+++ /dev/null
-/*
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
- *
- * Copyright 2017 Mike Becker, Olaf Wintermann All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-/**
- * @file stack.h
- *
- * Default stack memory allocation implementation.
- *
- * @author Mike Becker
- * @author Olaf Wintermann
- */
-
-#ifndef UCX_STACK_H
-#define UCX_STACK_H
-
-#include "ucx.h"
-#include "allocator.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-
-/**
- * UCX stack structure.
- */
-typedef struct {
- /** UcxAllocator based on this stack */
- UcxAllocator allocator;
-
- /** Stack size. */
- size_t size;
-
- /** Pointer to the bottom of the stack */
- char *space;
-
- /** Pointer to the top of the stack */
- char *top;
-} UcxStack;
-
-/**
- * Metadata for each UCX stack element.
- */
-struct ucx_stack_metadata {
- /**
- * Location of the previous element (<code>NULL</code> if this is the first)
- */
- char *prev;
-
- /** Size of this element */
- size_t size;
-};
-
-/**
- * Initializes UcxStack structure with memory.
- *
- * @param stack a pointer to an uninitialized stack structure
- * @param space the memory area that shall be managed
- * @param size size of the memory area
- * @return a new UcxStack structure
- */
-void ucx_stack_init(UcxStack *stack, char* space, size_t size);
-
-/**
- * Allocates stack memory.
- *
- * @param stack a pointer to the stack
- * @param n amount of memory to allocate
- * @return a pointer to the allocated memory or <code>NULL</code> on stack
- * overflow
- * @see ucx_allocator_malloc()
- */
-void *ucx_stack_malloc(UcxStack *stack, size_t n);
-
-/**
- * Allocates memory with #ucx_stack_malloc() and copies the specified data if
- * the allocation was successful.
- *
- * @param stack a pointer to the stack
- * @param n amount of memory to allocate
- * @param data a pointer to the data to copy
- * @return a pointer to the allocated memory
- * @see ucx_stack_malloc
- */
-void *ucx_stack_push(UcxStack *stack, size_t n, const void *data);
-
-/**
- * Allocates an array of stack memory
- *
- * The content of the allocated memory is set to zero.
- *
- * @param stack a pointer to the stack
- * @param nelem amount of elements to allocate
- * @param elsize amount of memory per element
- * @return a pointer to the allocated memory
- * @see ucx_allocator_calloc()
- */
-void *ucx_stack_calloc(UcxStack *stack, size_t nelem, size_t elsize);
-
-/**
- * Allocates memory with #ucx_stack_calloc() and copies the specified data if
- * the allocation was successful.
- *
- * @param stack a pointer to the stack
- * @param nelem amount of elements to allocate
- * @param elsize amount of memory per element
- * @param data a pointer to the data
- * @return a pointer to the allocated memory
- * @see ucx_stack_calloc
- */
-void *ucx_stack_pusharr(UcxStack *stack,
- size_t nelem, size_t elsize, const void *data);
-
-/**
- * Reallocates memory on the stack.
- *
- * Shrinking memory is always safe. Extending memory can be very expensive.
- *
- * @param stack the stack
- * @param ptr a pointer to the memory that shall be reallocated
- * @param n the new size of the memory
- * @return a pointer to the new location of the memory
- * @see ucx_allocator_realloc()
- */
-void *ucx_stack_realloc(UcxStack *stack, void *ptr, size_t n);
-
-/**
- * Frees memory on the stack.
- *
- * Freeing stack memory behaves in a special way.
- *
- * If the element, that should be freed, is the top most element of the stack,
- * it is removed from the stack. Otherwise it is marked as freed. Marked
- * elements are removed, when they become the top most elements of the stack.
- *
- * @param stack a pointer to the stack
- * @param ptr a pointer to the memory that shall be freed
- */
-void ucx_stack_free(UcxStack *stack, void *ptr);
-
-
-/**
- * Returns the size of the top most element.
- * @param stack a pointer to the stack
- * @return the size of the top most element
- */
-#define ucx_stack_topsize(stack) ((stack)->top ? ((struct ucx_stack_metadata*)\
- (stack)->top - 1)->size : 0)
-
-/**
- * Removes the top most element from the stack and copies the content to <code>
- * dest</code>, if specified.
- *
- * Use #ucx_stack_topsize()# to get the amount of memory that must be available
- * at the location of <code>dest</code>.
- *
- * @param stack a pointer to the stack
- * @param dest the location where the contents shall be written to, or <code>
- * NULL</code>, if the element shall only be removed.
- * @see ucx_stack_free
- * @see ucx_stack_popn
- */
-#define ucx_stack_pop(stack, dest) ucx_stack_popn(stack, dest, (size_t)-1)
-
-/**
- * Removes the top most element from the stack and copies the content to <code>
- * dest</code>.
- *
- * This function copies at most <code>n</code> bytes to the destination, but
- * the element is always freed as a whole.
- * If the element was larger than <code>n</code>, the remaining data is lost.
- *
- * @param stack a pointer to the stack
- * @param dest the location where the contents shall be written to
- * @param n copies at most n bytes to <code>dest</code>
- * @see ucx_stack_pop
- */
-void ucx_stack_popn(UcxStack *stack, void *dest, size_t n);
-
-/**
- * Returns the remaining available memory on the specified stack.
- *
- * @param stack a pointer to the stack
- * @return the remaining available memory
- */
-size_t ucx_stack_avail(UcxStack *stack);
-
-/**
- * Checks, if the stack is empty.
- *
- * @param stack a pointer to the stack
- * @return nonzero, if the stack is empty, zero otherwise
- */
-#define ucx_stack_empty(stack) (!(stack)->top)
-
-/**
- * Computes a recommended size for the stack memory area. Note, that
- * reallocations have not been taken into account, so you might need to reserve
- * twice as much memory to allow many reallocations.
- *
- * @param size the approximate payload
- * @param elems the approximate count of element allocations
- * @return a recommended size for the stack space based on the information
- * provided
- */
-#define ucx_stack_dim(size, elems) (size+sizeof(struct ucx_stack_metadata) * \
- (elems + 1))
-
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* UCX_STACK_H */
-
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