From af869f2b46b3e7f99a1c2857ef7353b8337c267b Mon Sep 17 00:00:00 2001
From: Bailey Thompson <bkthomps@edu.uwaterloo.ca>
Date: Mon, 10 Aug 2020 12:30:51 -0400
Subject: [PATCH] Reduce malloc calls in stack (#78)

---
 containers.h        |  4 ++--
 src/include/stack.h |  6 +++---
 src/stack.c         | 43 ++++++++++++-------------------------------
 tst/stack.c         | 14 --------------
 4 files changed, 17 insertions(+), 50 deletions(-)

diff --git a/containers.h b/containers.h
index 312a3df..265492b 100644
--- a/containers.h
+++ b/containers.h
@@ -455,13 +455,13 @@ deque deque_destroy(deque me);
  * The stack data structure, which adapts a container to provide a stack
  * (last-in first-out). Adapts the deque container.
  */
-typedef struct internal_stack *stack;
+typedef struct internal_deque *stack;
 
 /* Starting */
 stack stack_init(size_t data_size);
 
 /* Utility */
-int stack_size(stack me);
+size_t stack_size(stack me);
 int stack_is_empty(stack me);
 int stack_trim(stack me);
 void stack_copy_to_array(void *arr, stack me);
diff --git a/src/include/stack.h b/src/include/stack.h
index 337f88a..c53942e 100644
--- a/src/include/stack.h
+++ b/src/include/stack.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2019 Bailey Thompson
+ * Copyright (c) 2017-2020 Bailey Thompson
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,13 +29,13 @@
  * The stack data structure, which adapts a container to provide a stack
  * (last-in first-out). Adapts the deque container.
  */
-typedef struct internal_stack *stack;
+typedef struct internal_deque *stack;
 
 /* Starting */
 stack stack_init(size_t data_size);
 
 /* Utility */
-int stack_size(stack me);
+size_t stack_size(stack me);
 int stack_is_empty(stack me);
 int stack_trim(stack me);
 void stack_copy_to_array(void *arr, stack me);
diff --git a/src/stack.c b/src/stack.c
index 3c90417..b37608e 100644
--- a/src/stack.c
+++ b/src/stack.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2019 Bailey Thompson
+ * Copyright (c) 2017-2020 Bailey Thompson
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -23,10 +23,6 @@
 #include "include/deque.h"
 #include "include/stack.h"
 
-struct internal_stack {
-    deque deque_data;
-};
-
 /**
  * Initializes a stack.
  *
@@ -39,20 +35,7 @@ struct internal_stack {
  */
 stack stack_init(const size_t data_size)
 {
-    struct internal_stack *init;
-    if (data_size == 0) {
-        return NULL;
-    }
-    init = malloc(sizeof(struct internal_stack));
-    if (!init) {
-        return NULL;
-    }
-    init->deque_data = deque_init(data_size);
-    if (!init->deque_data) {
-        free(init);
-        return NULL;
-    }
-    return init;
+    return deque_init(data_size);
 }
 
 /**
@@ -62,9 +45,9 @@ stack stack_init(const size_t data_size)
  *
  * @return the size of the stack
  */
-int stack_size(stack me)
+size_t stack_size(stack me)
 {
-    return deque_size(me->deque_data);
+    return deque_size(me);
 }
 
 /**
@@ -76,7 +59,7 @@ int stack_size(stack me)
  */
 int stack_is_empty(stack me)
 {
-    return deque_is_empty(me->deque_data);
+    return deque_is_empty(me);
 }
 
 /**
@@ -89,7 +72,7 @@ int stack_is_empty(stack me)
  */
 int stack_trim(stack me)
 {
-    return deque_trim(me->deque_data);
+    return deque_trim(me);
 }
 
 /**
@@ -103,7 +86,7 @@ int stack_trim(stack me)
  */
 void stack_copy_to_array(void *const arr, stack me)
 {
-    deque_copy_to_array(arr, me->deque_data);
+    deque_copy_to_array(arr, me);
 }
 
 /**
@@ -121,7 +104,7 @@ void stack_copy_to_array(void *const arr, stack me)
  */
 int stack_push(stack me, void *const data)
 {
-    return deque_push_back(me->deque_data, data);
+    return deque_push_back(me, data);
 }
 
 /**
@@ -139,7 +122,7 @@ int stack_push(stack me, void *const data)
  */
 int stack_pop(void *const data, stack me)
 {
-    return deque_pop_back(data, me->deque_data) == 0;
+    return deque_pop_back(data, me) == 0;
 }
 
 /**
@@ -156,7 +139,7 @@ int stack_pop(void *const data, stack me)
  */
 int stack_top(void *const data, stack me)
 {
-    return deque_get_last(data, me->deque_data) == 0;
+    return deque_get_last(data, me) == 0;
 }
 
 /**
@@ -169,7 +152,7 @@ int stack_top(void *const data, stack me)
  */
 int stack_clear(stack me)
 {
-    return deque_clear(me->deque_data);
+    return deque_clear(me);
 }
 
 /**
@@ -182,7 +165,5 @@ int stack_clear(stack me)
  */
 stack stack_destroy(stack me)
 {
-    deque_destroy(me->deque_data);
-    free(me);
-    return NULL;
+    return deque_destroy(me);
 }
diff --git a/tst/stack.c b/tst/stack.c
index ac03a4b..f0c37b6 100644
--- a/tst/stack.c
+++ b/tst/stack.c
@@ -67,23 +67,9 @@ static void test_automated_trim(void)
     assert(!stack_destroy(me));
 }
 
-#if STUB_MALLOC
-static void test_init_out_of_memory(void)
-{
-    fail_malloc = 1;
-    assert(!stack_init(sizeof(int)));
-    delay_fail_malloc = 1;
-    fail_malloc = 1;
-    assert(!stack_init(sizeof(int)));
-}
-#endif
-
 void test_stack(void)
 {
     test_invalid_init();
     test_basic();
     test_automated_trim();
-#if STUB_MALLOC
-    test_init_out_of_memory();
-#endif
 }