Add QGCZlib::inflateGzipFile support

qgroundcontrol.pro

@@ -644,6 +644,7 @@ HEADERS += \
     src/QGCQGeoCoordinate.h \
     src/QGCTemporaryFile.h \
     src/QGCToolbox.h \
+    src/QGCZlib.h \
     src/QmlControls/AppMessages.h \
     src/QmlControls/EditPositionDialogController.h \
     src/QmlControls/FlightPathSegment.h \
@@ -859,6 +860,7 @@ SOURCES += \
     src/QGCQGeoCoordinate.cc \
     src/QGCTemporaryFile.cc \
     src/QGCToolbox.cc \
+    src/QGCZlib.cc \
     src/QmlControls/AppMessages.cc \
     src/QmlControls/EditPositionDialogController.cc \
     src/QmlControls/FlightPathSegment.cc \

src/QGCZlib.cc

@@ -0,0 +1,85 @@
+/****************************************************************************
+ *
+ * (c) 2009-2020 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
+ *
+ * QGroundControl is licensed according to the terms in the file
+ * COPYING.md in the root of the source code directory.
+ *
+ ****************************************************************************/
+
+#include "QGCZlib.h"
+
+#include <QFile>
+#include <QDir>
+#include <QtDebug>
+
+#include "zlib.h"
+
+bool QGCZlib::inflateGzipFile(const QString& gzippedFileName, const QString& decompressedFilename)
+{
+    bool            success                 = true;
+    int             ret;
+    const int       cBuffer                 = 1024 * 5;
+    unsigned char   inputBuffer[cBuffer];
+    unsigned char   outputBuffer[cBuffer];
+    z_stream        strm;
+
+    QFile inputFile(gzippedFileName);
+    if (!inputFile.open(QIODevice::ReadOnly)) {
+        qWarning() << "QGCZlib::inflateGzipFile: open input file failed" << gzippedFileName << inputFile.errorString();
+        return false;
+    }
+
+    QFile outputFile(decompressedFilename);
+    if (!outputFile.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
+        qWarning() << "QGCZlib::inflateGzipFile: open input file failed" << outputFile.fileName() << outputFile.errorString();
+        return false;
+    }
+
+    strm.zalloc     = nullptr;
+    strm.zfree      = nullptr;
+    strm.opaque     = nullptr;
+    strm.avail_in   = 0;
+    strm.next_in    = nullptr;
+
+    ret = inflateInit2(&strm, 16+MAX_WBITS);
+    if (ret != Z_OK) {
+        qWarning() << "QGCZlib::inflateGzipFile: inflateInit2 failed:" << ret;
+        goto Error;
+    }
+
+    do {
+        strm.avail_in = static_cast<unsigned>(inputFile.read((char*)inputBuffer, cBuffer));
+        if (strm.avail_in == 0) {
+            break;
+        }
+        strm.next_in = inputBuffer;
+
+        do {
+            strm.avail_out  = cBuffer;
+            strm.next_out   = outputBuffer;
+
+            ret = inflate(&strm, Z_NO_FLUSH);
+            if (ret != Z_OK && ret != Z_STREAM_END) {
+                qWarning() << "QGCZlib::inflateGzipFile: inflate failed:" << ret;
+                goto Error;
+            }
+
+            unsigned cBytesInflated = cBuffer - strm.avail_out;
+            qint64 cBytesWritten = outputFile.write((char*)outputBuffer, static_cast<int>(cBytesInflated));
+            if (cBytesWritten != cBytesInflated) {
+                qWarning() << "QGCZlib::inflateGzipFile: output file write failed:" << outputFile.fileName() << outputFile.errorString();
+                goto Error;
+
+            }
+        } while (strm.avail_out == 0);
+    } while (ret != Z_STREAM_END);
+
+Out:
+    inflateEnd(&strm);
+    return success;
+
+Error:
+    success = false;
+    goto Out;
+}

src/QGCZlib.h

@@ -0,0 +1,21 @@
+/****************************************************************************
+ *
+ * (c) 2009-2020 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
+ *
+ * QGroundControl is licensed according to the terms in the file
+ * COPYING.md in the root of the source code directory.
+ *
+ ****************************************************************************/
+
+#pragma once
+
+#include <QString>
+
+class QGCZlib
+{
+public:
+    /// Decompresses the specified file to the specified directory
+    ///     @param gzipFilename         Fully qualified path to gzip file
+    ///     @param decompressedFilename Fully qualified path to for file to decompress to
+    static bool inflateGzipFile(const QString& gzippedFileName, const QString& decompressedFilename);
+};