Initial commit

arm9/source/patches/PatchHeap.cpp

@@ -0,0 +1,100 @@
+#include "common.h"
+#include "PatchHeap.h"
+
+PatchHeap::PatchHeap()
+    : _freeBlocks(nullptr)
+{
+    _unusedBlockPool = &_blocks[0];
+    for (u32 i = 0; i < _blocks.size() - 1; i++)
+        _blocks[i].next = &_blocks[i + 1];
+    _blocks[_blocks.size() - 1].next = nullptr;
+}
+
+void PatchHeap::AddFreeSpace(void* block, u32 size)
+{
+    PatchHeapBlock* cur = _freeBlocks;
+
+    bool added = false;
+    while (cur)
+    {
+        if ((u8*)cur->block + cur->size == block)
+        {
+            cur->size += size;
+            added = true;
+            break;
+        }
+        else if ((u8*)block + size == cur->block)
+        {
+            cur->block = block;
+            cur->size += size;
+            added = true;
+            break;
+        }
+
+        cur = cur->next;
+    }
+
+    if (added)
+        return;
+
+    PatchHeapBlock* heapBlock = _unusedBlockPool;
+    _unusedBlockPool = _unusedBlockPool->next;
+
+    heapBlock->block = block;
+    heapBlock->size = size;
+    heapBlock->next = _freeBlocks;
+    _freeBlocks = heapBlock;
+}
+
+void* PatchHeap::Alloc(u32 size)
+{
+    PatchHeapBlock* prev = nullptr;
+    PatchHeapBlock* cur = _freeBlocks;
+
+    PatchHeapBlock* bestBlock = nullptr;
+    PatchHeapBlock* bestBlockPrev = nullptr;
+
+    while (cur)
+    {
+        if (cur->size >= size && (!bestBlock || cur->size < bestBlock->size))
+        {
+            bestBlock = cur;
+            bestBlockPrev = prev;
+            if (bestBlock->size == size)
+                break;
+        }
+
+        prev = cur;
+        cur = cur->next;
+    }
+
+    if (!bestBlock)
+    {
+        LOG_FATAL("No space found to put patch of size 0x%x\n", size);
+        while (1);
+        return nullptr;
+    }
+
+    void* result = bestBlock->block;
+
+    if (bestBlock->size == size)
+    {
+        if (bestBlockPrev)
+            bestBlockPrev->next = bestBlock->next;
+
+        if (_freeBlocks == bestBlock)
+            _freeBlocks = bestBlock->next;
+
+        bestBlock->next = _unusedBlockPool;
+        _unusedBlockPool = bestBlock;
+    }
+    else
+    {
+        bestBlock->block = (u8*)bestBlock->block + size;
+        bestBlock->size -= size;
+    }
+
+    LOG_DEBUG("Allocated 0x%p, size = 0x%X\n", result, size);
+
+    return result;
+}