Use an aligned memory allocator for the memfile

Author: hmaarrfk

src/core/others/ojph_file.cpp

@@ -43,6 +43,8 @@
 #include <cassert>
 #include <cstddef>
 
+#include <stdlib.h>
+
 #include "ojph_file.h"
 #include "ojph_message.h"
 
@@ -110,7 +112,11 @@ namespace ojph {
   mem_outfile::~mem_outfile()
   {
     if (buf)
+#ifdef OJPH_OS_WINDOWS
+      _aligned_free(buf);
+#else
       free(buf);
+#endif
     is_open = clear_mem = false;
     buf_size = used_size = 0;
     buf = cur_ptr = NULL;
@@ -198,15 +204,30 @@ namespace ojph {
   /** */
   void mem_outfile::expand_storage(size_t needed_size, bool clear_all)
   {
+    ui8 * new_buf = nullptr;
     if (needed_size > buf_size)
     {
       needed_size += (needed_size + 1) >> 1; // x1.5
-      si64 used_size = tell(); // current used size
-
-      if (this->buf)
-        this->buf = (ui8*)realloc(this->buf, needed_size);
-      else
-        this->buf = (ui8*)malloc(needed_size);
+      needed_size = (needed_size + 4095) & (~4095); // align to 4096
+      size_t used_size = (size_t)tell(); // current used size
+
+#ifdef OJPH_OS_WINDOWS
+      new_buf = (ui8*)_aligned_malloc(4096, needed_size);
+#else
+      new_buf = (ui8*)aligned_alloc(4096, needed_size);
+#endif
+      if (new_buf == nullptr)
+        OJPH_ERROR(0x00060004, "failed to allocate memory (%zu bytes)", needed_size);
+
+      if (this->buf != nullptr && this->buf != new_buf && !clear_all){
+        memcpy(new_buf, this->buf, used_size);
+#ifdef OJPH_OS_WINDOWS
+        _aligned_free(this->buf);
+#else
+        free(this->buf);
+#endif
+      }
+      this->buf = new_buf;
 
       if (clear_mem && !clear_all) // will be cleared later
         memset(this->buf + buf_size, 0, needed_size - this->buf_size);