return CSYNC_INSTRUCTION_DELETED; // nothing to do;
QScopedPointer<char, QScopedPointerPodDeleter> uri1(ne_path_escape((_remoteDir + item._file).toUtf8()));
QScopedPointer<char, QScopedPointerPodDeleter> uri2(ne_path_escape((_remoteDir + item._renameTarget).toUtf8()));
int rc = ne_move(_session, 1, uri1.data(), uri2.data());
if (updateErrorFromSession(rc)) {
// We set the instruction to UPDATED so next try we try to rename again
return CSYNC_INSTRUCTION_UPDATED;
}
updateMTimeAndETag(uri2.data(), item._modtime);
return CSYNC_INSTRUCTION_DELETED;
}
bool OwncloudPropagator::check_neon_session()
{
bool isOk = true;
if( !_session ) {
_errorCode = CSYNC_STATUS_PARAM_ERROR;
isOk = false;
} else {
const char *p = ne_get_error( _session );
_errorString = QString::fromUtf8(p);
if( !_errorString.isEmpty() ) {
int firstSpace = _errorString.indexOf(QChar(' '));
if( firstSpace > 0 ) {
bool ok;
QString numStr = _errorString.mid(0, firstSpace);
_httpStatusCode = numStr.toInt(&ok);
if( !ok ) {
_httpStatusCode = 0;
}
}
isOk = false;
}
}
return isOk;
}
// returns true in case there was an error
bool OwncloudPropagator::updateErrorFromSession(int neon_code, ne_request *req)
{
bool re = false;
if( neon_code != NE_OK ) {
qDebug("Neon error code was %d", neon_code);
re = true; // there was an error.
}
switch(neon_code) {
case NE_OK: /* Success, but still the possiblity of problems */
if( req != NULL ) {
const ne_status *status = ne_get_status(req);
if( status ) {
if( status->klass != 2 ) {
_httpStatusCode = status->code;
_errorCode = CSYNC_STATUS_HTTP_ERROR;
_errorString = QString::fromUtf8( status->reason_phrase );
re = true;
}
} else {
re = true; // can not get the status
}
} else {
// no neon request available.
re = check_neon_session();
}
break;
case NE_ERROR: /* Generic error; use ne_get_error(session) for message */
_errorString = QString::fromUtf8( ne_get_error(_session) );
_errorCode = CSYNC_STATUS_HTTP_ERROR;
break;
case NE_LOOKUP: /* Server or proxy hostname lookup failed */
_errorString = QString::fromUtf8( ne_get_error(_session) );
_errorCode = CSYNC_STATUS_LOOKUP_ERROR;
_hasFatalError = true;
break;
case NE_AUTH: /* User authentication failed on server */
_errorString = QString::fromUtf8( ne_get_error(_session) );
_errorCode = CSYNC_STATUS_REMOTE_ACCESS_ERROR;
_hasFatalError = true;
break;
case NE_PROXYAUTH: /* User authentication failed on proxy */
_errorString = QString::fromUtf8( ne_get_error(_session) );
_errorCode = CSYNC_STATUS_PROXY_AUTH_ERROR;
_hasFatalError = true;
break;
case NE_CONNECT: /* Could not connect to server */
_errorString = QString::fromUtf8( ne_get_error(_session) );
_errorCode = CSYNC_STATUS_CONNECT_ERROR;
_hasFatalError = true;
break;
case NE_TIMEOUT: /* Connection timed out */
_errorString = QString::fromUtf8( ne_get_error(_session) );
_errorCode = CSYNC_STATUS_TIMEOUT;
_hasFatalError = true;
break;
case NE_FAILED: /* The precondition failed */
case NE_RETRY: /* Retry request (ne_end_request ONLY) */
case NE_REDIRECT: /* See ne_redirect.h */
default:
_errorString = QString::fromUtf8( ne_get_error(_session) );
_errorCode = CSYNC_STATUS_HTTP_ERROR;
break;
}
return re;
}
void OwncloudPropagator::notify_status_cb(void* userdata, ne_session_status status,
const ne_session_status_info* info)
{
OwncloudPropagator* this_ = reinterpret_cast<OwncloudPropagator *>(userdata);
if ((status == ne_status_sending || status == ne_status_recving)) {
if (info->sr.total > 0) {
emit this_->progress(Progress::Context, this_->_currentFile,
this_->_chunked_done + info->sr.progress,
this_->_chunked_total_size ? this_->_chunked_total_size : info->sr.total );
}
if (this_->_chunked_total_size && info->sr.total > 0 && info->sr.total == info->sr.progress) {
this_->_chunked_done += info->sr.total;
}
}
/* throttle connection */
int bandwidth_limit = 0;
if (status == ne_status_sending) bandwidth_limit = this_->_uploadLimit;
if (status == ne_status_recving) bandwidth_limit = this_->_downloadLimit;
if (bandwidth_limit > 0) {
int64_t diff = this_->_lastTime.nsecsElapsed() / 1000;
int64_t len = info->sr.progress - this_->_lastProgress;
if (len > 0 && diff > 0 && (1000000 * len / diff) > (int64_t)bandwidth_limit) {
int64_t wait_time = (1000000 * len / bandwidth_limit) - diff;
if (wait_time > 0) {
usleep(wait_time);
}
}
this_->_lastProgress = info->sr.progress;
this_->_lastTime.start();
} else if (bandwidth_limit < 0 && bandwidth_limit > -100) {
int64_t diff = this_->_lastTime.nsecsElapsed() / 1000;
if (diff > 0) {
// -bandwidth_limit is the % of bandwidth
int64_t wait_time = -diff * (1 + 100.0 / bandwidth_limit);
if (wait_time > 0) {
usleep(wait_time);
}
}
this_->_lastTime.start();
}
}
}