From 4518b5941720dac75a16d9e571cb489a0d38deed Mon Sep 17 00:00:00 2001
From: Kayne Ruse <kayneruse@gmail.com>
Date: Sat, 19 Nov 2022 08:18:45 +0000
Subject: [PATCH] Added custom allocator support

---
 source/memory.c     | 25 ++++++++++++++++++++--
 source/memory.h     |  5 ++++-
 source/toy_common.h |  2 +-
 test/test_memory.c  | 52 ++++++++++++++++++++++++++++++++++++++++-----
 4 files changed, 75 insertions(+), 9 deletions(-)

diff --git a/source/memory.c b/source/memory.c
index 0a444da..feab031 100644
--- a/source/memory.c
+++ b/source/memory.c
@@ -5,7 +5,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-void* reallocate(void* pointer, size_t oldSize, size_t newSize) {
+//default allocator
+void* defaultAllocator(void* pointer, size_t oldSize, size_t newSize) {
 	if (newSize == 0 && oldSize == 0) {
 		//causes issues, so just skip out with a NO-OP
 		return NULL;
@@ -20,10 +21,30 @@ void* reallocate(void* pointer, size_t oldSize, size_t newSize) {
 	void* mem = realloc(pointer, newSize);
 
 	if (mem == NULL) {
-		fprintf(stderr, ERROR "[internal]Memory allocation error (requested %d for %ld, replacing %d)\n" ERROR, (int)newSize, (long int)pointer, (int)oldSize);
+		fprintf(stderr, ERROR "[internal] Memory allocation error (requested %d for %ld, replacing %d)\n" RESET, (int)newSize, (long int)pointer, (int)oldSize);
 		exit(-1);
 	}
 
 	return mem;
 }
 
+//exposed API
+static AllocatorFn allocator = defaultAllocator;
+
+void setAllocator(AllocatorFn fn) {
+	if (fn == NULL) {
+		fprintf(stderr, ERROR "[internal] Memory allocator error (can't be null)\n" RESET);
+		exit(-1);
+	}
+
+	if (fn == reallocate) {
+		fprintf(stderr, ERROR "[internal] Memory allocator error (can't loop the reallocate function)\n" RESET);
+		exit(-1);
+	}
+
+	allocator = fn;
+}
+
+void* reallocate(void* pointer, size_t oldSize, size_t newSize) {
+	return allocator(pointer, oldSize, newSize);
+}
\ No newline at end of file
diff --git a/source/memory.h b/source/memory.h
index c0d1aae..1dcabae 100644
--- a/source/memory.h
+++ b/source/memory.h
@@ -10,5 +10,8 @@
 #define SHRINK_ARRAY(type, pointer, oldCount, count) (type*)reallocate((type*)pointer, sizeof(type) * (oldCount), sizeof(type) * (count))
 #define FREE_ARRAY(type, pointer, oldCount) reallocate((type*)pointer, sizeof(type) * (oldCount), 0)
 
-void* reallocate(void* pointer, size_t oldSize, size_t newSize);
+//implementation details
+typedef void* (*AllocatorFn)(void* pointer, size_t oldSize, size_t newSize);
+void setAllocator(AllocatorFn);
 
+void* reallocate(void* pointer, size_t oldSize, size_t newSize);
diff --git a/source/toy_common.h b/source/toy_common.h
index 71369ac..0adba45 100644
--- a/source/toy_common.h
+++ b/source/toy_common.h
@@ -6,7 +6,7 @@
 
 #define TOY_VERSION_MAJOR 0
 #define TOY_VERSION_MINOR 6
-#define TOY_VERSION_PATCH 2
+#define TOY_VERSION_PATCH 3
 #define TOY_VERSION_BUILD __DATE__ " " __TIME__
 
 //platform exports/imports
diff --git a/test/test_memory.c b/test/test_memory.c
index 9c23174..bb1f15f 100644
--- a/test/test_memory.c
+++ b/test/test_memory.c
@@ -3,32 +3,74 @@
 #include "console_colors.h"
 
 #include <stdio.h>
+#include <stdlib.h>
 
-int main() {
+//the test allocator
+static int callCount = 0;
+
+void* allocator(void* pointer, size_t oldSize, size_t newSize) {
+	callCount++;
+
+	if (newSize == 0 && oldSize == 0) {
+		return NULL;
+	}
+
+	if (newSize == 0) {
+		free(pointer);
+		return NULL;
+	}
+
+	void* mem = realloc(pointer, newSize);
+
+	if (mem == NULL) {
+		exit(-1);
+	}
+
+	return mem;
+}
+
+void testMemoryAllocation() {
 	{
 		//test single pointer
 		int* integer = ALLOCATE(int, 1);
-
 		FREE(int, integer);
 	}
 
 	{
-		//test single pointer
+		//test single pointer array
 		int* array = ALLOCATE(int, 10);
 
+		array[1] = 42; //access the given memory
+
 		FREE_ARRAY(int, array, 10);
 	}
 
 	{
-		//test single pointer
+		//test multiple pointer arrays
 		int* array1 = ALLOCATE(int, 10);
 		int* array2 = ALLOCATE(int, 10);
 
+		array1[1] = 42; //access the given memory
+		array2[1] = 42; //access the given memory
+
 		FREE_ARRAY(int, array1, 10);
 		FREE_ARRAY(int, array2, 10);
 	}
+}
+
+int main() {
+	//test the default allocator
+	testMemoryAllocation();
+
+	//test the custom allocator
+	setAllocator(allocator);
+	testMemoryAllocation();
+
+	if (callCount != 8) {
+		fprintf(stderr, ERROR "Unexpected call count for custom allocator; was called %d times" RESET, callCount);
+		return -1;
+	}
 
 	printf(NOTICE "All good\n" RESET);
 	return 0;
 }
-