io/fileview: add FileView

This commit is contained in:
outfoxxed 2024-09-09 03:15:16 -07:00
parent 3a1eec0ed5
commit 85be3861ce
Signed by: outfoxxed
GPG key ID: 4C88A185FB89301E
6 changed files with 635 additions and 1 deletions

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@ -1,6 +1,8 @@
#pragma once
#include <type_traits>
#include <qtclasshelpermacros.h>
// NOLINTBEGIN
#define DROP_EMIT(object, func) \
DropEmitter(object, static_cast<void (*)(typeof(object))>([](typeof(object) o) { o->func(); }))
@ -72,6 +74,8 @@ private:
DECLARE_MEMBER_GET(name); \
DECLARE_MEMBER_SET(name, setter)
#define DECLARE_MEMBER_SETONLY(class, name, setter, member, signal) DECLARE_MEMBER(cl
#define DECLARE_MEMBER_FULL(class, name, setter, member, signal) \
DECLARE_MEMBER(class, name, member, signal); \
DECLARE_MEMBER_GETSET(name, setter)
@ -123,6 +127,8 @@ private:
#define DEFINE_MEMBER_GETSET(Class, name, setter) \
DEFINE_MEMBER_GET(Class, name) \
DEFINE_MEMBER_SET(Class, name, setter)
#define MEMBER_EMIT(name) std::remove_reference_t<decltype(*this)>::M_##name::emitter(this)
// NOLINTEND
template <typename T>
@ -154,6 +160,12 @@ public:
} else {
if (MemberMetadata::get(obj) == value) return DropEmitter();
obj->*member = value;
return MemberMetadata::emitter(obj);
}
}
static Ret emitter(Class* obj) {
if constexpr (signal != nullptr) {
return DropEmitter(obj, &MemberMetadata::emitForObject);
}
}
@ -170,3 +182,32 @@ public:
using Ref = const Type&;
using Ret = std::conditional_t<hasSignal, DropEmitter, void>;
};
class GuardedEmitBlocker {
public:
explicit GuardedEmitBlocker(bool* var): var(var) { *this->var = true; }
~GuardedEmitBlocker() { *this->var = false; }
Q_DISABLE_COPY_MOVE(GuardedEmitBlocker);
private:
bool* var;
};
template <auto signal>
class GuardedEmitter {
using Traits = MemberPointerTraits<decltype(signal)>;
using Class = Traits::Class;
bool blocked = false;
public:
GuardedEmitter() = default;
~GuardedEmitter() = default;
Q_DISABLE_COPY_MOVE(GuardedEmitter);
void call(Class* obj) {
if (!this->blocked) (obj->*signal)();
}
GuardedEmitBlocker block() { return GuardedEmitBlocker(&this->blocked); }
};

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@ -1,6 +1,7 @@
qt_add_library(quickshell-io STATIC
datastream.cpp
process.cpp
fileview.cpp
)
add_library(quickshell-io-init OBJECT init.cpp)
@ -9,7 +10,12 @@ if (SOCKETS)
target_sources(quickshell-io PRIVATE socket.cpp)
endif()
qt_add_qml_module(quickshell-io URI Quickshell.Io VERSION 0.1)
qt_add_qml_module(quickshell-io
URI Quickshell.Io
VERSION 0.1
QML_FILES
FileView.qml
)
target_link_libraries(quickshell-io PRIVATE ${QT_DEPS})
target_link_libraries(quickshell-io-init PRIVATE ${QT_DEPS})

48
src/io/FileView.qml Normal file
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@ -0,0 +1,48 @@
import Quickshell.Io
FileViewInternal {
property bool preload: this.__preload;
property bool blockLoading: this.__blockLoading;
property bool blockAllReads: this.__blockAllReads;
property string path: this.__path;
onPreloadChanged: this.__preload = preload;
onBlockLoadingChanged: this.__blockLoading = this.blockLoading;
onBlockAllReadsChanged: this.__blockAllReads = this.blockAllReads;
// Unfortunately path can't be kept as an empty string until the file loads
// without using QQmlPropertyValueInterceptor which is private. If we lean fully
// into using private code in the future, there will be no reason not to do it here.
onPathChanged: {
if (!this.preload) this.__preload = false;
this.__path = this.path;
if (this.preload) this.__preload = true;
}
// The C++ side can't force bindings to be resolved in a specific order so
// its done here. Functions are used to avoid the eager loading aspect of properties.
// Preload is set as it is below to avoid starting an async read from a preload
// if the user wants an initial blocking read.
function text(): string {
if (!this.preload) this.__preload = false;
this.__blockLoading = this.blockLoading;
this.__blockAllReads = this.blockAllReads;
this.__path = this.path;
const text = this.__text;
if (this.preload) this.__preload = true;
return text;
}
function data(): string {
if (!this.preload) this.__preload = false;
this.__blockLoading = this.blockLoading;
this.__blockAllReads = this.blockAllReads;
this.__path = this.path;
const data = this.__data;
if (this.preload) this.__preload = true;
return data;
}
}

302
src/io/fileview.cpp Normal file
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@ -0,0 +1,302 @@
#include "fileview.hpp"
#include <utility>
#include <qfileinfo.h>
#include <qlogging.h>
#include <qloggingcategory.h>
#include <qmutex.h>
#include <qnamespace.h>
#include <qobject.h>
#include <qobjectdefs.h>
#include <qthreadpool.h>
#include <qtmetamacros.h>
#include <qtypes.h>
#include "../core/util.hpp"
namespace qs::io {
Q_LOGGING_CATEGORY(logFileView, "quickshell.io.fileview", QtWarningMsg);
FileViewReader::FileViewReader(QString path, bool doStringConversion)
: doStringConversion(doStringConversion) {
this->state.path = std::move(path);
this->setAutoDelete(false);
this->blockMutex.lock();
}
void FileViewReader::run() {
FileViewReader::read(this->state, this->doStringConversion);
this->blockMutex.unlock();
QMetaObject::invokeMethod(this, &FileViewReader::finished, Qt::QueuedConnection);
}
void FileViewReader::block() {
// block until a lock can be acauired, then immediately drop it
auto unused = QMutexLocker(&this->blockMutex);
}
void FileViewReader::finished() {
emit this->done();
delete this;
}
void FileViewReader::read(FileViewState& state, bool doStringConversion) {
{
qCDebug(logFileView) << "Reader started for" << state.path;
auto info = QFileInfo(state.path);
state.exists = info.exists();
if (!state.exists) return;
if (!info.isFile()) {
qCCritical(logFileView) << state.path << "is not a file.";
goto error;
} else if (!info.isReadable()) {
qCCritical(logFileView) << "No permission to read" << state.path;
state.error = true;
goto error;
}
auto file = QFile(state.path);
if (!file.open(QFile::ReadOnly)) {
qCCritical(logFileView) << "Failed to open" << state.path;
goto error;
}
auto& data = state.data;
data = QByteArray(file.size(), Qt::Uninitialized);
qint64 i = 0;
while (true) {
auto r = file.read(data.data() + i, data.length() - i); // NOLINT
if (r == -1) {
qCCritical(logFileView) << "Failed to read" << state.path;
goto error;
} else if (r == 0) {
data.resize(i);
break;
}
i += r;
}
if (doStringConversion) {
state.text = QString::fromUtf8(state.data);
state.textDirty = false;
} else {
state.textDirty = true;
}
return;
}
error:
state.error = true;
}
void FileView::loadAsync(bool doStringConversion) {
if (!this->reader || this->pathInFlight != this->targetPath) {
this->cancelAsync();
this->pathInFlight = this->targetPath;
if (this->targetPath.isEmpty()) {
auto state = FileViewState();
this->updateState(state);
} else {
qCDebug(logFileView) << "Starting async load for" << this << "of" << this->targetPath;
this->reader = new FileViewReader(this->targetPath, doStringConversion);
QObject::connect(this->reader, &FileViewReader::done, this, &FileView::readerFinished);
QThreadPool::globalInstance()->start(this->reader); // takes ownership
}
}
}
void FileView::cancelAsync() {
if (this->reader) {
qCDebug(logFileView) << "Disowning async read for" << this;
QObject::disconnect(this->reader, nullptr, this, nullptr);
this->reader = nullptr;
}
}
void FileView::readerFinished() {
if (this->sender() != this->reader) {
qCWarning(logFileView) << "got read finished from dropped FileViewReader" << this->sender();
return;
}
qCDebug(logFileView) << "Async load finished for" << this;
this->updateState(this->reader->state);
this->reader = nullptr;
}
void FileView::reload() { this->updatePath(); }
bool FileView::blockUntilLoaded() {
if (this->reader != nullptr) {
QObject::disconnect(this->reader, nullptr, this, nullptr);
this->reader->block();
this->updateState(this->reader->state);
this->reader = nullptr;
return true;
} else return false;
}
void FileView::loadSync() {
if (this->targetPath.isEmpty()) {
auto state = FileViewState();
this->updateState(state);
} else if (!this->blockUntilLoaded()) {
auto state = FileViewState {.path = this->targetPath};
FileViewReader::read(state, false);
this->updateState(state);
}
}
void FileView::updateState(FileViewState& newState) {
DEFINE_DROP_EMIT_IF(newState.path != this->state.path, this, pathChanged);
// assume if the path was changed the data also changed
auto dataChanged = pathChanged || newState.data != this->state.data;
// DEFINE_DROP_EMIT_IF(newState.exists != this->state.exists, this, existsChanged);
this->mPrepared = true;
auto loadedChanged = this->setLoadedOrAsync(!newState.path.isEmpty() && newState.exists);
this->state.path = std::move(newState.path);
if (dataChanged) {
this->state.data = newState.data;
this->state.text = newState.text;
this->state.textDirty = newState.textDirty;
}
this->state.exists = newState.exists;
this->state.error = newState.error;
DropEmitter::call(
pathChanged,
// existsChanged,
loadedChanged
);
if (dataChanged) this->emitDataChanged();
if (this->state.error) emit this->loadFailed();
}
void FileView::textConversion() {
if (this->state.textDirty) {
this->state.text = QString::fromUtf8(this->state.data);
this->state.textDirty = false;
}
}
QString FileView::path() const { return this->state.path; }
void FileView::setPath(const QString& path) {
auto p = path.startsWith("file://") ? path.sliced(7) : path;
if (p == this->targetPath) return;
this->targetPath = p;
this->updatePath();
}
void FileView::updatePath() {
this->mPrepared = false;
if (this->targetPath.isEmpty()) {
auto state = FileViewState();
this->updateState(state);
} else if (this->mPreload) {
this->loadAsync(true);
} else {
// loadAsync will do this already
this->cancelAsync();
this->emitDataChanged();
}
}
bool FileView::shouldBlock() const {
return this->mBlockAllReads || (this->mBlockLoading && !this->mLoadedOrAsync);
}
QByteArray FileView::data() {
auto guard = this->dataChangedEmitter.block();
if (!this->mPrepared) {
if (this->shouldBlock()) this->loadSync();
else this->loadAsync(false);
}
return this->state.data;
}
QString FileView::text() {
auto guard = this->textChangedEmitter.block();
if (!this->mPrepared) {
if (this->shouldBlock()) this->loadSync();
else this->loadAsync(true);
}
this->textConversion();
return this->state.text;
}
void FileView::emitDataChanged() {
this->dataChangedEmitter.call(this);
this->textChangedEmitter.call(this);
emit this->dataChanged();
emit this->textChanged();
}
DEFINE_MEMBER_GETSET(FileView, isLoadedOrAsync, setLoadedOrAsync);
DEFINE_MEMBER_GET(FileView, shouldPreload);
DEFINE_MEMBER_GET(FileView, blockLoading);
DEFINE_MEMBER_GET(FileView, blockAllReads);
void FileView::setPreload(bool preload) {
if (preload != this->mPreload) {
this->mPreload = preload;
emit this->preloadChanged();
if (preload) this->emitDataChanged();
if (!this->mPrepared && this->mPreload) {
this->loadAsync(false);
}
}
}
void FileView::setBlockLoading(bool blockLoading) {
if (blockLoading != this->mBlockLoading) {
auto wasBlocking = this->shouldBlock();
this->mBlockLoading = blockLoading;
emit this->blockLoadingChanged();
if (!wasBlocking && this->shouldBlock()) {
this->emitDataChanged();
}
}
}
void FileView::setBlockAllReads(bool blockAllReads) {
if (blockAllReads != this->mBlockAllReads) {
auto wasBlocking = this->shouldBlock();
this->mBlockAllReads = blockAllReads;
emit this->blockAllReadsChanged();
if (!wasBlocking && this->shouldBlock()) {
this->emitDataChanged();
}
}
}
} // namespace qs::io

236
src/io/fileview.hpp Normal file
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@ -0,0 +1,236 @@
#pragma once
#include <qlogging.h>
#include <qmutex.h>
#include <qobject.h>
#include <qproperty.h>
#include <qqmlintegration.h>
#include <qqmlparserstatus.h>
#include <qrunnable.h>
#include <qtmetamacros.h>
#include "../core/doc.hpp"
#include "../core/util.hpp"
namespace qs::io {
struct FileViewState {
QString path;
QString text;
QByteArray data;
bool textDirty = false;
bool exists = false;
bool error = false;
};
class FileView;
class FileViewReader
: public QObject
, public QRunnable {
Q_OBJECT;
public:
explicit FileViewReader(QString path, bool doStringConversion);
void run() override;
void block();
FileViewState state;
static void read(FileViewState& state, bool doStringConversion);
signals:
void done();
private slots:
void finished();
private:
bool doStringConversion;
QMutex blockMutex;
};
///! Simplified reader for small files.
/// A reader for small to medium files that don't need seeking/cursor access,
/// suitable for most text files.
///
/// #### Example: Reading a JSON
/// ```qml
/// FileView {
/// id: jsonFile
/// path: Qt.resolvedUrl("./your.json")
/// // Forces the file to be loaded by the time we call JSON.parse().
/// // see blockLoading's property documentation for details.
/// blockLoading: true
/// }
///
/// readonly property var jsonData: JSON.parse(jsonFile.text())
/// ```
class FileView: public QObject {
Q_OBJECT;
// clang-format off
/// The path to the file that should be read, or an empty string to unload the file.
QSDOC_PROPERTY_OVERRIDE(QString path READ path WRITE setPath NOTIFY pathChanged);
/// If the file should be loaded in the background immediately when set. Defaults to true.
///
/// This may either increase or decrease the amount of time it takes to load the file
/// depending on how large the file is, how fast its storage is, and how you access its data.
QSDOC_PROPERTY_OVERRIDE(bool preload READ shouldPreload WRITE setPreload NOTIFY preloadChanged);
/// If @@text() and @@data() should block all operations until the file is loaded. Defaults to false.
///
/// If the file is already loaded, no blocking will occur.
/// If a file was loaded, and @@path was changed to a new file, no blocking will occur.
///
/// > [!WARNING] Blocking operations should be used carefully to avoid stutters and other performance
/// > degradations. Blocking means that your interface **WILL NOT FUNCTION** during the call.
/// >
/// > **We recommend you use a blocking load ONLY for files loaded before the windows of your shell
/// > are loaded, which happens after `Component.onCompleted` runs for the root component of your shell.**
/// >
/// > The most reasonable use case would be to load things like configuration files that the program
/// > must have available.
QSDOC_PROPERTY_OVERRIDE(bool blockLoading READ blockLoading WRITE setBlockLoading NOTIFY blockLoadingChanged);
/// If @@text() and @@data() should block all operations while a file loads. Defaults to false.
///
/// This is nearly identical to @@blockLoading, but will additionally block when
/// a file is loaded and @@path changes.
///
/// > [!WARNING] We cannot think of a valid use case for this.
/// > You almost definitely want @@blockLoading.
QSDOC_PROPERTY_OVERRIDE(bool blockAllReads READ blockAllReads WRITE setBlockAllReads NOTIFY blockAllReadsChanged);
QSDOC_HIDE Q_PROPERTY(QString __path READ path WRITE setPath NOTIFY pathChanged);
QSDOC_HIDE Q_PROPERTY(QString __text READ text NOTIFY internalTextChanged);
QSDOC_HIDE Q_PROPERTY(QByteArray __data READ data NOTIFY internalDataChanged);
QSDOC_HIDE Q_PROPERTY(bool __preload READ shouldPreload WRITE setPreload NOTIFY preloadChanged);
/// If a file is currently loaded, which may or may not be the one currently specified by @@path.
///
/// > [!INFO] If a file is loaded, @@path is changed, and a new file is loaded,
/// > this property will stay true the whole time.
/// > If @@path is set to an empty string to unload the file it will become false.
Q_PROPERTY(bool loaded READ isLoadedOrAsync NOTIFY loadedOrAsyncChanged);
QSDOC_HIDE Q_PROPERTY(bool __blockLoading READ blockLoading WRITE setBlockLoading NOTIFY blockLoadingChanged);
QSDOC_HIDE Q_PROPERTY(bool __blockAllReads READ blockAllReads WRITE setBlockAllReads NOTIFY blockAllReadsChanged);
// clang-format on
QML_NAMED_ELEMENT(FileViewInternal);
QSDOC_NAMED_ELEMENT(FileView);
public:
explicit FileView(QObject* parent = nullptr): QObject(parent) {}
/// Returns the data of the file specified by @@path as text.
///
/// If @@blockAllReads is true, all changes to @@path will cause the program to block
/// when this function is called.
///
/// If @@blockLoading is true, reading this property before the file has been loaded
/// will block, but changing @@path or calling @@reload() will return the old data
/// until the load completes.
///
/// If neither is true, an empty string will be returned if no file is loaded,
/// otherwise it will behave as in the case above.
///
/// > [!INFO] Due to technical limitations, @@text() could not be a property,
/// > however you can treat it like a property, it will trigger property updates
/// > as a property would, and the signal `textChanged()` is present.
//@ Q_INVOKABLE QString text();
/// Returns the data of the file specified by @@path as an [ArrayBuffer].
///
/// If @@blockAllReads is true, all changes to @@path will cause the program to block
/// when this function is called.
///
/// If @@blockLoading is true, reading this property before the file has been loaded
/// will block, but changing @@path or calling @@reload() will return the old data
/// until the load completes.
///
/// If neither is true, an empty buffer will be returned if no file is loaded,
/// otherwise it will behave as in the case above.
///
/// > [!INFO] Due to technical limitations, @@data() could not be a property,
/// > however you can treat it like a property, it will trigger property updates
/// > as a property would, and the signal `dataChanged()` is present.
///
/// [ArrayBuffer]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer
//@ Q_INVOKABLE QByteArray data();
/// Block all operations until the currently running load completes.
///
/// > [!WARNING] See @@blockLoading for an explanation and warning about blocking.
Q_INVOKABLE bool blockUntilLoaded();
/// Unload the loaded file and reload it, usually in response to changes.
///
/// This will not block if @@blockLoading is set, only if @@blockAllReads is true.
/// It acts the same as changing @@path to a new file, except loading the same file.
Q_INVOKABLE void reload();
[[nodiscard]] QString path() const;
void setPath(const QString& path);
[[nodiscard]] QByteArray data();
[[nodiscard]] QString text();
signals:
///! Fires if the file failed to load. A warning will be printed in the log.
void loadFailed();
void pathChanged();
QSDOC_HIDE void internalTextChanged();
QSDOC_HIDE void internalDataChanged();
QSDOC_HIDE void textChanged();
QSDOC_HIDE void dataChanged();
void preloadChanged();
void loadedOrAsyncChanged();
void blockLoadingChanged();
void blockAllReadsChanged();
private slots:
void readerFinished();
private:
void loadAsync(bool doStringConversion);
void cancelAsync();
void loadSync();
void updateState(FileViewState& newState);
void textConversion();
void updatePath();
[[nodiscard]] bool shouldBlock() const;
FileViewState state;
FileViewReader* reader = nullptr;
QString pathInFlight;
QString targetPath;
bool mAsyncUpdate = true;
bool mWritable = false;
bool mCreate = false;
bool mPreload = true;
bool mPrepared = false;
bool mLoadedOrAsync = false;
bool mBlockLoading = false;
bool mBlockAllReads = false;
GuardedEmitter<&FileView::internalTextChanged> textChangedEmitter;
GuardedEmitter<&FileView::internalDataChanged> dataChangedEmitter;
void emitDataChanged();
DECLARE_PRIVATE_MEMBER(
FileView,
isLoadedOrAsync,
setLoadedOrAsync,
mLoadedOrAsync,
loadedOrAsyncChanged
);
public:
DECLARE_MEMBER_WITH_GET(FileView, shouldPreload, mPreload, preloadChanged);
DECLARE_MEMBER_WITH_GET(FileView, blockLoading, mBlockLoading, blockLoadingChanged);
DECLARE_MEMBER_WITH_GET(FileView, blockAllReads, mBlockAllReads, blockAllReadsChanged);
void setPreload(bool preload);
void setBlockLoading(bool blockLoading);
void setBlockAllReads(bool blockAllReads);
};
} // namespace qs::io

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@ -4,5 +4,6 @@ headers = [
"datastream.hpp",
"socket.hpp",
"process.hpp",
"fileview.hpp",
]
-----