From e66ade1b8496d9086a6e9189e5a33cb3a6e73e22 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Fri, 30 Mar 2018 00:11:31 +0200
Subject: [PATCH] Factor out reusable part of wxLZMAInputStream into wxLZMAData

No changes yet, this is a pure refactoring in preparation for adding
wxLZMAOutputStream.
---
 include/wx/lzmastream.h   | 44 +++++++++++++++++++++++++--------
 src/common/lzmastream.cpp | 52 ++++++++++++++++++++-------------------
 2 files changed, 61 insertions(+), 35 deletions(-)

diff --git a/include/wx/lzmastream.h b/include/wx/lzmastream.h
index 3c2a77808f..604a2543a2 100644
--- a/include/wx/lzmastream.h
+++ b/include/wx/lzmastream.h
@@ -17,18 +17,48 @@
 #include "wx/stream.h"
 #include "wx/versioninfo.h"
 
+namespace wxPrivate
+{
+
+// Private wrapper for lzma_stream struct.
 struct wxLZMAStream;
 
+// Common part of input and output LZMA streams: this is just an implementation
+// detail and is not part of the public API.
+class WXDLLIMPEXP_BASE wxLZMAData
+{
+protected:
+    wxLZMAData();
+    ~wxLZMAData();
+
+    wxLZMAStream* m_stream;
+    wxUint8* m_streamBuf;
+    wxFileOffset m_pos;
+
+    wxDECLARE_NO_COPY_CLASS(wxLZMAData);
+};
+
+} // namespace wxPrivate
+
 // ----------------------------------------------------------------------------
 // Filter for decompressing data compressed using LZMA
 // ----------------------------------------------------------------------------
 
-class WXDLLIMPEXP_BASE wxLZMAInputStream : public wxFilterInputStream
+class WXDLLIMPEXP_BASE wxLZMAInputStream : public wxFilterInputStream,
+                                           private wxPrivate::wxLZMAData
 {
 public:
-    explicit wxLZMAInputStream(wxInputStream& stream);
-    explicit wxLZMAInputStream(wxInputStream* stream);
-    virtual ~wxLZMAInputStream();
+    explicit wxLZMAInputStream(wxInputStream& stream)
+        : wxFilterInputStream(stream)
+    {
+        Init();
+    }
+
+    explicit wxLZMAInputStream(wxInputStream* stream)
+        : wxFilterInputStream(stream)
+    {
+        Init();
+    }
 
     char Peek() wxOVERRIDE { return wxInputStream::Peek(); }
     wxFileOffset GetLength() const wxOVERRIDE { return wxInputStream::GetLength(); }
@@ -39,12 +69,6 @@ protected:
 
 private:
     void Init();
-
-    wxLZMAStream* m_stream;
-    wxUint8* m_inbuf;
-    wxFileOffset m_pos;
-
-    wxDECLARE_NO_COPY_CLASS(wxLZMAInputStream);
 };
 
 WXDLLIMPEXP_BASE wxVersionInfo wxGetLibLZMAVersionInfo();
diff --git a/src/common/lzmastream.cpp b/src/common/lzmastream.cpp
index b8aae286f1..e07460b7df 100644
--- a/src/common/lzmastream.cpp
+++ b/src/common/lzmastream.cpp
@@ -33,11 +33,14 @@
 
 #include <lzma.h>
 
+namespace wxPrivate
+{
+
 // ----------------------------------------------------------------------------
 // Constants
 // ----------------------------------------------------------------------------
 
-static const size_t wxLZMA_BUF_SIZE = 4096;
+const size_t wxLZMA_BUF_SIZE = 4096;
 
 // ----------------------------------------------------------------------------
 // Private helpers
@@ -58,6 +61,10 @@ struct wxLZMAStream : lzma_stream
     }
 };
 
+} // namespace wxPrivate
+
+using namespace wxPrivate;
+
 // ============================================================================
 // implementation
 // ============================================================================
@@ -80,28 +87,29 @@ wxVersionInfo wxGetLibLZMAVersionInfo()
            );
 }
 
+// ----------------------------------------------------------------------------
+// wxLZMAData: common helpers for compression and decompression
+// ----------------------------------------------------------------------------
+
+wxLZMAData::wxLZMAData()
+{
+    m_stream = new wxLZMAStream;
+    m_streamBuf = new wxUint8[wxLZMA_BUF_SIZE];
+    m_pos = 0;
+}
+
+wxLZMAData::~wxLZMAData()
+{
+    delete [] m_streamBuf;
+    delete m_stream;
+}
+
 // ----------------------------------------------------------------------------
 // wxLZMAInputStream: decompression
 // ----------------------------------------------------------------------------
 
-wxLZMAInputStream::wxLZMAInputStream(wxInputStream& stream)
-    : wxFilterInputStream(stream)
-{
-    Init();
-}
-
-wxLZMAInputStream::wxLZMAInputStream(wxInputStream* stream)
-    : wxFilterInputStream(stream)
-{
-    Init();
-}
-
 void wxLZMAInputStream::Init()
 {
-    m_stream = new wxLZMAStream;
-    m_inbuf = new wxUint8[wxLZMA_BUF_SIZE];
-    m_pos = 0;
-
     // We don't specify any memory usage limit nor any flags, not even
     // LZMA_CONCATENATED recommended by liblzma documentation, because we don't
     // foresee the need to support concatenated compressed files for now.
@@ -126,12 +134,6 @@ void wxLZMAInputStream::Init()
     m_lasterror = wxSTREAM_READ_ERROR;
 }
 
-wxLZMAInputStream::~wxLZMAInputStream()
-{
-    delete [] m_inbuf;
-    delete m_stream;
-}
-
 size_t wxLZMAInputStream::OnSysRead(void* outbuf, size_t size)
 {
     m_stream->next_out = static_cast<uint8_t*>(outbuf);
@@ -145,8 +147,8 @@ size_t wxLZMAInputStream::OnSysRead(void* outbuf, size_t size)
         // Get more input data if needed.
         if ( !m_stream->avail_in )
         {
-            m_parent_i_stream->Read(m_inbuf, wxLZMA_BUF_SIZE);
-            m_stream->next_in = m_inbuf;
+            m_parent_i_stream->Read(m_streamBuf, wxLZMA_BUF_SIZE);
+            m_stream->next_in = m_streamBuf;
             m_stream->avail_in = m_parent_i_stream->LastRead();
 
             if ( !m_stream->avail_in )