1 files changed, 187 insertions, 0 deletions
diff --git a/src/allocators.c b/src/allocators.c
new file mode 100644
index 0000000..c3f2021
--- /dev/null
+++ b/src/allocators.c
@@ -0,0 +1,187 @@
+#include <stdlib.h>
+
+typedef enum {
+    ALLOCATOR_ALLOCATE,
+    ALLOCATOR_REALLOCATE,
+    ALLOCATOR_DEALLOCATE,
+    ALLOCATOR_DELETE
+} Allocator_Message;
+
+#define ALLOCATOR_PROC(name)\
+    void *name(void *p, u64 size, Allocator_Message message, void *data)
+
+typedef ALLOCATOR_PROC(Allocator_Proc);
+
+typedef struct {
+    Allocator_Proc *proc;
+    void           *data;
+} Allocator;
+
+#define mem_alloc(alloc, size)        (alloc).proc(NULL, size, ALLOCATOR_ALLOCATE,   (alloc).data)
+#define mem_realloc(alloc, ptr, size) (alloc).proc(ptr,  size, ALLOCATOR_REALLOCATE, (alloc).data)
+#define mem_free(alloc, ptr)          (alloc).proc(ptr,  0,    ALLOCATOR_DEALLOCATE, (alloc).data)
+#define mem_delete(alloc)             (alloc).proc(NULL, 0,    ALLOCATOR_DELETE,     (alloc).data)
+
+
+Allocator get_stdlib_allocator(void);
+Allocator get_temporary_allocator(void);
+Allocator create_arena_allocator(u64 size);
+
+
+/// Stdlib Allocator
+ALLOCATOR_PROC(stdlib_allocator_proc) {
+    UNUSED(data);
+
+    switch (message) {
+        case ALLOCATOR_ALLOCATE:
+            return calloc(1, size);
+        case ALLOCATOR_REALLOCATE:
+            return realloc((u8*)p, size);
+        case ALLOCATOR_DEALLOCATE:
+            free((u8*)p);
+            break;
+        case ALLOCATOR_DELETE:
+            break;
+    }
+
+    return NULL;
+}
+
+Allocator get_stdlib_allocator(void) {
+    return CLITERAL(Allocator) { stdlib_allocator_proc, NULL };
+}
+
+
+/// Temp Allocator
+
+#define TEMP_SIZE MB(50)
+
+struct {
+    b32 initialized;
+    u64 index;
+    u8 data[TEMP_SIZE];
+} __temp_alloc;
+
+void temp_reset(void) {
+    __temp_alloc.index = 0;
+}
+
+void *temp_allocate(u64 size) {
+    if ((__temp_alloc.index + size) > TEMP_SIZE) {
+        TraceLog(LOG_ERROR, "Temp allocator wrapped!");
+        temp_reset();
+    }
+
+    if ((__temp_alloc.index + size) > TEMP_SIZE) {
+        TraceLog(LOG_ERROR, "Too much space requested!");
+        return NULL;
+    }
+
+
+    void *pos = (u8*)__temp_alloc.data + __temp_alloc.index;
+    __temp_alloc.index += size;
+    memset(pos, 0x00, size);
+    return pos;
+}
+
+ALLOCATOR_PROC(temp_allocator_proc) {
+    UNUSED(data);
+    UNUSED(p);
+
+    if (!__temp_alloc.initialized) {
+        __temp_alloc.initialized = true; 
+        temp_reset(); 
+    }
+
+    switch (message) {
+        case ALLOCATOR_ALLOCATE:
+            return temp_allocate(size);
+        case ALLOCATOR_REALLOCATE:
+        case ALLOCATOR_DEALLOCATE:
+            break;
+        case ALLOCATOR_DELETE:
+            temp_reset();
+            break;
+    }
+
+    return NULL;
+}
+
+Allocator get_temporary_allocator(void) {
+    return CLITERAL(Allocator) { temp_allocator_proc, NULL };
+}
+
+/// Arena allocator
+
+typedef struct Arena {
+    u64 size;
+    u64 occupied;
+    struct Arena *next;
+    u8 data[1]; // you dont have zero size arrays in MSVC...
+} Arena;
+
+Arena *arena_create(u64 size) {
+    Allocator alloc = get_stdlib_allocator();
+
+    Arena *arena = (Arena *)mem_alloc(alloc, size);
+
+    if (!arena) {
+        TraceLog(LOG_FATAL, "Buy mem, failed to create arena!");
+        return NULL;
+    }
+
+    memset(arena, 0, sizeof(Arena));
+    arena->size = size - sizeof(Arena);
+
+    return arena;
+}
+
+void arena_delete(Arena *arena) {
+    if (arena->next != NULL) {
+        arena_delete(arena->next);
+    }
+
+    Allocator alloc = get_stdlib_allocator();
+    mem_free(alloc, arena);
+}
+
+void *arena_allocate(u64 size, Arena *arena) {
+    if (size <= (arena->size - arena->occupied)) {
+        u8* pos = arena->data + arena->occupied;
+        arena->occupied += size;
+        return (void*)pos;
+    }
+
+    if (!arena->next) {
+        arena->next = arena_create((arena->size + sizeof(Arena)) * 2LL);
+    } 
+
+    return arena_allocate(size, arena->next);
+}
+
+ALLOCATOR_PROC(arena_allocator_proc) {
+    UNUSED(p);
+    assert(data != NULL);
+
+    Arena *arena = (Arena*)data;
+    
+    switch (message) {
+        case ALLOCATOR_ALLOCATE:
+            return arena_allocate(size, arena);
+        case ALLOCATOR_REALLOCATE:
+            TraceLog(LOG_ERROR, "Arena doesn't reallocate.");
+            break;
+        case ALLOCATOR_DEALLOCATE:
+            TraceLog(LOG_ERROR, "Arena doesn't free it's memory, please destroy arena itself.");
+            break;
+        case ALLOCATOR_DELETE:
+            arena_delete(arena);
+            break;
+    }
+
+    return NULL;
+}
+
+Allocator create_arena_allocator(u64 size) {
+    return CLITERAL(Allocator) { arena_allocator_proc, arena_create(size) };
+}