Qt大文件在线浏览，支持打开1GB以上文件

#include "textdocument.h" #include "textcursor.h" #include "textcursor_p.h" #include "textdocument_p.h" #include <QBuffer> #include <QIODevice> #include <QObject> #include <QString> #include <QString> #include <QFile> #include <QFileInfo> #include <QList> #include <QTextCharFormat> #include <QVariant> #include <QDesktopServices> #include <qalgorithms.h> // #define DEBUG_CACHE_HITS #ifndef TEXTDOCUMENT_FIND_INTERVAL_PERCENTAGE #define TEXTDOCUMENT_FIND_INTERVAL_PERCENTAGE 1000 #endif #ifndef TEXTDOCUMENT_MAX_INTERVAL #define TEXTDOCUMENT_MAX_INTERVAL 1000 #endif #ifdef TEXTDOCUMENT_FIND_SLEEP static void findSleep(const TextDocument *document) { Q_ASSERT(document); const int duration = document->property("TEXTDOCUMENT_FIND_SLEEP").toInt(); if (duration > 0) { usleep(duration * 1000); } } #endif TextDocument::TextDocument(QObject *parent) : QObject(parent), d(new TextDocumentPrivate(this)) { } TextDocument::~TextDocument() { { QWriteLocker locker(d->readWriteLock); foreach(TextCursorSharedPrivate *cursor, d->textCursors) { cursor->document = 0; } Chunk *c = d->first; while (c) { if (!(d->options & KeepTemporaryFiles) && !c->swap.isEmpty()) QFile::remove(c->swap); Chunk *tmp = c; c = c->next; delete tmp; } foreach(TextSection *section, d->sections) { section->d.document = 0; section->d.textEdit = 0; delete section; } if (d->ownDevice) delete d->device.data(); } delete d->readWriteLock; delete d; } bool TextDocument::load(QIODevice *device, DeviceMode mode, QTextCodec *codec) { QWriteLocker locker(d->readWriteLock); Q_ASSERT(device); if (!device->isReadable()) return false; Options options = d->options; if (options & ConvertCarriageReturns && mode == Sparse) { qWarning("TextDocument::load() ConvertCarriageReturns is incompatible with Sparse"); options &= ~ConvertCarriageReturns; } if ((options & (AutoDetectCarriageReturns|ConvertCarriageReturns)) == (AutoDetectCarriageReturns|ConvertCarriageReturns)) options &= ~AutoDetectCarriageReturns; foreach(TextSection *section, d->sections) { emit sectionRemoved(section); section->d.document = 0; delete section; } d->sections.clear(); if (d->documentSize > 0) { emit charactersRemoved(0, d->documentSize); } Chunk *c = d->first; while (c) { Chunk *tmp = c; c = c->next; delete tmp; } d->textCodec = codec; d->documentSize = device->size(); if (d->documentSize <= d->chunkSize && mode == Sparse && !(options & NoImplicitLoadAll)) mode = LoadAll; #if 0 if (codec && mode == Sparse) { qWarning("Sparse mode doesn't really work with unicode data yet. I am working on it.\n--\nAnders"); } #endif d->first = d->last = 0; if (d->device) { if (d->ownDevice && d->device.data() != device) // this is done when saving to the same file delete d->device.data(); } d->ownDevice = false; d->device = device; d->deviceMode = mode; #ifndef NO_TEXTDOCUMENT_CHUNK_CACHE d->cachedChunk = 0; d->cachedChunkPos = -1; d->cachedChunkData.clear(); #endif #ifndef NO_TEXTDOCUMENT_READ_CACHE d->cachePos = -1; d->cache.clear(); #endif switch (d->deviceMode) { case LoadAll: { device->seek(0); QTextStream ts(device); if (d->textCodec) ts.setCodec(d->textCodec); Chunk *current = 0; d->documentSize = 0; // in case of unicode do { Chunk *c = new Chunk; c->data = ts.read(d->chunkSize); if (options & AutoDetectCarriageReturns) { if (c->data.contains(QLatin1Char('\n'))) { options |= ConvertCarriageReturns; } options &= ~AutoDetectCarriageReturns; } if (options & ConvertCarriageReturns) c->data.remove(QLatin1Char('\r')); d->documentSize += c->data.size(); if (current) { current->next = c; c->previous = current; } else { d->first = c; } current = c; } while (!ts.atEnd()); d->last = current; break; } case Sparse: { int index = 0; Chunk *current = 0; do { Chunk *chunk = new Chunk; chunk->from = index; chunk->length = qMin<int>(d->documentSize - index, d->chunkSize); if (!current) { d->first = chunk; } else { chunk->previous = current; current->next = chunk; } current = chunk; index += chunk->length; } while (index < d->documentSize); d->last = current; break; } } // if (d->first) // d->first->firstLineIndex = 0; emit charactersAdded(0, d->documentSize); emit documentSizeChanged(d->documentSize); emit textChanged(); setModified(false); return true; } bool TextDocument::load(const QString &fileName, DeviceMode mode, QTextCodec *codec) { if (mode == LoadAll) { QFile from(fileName); return from.open(QIODevice::ReadOnly) && load(&from, mode, codec); } else { QFile *file = new QFile(fileName); if (file->open(QIODevice::ReadOnly) && load(file, mode, codec)) { d->ownDevice = true; return true; } else { delete file; d->ownDevice = false; return false; } } } void TextDocument::clear() { setText(QString()); } QString TextDocument::read(int pos, int size) const { QReadLocker locker(d->readWriteLock); Q_ASSERT(size >= 0); if (size == 0 || pos == d->documentSize) { return QString(); } Q_ASSERT(pos < d->documentSize); #ifndef NO_TEXTDOCUMENT_READ_CACHE #ifdef DEBUG_CACHE_HITS static int hits = 0; static int misses = 0; #endif if (d->cachePos != -1 && pos >= d->cachePos && d->cache.size() - (pos - d->cachePos) >= size) { #ifdef DEBUG_CACHE_HITS qWarning() << "read hits" << ++hits << "misses" << misses; #endif return d->cache.mid(pos - d->cachePos, size); } #ifdef DEBUG_CACHE_HITS qWarning() << "read hits" << hits << "misses" << ++misses; #endif #endif QString ret(size, '\0'); int written = 0; int offset; Chunk *c = d->chunkAt(pos, &offset); Q_ASSERT(c); int chunkPos = pos - offset; while (written < size && c) { const int max = qMin(size - written, c->size() - offset); const QString data = d->chunkData(c, chunkPos); chunkPos += data.size(); ret.replace(written, max, data.constData() + offset, max); written += max; offset = 0; c = c->next; } if (written < size) { ret.truncate(written); } Q_ASSERT(!c || written == size); #ifndef NO_TEXTDOCUMENT_READ_CACHE d->cachePos = pos; d->cache = ret; #endif return ret; } QStringRef TextDocument::readRef(int pos, int size) const { QReadLocker locker(d->readWriteLock); int offset; Chunk *c = d->chunkAt(pos, &offset); if (c && pos + offset + size <= c->size()) { const QString string = d->chunkData(c, pos - offset); return string.midRef(offset, size); } return QStringRef(); } bool TextDocument::save(const QString &file) { QFile from(file); return from.open(QIODevice::WriteOnly) && save(&from); } bool TextDocument::save() { return d->device && save(d->device.data()); } static bool isSameFile(const QIODevice *left, const QIODevice *right) { if (left == right) return true; if (const QFile *lf = qobject_cast<con