1 files changed, 69 insertions, 0 deletions
diff --git a/thirdparty/tourist/foundation/src/allocator.cpp b/thirdparty/tourist/foundation/src/allocator.cpp
new file mode 100644
index 000000000..c6f021ad2
--- /dev/null
+++ b/thirdparty/tourist/foundation/src/allocator.cpp
@@ -0,0 +1,69 @@
+#include <foundation/buffer.h>
+#include <foundation/malloc.h>
+
+#include "slab.h"
+
+//------------------------------------------------------------------------------
+Allocator::~Allocator()
+{
+    if (_slab != nullptr)
+        _slab->dec_ref();
+}
+
+//------------------------------------------------------------------------------
+MutableBuffer Allocator::create_buffer(uint32 size)
+{
+    auto create_slab = [this] (uint32 slab_size) {
+        auto* slab = tt_malloc<Slab>(slab_size + sizeof(Slab));
+        slab->_allocator = this;
+        slab->_size = slab_size;
+        slab->_refs.store_relaxed(0);
+        return slab;
+    };
+
+    enum {
+        PACKET_PAGE_SIZE    = 4 << 10,
+        PACKET_SLAB_SIZE    = 1 << 20,
+        PACKET_ALIGN        = 32 - 1,
+    };
+
+    if (size > PACKET_PAGE_SIZE)
+    {
+        Slab* slab = create_slab(size);
+        return MutableBuffer(slab, size, 0);
+    }
+
+    uint32 alloc_size = (size + PACKET_ALIGN) & ~PACKET_ALIGN;
+
+    UniqueLock _(_lock);
+
+    if (alloc_size > _slab_free && _slab != nullptr)
+    {
+        _slab->dec_ref();
+        _slab = nullptr;
+    }
+
+    if (_slab == nullptr)
+    {
+        _slab_free = PACKET_SLAB_SIZE;
+        _slab = create_slab(_slab_free);
+        _slab->inc_ref();
+    }
+
+    uint32 offset = PACKET_SLAB_SIZE - _slab_free;
+    _slab_free -= alloc_size;
+    return MutableBuffer(_slab, size, offset);
+}
+
+//------------------------------------------------------------------------------
+void Allocator::free_slab(Slab* slab)
+{
+    tt_free(slab);
+}
+
+//------------------------------------------------------------------------------
+Allocator& Allocator::get_from(Buffer& buffer)      { return get_from(buffer._slab); }
+Allocator& Allocator::get_from(BufferRef& ref)      { return get_from(ref.get_slab()); }
+Allocator& Allocator::get_from(BufferStream& stream){ return get_from(stream.get_slab()); }
+Allocator& Allocator::get_from(Pointer& pointer)    { return get_from(pointer.get_slab()); }
+Allocator& Allocator::get_from(const Slab* slab)    { return slab->get_allocator(); }