moved to shstk

libs/utils/chunkstream.cpp

@@ -0,0 +1,113 @@
+#include "chunkstream.h"
+
+
+void ChunkStream::setSource(const QByteArray & data) {
+	stream_.setVersion(QDataStream::Qt_4_8);
+	data_ = const_cast<QByteArray*>(&data);
+	_init();
+}
+
+
+void ChunkStream::setSource(QByteArray * data) {
+	stream_.setVersion(QDataStream::Qt_4_8);
+	data_ = (data ? data : &tmp_data);
+	_init();
+}
+
+
+void ChunkStream::setSource(QDataStream & str) {
+	stream_.setVersion(QDataStream::Qt_4_8);
+	str >> tmp_data;
+	data_ = &tmp_data;
+	_init();
+}
+
+
+int ChunkStream::read() {
+	switch (version_) {
+	case Version_1:
+		stream_ >> last_id >> last_data;
+		break;
+	case Version_2:
+		last_id = readVInt(stream_);
+		last_data.resize(readVInt(stream_));
+		//piCout << last_id << last_data.size();
+		stream_.readRawData(last_data.data(), last_data.size());
+		break;
+	default: break;
+	}
+	return last_id;
+}
+
+
+void ChunkStream::readAll() {
+	data_map.clear();
+	while (!atEnd()) {
+		read();
+		data_map[last_id] = last_data;
+	}
+}
+
+
+ChunkStream::~ChunkStream() {
+
+}
+
+
+void ChunkStream::_init() {
+	last_id = -1;
+	last_data.clear();
+	buffer.close();
+	buffer.setBuffer(data_);
+	buffer.open(QIODevice::ReadWrite);
+	stream_.setDevice(&buffer);
+	if (!data_->isEmpty()) {
+		uchar v = data_->at(0);
+		if ((v & 0x80) == 0x80) {
+			v &= 0x7f;
+			switch (v) {
+			case 2:  version_ = (uchar)Version_2; stream_.skipRawData(1); break;
+			default: version_ = Version_1; break;
+			}
+		} else
+			version_ = Version_1;
+	}
+}
+
+
+uint ChunkStream::readVInt(QDataStream & s) {
+	if (s.atEnd()) return 0;
+	uchar bytes[4]; s >> bytes[0];
+	uchar abc = 0;
+	for (abc = 0; abc < 3; ++abc) {
+		uchar mask = (0x80 >> abc);
+		if ((bytes[0] & mask) == mask) {
+			//if (s.isEmpty()) return 0;
+			bytes[0] &= (mask - 1);
+			s >> bytes[abc + 1];
+		} else break;
+	}
+	uint ret = 0;
+	for (int i = 0; i <= abc; ++i) {
+		ret += (bytes[i] << (8 * ((int)abc - i)));
+	}
+	return ret;
+}
+
+
+void ChunkStream::writeVInt(QDataStream & s, uint val) {
+	if (val > 0xfffffff) return;
+	if (val <= 0x7f) {
+		s << uchar(val);
+		return;
+	}
+	if (val <= 0x3fff) {
+		s << uchar((val >> 8) | 0x80) << uchar(val & 0xff);
+		return;
+	}
+	if (val <= 0x1fffff) {
+		s << uchar((val >> 16) | 0xc0) << uchar((val >> 8) & 0xff) << uchar(val & 0xff);
+		return;
+	}
+	s << uchar((val >> 24) | 0xe0) << uchar((val >> 16) & 0xff) << uchar((val >> 8) & 0xff) << uchar(val & 0xff);
+}