intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 33 insertions, 0 deletions

diff --git a/util/memory/mmapalloc.cpp b/util/memory/mmapalloc.cpp
new file mode 100644
index 00000000000..ec618cc8084
--- /dev/null
+++ b/util/memory/mmapalloc.cpp
@@ -0,0 +1,33 @@
+#include "alloc.h"
+#include "mmapalloc.h"
+
+#include <util/system/filemap.h>
+#include <util/generic/singleton.h>
+
+namespace {
+    class TMmapAllocator: public IAllocator {
+    public:
+        TBlock Allocate(size_t len) override {
+            TMappedAllocation m(len + sizeof(TMappedAllocation));
+            TMappedAllocation* real = (TMappedAllocation*)m.Data();
+
+            (new (real) TMappedAllocation(0))->swap(m);
+
+            TBlock ret = {real + 1, len};
+
+            return ret;
+        }
+
+        void Release(const TBlock& block) override {
+            TMappedAllocation tmp(0);
+            TMappedAllocation* real = ((TMappedAllocation*)block.Data) - 1;
+
+            real->swap(tmp);
+            real->~TMappedAllocation();
+        }
+    };
+}
+
+IAllocator* MmapAllocator() {
+    return SingletonWithPriority<TMmapAllocator, 0>();
+}