Byte Arrays

Byte Arrays — arrays of bytes, which grow automatically as elements are added.

Synopsis


#include <glib.h>


                    GByteArray;
GByteArray*         g_byte_array_new                    (void);
GByteArray*         g_byte_array_sized_new              (guint reserved_size);
GByteArray*         g_byte_array_append                 (GByteArray *array,
                                                         const guint8 *data,
                                                         guint len);
GByteArray*         g_byte_array_prepend                (GByteArray *array,
                                                         const guint8 *data,
                                                         guint len);
GByteArray*         g_byte_array_remove_index           (GByteArray *array,
                                                         guint index_);
GByteArray*         g_byte_array_remove_index_fast      (GByteArray *array,
                                                         guint index_);
GByteArray*         g_byte_array_remove_range           (GByteArray *array,
                                                         guint index_,
                                                         guint length);
void                g_byte_array_sort                   (GByteArray *array,
                                                         GCompareFunc compare_func);
void                g_byte_array_sort_with_data         (GByteArray *array,
                                                         GCompareDataFunc compare_func,
                                                         gpointer user_data);
GByteArray*         g_byte_array_set_size               (GByteArray *array,
                                                         guint length);
guint8*             g_byte_array_free                   (GByteArray *array,
                                                         gboolean free_segment);

Description

GByteArray is 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().

Example 24. Using a GByteArray

  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);

Details

GByteArray

typedef struct {
  guint8 *data;
  guint	  len;
} GByteArray;

The GByteArray struct allows access to the public fields of a GByteArray.

guint8 *data; a pointer to the element data. The data may be moved as elements are added to the GByteArray.
guint len; the number of elements in the GByteArray.

g_byte_array_new ()

GByteArray*         g_byte_array_new                    (void);

Creates a new GByteArray.

Returns : the new GByteArray.

g_byte_array_sized_new ()

GByteArray*         g_byte_array_sized_new              (guint reserved_size);

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.

reserved_size : number of bytes preallocated.
Returns : the new GByteArray.

g_byte_array_append ()

GByteArray*         g_byte_array_append                 (GByteArray *array,
                                                         const guint8 *data,
                                                         guint len);

Adds the given bytes to the end of the GByteArray. The array will grow in size automatically if necessary.

array : a GByteArray.
data : the byte data to be added.
len : the number of bytes to add.
Returns : the GByteArray.

g_byte_array_prepend ()

GByteArray*         g_byte_array_prepend                (GByteArray *array,
                                                         const guint8 *data,
                                                         guint len);

Adds the given data to the start of the GByteArray. The array will grow in size automatically if necessary.

array : a GByteArray.
data : the byte data to be added.
len : the number of bytes to add.
Returns : the GByteArray.

g_byte_array_remove_index ()

GByteArray*         g_byte_array_remove_index           (GByteArray *array,
                                                         guint index_);

Removes the byte at the given index from a GByteArray. The following bytes are moved down one place.

array : a GByteArray.
index_ : the index of the byte to remove.
Returns : the GByteArray.

g_byte_array_remove_index_fast ()

GByteArray*         g_byte_array_remove_index_fast      (GByteArray *array,
                                                         guint index_);

Removes the byte at the given index from a GByteArray. The last element in the array is used to fill in the space, so this function does not preserve the order of the GByteArray. But it is faster than g_byte_array_remove_index().

array : a GByteArray.
index_ : the index of the byte to remove.
Returns : the GByteArray.

g_byte_array_remove_range ()

GByteArray*         g_byte_array_remove_range           (GByteArray *array,
                                                         guint index_,
                                                         guint length);

Removes the given number of bytes starting at the given index from a GByteArray. The following elements are moved to close the gap.

array : a GByteArray.
index_ : the index of the first byte to remove.
length : the number of bytes to remove.
Returns : the GByteArray.

Since 2.4

g_byte_array_sort ()

void                g_byte_array_sort                   (GByteArray *array,
                                                         GCompareFunc compare_func);

Sorts a byte array, using compare_func which should be a qsort()-style comparison function (returns less than zero for first arg is less than second arg, zero for equal, greater than zero if first arg is greater than second arg).

If two array elements compare equal, their order in the sorted array is undefined.

array : a GByteArray.
compare_func : comparison function.

g_byte_array_sort_with_data ()

void                g_byte_array_sort_with_data         (GByteArray *array,
                                                         GCompareDataFunc compare_func,
                                                         gpointer user_data);

Like g_byte_array_sort(), but the comparison function takes an extra user data argument.

array : a GByteArray.
compare_func : comparison function.
user_data : data to pass to compare_func.

g_byte_array_set_size ()

GByteArray*         g_byte_array_set_size               (GByteArray *array,
                                                         guint length);

Sets the size of the GByteArray, expanding it if necessary.

array : a GByteArray.
length : the new size of the GByteArray.
Returns : the GByteArray.

g_byte_array_free ()

guint8*             g_byte_array_free                   (GByteArray *array,
                                                         gboolean free_segment);

Frees the memory allocated by the GByteArray. If free_segment is TRUE it frees the actual byte data.

array : a GByteArray.
free_segment : if TRUE the actual byte data is freed as well.
Returns : the element data if free_segment is FALSE, otherwise NULL