Qt: Add GUI support for saving in LZ4 format

Add GUI support for saving in LZ4 format as well as gzip and
uncompressed. Replace the current checkbox with a group box.
The group box looks better alongside the packet range group box
for Export Packet Dissections and would be appropriate to
substitute into the Capture Options dialog in a later commit;
a combobox might look more natural for the ordinary Save As window.

Change the work to fix up the file extension a bit, so that
it can switch between .gz and .lz4

README.md

@@ -89,10 +89,14 @@ the required compression library was available when Wireshark was compiled.
 Currently supported compression formats are:
 
 - GZIP
-- ZSTD
 - LZ4
+- ZSTD
 
-You can disable zlib support by running `cmake -DENABLE_ZLIB=OFF`.
+GZIP and LZ4 (when using independent blocks, which is the default) support
+fast random seeking, which offers much better GUI performance on large files.
+Any of these compression formats can be disabled at compile time by passing
+the corresponding option to cmake, i.e., `cmake -DENABLE_ZLIB=OFF`,
+`cmake -DENABLE_LZ4=OFF`, or `cmake -DENABLE_ZSTD=OFF`.
 
 Although Wireshark can read AIX iptrace files, the documentation on
 AIX's iptrace packet-trace command is sparse.  The `iptrace` command

doc/release-notes.adoc

@@ -379,6 +379,15 @@ The following features are either new or have been significantly updated since v
 
 * Global profiles can be used in tshark by using `--global-profile` option.
 
+* Fast random access is supported with LZ4 compressed files (when compressed
+  with independent blocks, which is the default). This provides much more
+  responsive GUI performance when jumping to different packets. gzip compressed
+  files also support fast random seeking (since 1.8.0), but Zstd compressed
+  do not.
+
+* Existing capture files can be saved with LZ4 compression. LZ4 has an emphasis
+  on speed and may be particularly useful for large files.
+
 === Removed Features and Support
 
 * The tshark `-G` option with no argument is deprecated and will be removed in

ui/logray/CMakeLists.txt

@@ -22,6 +22,7 @@ set(WIRESHARK_WIDGET_HEADERS
 	${CMAKE_SOURCE_DIR}/ui/qt/widgets/capture_filter_combo.h
 	${CMAKE_SOURCE_DIR}/ui/qt/widgets/capture_filter_edit.h
 	${CMAKE_SOURCE_DIR}/ui/qt/widgets/clickable_label.h
+	${CMAKE_SOURCE_DIR}/ui/qt/widgets/compression_group_box.h
 	${CMAKE_SOURCE_DIR}/ui/qt/widgets/copy_from_profile_button.h
 	${CMAKE_SOURCE_DIR}/ui/qt/widgets/detachable_tabwidget.h
 	${CMAKE_SOURCE_DIR}/ui/qt/widgets/display_filter_combo.h
@@ -261,6 +262,7 @@ set(WIRESHARK_WIDGET_SRCS
 	${CMAKE_SOURCE_DIR}/ui/qt/widgets/capture_filter_combo.cpp
 	${CMAKE_SOURCE_DIR}/ui/qt/widgets/capture_filter_edit.cpp
 	${CMAKE_SOURCE_DIR}/ui/qt/widgets/clickable_label.cpp
+	${CMAKE_SOURCE_DIR}/ui/qt/widgets/compression_group_box.cpp
 	${CMAKE_SOURCE_DIR}/ui/qt/widgets/copy_from_profile_button.cpp
 	${CMAKE_SOURCE_DIR}/ui/qt/widgets/detachable_tabwidget.cpp
 	${CMAKE_SOURCE_DIR}/ui/qt/widgets/display_filter_combo.cpp

ui/qt/CMakeLists.txt

@@ -22,6 +22,7 @@ set(WIRESHARK_WIDGET_HEADERS
 	widgets/capture_filter_combo.h
 	widgets/capture_filter_edit.h
 	widgets/clickable_label.h
+	widgets/compression_group_box.h
 	widgets/copy_from_profile_button.h
 	widgets/detachable_tabwidget.h
 	widgets/display_filter_combo.h
@@ -290,6 +291,7 @@ set(WIRESHARK_WIDGET_SRCS
 	widgets/capture_filter_combo.cpp
 	widgets/capture_filter_edit.cpp
 	widgets/clickable_label.cpp
+	widgets/compression_group_box.cpp
 	widgets/copy_from_profile_button.cpp
 	widgets/detachable_tabwidget.cpp
 	widgets/display_filter_combo.cpp

ui/qt/capture_file_dialog.cpp

@@ -418,23 +418,22 @@ void CaptureFileDialog::fixFilenameExtension()
     }
 
     // Fixup the new suffix based on whether we're compressing or not.
-    if (compressionType() == WTAP_UNCOMPRESSED) {
+    // Strip off any compression suffix
-        // Not compressing; strip off any compression suffix
+    GSList *compression_type_extensions = wtap_get_all_compression_type_extensions_list();
-        GSList *compression_type_extensions = wtap_get_all_compression_type_extensions_list();
+    for (GSList *compression_type_extension = compression_type_extensions;
-        for (GSList *compression_type_extension = compression_type_extensions;
+        compression_type_extension != NULL;
-            compression_type_extension != NULL;
+        compression_type_extension = g_slist_next(compression_type_extension)) {
-            compression_type_extension = g_slist_next(compression_type_extension)) {
+        QString suffix = QString(".") + (char *)compression_type_extension->data;
-            QString suffix = QString(".") + (char *)compression_type_extension->data;
+        if (new_suffix.endsWith(suffix)) {
-            if (new_suffix.endsWith(suffix)) {
+            //
-                //
+            // It ends with this compression suffix; chop it off.
-                // It ends with this compression suffix; chop it off.
+            //
-                //
+            new_suffix.chop(suffix.size());
-                new_suffix.chop(suffix.size());
+            break;
-                break;
-            }
         }
-        g_slist_free(compression_type_extensions);
+    }
-    } else {
+    g_slist_free(compression_type_extensions);
+    if (compressionType() != WTAP_UNCOMPRESSED) {
         // Compressing; append the appropriate compression suffix.
         QString compressed_file_extension = QString(".") + wtap_compression_type_extension(compressionType());
         if (valid_extensions.contains(new_suffix + compressed_file_extension)) {
@@ -503,7 +502,7 @@ int CaptureFileDialog::selectedFileType() {
 }
 
 wtap_compression_type CaptureFileDialog::compressionType() {
-    return compress_.isChecked() ? WTAP_GZIP_COMPRESSED : WTAP_UNCOMPRESSED;
+    return compress_group_box_.compressionType();
 }
 
 void CaptureFileDialog::addDisplayFilterEdit(QString &display_filter) {
@@ -539,15 +538,11 @@ void CaptureFileDialog::addFormatTypeSelector(QVBoxLayout &v_box) {
 }
 
 void CaptureFileDialog::addGzipControls(QVBoxLayout &v_box) {
-    compress_.setText(tr("Compress with g&zip"));
+    if (wtap_dump_can_compress(default_ft_)) {
-    if (cap_file_->compression_type == WTAP_GZIP_COMPRESSED &&
+        compress_group_box_.setCompressionType(cap_file_->compression_type);
-        wtap_dump_can_compress(default_ft_)) {
-        compress_.setChecked(true);
-    } else {
-        compress_.setChecked(false);
     }
-    v_box.addWidget(&compress_, 0, Qt::AlignTop);
+    v_box.addWidget(&compress_group_box_, 0, Qt::AlignTop);
-    connect(&compress_, &QCheckBox::stateChanged, this, &CaptureFileDialog::fixFilenameExtension);
+    connect(&compress_group_box_, &CompressionGroupBox::stateChanged, this, &CaptureFileDialog::fixFilenameExtension);
 
 }
 

ui/qt/capture_file_dialog.h

@@ -13,6 +13,7 @@
 #include <ui/qt/widgets/wireshark_file_dialog.h>
 
 #include <ui/qt/widgets/display_filter_edit.h>
+#include <ui/qt/widgets/compression_group_box.h>
 #include "packet_range_group_box.h"
 #include "ui/help_url.h"
 
@@ -117,7 +118,7 @@ private:
 
     int default_ft_;
 
-    QCheckBox compress_;
+    CompressionGroupBox compress_group_box_;
 
     PacketRangeGroupBox packet_range_group_box_;
     QPushButton *save_bt_;

ui/qt/widgets/compression_group_box.cpp

@@ -0,0 +1,64 @@
+/* @file
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "compression_group_box.h"
+
+#include <QRadioButton>
+#include <QButtonGroup>
+#include <QVBoxLayout>
+
+CompressionGroupBox::CompressionGroupBox(QWidget *parent) :
+    QGroupBox(parent)
+{
+    setTitle(tr("Compression options"));
+    setFlat(true);
+
+
+    bg_ = new QButtonGroup(this);
+    QVBoxLayout *vbox = new QVBoxLayout();
+
+    QRadioButton *radio1 = new QRadioButton(tr("&Uncompressed"));
+    bg_->addButton(radio1, WTAP_UNCOMPRESSED);
+    vbox->addWidget(radio1);
+
+#if defined (HAVE_ZLIB) || defined (HAVE_ZLIBNG)
+    QRadioButton *radio2 = new QRadioButton(tr("Compress with g&zip"));
+    bg_->addButton(radio2, WTAP_GZIP_COMPRESSED);
+    vbox->addWidget(radio2);
+#endif
+#ifdef HAVE_LZ4FRAME_H
+    QRadioButton *radio3 = new QRadioButton(tr("Compress with &LZ4"));
+    bg_->addButton(radio3, WTAP_LZ4_COMPRESSED);
+    vbox->addWidget(radio3);
+#endif
+
+    radio1->setChecked(true);
+
+    setLayout(vbox);
+
+    connect(bg_, &QButtonGroup::idToggled, [=] { emit stateChanged(); });
+}
+
+CompressionGroupBox::~CompressionGroupBox()
+{
+}
+
+wtap_compression_type CompressionGroupBox::compressionType() const
+{
+    return static_cast<wtap_compression_type>(bg_->checkedId());
+}
+
+void CompressionGroupBox::setCompressionType(wtap_compression_type type)
+{
+    QAbstractButton *button = bg_->button(type);
+    if (button != nullptr) {
+        button->setChecked(true);
+    }
+}
+

ui/qt/widgets/compression_group_box.h

@@ -0,0 +1,41 @@
+/** @file
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef COMPRESSION_GROUP_BOX_H
+#define COMPRESSION_GROUP_BOX_H
+
+#include <config.h>
+
+#include <QGroupBox>
+
+#include <wiretap/wtap.h>
+
+class QButtonGroup;
+
+/**
+ * UI element for selecting compression type from among those supported.
+ */
+class CompressionGroupBox : public QGroupBox
+{
+    Q_OBJECT
+
+public:
+    explicit CompressionGroupBox(QWidget *parent = 0);
+    ~CompressionGroupBox();
+    wtap_compression_type compressionType() const;
+    void setCompressionType(wtap_compression_type type);
+
+signals:
+    void stateChanged();
+
+private:
+    QButtonGroup *bg_;
+};
+
+#endif // COMPRESSION_GROUP_BOX_H

wiretap/file_access.c

@@ -2124,7 +2124,7 @@ wtap_dump_can_open(int file_type_subtype)
  * Return whether we know how to write a compressed file of the specified
  * file type.
  */
-#if defined (HAVE_ZLIB) || defined (HAVE_ZLIBNG)
+#if defined (HAVE_ZLIB) || defined (HAVE_ZLIBNG) || defined (HAVE_LZ4FRAME_H)
 bool
 wtap_dump_can_compress(int file_type_subtype)
 {