重构

Memory/c_BuddyAllocator.h

@@ -0,0 +1,96 @@
+#ifndef INCLUDED_C_BUDDYALLOCATOR_H
+#define INCLUDED_C_BUDDYALLOCATOR_H
+
+#ifndef INCLUDED_C_BUDDY_H
+#include <c_Buddy.h>
+#endif /*INCLUDED_C_BUDDY_H*/
+
+
+#ifndef INCLUDED_C_ALLOCATOR_H
+#include <c_Allocator.h>
+#endif /*INCLUDED_C_ALLOCATOR_H*/
+
+
+/* ------------------------------------------------------------------------------------------------------------------ */
+/*  */
+
+typedef struct {
+    c_Buddy_t* buddy;
+}c_BuddyAllocator_t;
+
+C_STATIC_FORCE_INLINE
+void c_BuddyAllocator_Init(c_BuddyAllocator_t* allocator, c_Buddy_t* buddy) {
+    allocator->buddy = buddy;
+}
+
+/* ------------------------------------------------------------------------------------------------------------------ */
+/*  */
+
+C_STATIC_FORCE_INLINE
+C_ALLOCATOR_ALLOC_FN(c_BuddyAllocator_Alloc) {
+    c_BuddyAllocator_t* self = (c_BuddyAllocator_t*)ud;
+    if (!self || !self->buddy) return NULL;
+    return c_Buddy_Alloc(self->buddy, (int)nBytes);
+}
+
+C_STATIC_FORCE_INLINE
+C_ALLOCATOR_FREE_FN(c_BuddyAllocator_Free) {
+    c_BuddyAllocator_t* self = (c_BuddyAllocator_t*)ud;
+    if (!self || !self->buddy) return;
+    c_Buddy_Free(self->buddy, ptr);
+}
+
+C_STATIC_FORCE_INLINE
+C_ALLOCATOR_REALLOC_FN(c_BuddyAllocator_Realloc) {
+    c_BuddyAllocator_t* self = (c_BuddyAllocator_t*)ud;
+    if (!self || !self->buddy) return NULL;
+    // 情况 1: 指针为空，直接分配新内存
+    if (!ptr) {
+        return c_Buddy_Alloc(self->buddy, (int)nNewSize);
+    }
+    // 情况 2: 新大小为 0，直接释放内存
+    if (nNewSize==0) {
+        c_Buddy_Free(self->buddy, ptr);
+        return NULL;
+    }
+    // 核心优化：利用 Header 逆向获取该块在底层伙伴系统中的真实物理大小
+    const c_BuddyBlock_t *block = (c_BuddyBlock_t *) ((uint8_t *) ptr - self->buddy->alignment);
+    const int actual_block_size = block->size;
+
+    // 【就地复用判定】：如果新申请的大小没有超过当前伙伴块的物理承载上限，并且新大小不至于小到需要缩容割裂
+    // 直接返回原指针，零拷贝，零内存搬迁！
+    if ((int)nNewSize <= actual_block_size && (int)nNewSize > (actual_block_size / 2)) {
+        return ptr;
+    }
+
+    // 情况 3: 伙伴块大小不匹配（需要升级或降级阶数），申请新块
+    void* new_ptr = c_Buddy_Alloc(self->buddy, (int)nNewSize);
+    if (!new_ptr) return NULL;
+
+    // 计算安全的拷贝长度
+    const c_size_t copy_size = ((c_size_t)actual_block_size < nNewSize) ? (c_size_t)actual_block_size : nNewSize;
+
+    // 数据迁移
+    memcpy(new_ptr, ptr, copy_size);
+
+    // 释放旧伙伴块
+    c_Buddy_Free(self->buddy, ptr);
+
+    return new_ptr;
+}
+
+/* ------------------------------------------------------------------------------------------------------------------ */
+/*  */
+
+C_STATIC_FORCE_INLINE
+c_Allocator_t c_BuddyAllocator_Build(c_BuddyAllocator_t* self, c_Buddy_t* buddy) {
+    c_BuddyAllocator_Init(self, buddy);
+    c_Allocator_t allocator={0};
+    allocator.ud = self;
+    allocator.alloc = c_BuddyAllocator_Alloc;
+    allocator.free = c_BuddyAllocator_Free;
+    allocator.realloc = c_BuddyAllocator_Realloc;
+    return allocator;
+}
+
+#endif /*INCLUDED_C_BUDDYALLOCATOR_H*/