/** * WinPR: Windows Portable Runtime * System.Collections.Stack * * Copyright 2012 Marc-Andre Moreau * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include /** * C equivalent of the C# Stack Class: * http://msdn.microsoft.com/en-us/library/system.collections.stack.aspx */ /** * Properties */ /** * Gets the number of elements contained in the Stack. */ int Stack_Count(wStack* stack) { int ret; if (stack->synchronized) EnterCriticalSection(&stack->lock); ret = stack->size; if (stack->synchronized) LeaveCriticalSection(&stack->lock); return ret; } /** * Gets a value indicating whether access to the Stack is synchronized (thread safe). */ BOOL Stack_IsSynchronized(wStack* stack) { return stack->synchronized; } /** * Methods */ /** * Removes all objects from the Stack. */ void Stack_Clear(wStack* stack) { int index; if (stack->synchronized) EnterCriticalSection(&stack->lock); for (index = 0; index < stack->size; index++) { if (stack->object.fnObjectFree) stack->object.fnObjectFree(stack->array[index]); stack->array[index] = NULL; } stack->size = 0; if (stack->synchronized) LeaveCriticalSection(&stack->lock); } /** * Determines whether an element is in the Stack. */ BOOL Stack_Contains(wStack* stack, void* obj) { int i; BOOL found = FALSE; if (stack->synchronized) EnterCriticalSection(&stack->lock); for (i = 0; i < stack->size; i++) { if (stack->object.fnObjectEquals(stack->array[i], obj)) { found = TRUE; break; } } if (stack->synchronized) LeaveCriticalSection(&stack->lock); return found; } /** * Inserts an object at the top of the Stack. */ void Stack_Push(wStack* stack, void* obj) { if (stack->synchronized) EnterCriticalSection(&stack->lock); if ((stack->size + 1) >= stack->capacity) { int new_cap; void **new_arr; new_cap = stack->capacity * 2; new_arr = (void**) realloc(stack->array, sizeof(void*) * new_cap); if (!new_arr) return; stack->array = new_arr; stack->capacity = new_cap; } stack->array[(stack->size)++] = obj; if (stack->synchronized) LeaveCriticalSection(&stack->lock); } /** * Removes and returns the object at the top of the Stack. */ void* Stack_Pop(wStack* stack) { void* obj = NULL; if (stack->synchronized) EnterCriticalSection(&stack->lock); if (stack->size > 0) obj = stack->array[--(stack->size)]; if (stack->synchronized) LeaveCriticalSection(&stack->lock); return obj; } /** * Returns the object at the top of the Stack without removing it. */ void* Stack_Peek(wStack* stack) { void* obj = NULL; if (stack->synchronized) EnterCriticalSection(&stack->lock); if (stack->size > 0) obj = stack->array[stack->size]; if (stack->synchronized) LeaveCriticalSection(&stack->lock); return obj; } static BOOL default_stack_equals(void *obj1, void *obj2) { return (obj1 == obj2); } /** * Construction, Destruction */ wStack* Stack_New(BOOL synchronized) { wStack* stack = NULL; stack = (wStack *)calloc(1, sizeof(wStack)); if (!stack) return NULL; stack->object.fnObjectEquals = default_stack_equals; stack->synchronized = synchronized; stack->capacity = 32; stack->array = (void**) malloc(sizeof(void*) * stack->capacity); if (!stack->array) goto out_free; if (stack->synchronized && !InitializeCriticalSectionAndSpinCount(&stack->lock, 4000)) goto out_free_array; return stack; out_free_array: free(stack->array); out_free: free(stack); return NULL; } void Stack_Free(wStack* stack) { if (stack) { if (stack->synchronized) DeleteCriticalSection(&stack->lock); free(stack->array); free(stack); } }