Byte Arrays

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

## Synopsis

    #include <glib.h>

    struct              GByteArray;
    GByteArray *        g_byte_array_new                    (void);
    GByteArray *        g_byte_array_sized_new              (guint reserved_size);
    GByteArray *        g_byte_array_ref                    (GByteArray *array);
    void                g_byte_array_unref                  (GByteArray *array);
    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 23. Using a GByteArray

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    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

### struct GByteArray

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

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 with a reference count of 1.

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_ref ()

    GByteArray *        g_byte_array_ref                    (GByteArray *array);

Atomically increments the reference count of `array` by one. This function is MT-safe and may be called from any thread.

`array` : | A GByteArray.
Returns : | The passed in GByteArray.

Since 2.22

### g_byte_array_unref ()

    void                g_byte_array_unref                  (GByteArray *array);

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 MT-safe and may be called from any thread.

`array` : | A GByteArray.

Since 2.22

### 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. If you want equal elements to keep their order &8211; i.e. you want a stable sort &8211; you can write a comparison function that, if two elements would otherwise compare equal, compares them by their addresses.

`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. 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.

`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`. The element data should be freed using `g_free()`.