mirror of https://gitee.com/openkylin/glib2.0.git
147 lines
3.9 KiB
C
147 lines
3.9 KiB
C
/* GLIB - Library of useful routines for C programming
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* Copyright (C) 1995-1998 Peter Mattis, Spencer Kimball and Josh MacDonald
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*
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* SPDX-License-Identifier: LGPL-2.1-or-later
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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* Modified by the GLib Team and others 1997-2000. See the AUTHORS
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* file for a list of people on the GLib Team. See the ChangeLog
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* files for a list of changes. These files are distributed with
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* GLib at ftp://ftp.gtk.org/pub/gtk/.
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*/
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#include "config.h"
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/* we know we are deprecated here, no need for warnings */
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#ifndef GLIB_DISABLE_DEPRECATION_WARNINGS
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#define GLIB_DISABLE_DEPRECATION_WARNINGS
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#endif
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#include "gtrashstack.h"
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/**
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* GTrashStack:
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* @next: pointer to the previous element of the stack,
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* gets stored in the first `sizeof (gpointer)`
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* bytes of the element
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*
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* A `GTrashStack` is an efficient way to keep a stack of unused allocated
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* memory chunks. Each memory chunk is required to be large enough to hold
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* a `gpointer`. This allows the stack to be maintained without any space
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* overhead, since the stack pointers can be stored inside the memory chunks.
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*
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* There is no function to create a `GTrashStack`. A `NULL` `GTrashStack*`
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* is a perfectly valid empty stack.
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*
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* Each piece of memory that is pushed onto the stack is cast to a
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* `GTrashStack*`.
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*
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* There is no longer any good reason to use `GTrashStack`. If you have
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* extra pieces of memory, `free()` them and allocate them again later.
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*
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* Deprecated: 2.48: `GTrashStack` is deprecated without replacement
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*/
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/**
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* g_trash_stack_push:
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* @stack_p: a #GTrashStack
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* @data_p: (not nullable): the piece of memory to push on the stack
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*
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* Pushes a piece of memory onto a #GTrashStack.
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* Deprecated: 2.48: #GTrashStack is deprecated without replacement
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*/
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void
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g_trash_stack_push (GTrashStack **stack_p,
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gpointer data_p)
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{
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GTrashStack *data = (GTrashStack *) data_p;
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data->next = *stack_p;
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*stack_p = data;
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}
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/**
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* g_trash_stack_pop:
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* @stack_p: a #GTrashStack
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*
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* Pops a piece of memory off a #GTrashStack.
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*
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* Returns: the element at the top of the stack
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* Deprecated: 2.48: #GTrashStack is deprecated without replacement
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*/
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gpointer
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g_trash_stack_pop (GTrashStack **stack_p)
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{
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GTrashStack *data;
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data = *stack_p;
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if (data)
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{
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*stack_p = data->next;
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/* NULLify private pointer here, most platforms store NULL as
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* subsequent 0 bytes
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*/
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data->next = NULL;
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}
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return data;
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}
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/**
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* g_trash_stack_peek:
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* @stack_p: a #GTrashStack
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*
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* Returns the element at the top of a #GTrashStack
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* which may be %NULL.
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*
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* Returns: the element at the top of the stack
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* Deprecated: 2.48: #GTrashStack is deprecated without replacement
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*/
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gpointer
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g_trash_stack_peek (GTrashStack **stack_p)
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{
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GTrashStack *data;
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data = *stack_p;
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return data;
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}
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/**
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* g_trash_stack_height:
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* @stack_p: a #GTrashStack
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*
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* Returns the height of a #GTrashStack.
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*
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* Note that execution of this function is of O(N) complexity
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* where N denotes the number of items on the stack.
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*
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* Returns: the height of the stack
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* Deprecated: 2.48: #GTrashStack is deprecated without replacement
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*/
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guint
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g_trash_stack_height (GTrashStack **stack_p)
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{
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GTrashStack *data;
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guint i = 0;
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for (data = *stack_p; data; data = data->next)
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i++;
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return i;
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}
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