Imported existing sources

gzipdevice.cpp

@@ -0,0 +1,77 @@
+#include "gzipdevice.h"
+
+#include <QFile>
+
+#include <stdexcept>
+
+GzipDevice::GzipDevice(QFile &file, QObject *parent) :
+    QIODevice(parent),
+    m_file(file)
+{
+    if (!m_file.isOpen())
+        throw std::runtime_error("file is not open");
+
+    setOpenMode(QIODevice::ReadOnly);
+
+    // Prepare inflater status
+    strm.zalloc = Z_NULL;
+    strm.zfree = Z_NULL;
+    strm.opaque = Z_NULL;
+    strm.avail_in = 0;
+    strm.next_in = Z_NULL;
+
+    // Initialize inflater
+    m_result = inflateInit2(&strm, 15 + 16);
+    if (m_result != Z_OK)
+        throw std::runtime_error("could not init z_stream");
+}
+
+GzipDevice::~GzipDevice()
+{
+    inflateEnd(&strm);
+}
+
+bool GzipDevice::isSequential() const
+{
+    return true;
+}
+
+bool GzipDevice::atEnd() const
+{
+    return m_result == Z_STREAM_END;
+}
+
+qint64 GzipDevice::readData(char *data, qint64 maxlen)
+{
+    if (strm.avail_in == 0)
+    {
+        strm.next_in = reinterpret_cast<unsigned char *>(m_readBuffer);
+        strm.avail_in = m_file.read(m_readBuffer, m_readBufferSize);
+    }
+
+    strm.next_out = reinterpret_cast<unsigned char*>(data);
+    strm.avail_out = maxlen;
+
+    m_result = inflate(&strm, Z_NO_FLUSH);
+
+    switch (m_result) {
+    case Z_NEED_DICT:
+        throw std::runtime_error("decompression failed: Z_NEED_DICT");
+    case Z_DATA_ERROR:
+        throw std::runtime_error("decompression failed: Z_DATA_ERROR");
+    case Z_MEM_ERROR:
+        throw std::runtime_error("decompression failed: Z_MEM_ERROR");
+    case Z_STREAM_ERROR:
+        throw std::runtime_error("decompression failed: Z_STREAM_ERROR");
+    }
+
+    return maxlen-strm.avail_out;
+}
+
+qint64 GzipDevice::writeData(const char *data, qint64 len)
+{
+    Q_UNUSED(data)
+    Q_UNUSED(len)
+    qFatal("no writes allowed in GzipDevice!");
+    return -1;
+}