[fix][performance] Disable vmsplice because it generates wrong results

src/core/FileUtils.hpp

@@ -36,15 +36,25 @@
     #include <sys/uio.h>
     #include <unistd.h>
 
-    #if not defined( HAVE_VMSPLICE ) and defined( __linux__ ) and defined( F_GETPIPE_SZ )
-        #define HAVE_VMSPLICE
-    #endif
+    //#if not defined( HAVE_VMSPLICE ) and defined( __linux__ ) and defined( F_GETPIPE_SZ )
+    //    #define HAVE_VMSPLICE
+    //#endif
 
     #if not defined( HAVE_IOVEC ) and defined( __linux__ )
         #define HAVE_IOVEC
     #endif
 #endif
 
+/**
+ * Disable vmsplice because it STILL has bugs. In this case it seems to happen because rapidgzip quits
+ * before everything has been read. This seems to cause a free and possible reuse of the memory section
+ * during the shutdown process and causes invalid output. I guess the only real way to get this to work
+ * is as stated below with a custom mmap allocator + vmsplice gift.
+ * Too bad, because it gave quite some performance, but it's no use when the results are wrong.
+ * https://github.com/mxmlnkn/rapidgzip/issues/39
+ */
+#undef HAVE_VMSPLICE
+
 
 #if defined( HAVE_VMSPLICE )
     #include <any>

src/rapidgzip/ChunkData.hpp

@@ -695,7 +695,6 @@ writeAll( const std::shared_ptr<ChunkData>& chunkData,
 #else
     using rapidgzip::deflate::DecodedData;
 
-    bool splicable = true;
     for ( auto it = DecodedData::Iterator( *chunkData, offsetInBlock, dataToWriteSize );
           static_cast<bool>( it ); ++it )
     {