From c4af3f9583d5f8bd37624cd72edaac90a10250c1 Mon Sep 17 00:00:00 2001
From: Krzysztof Gabis <kgabis@gmail.com>
Date: Tue, 11 Dec 2012 11:47:18 +0100
Subject: [PATCH] Changed object's and array's initlalization to be lazy.

Now object's names and values and array's items are allocated (with starting capacity) only after first item is added.
This will prevent wasting memory when parsing empty objects and arrays.
---
 parson.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/parson.c b/parson.c
index 5712848..73047f1 100644
--- a/parson.c
+++ b/parson.c
@@ -37,6 +37,7 @@
 #define sizeof_token(a)       (sizeof(a) - 1)
 #define skip_char(str)        ((*str)++)
 #define skip_whitespaces(str) while (isspace(**string)) { skip_char(string); }
+#define MAX(a, b)             ((a) > (b) ? (a) : (b))
 
 #define parson_malloc(a)     malloc(a)
 #define parson_free(a)       free((void*)a)
@@ -139,11 +140,9 @@ static int is_decimal(const char *string, size_t length) {
 static JSON_Object * json_object_init(void) {
     JSON_Object *new_obj = (JSON_Object*)parson_malloc(sizeof(JSON_Object));
     if (!new_obj) { return NULL; }
-    new_obj->names = (const char**)parson_malloc(sizeof(char*) * STARTING_CAPACITY);
-    if (!new_obj->names) { parson_free(new_obj); return NULL; }
-    new_obj->values = (JSON_Value**)parson_malloc(sizeof(JSON_Value*) * STARTING_CAPACITY);
-    if (!new_obj->values) { parson_free(new_obj->names); parson_free(new_obj); return NULL; }
-    new_obj->capacity = STARTING_CAPACITY;
+    new_obj->names = (const char**)NULL;
+    new_obj->values = (JSON_Value**)NULL;
+    new_obj->capacity = 0;
     new_obj->count = 0;
     return new_obj;
 }
@@ -151,7 +150,7 @@ static JSON_Object * json_object_init(void) {
 static int json_object_add(JSON_Object *object, const char *name, JSON_Value *value) {
     size_t index;
     if (object->count >= object->capacity) {
-        size_t new_capacity = object->capacity * 2;
+        size_t new_capacity = MAX(object->capacity * 2, STARTING_CAPACITY);
         if (new_capacity > OBJECT_MAX_CAPACITY) { return ERROR; }
         if (json_object_resize(object, new_capacity) == ERROR) { return ERROR; }
     }
@@ -195,16 +194,15 @@ static void json_object_free(JSON_Object *object) {
 static JSON_Array * json_array_init(void) {
     JSON_Array *new_array = (JSON_Array*)parson_malloc(sizeof(JSON_Array));
     if (!new_array) { return NULL; }
-    new_array->items = (JSON_Value**)parson_malloc(STARTING_CAPACITY * sizeof(JSON_Value*));
-    if (!new_array->items) { parson_free(new_array); return NULL; }
-    new_array->capacity = STARTING_CAPACITY;
+    new_array->items = (JSON_Value**)NULL;
+    new_array->capacity = 0;
     new_array->count = 0;
     return new_array;
 }
 
 static int json_array_add(JSON_Array *array, JSON_Value *value) {
     if (array->count >= array->capacity) {
-        size_t new_capacity = array->capacity * 2;
+        size_t new_capacity = MAX(array->capacity * 2, STARTING_CAPACITY);
         if (new_capacity > ARRAY_MAX_CAPACITY) { return ERROR; }
         if (!json_array_resize(array, new_capacity)) { return ERROR; }
     }