intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 118 insertions, 0 deletions

diff --git a/util/memory/segpool_alloc.h b/util/memory/segpool_alloc.h
new file mode 100644
index 0000000000..1a83b7a543
--- /dev/null
+++ b/util/memory/segpool_alloc.h
@@ -0,0 +1,118 @@
+#pragma once
+
+#include "segmented_string_pool.h"
+
+/**
+  This is a partially implemented allocator class that uses segmented_pool
+  as its allocatior base.
+  In fact, segpool_alloc can only allocate, it can't deallocate. Therefore,
+  it should be used with add-only containers that are just clear()'ed in the
+  end of their life cycle.
+
+  External segmented_pool object must be cleared explicitly after all
+  containers use it in their allocator are cleared.
+  Single segmented_pool object may be used for several containers.
+
+  Use segpool_alloc_vt as allocator template parameter for container.
+  Example:
+  using TSomething = THashMap<A, B, hash<A>, TEqualTo<A>, segpool_alloc_vt>;
+  ...
+  TSomething something;
+  something.GetNodeAllocator().pool = &alloc_pool;
+
+  Some containers may provide no way to access their allocator. In that case,
+  if you want to use them with segpool_alloc_vt, you should first either
+  hack them, or fix segpool_alloc so that it would create ref-counted
+  segmented_pool object on it's own
+
+  ! Only tested with THashMap
+*/
+
+template <class _Tp>
+struct segpool_alloc {
+    using pool_type = segmented_pool<char>;
+    pool_type* pool;
+    using pointer = _Tp*;
+    using const_pointer = const _Tp*;
+    using reference = _Tp&;
+    using const_reference = const _Tp&;
+    using size_type = size_t;
+    using difference_type = ptrdiff_t;
+    using value_type = _Tp;
+#ifndef NDEBUG
+    ui64 pool_count, malloc_count, pool_free_count, malloc_free_count;
+#endif
+    segpool_alloc()
+        : pool(nullptr)
+    {
+        Y_IF_DEBUG(pool_count = malloc_count = pool_free_count = malloc_free_count = 0);
+    }
+    segpool_alloc(pool_type* p)
+        : pool(p)
+    {
+        Y_IF_DEBUG(pool_count = malloc_count = pool_free_count = malloc_free_count = 0);
+    }
+    segpool_alloc(const segpool_alloc& a)
+        : pool(a.pool)
+    {
+        Y_IF_DEBUG(pool_count = malloc_count = pool_free_count = malloc_free_count = 0);
+    }
+    template <class _Tp1>
+    segpool_alloc(const segpool_alloc<_Tp1>& a)
+        : pool(a.pool)
+    {
+        Y_IF_DEBUG(pool_count = malloc_count = pool_free_count = malloc_free_count = 0);
+    }
+    _Tp* allocate(size_t __n) {
+        if (!pool) {
+            _Tp* data = (_Tp*)malloc(__n * sizeof(_Tp));
+            Y_IF_DEBUG(if (data) malloc_count++);
+            return data;
+        }
+        _Tp* data = (_Tp*)pool->append(nullptr, __n * sizeof(_Tp));
+        Y_IF_DEBUG(pool_count++);
+        return data;
+    }
+    void deallocate(pointer __p, size_t /*__n*/) {
+        if (!pool) {
+            Y_IF_DEBUG(malloc_free_count++);
+            free(__p);
+        } else {
+            Y_IF_DEBUG(pool_free_count++);
+            ;
+        }
+    }
+    ~segpool_alloc() {
+        //assert(pool_count == pool_free_count && malloc_count == malloc_free_count); <- uncomment when swap() problem is solved
+        //printf("in ~segpool_alloc: size = %u, pool_count = %" PRId64 ", malloc_count = %" PRId64 ", pool_free_count = %" PRId64 ", malloc_free_count = %" PRId64 "\n",
+        //        sizeof(_Tp), pool_count, malloc_count, pool_free_count, malloc_free_count);
+        //fflush(stdout);
+    }
+    template <class _Tp1>
+    struct rebind {
+        using other = segpool_alloc<_Tp1>;
+    };
+    size_type max_size() const {
+        return size_type(-1) / sizeof(_Tp);
+    }
+    void construct(pointer __p, const _Tp& __val) {
+        new (__p) _Tp(__val);
+    }
+    void destroy(pointer __p) {
+        (void)__p; /* Make MSVC happy. */
+        __p->~_Tp();
+    }
+};
+
+template <class _Tp>
+inline bool operator==(const segpool_alloc<_Tp>& a1, const segpool_alloc<_Tp>& a2) {
+    return a1.pool == a2.pool;
+}
+
+template <class _Tp>
+inline bool operator!=(const segpool_alloc<_Tp>& a1, const segpool_alloc<_Tp>& a2) {
+    return a1.pool != a2.pool;
+}
+
+// Any type since it is supposed to be rebound anyway.
+using segpool_alloc_vt = segpool_alloc<int>;