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Android: Support pregenerated cache in assets file engine

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This provides a way for androiddeployqt to pregenerate the
entry list cache for the assets file engine, greatly improving
performance the first time a directory is read. If the file
is not present, the cache will operate as before.

Some numbers from testing on Samsung Galaxy 2, doing
QDir::entryList() on a directory inside the assets folder:

10 files
--------
Before:
     280 ms for first read,
       5 ms for subsequent reads
After:
       2 ms for reading pregenerated cache
       5 ms for first read
       5 ms for subsequent reads

2000 files
----------
Before:
    1000 ms for first read,
     150 ms for subsequent reads
After:
       5 ms for reading pregenerated cache
     150 ms for first read
     150 ms for subsequent reads

4000 files
----------
Before:
     3000 ms for first read
      300 ms for subsequent reads
After:
        8 ms for reading pregenerated cache
      300 ms for first read
      300 ms for subsequent reads

[ChangeLog][Android] Speed up first time directory listing
in assets by using pregenerated entry list.

Task-number: QTBUG-33704
Change-Id: I3973a1d823b8b38e88a2cc7843326cbe885f8bc2
Reviewed-by: Christian Stromme <christian.stromme@digia.com>
This commit is contained in:
Eskil Abrahamsen Blomfeldt 2014-01-30 14:25:42 +01:00 committed by The Qt Project
parent f3ed93e486
commit b79e734767
2 changed files with 107 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

128
src/plugins/platforms/android/qandroidassetsfileenginehandler.cpp
View File

@ -51,10 +51,12 @@ struct AndroidAssetDir
{
AndroidAssetDir(AAssetDir* ad)
{
const char *fileName;
while ((fileName = AAssetDir_getNextFileName(ad)))
m_items.push_back(QString::fromUtf8(fileName));
AAssetDir_close(ad);
if (ad) {
const char *fileName;
while ((fileName = AAssetDir_getNextFileName(ad)))
m_items.push_back(QString::fromUtf8(fileName));
AAssetDir_close(ad);
}
}
FilesList m_items;
};
@ -82,7 +84,10 @@ public:
{
if (m_index < 0 || m_index >= m_items.size())
return QString();
return m_items[m_index];
QString fileName = m_items[m_index];
if (fileName.endsWith(QLatin1Char('/')))
fileName.chop(1);
return fileName;
}
virtual QString currentFilePath() const
@ -254,33 +259,106 @@ private:
};
AndroidAssetsFileEngineHandler::AndroidAssetsFileEngineHandler():m_assetsCache(std::max(5, qgetenv("QT_ANDROID_MAX_ASSETS_CACHE_SIZE").toInt()))
AndroidAssetsFileEngineHandler::AndroidAssetsFileEngineHandler()
: m_assetsCache(std::max(5, qgetenv("QT_ANDROID_MAX_ASSETS_CACHE_SIZE").toInt()))
, m_hasPrepopulatedCache(false)
{
m_assetManager = QtAndroid::assetManager();
prepopulateCache();
}
AndroidAssetsFileEngineHandler::~AndroidAssetsFileEngineHandler()
{
}
void AndroidAssetsFileEngineHandler::prepopulateCache()
{
QMutexLocker locker(&m_assetsCacheMutext);
Q_ASSERT(m_assetsCache.isEmpty());
// Failsafe: Don't read cache files that are larger than 1MB
static qint64 maxPrepopulatedCacheSize = qMax(1024LL * 1024LL,
qgetenv("QT_ANDROID_MAX_PREPOPULATED_ASSETS_CACHE_SIZE").toLongLong());
const char *fileName = "--Added-by-androiddeployqt--/qt_cache_pregenerated_file_list";
AAsset *asset = AAssetManager_open(m_assetManager, fileName, AASSET_MODE_BUFFER);
if (asset) {
m_hasPrepopulatedCache = true;
AndroidAbstractFileEngine fileEngine(asset, QString::fromLatin1(fileName));
if (fileEngine.open(QIODevice::ReadOnly)) {
qint64 size = fileEngine.size();
if (size <= maxPrepopulatedCacheSize) {
QByteArray bytes(size, Qt::Uninitialized);
qint64 read = fileEngine.read(bytes.data(), size);
if (read != size) {
qWarning("Failed to read prepopulated cache");
return;
}
QDataStream stream(&bytes, QIODevice::ReadOnly);
stream.setVersion(QDataStream::Qt_5_3);
if (stream.status() != QDataStream::Ok) {
qWarning("Failed to read prepopulated cache");
return;
}
while (!stream.atEnd()) {
QString directoryName;
stream >> directoryName;
int fileCount;
stream >> fileCount;
QVector<QString> fileList;
fileList.reserve(fileCount);
while (fileCount--) {
QString fileName;
stream >> fileName;
fileList.append(fileName);
}
QSharedPointer<AndroidAssetDir> *aad = new QSharedPointer<AndroidAssetDir>(new AndroidAssetDir(0));
(*aad)->m_items = fileList;
// Cost = 0, because we should always cache everything if there's a prepopulated cache
QByteArray key = directoryName != QLatin1String("/")
? QByteArray("assets:/") + directoryName.toUtf8()
: QByteArray("assets:");
bool ok = m_assetsCache.insert(key, aad, 0);
if (!ok)
qWarning("Failed to insert in cache: %s", qPrintable(directoryName));
}
} else {
qWarning("Prepopulated cache is too large to read.\n"
"Use environment variable QT_ANDROID_MAX_PREPOPULATED_ASSETS_CACHE_SIZE to adjust size.");
}
}
}
}
QAbstractFileEngine * AndroidAssetsFileEngineHandler::create(const QString &fileName) const
{
if (fileName.isEmpty())
return 0;
if (!fileName.startsWith(QLatin1String("assets:/")))
static QLatin1String assetsPrefix("assets:");
if (!fileName.startsWith(assetsPrefix))
return 0;
int prefixSize=8;
static int prefixSize = assetsPrefix.size() + 1;
QByteArray path;
if (!fileName.endsWith(QLatin1Char('/'))) {
path = fileName.toUtf8();
AAsset *asset = AAssetManager_open(m_assetManager,
path.constData() + prefixSize,
AASSET_MODE_BUFFER);
if (asset)
return new AndroidAbstractFileEngine(asset, fileName);
if (path.size() > prefixSize) {
AAsset *asset = AAssetManager_open(m_assetManager,
path.constData() + prefixSize,
AASSET_MODE_BUFFER);
if (asset)
return new AndroidAbstractFileEngine(asset, fileName);
}
}
if (!path.size())
@ -290,17 +368,19 @@ QAbstractFileEngine * AndroidAssetsFileEngineHandler::create(const QString &file
QSharedPointer<AndroidAssetDir> *aad = m_assetsCache.object(path);
m_assetsCacheMutext.unlock();
if (!aad) {
AAssetDir *assetDir = AAssetManager_openDir(m_assetManager, path.constData() + prefixSize);
if (assetDir) {
if (AAssetDir_getNextFileName(assetDir)) {
AAssetDir_rewind(assetDir);
aad = new QSharedPointer<AndroidAssetDir>(new AndroidAssetDir(assetDir));
m_assetsCacheMutext.lock();
m_assetsCache.insert(path, aad);
m_assetsCacheMutext.unlock();
return new AndroidAbstractFileEngine(*aad, fileName);
} else {
AAssetDir_close(assetDir);
if (!m_hasPrepopulatedCache && path.size() > prefixSize) {
AAssetDir *assetDir = AAssetManager_openDir(m_assetManager, path.constData() + prefixSize);
if (assetDir) {
if (AAssetDir_getNextFileName(assetDir)) {
AAssetDir_rewind(assetDir);
aad = new QSharedPointer<AndroidAssetDir>(new AndroidAssetDir(assetDir));
m_assetsCacheMutext.lock();
m_assetsCache.insert(path, aad);
m_assetsCacheMutext.unlock();
return new AndroidAbstractFileEngine(*aad, fileName);
} else {
AAssetDir_close(assetDir);
}
}
}
} else {

3
src/plugins/platforms/android/qandroidassetsfileenginehandler.h
View File

@ -58,9 +58,12 @@ public:
QAbstractFileEngine *create(const QString &fileName) const;
private:
void prepopulateCache();
AAssetManager *m_assetManager;
mutable QCache<QByteArray, QSharedPointer<AndroidAssetDir>> m_assetsCache;
mutable QMutex m_assetsCacheMutext;
bool m_hasPrepopulatedCache;
};
#endif // QANDROIDASSETSFILEENGINEHANDLER_H