ctf: btr: avoid reallocation in stack

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>

diff --git a/plugins/ctf/common/btr/btr.c b/plugins/ctf/common/btr/btr.c
index 2f0f13f1dc1196cca8a9b77609d18a7c531ed30e..c255c76ce0ce4cfd64316d56f310c0907b0e6746 100644 (file)
--- a/plugins/ctf/common/btr/btr.c
+++ b/plugins/ctf/common/btr/btr.c
@@ -58,8 +58,6 @@ struct stack_entry {
         *   * Array
         *   * Sequence
         *   * Variant
-        *
-        * Owned by this.
         */
        struct bt_field_type *base_type;
 
@@ -72,8 +70,11 @@ struct stack_entry {
 
 /* Visit stack */
 struct stack {
-       /* Entries (struct stack_entry *) (top is last element) */
-       GPtrArray *entries;
+       /* Entries (struct stack_entry) */
+       GArray *entries;
+
+       /* Number of active entries */
+       size_t size;
 };
 
 /* Reading states */
@@ -176,14 +177,6 @@ const char *btr_state_string(enum btr_state state)
        }
 }
 
-static
-void stack_entry_free_func(gpointer data)
-{
-       struct stack_entry *entry = data;
-
-       g_free(entry);
-}
-
 static
 struct stack *stack_new(void)
 {
@@ -195,9 +188,9 @@ struct stack *stack_new(void)
                goto error;
        }
 
-       stack->entries = g_ptr_array_new_with_free_func(stack_entry_free_func);
+       stack->entries = g_array_new(FALSE, TRUE, sizeof(struct stack_entry));
        if (!stack->entries) {
-               BT_LOGE_STR("Failed to allocate a GPtrArray.");
+               BT_LOGE_STR("Failed to allocate a GArray.");
                goto error;
        }
 
@@ -206,7 +199,6 @@ struct stack *stack_new(void)
 
 error:
        g_free(stack);
-
        return NULL;
 }
 
@@ -218,7 +210,11 @@ void stack_destroy(struct stack *stack)
        }
 
        BT_LOGD("Destroying stack: addr=%p", stack);
-       g_ptr_array_free(stack->entries, TRUE);
+
+       if (stack->entries) {
+               g_array_free(stack->entries, TRUE);
+       }
+
        g_free(stack);
 }
 
@@ -260,31 +256,27 @@ static
 int stack_push(struct stack *stack, struct bt_field_type *base_type,
        size_t base_len)
 {
-       int ret = 0;
        struct stack_entry *entry;
 
        BT_ASSERT(stack);
        BT_ASSERT(base_type);
        BT_LOGV("Pushing field type on stack: stack-addr=%p, "
                "ft-addr=%p, ft-id=%s, base-length=%zu, "
-               "stack-size-before=%u, stack-size-after=%u",
+               "stack-size-before=%zu, stack-size-after=%zu",
                stack, base_type, bt_common_field_type_id_string(
                        bt_field_type_get_type_id(base_type)),
-               base_len, stack->entries->len, stack->entries->len + 1);
-       entry = g_new0(struct stack_entry, 1);
-       if (!entry) {
-               BT_LOGE("Failed to allocate one stack entry: stack-addr=%p",
-                       stack);
-               ret = BT_BTR_STATUS_ERROR;
-               goto end;
+               base_len, stack->size, stack->size + 1);
+
+       if (stack->entries->len == stack->size) {
+               g_array_set_size(stack->entries, stack->size + 1);
        }
 
+       entry = &g_array_index(stack->entries, struct stack_entry, stack->size);
        entry->base_type = base_type;
        entry->base_len = base_len;
-       g_ptr_array_add(stack->entries, entry);
-
-end:
-       return ret;
+       entry->index = 0;
+       stack->size++;
+       return 0;
 }
 
 static
@@ -313,7 +305,7 @@ static inline
 unsigned int stack_size(struct stack *stack)
 {
        BT_ASSERT(stack);
-       return stack->entries->len;
+       return stack->size;
 }
 
 static
@@ -324,7 +316,7 @@ void stack_pop(struct stack *stack)
        BT_LOGV("Popping from stack: "
                "stack-addr=%p, stack-size-before=%u, stack-size-after=%u",
                stack, stack->entries->len, stack->entries->len - 1);
-       g_ptr_array_remove_index(stack->entries, stack->entries->len - 1);
+       stack->size--;
 }
 
 static inline
@@ -337,12 +329,7 @@ static
 void stack_clear(struct stack *stack)
 {
        BT_ASSERT(stack);
-
-       if (!stack_empty(stack)) {
-               g_ptr_array_remove_range(stack->entries, 0, stack_size(stack));
-       }
-
-       BT_ASSERT(stack_empty(stack));
+       stack->size = 0;
 }
 
 static inline
@@ -350,8 +337,8 @@ struct stack_entry *stack_top(struct stack *stack)
 {
        BT_ASSERT(stack);
        BT_ASSERT(stack_size(stack));
-
-       return g_ptr_array_index(stack->entries, stack->entries->len - 1);
+       return &g_array_index(stack->entries, struct stack_entry,
+               stack->size - 1);
 }
 
 static inline