Qx v0.5.7
Qt Extensions Library
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The AsyncDownloadManager class is used to queue and process one or more downloads in an asynchronous manner using signals and slots. More...
#include <qx/network/qx-downloadmanager.h>
Public Slots | |
void | abort () |
void | processQueue () |
Signals | |
void | authenticationRequired (QString prompt, QAuthenticator *authenticator) |
void | downloadFinished (Qx::DownloadOpReport downloadReport) |
void | downloadProgress (qint64 bytesCurrent) |
void | downloadTotalChanged (quint64 bytesTotal) |
void | finished (Qx::DownloadManagerReport report) |
void | preSharedKeyAuthenticationRequired (QString prompt, QSslPreSharedKeyAuthenticator *authenticator) |
void | proxyAuthenticationRequired (QString prompt, QAuthenticator *authenticator) |
void | sslErrors (Qx::Error errorMsg, bool *ignore) |
Public Member Functions | |
AsyncDownloadManager (QObject *parent=nullptr) | |
void | appendTask (const DownloadTask &task) |
void | clearTasks () |
int | enumerationTimeout () const |
bool | hasTasks () const |
bool | isDeletePartialDownloads () const |
bool | isOverwrite () const |
bool | isProcessing () const |
bool | isSkipEnumeration () const |
bool | isStopOnError () const |
int | maxSimultaneous () const |
QNetworkRequest::RedirectPolicy | redirectPolicy () const |
void | setDeletePartialDownloads (bool deletePartialDownloads) |
void | setEnumerationTimeout (int timeout=500) |
void | setMaxSimultaneous (int maxSimultaneous) |
void | setOverwrite (bool overwrite) |
void | setRedirectPolicy (QNetworkRequest::RedirectPolicy redirectPolicy) |
void | setSkipEnumeration (bool skipEnumeration) |
void | setStopOnError (bool stopOnError) |
void | setTransferTimeout (int timeout=QNetworkRequest::DefaultTransferTimeoutConstant) |
void | setVerificationMethod (QCryptographicHash::Algorithm method) |
int | taskCount () const |
int | transferTimeout () const |
QCryptographicHash::Algorithm | verificationMethod () const |
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QObject (QObject *parent) | |
QBindable< QString > | bindableObjectName () |
bool | blockSignals (bool block) |
const QObjectList & | children () const const |
QMetaObject::Connection | connect (const QObject *sender, const char *signal, const char *method, Qt::ConnectionType type) const const |
void | deleteLater () |
void | destroyed (QObject *obj) |
bool | disconnect (const char *signal, const QObject *receiver, const char *method) const const |
bool | disconnect (const QObject *receiver, const char *method) const const |
void | dumpObjectInfo () const const |
void | dumpObjectTree () const const |
QList< QByteArray > | dynamicPropertyNames () const const |
virtual bool | event (QEvent *e) |
virtual bool | eventFilter (QObject *watched, QEvent *event) |
T | findChild (const QString &name, Qt::FindChildOptions options) const const |
QList< T > | findChildren (const QRegularExpression &re, Qt::FindChildOptions options) const const |
QList< T > | findChildren (const QString &name, Qt::FindChildOptions options) const const |
QList< T > | findChildren (Qt::FindChildOptions options) const const |
bool | inherits (const char *className) const const |
void | installEventFilter (QObject *filterObj) |
bool | isQuickItemType () const const |
bool | isWidgetType () const const |
bool | isWindowType () const const |
void | killTimer (int id) |
virtual const QMetaObject * | metaObject () const const |
void | moveToThread (QThread *targetThread) |
QString | objectName () const const |
void | objectNameChanged (const QString &objectName) |
QObject * | parent () const const |
QVariant | property (const char *name) const const |
Q_CLASSINFO (Name, Value) | |
Q_EMIT Q_EMIT | |
Q_ENUM (...) | |
Q_ENUM_NS (...) | |
Q_ENUMS (...) | |
Q_FLAG (...) | |
Q_FLAG_NS (...) | |
Q_FLAGS (...) | |
Q_GADGET Q_GADGET | |
Q_GADGET_EXPORT (EXPORT_MACRO) | |
Q_INTERFACES (...) | |
Q_INVOKABLE Q_INVOKABLE | |
Q_MOC_INCLUDE Q_MOC_INCLUDE | |
Q_NAMESPACE Q_NAMESPACE | |
Q_NAMESPACE_EXPORT (EXPORT_MACRO) | |
Q_OBJECT Q_OBJECT | |
Q_PROPERTY (...) | |
Q_REVISION Q_REVISION | |
Q_SET_OBJECT_NAME (Object) | |
Q_SIGNAL Q_SIGNAL | |
Q_SIGNALS Q_SIGNALS | |
Q_SLOT Q_SLOT | |
Q_SLOTS Q_SLOTS | |
T | qobject_cast (const QObject *object) |
T | qobject_cast (QObject *object) |
QT_NO_NARROWING_CONVERSIONS_IN_CONNECT QT_NO_NARROWING_CONVERSIONS_IN_CONNECT | |
void | removeEventFilter (QObject *obj) |
void | setObjectName (const QString &name) |
void | setObjectName (QAnyStringView name) |
void | setParent (QObject *parent) |
bool | setProperty (const char *name, const QVariant &value) |
bool | signalsBlocked () const const |
int | startTimer (int interval, Qt::TimerType timerType) |
int | startTimer (std::chrono::milliseconds time, Qt::TimerType timerType) |
QThread * | thread () const const |
Additional Inherited Members | |
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QMetaObject::Connection | connect (const QObject *sender, const char *signal, const QObject *receiver, const char *method, Qt::ConnectionType type) |
QMetaObject::Connection | connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type) |
QMetaObject::Connection | connect (const QObject *sender, PointerToMemberFunction signal, const QObject *context, Functor functor, Qt::ConnectionType type) |
QMetaObject::Connection | connect (const QObject *sender, PointerToMemberFunction signal, const QObject *receiver, PointerToMemberFunction method, Qt::ConnectionType type) |
QMetaObject::Connection | connect (const QObject *sender, PointerToMemberFunction signal, Functor functor) |
bool | disconnect (const QMetaObject::Connection &connection) |
bool | disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *method) |
bool | disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method) |
bool | disconnect (const QObject *sender, PointerToMemberFunction signal, const QObject *receiver, PointerToMemberFunction method) |
QString | tr (const char *sourceText, const char *disambiguation, int n) |
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typedef | QObjectList |
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virtual void | childEvent (QChildEvent *event) |
virtual void | connectNotify (const QMetaMethod &signal) |
virtual void | customEvent (QEvent *event) |
virtual void | disconnectNotify (const QMetaMethod &signal) |
bool | isSignalConnected (const QMetaMethod &signal) const const |
int | receivers (const char *signal) const const |
QObject * | sender () const const |
int | senderSignalIndex () const const |
virtual void | timerEvent (QTimerEvent *event) |
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objectName | |
An asynchronous download manager can process an arbitrary number of download tasks while tracking overall progress, forwarding events that require user interaction, and mediating connections.
Optional file content verification is available for tasks provided with non-empty checksums, which are compared using the algorithm set via setVerificationMethod().
Qx::AsyncDownloadManager::AsyncDownloadManager | ( | QObject * | parent = nullptr | ) |
Constructs an empty asynchronous download manager with parent parent.
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slot |
Aborts all in-progress and remaining downloads immediately.
The outcome of the following manager's report is set to Outcome::Abort.
void Qx::AsyncDownloadManager::appendTask | ( | const DownloadTask & | task | ) |
Inserts task into the download queue.
If the same task is already present in the queue then this function does nothing.
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signal |
This signal is emitted whenever a final server requests authentication before it delivers the requested contents, with prompt providing user-friendly text that describes the request.
The slot connected to this signal should provide the requested credentials via authenticator, or else the download that requires this authentication will fail with an error. If no slots are connected to this signal then downloads that require authentication will always fail.
The manager caches the provided credentials internally and will send the same values if the server requires authentication again, without emitting the authenticationRequired() signal. If it rejects the credentials, this signal will be emitted again.
void Qx::AsyncDownloadManager::clearTasks | ( | ) |
Removes all tasks from the download manager queue.
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signal |
This signal is emitted when a single download has finished, with downloadReport containing identifying and outcome related info.
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signal |
This signal is emitted to indicate the progress of all downloads handled by the manager.
It will always be emitted with a value of 0
when processing is first started in order to induce a busy state in connected progress bars.
The bytesCurrent parameter indicates the total number of bytes received since queue processing was started.
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signal |
This signal is emitted to indicate that total number of bytes required to complete all downloads has changed, with bytesTotal containing the new value.
This will always be emitted at least twice:
0
when processing is first started in order to induce a busy state in connected progress bars. It may be emitted again later when a download is started if the initially reported size was determined to be inaccurate.
int Qx::AsyncDownloadManager::enumerationTimeout | ( | ) | const |
Returns the enumeration timeout of the manager, which is how long the initial file size query for a download has to complete before the manager falls back to predicting its size.
The default is 500ms.
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signal |
This signal is emitted when processing completes, either because the queue was successfully exhausted, or because a fatal error or user abortion caused it to end prematurely,
The signal parameter report details the outcome of the download procedure.
bool Qx::AsyncDownloadManager::hasTasks | ( | ) | const |
Returns true
if the manager has tasks left to process; otherwise returns false
.
bool Qx::AsyncDownloadManager::isDeletePartialDownloads | ( | ) | const |
Returns true
if the manager is configured to remove any incomplete downloads after they fail or are aborted; otherwise, returns false
.
The default is false
.
bool Qx::AsyncDownloadManager::isOverwrite | ( | ) | const |
Returns true
if the manager is configured to overwrite local files that already exist; otherwise returns false
.
The default is false
.
bool Qx::AsyncDownloadManager::isProcessing | ( | ) | const |
Returns true
if the manager is currently processing its download queue; otherwise returns false
.
bool Qx::AsyncDownloadManager::isSkipEnumeration | ( | ) | const |
Returns true
if the manager is configured to query the size of all queued tasks before actually initiating any downloads; otherwise, returns false
.
If enumeration is disabled, total download progress reported by the manager will be limited in scope to only active and finished downloads, as the size of future download tasks cannot be determined until they are started. This means that every time a new download is initiated the total byte count reported by the manager will increase, causing all connected progress indicators to move backwards.
For this reason, when enumeration is disabled it is recommended to ignore the size of each download and instead track overall progress by task count only, using either taskCount() or downloadFinished() and comparing to the original queue size of the manager before processing began.
The default is false
.
bool Qx::AsyncDownloadManager::isStopOnError | ( | ) | const |
Returns true
if the manager is configured to automatically halt all downloads if one fails; otherwise returns false
.
The default is false
.
int Qx::AsyncDownloadManager::maxSimultaneous | ( | ) | const |
Returns the number of allowed simultaneous downloads.
The default is 3.
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signal |
This signal is emitted if a sever SSL/TLS handshake negotiates a PSK ciphersuite, and therefore a PSK authentication is then required. prompt provides a user-friendly text that describes the request.
The slot connected to this signal should provide the requested key via authenticator, or else the download that requires this authentication will fail with an error. If no slots are connected to this signal then downloads that require PSK authentication will always fail.
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slot |
Starts processing the download queue, which prevents further modifications to the queue.
Various signals of this class are used to communicate download progress or issues with downloads while processing is in-progress.
If the manager's queue is empty or the manager is already processing the queue this function does nothing.
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signal |
This signal is emitted whenever a proxy requests authentication, with prompt providing user-friendly text that describes the request.
The slot connected to this signal should provide the requested credentials via authenticator, or else all downloads that rely on the proxy will fail with an error. If no slots are connected to this signal then downloads that involve authenticated proxies will always fail.
The manager caches the provided credentials internally and will send the same values if the proxy requires authentication again, without emitting the proxyAuthenticationRequired() signal. If it rejects the credentials, this signal will be emitted again.
QNetworkRequest::RedirectPolicy Qx::AsyncDownloadManager::redirectPolicy | ( | ) | const |
Returns the directory policy of the manager.
The default is QNetworkRequest::NoLessSafeRedirectPolicy.
void Qx::AsyncDownloadManager::setDeletePartialDownloads | ( | bool | deletePartialDownloads | ) |
Configures the manager to automatically remove incomplete files after a download fails or is aborted if deletePartialDownloads is true
; otherwise, partial downloads are kept.
void Qx::AsyncDownloadManager::setEnumerationTimeout | ( | int | timeout = 500 | ) |
Sets timeout as the enumeration timeout in milliseconds.
The manager falls back to guessing a files size based on previous size queries if a given size query fails to complete before the timeout expires.
Zero means no timer is set.
void Qx::AsyncDownloadManager::setMaxSimultaneous | ( | int | maxSimultaneous | ) |
Sets the number of allowed simultaneous downloads to maxSimultaneous.
A value less than one results in no limit
void Qx::AsyncDownloadManager::setOverwrite | ( | bool | overwrite | ) |
Configures the manager to overwrite existing local files that already exist if overwrite is true
; otherwise the download task that maps to destination will be aborted.
void Qx::AsyncDownloadManager::setRedirectPolicy | ( | QNetworkRequest::RedirectPolicy | redirectPolicy | ) |
Sets the redirect policy of the manager to redirectPolicy. This policy will affect all subsequent requests created by the manager.
Use this function to enable or disable HTTP redirects on the manager's level.
The default value is QNetworkRequest::NoLessSafeRedirectPolicy.
void Qx::AsyncDownloadManager::setSkipEnumeration | ( | bool | skipEnumeration | ) |
Specifies whether or not the manager should attempt to query the size of all queued tasks before actually initiating any downloads.
void Qx::AsyncDownloadManager::setStopOnError | ( | bool | stopOnError | ) |
Configures the manager to automatically halt all downloads after a single failure on if stopOnError is true
.
void Qx::AsyncDownloadManager::setTransferTimeout | ( | int | timeout = QNetworkRequest::DefaultTransferTimeoutConstant | ) |
Sets timeout as the transfer timeout in milliseconds.
Transfers are aborted if no bytes are transferred before the timeout expires.
Zero means no timer is set.
void Qx::AsyncDownloadManager::setVerificationMethod | ( | QCryptographicHash::Algorithm | method | ) |
Sets the hash algorithm used to verify downloads for tasks that include a checksum.
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signal |
This signal is emitted if the SSL/TLS session encountered errors during the set up, including certificate verification errors. The errorMsg parameter details the errors.
To indicate that the errors are not fatal and that the connection should proceed, the ignore parameter should be set to true
; otherwise the task experiencing the errors will be halted with an error.
This signal can be used to display an error message to the user indicating that security may be compromised.
See also QNetworkAccessManager::sslErrors().
int Qx::AsyncDownloadManager::taskCount | ( | ) | const |
Returns current number of download tasks remaining, which includes pending and active downloads.
int Qx::AsyncDownloadManager::transferTimeout | ( | ) | const |
Returns the transfer timeout of the manager.
The default is zero, which means the timeout is disabled.
QCryptographicHash::Algorithm Qx::AsyncDownloadManager::verificationMethod | ( | ) | const |
Returns the hash algorithm used to verify downloads for tasks that include a checksum.
The default is QCryptographicHash::Sha256.