Basic CGameAllocator implementation (WIP)

Runtime/CGameAllocator.cpp

@@ -0,0 +1,61 @@
+#include "CGameAllocator.hpp"
+
+namespace urde
+{
+logvisor::Module AllocLog("urde::CGameAllocator");
+
+std::vector<CGameAllocator::SAllocationDescription> CGameAllocator::m_allocations;
+
+u8* CGameAllocator::Alloc(size_t len)
+{
+    size_t roundedLen = ROUND_UP_64(len + sizeof(SChunkDescription));
+    for (SAllocationDescription& alloc : m_allocations)
+    {
+        /* We need to supply enough room for allocation information */
+        if (alloc.freeOffset + roundedLen < alloc.allocSize)
+        {
+            u8* ptr = alloc.memptr.get() + alloc.freeOffset;
+            SChunkDescription* chunkInfo = reinterpret_cast<SChunkDescription*>(ptr);
+            *chunkInfo = SChunkDescription();
+            chunkInfo->parent = &alloc;
+            chunkInfo->len = len;
+            alloc.freeOffset += roundedLen;
+            return ptr + sizeof(SChunkDescription);
+        }
+    }
+
+    /* 1MiB minimum allocation to prevent constantly allocating small amounts of memory */
+    size_t allocSz = len;
+    if (allocSz < (1 * 1024 * 1024 * 1024))
+        allocSz = 1 * 1024 * 1024 * 1024;
+
+    /* Pad size to allow for allocation information */
+    allocSz = ROUND_UP_64(allocSz + sizeof(SChunkDescription));
+    m_allocations.emplace_back();
+    m_allocations.back().memptr.reset(new u8[allocSz]);
+    u8* ptr = m_allocations.back().memptr.get();
+    m_allocations.back().allocSize = allocSz;
+    m_allocations.back().freeOffset += roundedLen;
+    SChunkDescription* chunkInfo = reinterpret_cast<SChunkDescription*>(ptr);
+    *chunkInfo = SChunkDescription();
+    chunkInfo->parent = &m_allocations.back();
+    chunkInfo->len = len;
+    return ptr + sizeof(SChunkDescription);
+}
+
+void CGameAllocator::Free(u8* ptr)
+{
+    SChunkDescription* info = reinterpret_cast<SChunkDescription*>(ptr - sizeof(SChunkDescription));
+    if (info->magic != 0xE8E8E8E8 || info->sentinal != 0xEFEFEFEF)
+    {
+        AllocLog.report(logvisor::Fatal, _S("Invalid chunk description, memory corruption!"));
+        return;
+    }
+
+    SAllocationDescription& alloc = *info->parent;
+    size_t roundedLen = ROUND_UP_32(info->len + sizeof(SChunkDescription));
+    alloc.freeOffset -= roundedLen;
+    /* Invalidate chunk allocation descriptor */
+    memset(info, 0, ROUND_UP_64(info->len + sizeof(SChunkDescription)));
+}
+}