unicorn/glib_compat/garray.c

/* GLIB - Library of useful routines for C programming
 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

/*
 * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
 * file for a list of people on the GLib Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GLib at ftp://ftp.gtk.org/pub/gtk/. 
 */

/* 
 * MT safe
 */

//#include "config.h"

#include <string.h>
#include <stdlib.h>

#include "glib_compat.h"

#define g_mem_gc_friendly FALSE

/**
 * SECTION:arrays
 * @title: Arrays
 * @short_description: arrays of arbitrary elements which grow
 *     automatically as elements are added
 *
 * Arrays are similar to standard C arrays, except that they grow
 * automatically as elements are added.
 *
 * Array elements can be of any size (though all elements of one array
 * are the same size), and the array can be automatically cleared to
 * '0's and zero-terminated.
 *
 * To create a new array use g_array_new().
 *
 * To add elements to an array, use g_array_append_val(),
 * g_array_append_vals(), g_array_prepend_val(), and
 * g_array_prepend_vals().
 *
 * To access an element of an array, use g_array_index().
 *
 * To set the size of an array, use g_array_set_size().
 *
 * To free an array, use g_array_free().
 *
 * Here is an example that stores integers in a #GArray:
 * |[<!-- language="C" -->
 *   GArray *garray;
 *   gint i;
 *   // We create a new array to store gint values.
 *   // We don't want it zero-terminated or cleared to 0's.
 *   garray = g_array_new (FALSE, FALSE, sizeof (gint));
 *   for (i = 0; i < 10000; i++)
 *     g_array_append_val (garray, i);
 *   for (i = 0; i < 10000; i++)
 *     if (g_array_index (garray, gint, i) != i)
 *       g_print ("ERROR: got %d instead of %d\n",
 *                g_array_index (garray, gint, i), i);
 *   g_array_free (garray, TRUE);
 * ]|
 */

#define MIN_ARRAY_SIZE  16

typedef struct _GRealArray  GRealArray;

/**
 * GArray:
 * @data: a pointer to the element data. The data may be moved as
 *     elements are added to the #GArray.
 * @len: the number of elements in the #GArray not including the
 *     possible terminating zero element.
 *
 * Contains the public fields of a GArray.
 */
struct _GRealArray
{
    guint8 *data;
    guint   len;
    guint   alloc;
    guint   elt_size;
    guint   zero_terminated : 1;
    guint   clear : 1;
    // gatomicrefcount ref_count;
    GDestroyNotify clear_func;
};

/**
 * g_array_index:
 * @a: a #GArray
 * @t: the type of the elements
 * @i: the index of the element to return
 *
 * Returns the element of a #GArray at the given index. The return
 * value is cast to the given type.
 *
 * This example gets a pointer to an element in a #GArray:
 * |[<!-- language="C" -->
 *   EDayViewEvent *event;
 *   // This gets a pointer to the 4th element in the array of
 *   // EDayViewEvent structs.
 *   event = &g_array_index (events, EDayViewEvent, 3);
 * ]|
 *
 * Returns: the element of the #GArray at the index given by @i
 */

#define g_array_elt_len(array,i) ((array)->elt_size * (i))
#define g_array_elt_pos(array,i) ((array)->data + g_array_elt_len((array),(i)))
#define g_array_elt_zero(array, pos, len)                               \
    (memset (g_array_elt_pos ((array), pos), 0,  g_array_elt_len ((array), len)))
#define g_array_zero_terminate(array) G_STMT_START{                     \
    if ((array)->zero_terminated)                                         \
    g_array_elt_zero ((array), (array)->len, 1);                        \
}G_STMT_END

static guint g_nearest_pow        (guint       num);
static void  g_array_maybe_expand (GRealArray *array,
        guint       len);

/**
 * g_array_new:
 * @zero_terminated: %TRUE if the array should have an extra element at
 *     the end which is set to 0
 * @clear_: %TRUE if #GArray elements should be automatically cleared
 *     to 0 when they are allocated
 * @element_size: the size of each element in bytes
 *
 * Creates a new #GArray with a reference count of 1.
 *
 * Returns: the new #GArray
 */
GArray* g_array_new (gboolean zero_terminated,
        gboolean clear,
        guint    elt_size)
{
    g_return_val_if_fail (elt_size > 0, NULL);

    return g_array_sized_new (zero_terminated, clear, elt_size, 0);
}

/**
 * g_array_sized_new:
 * @zero_terminated: %TRUE if the array should have an extra element at
 *     the end with all bits cleared
 * @clear_: %TRUE if all bits in the array should be cleared to 0 on
 *     allocation
 * @element_size: size of each element in the array
 * @reserved_size: number of elements preallocated
 *
 * Creates a new #GArray with @reserved_size elements preallocated and
 * a reference count of 1. This avoids frequent reallocation, if you
 * are going to add many elements to the array. Note however that the
 * size of the array is still 0.
 *
 * Returns: the new #GArray
 */
GArray* g_array_sized_new (gboolean zero_terminated,
        gboolean clear,
        guint    elt_size,
        guint    reserved_size)
{
    GRealArray *array;

    g_return_val_if_fail (elt_size > 0, NULL);

    array = g_slice_new (GRealArray);

    array->data            = NULL;
    array->len             = 0;
    array->alloc           = 0;
    array->zero_terminated = (zero_terminated ? 1 : 0);
    array->clear           = (clear ? 1 : 0);
    array->elt_size        = elt_size;
    array->clear_func      = NULL;

    // g_atomic_ref_count_init (&array->ref_count);

    if (array->zero_terminated || reserved_size != 0)
    {
        g_array_maybe_expand (array, reserved_size);
        g_array_zero_terminate(array);
    }

    return (GArray*) array;
}

/**
 * g_array_set_clear_func:
 * @array: A #GArray
 * @clear_func: a function to clear an element of @array
 *
 * Sets a function to clear an element of @array.
 *
 * The @clear_func will be called when an element in the array
 * data segment is removed and when the array is freed and data
 * segment is deallocated as well. @clear_func will be passed a
 * pointer to the element to clear, rather than the element itself.
 *
 * Note that in contrast with other uses of #GDestroyNotify
 * functions, @clear_func is expected to clear the contents of
 * the array element it is given, but not free the element itself.
 *
 * Since: 2.32
 */
void g_array_set_clear_func (GArray         *array,
        GDestroyNotify  clear_func)
{
    GRealArray *rarray = (GRealArray *) array;

    g_return_if_fail (array != NULL);

    rarray->clear_func = clear_func;
}

/**
 * g_array_ref:
 * @array: A #GArray
 *
 * Atomically increments the reference count of @array by one.
 * This function is thread-safe and may be called from any thread.
 *
 * Returns: The passed in #GArray
 *
 * Since: 2.22
 */
GArray *g_array_ref (GArray *array)
{
    //GRealArray *rarray = (GRealArray*) array;
    g_return_val_if_fail (array, NULL);

    // g_atomic_ref_count_inc (&rarray->ref_count);

    return array;
}

typedef enum
{
    FREE_SEGMENT = 1 << 0,
    PRESERVE_WRAPPER = 1 << 1
} ArrayFreeFlags;

static gchar *array_free (GRealArray *, ArrayFreeFlags);

/**
 * g_array_unref:
 * @array: A #GArray
 *
 * Atomically decrements the reference count of @array by one. If the
 * reference count drops to 0, all memory allocated by the array is
 * released. This function is thread-safe and may be called from any
 * thread.
 *
 * Since: 2.22
 */
void g_array_unref (GArray *array)
{
    GRealArray *rarray = (GRealArray*) array;
    g_return_if_fail (array);

    // if (g_atomic_ref_count_dec (&rarray->ref_count))
    array_free (rarray, FREE_SEGMENT);
}

/**
 * g_array_get_element_size:
 * @array: A #GArray
 *
 * Gets the size of the elements in @array.
 *
 * Returns: Size of each element, in bytes
 *
 * Since: 2.22
 */
guint g_array_get_element_size (GArray *array)
{
    GRealArray *rarray = (GRealArray*) array;

    g_return_val_if_fail (array, 0);

    return rarray->elt_size;
}

/**
 * g_array_free:
 * @array: a #GArray
 * @free_segment: if %TRUE the actual element data is freed as well
 *
 * Frees the memory allocated for the #GArray. If @free_segment is
 * %TRUE it frees the memory block holding the elements as well. Pass
 * %FALSE if you want to free the #GArray wrapper but preserve the
 * underlying array for use elsewhere. If the reference count of
 * @array is greater than one, the #GArray wrapper is preserved but
 * the size of  @array will be set to zero.
 *
 * If array contents point to dynamically-allocated memory, they should
 * be freed separately if @free_seg is %TRUE and no @clear_func
 * function has been set for @array.
 *
 * This function is not thread-safe. If using a #GArray from multiple
 * threads, use only the atomic g_array_ref() and g_array_unref()
 * functions.
 *
 * Returns: the element data if @free_segment is %FALSE, otherwise
 *     %NULL. The element data should be freed using g_free().
 */
gchar *g_array_free (GArray   *farray,
        gboolean  free_segment)
{
    GRealArray *array = (GRealArray*) farray;
    ArrayFreeFlags flags;

    g_return_val_if_fail (array, NULL);

    flags = (free_segment ? FREE_SEGMENT : 0);

    /* if others are holding a reference, preserve the wrapper but do free/return the data */
    //if (!g_atomic_ref_count_dec (&array->ref_count))
    flags |= PRESERVE_WRAPPER;

    return array_free (array, flags);
}

static gchar *array_free (GRealArray *array, ArrayFreeFlags flags)
{
    gchar *segment;

    if (flags & FREE_SEGMENT)
    {
        if (array->clear_func != NULL)
        {
            guint i;

            for (i = 0; i < array->len; i++)
                array->clear_func (g_array_elt_pos (array, i));
        }

        g_free (array->data);
        segment = NULL;
    }
    else
        segment = (gchar*) array->data;

    if (flags & PRESERVE_WRAPPER)
    {
        array->data            = NULL;
        array->len             = 0;
        array->alloc           = 0;
    }
    else
    {
        g_slice_free1 (sizeof (GRealArray), array);
    }

    return segment;
}

/**
 * g_array_append_vals:
 * @array: a #GArray
 * @data: (not nullable): a pointer to the elements to append to the end of the array
 * @len: the number of elements to append
 *
 * Adds @len elements onto the end of the array.
 *
 * Returns: the #GArray
 */
/**
 * g_array_append_val:
 * @a: a #GArray
 * @v: the value to append to the #GArray
 *
 * Adds the value on to the end of the array. The array will grow in
 * size automatically if necessary.
 *
 * g_array_append_val() is a macro which uses a reference to the value
 * parameter @v. This means that you cannot use it with literal values
 * such as "27". You must use variables.
 *
 * Returns: the #GArray
 */
GArray* g_array_append_vals (GArray *farray, gconstpointer data, guint len)
{
    GRealArray *array = (GRealArray*) farray;

    g_return_val_if_fail (array, NULL);

    if (len == 0)
        return farray;

    g_array_maybe_expand (array, len);

    memcpy (g_array_elt_pos (array, array->len), data, 
            g_array_elt_len (array, len));

    array->len += len;

    g_array_zero_terminate (array);

    return farray;
}

/**
 * g_array_prepend_vals:
 * @array: a #GArray
 * @data: (nullable): a pointer to the elements to prepend to the start of the array
 * @len: the number of elements to prepend, which may be zero
 *
 * Adds @len elements onto the start of the array.
 *
 * @data may be %NULL if (and only if) @len is zero. If @len is zero, this
 * function is a no-op.
 *
 * This operation is slower than g_array_append_vals() since the
 * existing elements in the array have to be moved to make space for
 * the new elements.
 *
 * Returns: the #GArray
 */
/**
 * g_array_prepend_val:
 * @a: a #GArray
 * @v: the value to prepend to the #GArray
 *
 * Adds the value on to the start of the array. The array will grow in
 * size automatically if necessary.
 *
 * This operation is slower than g_array_append_val() since the
 * existing elements in the array have to be moved to make space for
 * the new element.
 *
 * g_array_prepend_val() is a macro which uses a reference to the value
 * parameter @v. This means that you cannot use it with literal values
 * such as "27". You must use variables.
 *
 * Returns: the #GArray
 */
GArray* g_array_prepend_vals (GArray *farray, gconstpointer  data, guint len)
{
    GRealArray *array = (GRealArray*) farray;

    g_return_val_if_fail (array, NULL);

    if (len == 0)
        return farray;

    g_array_maybe_expand (array, len);

    memmove (g_array_elt_pos (array, len), g_array_elt_pos (array, 0),
            g_array_elt_len (array, array->len));

    memcpy (g_array_elt_pos (array, 0), data, g_array_elt_len (array, len));

    array->len += len;

    g_array_zero_terminate (array);

    return farray;
}

/**
 * g_array_insert_vals:
 * @array: a #GArray
 * @index_: the index to place the elements at
 * @data: (nullable): a pointer to the elements to insert
 * @len: the number of elements to insert
 *
 * Inserts @len elements into a #GArray at the given index.
 *
 * If @index_ is greater than the array's current length, the array is expanded.
 * The elements between the old end of the array and the newly inserted elements
 * will be initialised to zero if the array was configured to clear elements;
 * otherwise their values will be undefined.
 *
 * @data may be %NULL if (and only if) @len is zero. If @len is zero, this
 * function is a no-op.
 *
 * Returns: the #GArray
 */
/**
 * g_array_insert_val:
 * @a: a #GArray
 * @i: the index to place the element at
 * @v: the value to insert into the array
 *
 * Inserts an element into an array at the given index.
 *
 * g_array_insert_val() is a macro which uses a reference to the value
 * parameter @v. This means that you cannot use it with literal values
 * such as "27". You must use variables.
 *
 * Returns: the #GArray
 */
GArray* g_array_insert_vals (GArray        *farray,
        guint          index_,
        gconstpointer  data,
        guint          len)
{
    GRealArray *array = (GRealArray*) farray;

    g_return_val_if_fail (array, NULL);

    if (len == 0)
        return farray;

    /* Is the index off the end of the array, and hence do we need to over-allocate
     * and clear some elements? */
    if (index_ >= array->len)
    {
        g_array_maybe_expand (array, index_ - array->len + len);
        return g_array_append_vals (g_array_set_size (farray, index_), data, len);
    }

    g_array_maybe_expand (array, len);

    memmove (g_array_elt_pos (array, len + index_),
            g_array_elt_pos (array, index_),
            g_array_elt_len (array, array->len - index_));

    memcpy (g_array_elt_pos (array, index_), data, g_array_elt_len (array, len));

    array->len += len;

    g_array_zero_terminate (array);

    return farray;
}

/**
 * g_array_set_size:
 * @array: a #GArray
 * @length: the new size of the #GArray
 *
 * Sets the size of the array, expanding it if necessary. If the array
 * was created with @clear_ set to %TRUE, the new elements are set to 0.
 *
 * Returns: the #GArray
 */
GArray* g_array_set_size (GArray *farray,
        guint   length)
{
    GRealArray *array = (GRealArray*) farray;

    g_return_val_if_fail (array, NULL);

    if (length > array->len)
    {
        g_array_maybe_expand (array, length - array->len);

        if (array->clear)
            g_array_elt_zero (array, array->len, length - array->len);
    }
    else if (length < array->len)
        g_array_remove_range (farray, length, array->len - length);

    array->len = length;

    g_array_zero_terminate (array);

    return farray;
}

/**
 * g_array_remove_index:
 * @array: a #GArray
 * @index_: the index of the element to remove
 *
 * Removes the element at the given index from a #GArray. The following
 * elements are moved down one place.
 *
 * Returns: the #GArray
 */
GArray* g_array_remove_index (GArray *farray,
        guint   index_)
{
    GRealArray* array = (GRealArray*) farray;

    g_return_val_if_fail (array, NULL);

    g_return_val_if_fail (index_ < array->len, NULL);

    if (array->clear_func != NULL)
        array->clear_func (g_array_elt_pos (array, index_));

    if (index_ != array->len - 1)
        memmove (g_array_elt_pos (array, index_),
                g_array_elt_pos (array, index_ + 1),
                g_array_elt_len (array, array->len - index_ - 1));

    array->len -= 1;

    if (g_mem_gc_friendly)
        g_array_elt_zero (array, array->len, 1);
    else
        g_array_zero_terminate (array);

    return farray;
}

/**
 * g_array_remove_index_fast:
 * @array: a @GArray
 * @index_: the index of the element to remove
 *
 * Removes the element at the given index from a #GArray. The last
 * element in the array is used to fill in the space, so this function
 * does not preserve the order of the #GArray. But it is faster than
 * g_array_remove_index().
 *
 * Returns: the #GArray
 */
GArray* g_array_remove_index_fast (GArray *farray,
        guint   index_)
{
    GRealArray* array = (GRealArray*) farray;

    g_return_val_if_fail (array, NULL);

    g_return_val_if_fail (index_ < array->len, NULL);

    if (array->clear_func != NULL)
        array->clear_func (g_array_elt_pos (array, index_));

    if (index_ != array->len - 1)
        memcpy (g_array_elt_pos (array, index_),
                g_array_elt_pos (array, array->len - 1),
                g_array_elt_len (array, 1));

    array->len -= 1;

    if (g_mem_gc_friendly)
        g_array_elt_zero (array, array->len, 1);
    else
        g_array_zero_terminate (array);

    return farray;
}

/**
 * g_array_remove_range:
 * @array: a @GArray
 * @index_: the index of the first element to remove
 * @length: the number of elements to remove
 *
 * Removes the given number of elements starting at the given index
 * from a #GArray.  The following elements are moved to close the gap.
 *
 * Returns: the #GArray
 *
 * Since: 2.4
 */
GArray* g_array_remove_range (GArray *farray,
        guint   index_,
        guint   length)
{
    GRealArray *array = (GRealArray*) farray;

    g_return_val_if_fail (array, NULL);
    g_return_val_if_fail (index_ <= array->len, NULL);
    g_return_val_if_fail (index_ + length <= array->len, NULL);

    if (array->clear_func != NULL)
    {
        guint i;

        for (i = 0; i < length; i++)
            array->clear_func (g_array_elt_pos (array, index_ + i));
    }

    if (index_ + length != array->len)
        memmove (g_array_elt_pos (array, index_),
                g_array_elt_pos (array, index_ + length),
                (array->len - (index_ + length)) * array->elt_size);

    array->len -= length;
    if (g_mem_gc_friendly)
        g_array_elt_zero (array, array->len, length);
    else
        g_array_zero_terminate (array);

    return farray;
}

/* Returns the smallest power of 2 greater than n, or n if
 * such power does not fit in a guint
 */
static guint g_nearest_pow (guint num)
{
    guint n = num - 1;

    g_assert (num > 0);

    n |= n >> 1;
    n |= n >> 2;
    n |= n >> 4;
    n |= n >> 8;
    n |= n >> 16;
#if SIZEOF_INT == 8
    n |= n >> 32;
#endif

    return n + 1;
}

static void g_array_maybe_expand (GRealArray *array, guint len)
{
    guint want_alloc;

    /* Detect potential overflow */
    //if ((G_MAXUINT - array->len) < len)
    //  g_error ("adding %u to array would overflow", len);

    want_alloc = g_array_elt_len (array, array->len + len +
            array->zero_terminated);

    if (want_alloc > array->alloc)
    {
        want_alloc = g_nearest_pow (want_alloc);
        want_alloc = MAX (want_alloc, MIN_ARRAY_SIZE);

        array->data = g_realloc (array->data, want_alloc);

        if (g_mem_gc_friendly)
            memset (array->data + array->alloc, 0, want_alloc - array->alloc);

        array->alloc = want_alloc;
    }
}

/**
 * SECTION:arrays_pointer
 * @title: Pointer Arrays
 * @short_description: arrays of pointers to any type of data, which
 *     grow automatically as new elements are added
 *
 * Pointer Arrays are similar to Arrays but are used only for storing
 * pointers.
 *
 * If you remove elements from the array, elements at the end of the
 * array are moved into the space previously occupied by the removed
 * element. This means that you should not rely on the index of particular
 * elements remaining the same. You should also be careful when deleting
 * elements while iterating over the array.
 *
 * To create a pointer array, use g_ptr_array_new().
 *
 * To add elements to a pointer array, use g_ptr_array_add().
 *
 * To remove elements from a pointer array, use g_ptr_array_remove(),
 * g_ptr_array_remove_index() or g_ptr_array_remove_index_fast().
 *
 * To access an element of a pointer array, use g_ptr_array_index().
 *
 * To set the size of a pointer array, use g_ptr_array_set_size().
 *
 * To free a pointer array, use g_ptr_array_free().
 *
 * An example using a #GPtrArray:
 * |[<!-- language="C" -->
 *   GPtrArray *array;
 *   gchar *string1 = "one";
 *   gchar *string2 = "two";
 *   gchar *string3 = "three";
 *
 *   array = g_ptr_array_new ();
 *   g_ptr_array_add (array, (gpointer) string1);
 *   g_ptr_array_add (array, (gpointer) string2);
 *   g_ptr_array_add (array, (gpointer) string3);
 *
 *   if (g_ptr_array_index (array, 0) != (gpointer) string1)
 *     g_print ("ERROR: got %p instead of %p\n",
 *              g_ptr_array_index (array, 0), string1);
 *
 *   g_ptr_array_free (array, TRUE);
 * ]|
 */

typedef struct _GRealPtrArray  GRealPtrArray;

/**
 * GPtrArray:
 * @pdata: points to the array of pointers, which may be moved when the
 *     array grows
 * @len: number of pointers in the array
 *
 * Contains the public fields of a pointer array.
 */
struct _GRealPtrArray
{
    gpointer       *pdata;
    guint           len;
    guint           alloc;
    // gatomicrefcount ref_count;
    GDestroyNotify  element_free_func;
};

/**
 * g_ptr_array_index:
 * @array: a #GPtrArray
 * @index_: the index of the pointer to return
 *
 * Returns the pointer at the given index of the pointer array.
 *
 * This does not perform bounds checking on the given @index_,
 * so you are responsible for checking it against the array length.
 *
 * Returns: the pointer at the given index
 */

static void g_ptr_array_maybe_expand (GRealPtrArray *array, guint len);

/**
 * g_ptr_array_new:
 *
 * Creates a new #GPtrArray with a reference count of 1.
 *
 * Returns: the new #GPtrArray
 */
GPtrArray *g_ptr_array_new (void)
{
    return g_ptr_array_sized_new (0);
}

/**
 * g_ptr_array_steal:
 * @array: a #GPtrArray.
 * @len: (optional) (out caller-allocates): pointer to retrieve the number of
 *    elements of the original array
 *
 * Frees the data in the array and resets the size to zero, while
 * the underlying array is preserved for use elsewhere and returned
 * to the caller.
 *
 * Even if set, the #GDestroyNotify function will never be called
 * on the current contents of the array and the caller is
 * responsible for freeing the array elements.
 *
 * An example of use:
 * |[<!-- language="C" -->
 * g_autoptr(GPtrArray) chunk_buffer = g_ptr_array_new_with_free_func (g_bytes_unref);
 *
 * // Some part of your application appends a number of chunks to the pointer array.
 * g_ptr_array_add (chunk_buffer, g_bytes_new_static ("hello", 5));
 * g_ptr_array_add (chunk_buffer, g_bytes_new_static ("world", 5));
 *
 * ...
 *
 * // Periodically, the chunks need to be sent as an array-and-length to some
 * // other part of the program.
 * GBytes **chunks;
 * gsize n_chunks;
 *
 * chunks = g_ptr_array_steal (chunk_buffer, &n_chunks);
 * for (gsize i = 0; i < n_chunks; i++)
 *   {
 *     // Do something with each chunk here, and then free them, since
 *     // g_ptr_array_steal() transfers ownership of all the elements and the
 *     // array to the caller.
 *     ...
 *
 *     g_bytes_unref (chunks[i]);
 *   }
 *
 * g_free (chunks);
 *
 * // After calling g_ptr_array_steal(), the pointer array can be reused for the
 * // next set of chunks.
 * g_assert (chunk_buffer->len == 0);
 * ]|
 *
 * Returns: (transfer full): the element data, which should be
 *     freed using g_free().
 *
 * Since: 2.64
 */
gpointer *g_ptr_array_steal (GPtrArray *array, gsize *len)
{
    GRealPtrArray *rarray;
    gpointer *segment;

    g_return_val_if_fail (array != NULL, NULL);

    rarray = (GRealPtrArray *) array;
    segment = (gpointer *) rarray->pdata;

    if (len != NULL)
        *len = rarray->len;

    rarray->pdata = NULL;
    rarray->len   = 0;
    rarray->alloc = 0;
    return segment;
}

/**
 * g_ptr_array_copy:
 * @array: #GPtrArray to duplicate
 * @func: (nullable): a copy function used to copy every element in the array
 * @user_data: user data passed to the copy function @func, or %NULL
 *
 * Makes a full (deep) copy of a #GPtrArray.
 *
 * @func, as a #GCopyFunc, takes two arguments, the data to be copied
 * and a @user_data pointer. On common processor architectures, it's safe to
 * pass %NULL as @user_data if the copy function takes only one argument. You
 * may get compiler warnings from this though if compiling with GCC's
 * `-Wcast-function-type` warning.
 *
 * If @func is %NULL, then only the pointers (and not what they are
 * pointing to) are copied to the new #GPtrArray.
 *
 * The copy of @array will have the same #GDestroyNotify for its elements as
 * @array.
 *
 * Returns: (transfer full): a deep copy of the initial #GPtrArray.
 *
 * Since: 2.62
 **/
GPtrArray *g_ptr_array_copy (GPtrArray *array, GCopyFunc func, gpointer user_data)
{
    gsize i;
    GPtrArray *new_array;

    g_return_val_if_fail (array != NULL, NULL);

    new_array = g_ptr_array_sized_new (array->len);
    g_ptr_array_set_free_func (new_array, ((GRealPtrArray *) array)->element_free_func);

    if (func != NULL)
    {
        for (i = 0; i < array->len; i++)
            new_array->pdata[i] = func (array->pdata[i], user_data);
    }
    else if (array->len > 0)
    {
        memcpy (new_array->pdata, array->pdata,
                array->len * sizeof (*array->pdata));
    }

    new_array->len = array->len;

    return new_array;
}

/**
 * g_ptr_array_sized_new:
 * @reserved_size: number of pointers preallocated
 *
 * Creates a new #GPtrArray with @reserved_size pointers preallocated
 * and a reference count of 1. This avoids frequent reallocation, if
 * you are going to add many pointers to the array. Note however that
 * the size of the array is still 0.
 *
 * Returns: the new #GPtrArray
 */
GPtrArray *g_ptr_array_sized_new (guint reserved_size)
{
    GRealPtrArray *array;

    array = g_slice_new (GRealPtrArray);

    array->pdata = NULL;
    array->len = 0;
    array->alloc = 0;
    array->element_free_func = NULL;

    // g_atomic_ref_count_init (&array->ref_count);

    if (reserved_size != 0)
        g_ptr_array_maybe_expand (array, reserved_size);

    return (GPtrArray*) array;  
}

/**
 * g_array_copy:
 * @array: A #GArray.
 *
 * Create a shallow copy of a #GArray. If the array elements consist of
 * pointers to data, the pointers are copied but the actual data is not.
 *
 * Returns: (transfer container): A copy of @array.
 *
 * Since: 2.62
 **/
GArray *g_array_copy (GArray *array)
{
    GRealArray *rarray = (GRealArray *) array;
    GRealArray *new_rarray;

    g_return_val_if_fail (rarray != NULL, NULL);

    new_rarray =
        (GRealArray *) g_array_sized_new (rarray->zero_terminated, rarray->clear,
                rarray->elt_size, rarray->alloc / rarray->elt_size);
    new_rarray->len = rarray->len;
    if (rarray->len > 0)
        memcpy (new_rarray->data, rarray->data, rarray->len * rarray->elt_size);

    g_array_zero_terminate (new_rarray);

    return (GArray *) new_rarray;
}

/**
 * g_ptr_array_new_with_free_func:
 * @element_free_func: (nullable): A function to free elements with
 *     destroy @array or %NULL
 *
 * Creates a new #GPtrArray with a reference count of 1 and use
 * @element_free_func for freeing each element when the array is destroyed
 * either via g_ptr_array_unref(), when g_ptr_array_free() is called with
 * @free_segment set to %TRUE or when removing elements.
 *
 * Returns: A new #GPtrArray
 *
 * Since: 2.22
 */
GPtrArray *g_ptr_array_new_with_free_func (GDestroyNotify element_free_func)
{
    GPtrArray *array;

    array = g_ptr_array_new ();
    g_ptr_array_set_free_func (array, element_free_func);

    return array;
}

/**
 * g_ptr_array_new_full:
 * @reserved_size: number of pointers preallocated
 * @element_free_func: (nullable): A function to free elements with
 *     destroy @array or %NULL
 *
 * Creates a new #GPtrArray with @reserved_size pointers preallocated
 * and a reference count of 1. This avoids frequent reallocation, if
 * you are going to add many pointers to the array. Note however that
 * the size of the array is still 0. It also set @element_free_func
 * for freeing each element when the array is destroyed either via
 * g_ptr_array_unref(), when g_ptr_array_free() is called with
 * @free_segment set to %TRUE or when removing elements.
 *
 * Returns: A new #GPtrArray
 *
 * Since: 2.30
 */
GPtrArray *g_ptr_array_new_full (guint reserved_size, GDestroyNotify element_free_func)
{
    GPtrArray *array;

    array = g_ptr_array_sized_new (reserved_size);
    g_ptr_array_set_free_func (array, element_free_func);

    return array;
}

/**
 * g_ptr_array_set_free_func:
 * @array: A #GPtrArray
 * @element_free_func: (nullable): A function to free elements with
 *     destroy @array or %NULL
 *
 * Sets a function for freeing each element when @array is destroyed
 * either via g_ptr_array_unref(), when g_ptr_array_free() is called
 * with @free_segment set to %TRUE or when removing elements.
 *
 * Since: 2.22
 */
void g_ptr_array_set_free_func (GPtrArray *array, GDestroyNotify element_free_func)
{
    GRealPtrArray *rarray = (GRealPtrArray *)array;

    g_return_if_fail (array);

    rarray->element_free_func = element_free_func;
}

static void g_ptr_array_maybe_expand (GRealPtrArray *array, guint len)
{
    /* Detect potential overflow */
    //if ((G_MAXUINT - array->len) < len)
    //  g_error ("adding %u to array would overflow", len);

    if ((array->len + len) > array->alloc)
    {
        guint old_alloc = array->alloc;
        array->alloc = g_nearest_pow (array->len + len);
        array->alloc = MAX (array->alloc, MIN_ARRAY_SIZE);
        array->pdata = g_realloc (array->pdata, sizeof (gpointer) * array->alloc);
        if (g_mem_gc_friendly)
            for ( ; old_alloc < array->alloc; old_alloc++)
                array->pdata [old_alloc] = NULL;
    }
}

/**
 * g_ptr_array_set_size:
 * @array: a #GPtrArray
 * @length: the new length of the pointer array
 *
 * Sets the size of the array. When making the array larger,
 * newly-added elements will be set to %NULL. When making it smaller,
 * if @array has a non-%NULL #GDestroyNotify function then it will be
 * called for the removed elements.
 */
void g_ptr_array_set_size  (GPtrArray *array, gint length)
{
    GRealPtrArray *rarray = (GRealPtrArray *)array;
    guint length_unsigned;

    g_return_if_fail (rarray);
    g_return_if_fail (rarray->len == 0 || (rarray->len != 0 && rarray->pdata != NULL));
    g_return_if_fail (length >= 0);

    length_unsigned = (guint) length;

    if (length_unsigned > rarray->len)
    {
        guint i;
        g_ptr_array_maybe_expand (rarray, (length_unsigned - rarray->len));
        /* This is not 
         *     memset (array->pdata + array->len, 0,
         *            sizeof (gpointer) * (length_unsigned - array->len));
         * to make it really portable. Remember (void*)NULL needn't be
         * bitwise zero. It of course is silly not to use memset (..,0,..).
         */
        for (i = rarray->len; i < length_unsigned; i++)
            rarray->pdata[i] = NULL;
    }
    else if (length_unsigned < rarray->len)
        g_ptr_array_remove_range (array, length_unsigned, rarray->len - length_unsigned);

    rarray->len = length_unsigned;
}

static gpointer ptr_array_remove_index (GPtrArray *array,
        guint      index_,
        gboolean   fast,
        gboolean   free_element)
{
    GRealPtrArray *rarray = (GRealPtrArray *) array;
    gpointer result;

    g_return_val_if_fail (rarray, NULL);
    g_return_val_if_fail (rarray->len == 0 || (rarray->len != 0 && rarray->pdata != NULL), NULL);

    g_return_val_if_fail (index_ < rarray->len, NULL);

    result = rarray->pdata[index_];

    if (rarray->element_free_func != NULL && free_element)
        rarray->element_free_func (rarray->pdata[index_]);

    if (index_ != rarray->len - 1 && !fast)
        memmove (rarray->pdata + index_, rarray->pdata + index_ + 1,
                sizeof (gpointer) * (rarray->len - index_ - 1));
    else if (index_ != rarray->len - 1)
        rarray->pdata[index_] = rarray->pdata[rarray->len - 1];

    rarray->len -= 1;

    if (g_mem_gc_friendly)
        rarray->pdata[rarray->len] = NULL;

    return result;
}

/**
 * g_ptr_array_remove_index:
 * @array: a #GPtrArray
 * @index_: the index of the pointer to remove
 *
 * Removes the pointer at the given index from the pointer array.
 * The following elements are moved down one place. If @array has
 * a non-%NULL #GDestroyNotify function it is called for the removed
 * element. If so, the return value from this function will potentially point
 * to freed memory (depending on the #GDestroyNotify implementation).
 *
 * Returns: (nullable): the pointer which was removed
 */
gpointer g_ptr_array_remove_index (GPtrArray *array, guint index_)
{
    return ptr_array_remove_index (array, index_, FALSE, TRUE);
}

/**
 * g_ptr_array_remove_index_fast:
 * @array: a #GPtrArray
 * @index_: the index of the pointer to remove
 *
 * Removes the pointer at the given index from the pointer array.
 * The last element in the array is used to fill in the space, so
 * this function does not preserve the order of the array. But it
 * is faster than g_ptr_array_remove_index(). If @array has a non-%NULL
 * #GDestroyNotify function it is called for the removed element. If so, the
 * return value from this function will potentially point to freed memory
 * (depending on the #GDestroyNotify implementation).
 *
 * Returns: (nullable): the pointer which was removed
 */
gpointer g_ptr_array_remove_index_fast (GPtrArray *array, guint index_)
{
    return ptr_array_remove_index (array, index_, TRUE, TRUE);
}

/**
 * g_ptr_array_steal_index:
 * @array: a #GPtrArray
 * @index_: the index of the pointer to steal
 *
 * Removes the pointer at the given index from the pointer array.
 * The following elements are moved down one place. The #GDestroyNotify for
 * @array is *not* called on the removed element; ownership is transferred to
 * the caller of this function.
 *
 * Returns: (transfer full) (nullable): the pointer which was removed
 * Since: 2.58
 */
gpointer g_ptr_array_steal_index (GPtrArray *array, guint index_)
{
    return ptr_array_remove_index (array, index_, FALSE, FALSE);
}

/**
 * g_ptr_array_steal_index_fast:
 * @array: a #GPtrArray
 * @index_: the index of the pointer to steal
 *
 * Removes the pointer at the given index from the pointer array.
 * The last element in the array is used to fill in the space, so
 * this function does not preserve the order of the array. But it
 * is faster than g_ptr_array_steal_index(). The #GDestroyNotify for @array is
 * *not* called on the removed element; ownership is transferred to the caller
 * of this function.
 *
 * Returns: (transfer full) (nullable): the pointer which was removed
 * Since: 2.58
 */
gpointer g_ptr_array_steal_index_fast (GPtrArray *array, guint index_)
{
    return ptr_array_remove_index (array, index_, TRUE, FALSE);
}

/**
 * g_ptr_array_remove_range:
 * @array: a @GPtrArray
 * @index_: the index of the first pointer to remove
 * @length: the number of pointers to remove
 *
 * Removes the given number of pointers starting at the given index
 * from a #GPtrArray. The following elements are moved to close the
 * gap. If @array has a non-%NULL #GDestroyNotify function it is
 * called for the removed elements.
 *
 * Returns: the @array
 *
 * Since: 2.4
 */
GPtrArray* g_ptr_array_remove_range (GPtrArray *array, guint index_, guint length)
{
    GRealPtrArray *rarray = (GRealPtrArray *)array;
    guint n;

    g_return_val_if_fail (rarray != NULL, NULL);
    g_return_val_if_fail (rarray->len == 0 || (rarray->len != 0 && rarray->pdata != NULL), NULL);
    g_return_val_if_fail (index_ <= rarray->len, NULL);
    g_return_val_if_fail (index_ + length <= rarray->len, NULL);

    if (rarray->element_free_func != NULL)
    {
        for (n = index_; n < index_ + length; n++)
            rarray->element_free_func (rarray->pdata[n]);
    }

    if (index_ + length != rarray->len)
    {
        memmove (&rarray->pdata[index_],
                &rarray->pdata[index_ + length],
                (rarray->len - (index_ + length)) * sizeof (gpointer));
    }

    rarray->len -= length;
    if (g_mem_gc_friendly)
    {
        guint i;
        for (i = 0; i < length; i++)
            rarray->pdata[rarray->len + i] = NULL;
    }

    return array;
}

/**
 * g_ptr_array_remove:
 * @array: a #GPtrArray
 * @data: the pointer to remove
 *
 * Removes the first occurrence of the given pointer from the pointer
 * array. The following elements are moved down one place. If @array
 * has a non-%NULL #GDestroyNotify function it is called for the
 * removed element.
 *
 * It returns %TRUE if the pointer was removed, or %FALSE if the
 * pointer was not found.
 *
 * Returns: %TRUE if the pointer is removed, %FALSE if the pointer
 *     is not found in the array
 */
gboolean g_ptr_array_remove (GPtrArray *array, gpointer data)
{
    guint i;

    g_return_val_if_fail (array, FALSE);
    g_return_val_if_fail (array->len == 0 || (array->len != 0 && array->pdata != NULL), FALSE);

    for (i = 0; i < array->len; i += 1)
    {
        if (array->pdata[i] == data)
        {
            g_ptr_array_remove_index (array, i);
            return TRUE;
        }
    }

    return FALSE;
}

/**
 * g_ptr_array_remove_fast:
 * @array: a #GPtrArray
 * @data: the pointer to remove
 *
 * Removes the first occurrence of the given pointer from the pointer
 * array. The last element in the array is used to fill in the space,
 * so this function does not preserve the order of the array. But it
 * is faster than g_ptr_array_remove(). If @array has a non-%NULL
 * #GDestroyNotify function it is called for the removed element.
 *
 * It returns %TRUE if the pointer was removed, or %FALSE if the
 * pointer was not found.
 *
 * Returns: %TRUE if the pointer was found in the array
 */
gboolean g_ptr_array_remove_fast (GPtrArray *array, gpointer data)
{
    GRealPtrArray *rarray = (GRealPtrArray *)array;
    guint i;

    g_return_val_if_fail (rarray, FALSE);
    g_return_val_if_fail (rarray->len == 0 || (rarray->len != 0 && rarray->pdata != NULL), FALSE);

    for (i = 0; i < rarray->len; i += 1)
    {
        if (rarray->pdata[i] == data)
        {
            g_ptr_array_remove_index_fast (array, i);
            return TRUE;
        }
    }

    return FALSE;
}

/**
 * g_ptr_array_add:
 * @array: a #GPtrArray
 * @data: the pointer to add
 *
 * Adds a pointer to the end of the pointer array. The array will grow
 * in size automatically if necessary.
 */
void g_ptr_array_add (GPtrArray *array, gpointer data)
{
    GRealPtrArray *rarray = (GRealPtrArray *)array;

    g_return_if_fail (rarray);
    g_return_if_fail (rarray->len == 0 || (rarray->len != 0 && rarray->pdata != NULL));

    g_ptr_array_maybe_expand (rarray, 1);

    rarray->pdata[rarray->len++] = data;
}

/**
 * g_ptr_array_extend:
 * @array_to_extend: a #GPtrArray.
 * @array: (transfer none): a #GPtrArray to add to the end of @array_to_extend.
 * @func: (nullable): a copy function used to copy every element in the array
 * @user_data: user data passed to the copy function @func, or %NULL
 *
 * Adds all pointers of @array to the end of the array @array_to_extend.
 * The array will grow in size automatically if needed. @array_to_extend is
 * modified in-place.
 *
 * @func, as a #GCopyFunc, takes two arguments, the data to be copied
 * and a @user_data pointer. On common processor architectures, it's safe to
 * pass %NULL as @user_data if the copy function takes only one argument. You
 * may get compiler warnings from this though if compiling with GCC's
 * `-Wcast-function-type` warning.
 *
 * If @func is %NULL, then only the pointers (and not what they are
 * pointing to) are copied to the new #GPtrArray.
 *
 * Since: 2.62
 **/
void g_ptr_array_extend (GPtrArray  *array_to_extend,
                GPtrArray  *array,
                GCopyFunc   func,
                gpointer    user_data)
{
    GRealPtrArray *rarray_to_extend = (GRealPtrArray *) array_to_extend;
    gsize i;

    g_return_if_fail (array_to_extend != NULL);
    g_return_if_fail (array != NULL);

    g_ptr_array_maybe_expand (rarray_to_extend, array->len);

    if (func != NULL)
    {
        for (i = 0; i < array->len; i++)
            rarray_to_extend->pdata[i + rarray_to_extend->len] =
                func (array->pdata[i], user_data);
    }
    else if (array->len > 0)
    {
        memcpy (rarray_to_extend->pdata + rarray_to_extend->len, array->pdata,
                array->len * sizeof (*array->pdata));
    }

    rarray_to_extend->len += array->len;
}

/**
 * g_ptr_array_insert:
 * @array: a #GPtrArray
 * @index_: the index to place the new element at, or -1 to append
 * @data: the pointer to add.
 *
 * Inserts an element into the pointer array at the given index. The 
 * array will grow in size automatically if necessary.
 *
 * Since: 2.40
 */
void g_ptr_array_insert (GPtrArray *array, gint index_, gpointer data)
{
    GRealPtrArray *rarray = (GRealPtrArray *)array;

    g_return_if_fail (rarray);
    g_return_if_fail (index_ >= -1);
    g_return_if_fail (index_ <= (gint)rarray->len);

    g_ptr_array_maybe_expand (rarray, 1);

    if (index_ < 0)
        index_ = rarray->len;

    if ((guint) index_ < rarray->len)
        memmove (&(rarray->pdata[index_ + 1]),
                &(rarray->pdata[index_]),
                (rarray->len - index_) * sizeof (gpointer));

    rarray->len++;
    rarray->pdata[index_] = data;
}

/**
 * g_ptr_array_foreach:
 * @array: a #GPtrArray
 * @func: the function to call for each array element
 * @user_data: user data to pass to the function
 * 
 * Calls a function for each element of a #GPtrArray. @func must not
 * add elements to or remove elements from the array.
 *
 * Since: 2.4
 */
void g_ptr_array_foreach (GPtrArray *array, GFunc func, gpointer user_data)
{
    guint i;

    g_return_if_fail (array);

    for (i = 0; i < array->len; i++)
        (*func) (array->pdata[i], user_data);
}

/**
 * SECTION:arrays_byte
 * @title: Byte Arrays
 * @short_description: arrays of bytes
 *
 * #GByteArray is a mutable array of bytes based on #GArray, to provide arrays
 * of bytes which grow automatically as elements are added.
 *
 * To create a new #GByteArray use g_byte_array_new(). To add elements to a
 * #GByteArray, use g_byte_array_append(), and g_byte_array_prepend().
 *
 * To set the size of a #GByteArray, use g_byte_array_set_size().
 *
 * To free a #GByteArray, use g_byte_array_free().
 *
 * An example for using a #GByteArray:
 * |[<!-- language="C" -->
 *   GByteArray *gbarray;
 *   gint i;
 *
 *   gbarray = g_byte_array_new ();
 *   for (i = 0; i < 10000; i++)
 *     g_byte_array_append (gbarray, (guint8*) "abcd", 4);
 *
 *   for (i = 0; i < 10000; i++)
 *     {
 *       g_assert (gbarray->data[4*i] == 'a');
 *       g_assert (gbarray->data[4*i+1] == 'b');
 *       g_assert (gbarray->data[4*i+2] == 'c');
 *       g_assert (gbarray->data[4*i+3] == 'd');
 *     }
 *
 *   g_byte_array_free (gbarray, TRUE);
 * ]|
 *
 * See #GBytes if you are interested in an immutable object representing a
 * sequence of bytes.
 */

/**
 * GByteArray:
 * @data: a pointer to the element data. The data may be moved as
 *     elements are added to the #GByteArray
 * @len: the number of elements in the #GByteArray
 *
 * Contains the public fields of a GByteArray.
 */

/**
 * g_byte_array_new:
 *
 * Creates a new #GByteArray with a reference count of 1.
 *
 * Returns: (transfer full): the new #GByteArray
 */
GByteArray *g_byte_array_new (void)
{
    return (GByteArray *)g_array_sized_new (FALSE, FALSE, 1, 0);
}

/**
 * g_byte_array_sized_new:
 * @reserved_size: number of bytes preallocated
 *
 * Creates a new #GByteArray with @reserved_size bytes preallocated.
 * This avoids frequent reallocation, if you are going to add many
 * bytes to the array. Note however that the size of the array is still
 * 0.
 *
 * Returns: the new #GByteArray
 */
GByteArray* g_byte_array_sized_new (guint reserved_size)
{
    return (GByteArray *)g_array_sized_new (FALSE, FALSE, 1, reserved_size);
}

/**
 * g_byte_array_free:
 * @array: a #GByteArray
 * @free_segment: if %TRUE the actual byte data is freed as well
 *
 * Frees the memory allocated by the #GByteArray. If @free_segment is
 * %TRUE it frees the actual byte data. If the reference count of
 * @array is greater than one, the #GByteArray wrapper is preserved but
 * the size of @array will be set to zero.
 *
 * Returns: the element data if @free_segment is %FALSE, otherwise
 *          %NULL.  The element data should be freed using g_free().
 */
guint8* g_byte_array_free (GByteArray *array, gboolean free_segment)
{
    return (guint8 *)g_array_free ((GArray *)array, free_segment);
}

/**
 * g_byte_array_append:
 * @array: a #GByteArray
 * @data: the byte data to be added
 * @len: the number of bytes to add
 *
 * Adds the given bytes to the end of the #GByteArray.
 * The array will grow in size automatically if necessary.
 *
 * Returns: the #GByteArray
 */
GByteArray* g_byte_array_append (GByteArray *array, const guint8 *data, guint len)
{
    g_array_append_vals ((GArray *)array, (guint8 *)data, len);

    return array;
}

/**
 * g_byte_array_prepend:
 * @array: a #GByteArray
 * @data: the byte data to be added
 * @len: the number of bytes to add
 *
 * Adds the given data to the start of the #GByteArray.
 * The array will grow in size automatically if necessary.
 *
 * Returns: the #GByteArray
 */
GByteArray *g_byte_array_prepend (GByteArray *array, const guint8 *data, guint len)
{
    g_array_prepend_vals ((GArray *)array, (guint8 *)data, len);

    return array;
}

/**
 * g_byte_array_set_size:
 * @array: a #GByteArray
 * @length: the new size of the #GByteArray
 *
 * Sets the size of the #GByteArray, expanding it if necessary.
 *
 * Returns: the #GByteArray
 */
GByteArray *g_byte_array_set_size (GByteArray *array, guint length)
{
    g_array_set_size ((GArray *)array, length);

    return array;
}