Azure IoT common library
Fork of azure_c_shared_utility by
singlylinkedlist.c
- Committer:
- AzureIoTClient
- Date:
- 2017-02-24
- Revision:
- 21:b92006c5b9ff
- Parent:
- 19:2e0811512ceb
- Child:
- 30:ce3813c5a692
File content as of revision 21:b92006c5b9ff:
// Copyright (c) Microsoft. All rights reserved. // Licensed under the MIT license. See LICENSE file in the project root for full license information. #include <stdlib.h> #include "azure_c_shared_utility/gballoc.h" #include "azure_c_shared_utility/singlylinkedlist.h" #include "azure_c_shared_utility/optimize_size.h" typedef struct LIST_ITEM_INSTANCE_TAG { const void* item; void* next; } LIST_ITEM_INSTANCE; typedef struct SINGLYLINKEDLIST_INSTANCE_TAG { LIST_ITEM_INSTANCE* head; } LIST_INSTANCE; SINGLYLINKEDLIST_HANDLE singlylinkedlist_create(void) { LIST_INSTANCE* result; /* Codes_SRS_LIST_01_001: [singlylinkedlist_create shall create a new list and return a non-NULL handle on success.] */ result = (LIST_INSTANCE*)malloc(sizeof(LIST_INSTANCE)); if (result != NULL) { /* Codes_SRS_LIST_01_002: [If any error occurs during the list creation, singlylinkedlist_create shall return NULL.] */ result->head = NULL; } return result; } void singlylinkedlist_destroy(SINGLYLINKEDLIST_HANDLE list) { /* Codes_SRS_LIST_01_004: [If the list argument is NULL, no freeing of resources shall occur.] */ if (list != NULL) { LIST_INSTANCE* list_instance = (LIST_INSTANCE*)list; while (list_instance->head != NULL) { LIST_ITEM_INSTANCE* current_item = list_instance->head; list_instance->head = (LIST_ITEM_INSTANCE*)current_item->next; free(current_item); } /* Codes_SRS_LIST_01_003: [singlylinkedlist_destroy shall free all resources associated with the list identified by the handle argument.] */ free(list_instance); } } LIST_ITEM_HANDLE singlylinkedlist_add(SINGLYLINKEDLIST_HANDLE list, const void* item) { LIST_ITEM_INSTANCE* result; /* Codes_SRS_LIST_01_006: [If any of the arguments is NULL, singlylinkedlist_add shall not add the item to the list and return NULL.] */ if ((list == NULL) || (item == NULL)) { result = NULL; } else { LIST_INSTANCE* list_instance = (LIST_INSTANCE*)list; result = (LIST_ITEM_INSTANCE*)malloc(sizeof(LIST_ITEM_INSTANCE)); if (result == NULL) { /* Codes_SRS_LIST_01_007: [If allocating the new list node fails, singlylinkedlist_add shall return NULL.] */ result = NULL; } else { /* Codes_SRS_LIST_01_005: [singlylinkedlist_add shall add one item to the tail of the list and on success it shall return a handle to the added item.] */ result->next = NULL; result->item = item; if (list_instance->head == NULL) { list_instance->head = result; } else { LIST_ITEM_INSTANCE* current = list_instance->head; while (current->next != NULL) { current = (LIST_ITEM_INSTANCE*)current->next; } current->next = result; } } } return result; } int singlylinkedlist_remove(SINGLYLINKEDLIST_HANDLE list, LIST_ITEM_HANDLE item) { int result; /* Codes_SRS_LIST_01_024: [If any of the arguments list or item_handle is NULL, singlylinkedlist_remove shall fail and return a non-zero value.] */ if ((list == NULL) || (item == NULL)) { result = __FAILURE__; } else { LIST_INSTANCE* list_instance = (LIST_INSTANCE*)list; LIST_ITEM_INSTANCE* current_item = list_instance->head; LIST_ITEM_INSTANCE* previous_item = NULL; while (current_item != NULL) { if (current_item == item) { if (previous_item != NULL) { previous_item->next = current_item->next; } else { list_instance->head = (LIST_ITEM_INSTANCE*)current_item->next; } free(current_item); break; } previous_item = current_item; current_item = (LIST_ITEM_INSTANCE*)current_item->next; } if (current_item == NULL) { /* Codes_SRS_LIST_01_025: [If the item item_handle is not found in the list, then singlylinkedlist_remove shall fail and return a non-zero value.] */ result = __FAILURE__; } else { /* Codes_SRS_LIST_01_023: [singlylinkedlist_remove shall remove a list item from the list and on success it shall return 0.] */ result = 0; } } return result; } LIST_ITEM_HANDLE singlylinkedlist_get_head_item(SINGLYLINKEDLIST_HANDLE list) { LIST_ITEM_HANDLE result; if (list == NULL) { /* Codes_SRS_LIST_01_009: [If the list argument is NULL, singlylinkedlist_get_head_item shall return NULL.] */ result = NULL; } else { LIST_INSTANCE* list_instance = (LIST_INSTANCE*)list; /* Codes_SRS_LIST_01_008: [singlylinkedlist_get_head_item shall return the head of the list.] */ /* Codes_SRS_LIST_01_010: [If the list is empty, singlylinkedlist_get_head_item_shall_return NULL.] */ result = list_instance->head; } return result; } LIST_ITEM_HANDLE singlylinkedlist_get_next_item(LIST_ITEM_HANDLE item_handle) { LIST_ITEM_HANDLE result; if (item_handle == NULL) { /* Codes_SRS_LIST_01_019: [If item_handle is NULL then singlylinkedlist_get_next_item shall return NULL.] */ result = NULL; } else { /* Codes_SRS_LIST_01_018: [singlylinkedlist_get_next_item shall return the next item in the list following the item item_handle.] */ result = (LIST_ITEM_HANDLE)((LIST_ITEM_INSTANCE*)item_handle)->next; } return result; } const void* singlylinkedlist_item_get_value(LIST_ITEM_HANDLE item_handle) { const void* result; if (item_handle == NULL) { /* Codes_SRS_LIST_01_021: [If item_handle is NULL, singlylinkedlist_item_get_value shall return NULL.] */ result = NULL; } else { /* Codes_SRS_LIST_01_020: [singlylinkedlist_item_get_value shall return the value associated with the list item identified by the item_handle argument.] */ result = ((LIST_ITEM_INSTANCE*)item_handle)->item; } return result; } LIST_ITEM_HANDLE singlylinkedlist_find(SINGLYLINKEDLIST_HANDLE list, LIST_MATCH_FUNCTION match_function, const void* match_context) { LIST_ITEM_HANDLE result; if ((list == NULL) || (match_function == NULL)) { /* Codes_SRS_LIST_01_012: [If the list or the match_function argument is NULL, singlylinkedlist_find shall return NULL.] */ result = NULL; } else { LIST_INSTANCE* list_instance = (LIST_INSTANCE*)list; LIST_ITEM_INSTANCE* current = list_instance->head; /* Codes_SRS_LIST_01_011: [singlylinkedlist_find shall iterate through all items in a list and return the first one that satisfies a certain match function.] */ while (current != NULL) { /* Codes_SRS_LIST_01_014: [list find shall determine whether an item satisfies the match criteria by invoking the match function for each item in the list until a matching item is found.] */ /* Codes_SRS_LIST_01_013: [The match_function shall get as arguments the list item being attempted to be matched and the match_context as is.] */ if (match_function((LIST_ITEM_HANDLE)current, match_context) == true) { /* Codes_SRS_LIST_01_017: [If the match function returns true, singlylinkedlist_find shall consider that item as matching.] */ break; } /* Codes_SRS_LIST_01_016: [If the match function returns false, singlylinkedlist_find shall consider that item as not matching.] */ current = (LIST_ITEM_INSTANCE*)current->next; } if (current == NULL) { /* Codes_SRS_LIST_01_015: [If the list is empty, singlylinkedlist_find shall return NULL.] */ result = NULL; } else { result = current; } } return result; }