HarfBuzz Reference Manual: hb-blob

hb-blob

Functions

hb_blob_t *	hb_blob_create ()
hb_blob_t *	hb_blob_create_sub_blob ()
void	hb_blob_destroy ()
const char *	hb_blob_get_data ()
char *	hb_blob_get_data_writable ()
hb_blob_t *	hb_blob_get_empty ()
unsigned int	hb_blob_get_length ()
void *	hb_blob_get_user_data ()
hb_bool_t	hb_blob_is_immutable ()
void	hb_blob_make_immutable ()
hb_blob_t *	hb_blob_reference ()
hb_bool_t	hb_blob_set_user_data ()

Types and Values

typedef	hb_blob_t
enum	hb_memory_mode_t

Object Hierarchy

    GBoxed
    ╰── hb_blob_t
    GEnum
    ╰── hb_memory_mode_t

Description

Functions

hb_blob_create ()

hb_blob_t *
hb_blob_create (const char *data,
                unsigned int length,
                hb_memory_mode_t mode,
                void *user_data,
                hb_destroy_func_t destroy);

Creates a new "blob" object wrapping data . The mode parameter is used to negotiate ownership and lifecycle of data .

Parameters

data	Pointer to blob data.
length	Length of `data` in bytes.
mode	Memory mode for `data` .
user_data	Data parameter to pass to `destroy` .
destroy	Callback to call when `data` is not needed anymore.

Returns

New blob, or the empty blob if something failed or if length is zero. Destroy with hb_blob_destroy().

Since 1.0

hb_blob_create_sub_blob ()

hb_blob_t *
hb_blob_create_sub_blob (hb_blob_t *parent,
                         unsigned int offset,
                         unsigned int length);

Returns a blob that represents a range of bytes in parent . The new blob is always created with HB_MEMORY_MODE_READONLY, meaning that it will never modify data in the parent blob. The parent data is not expected to be modified, and will result in undefined behavior if it is.

Makes parent immutable.

Parameters

parent	Parent blob.
offset	Start offset of sub-blob within `parent` , in bytes.
length	Length of sub-blob.

Returns

New blob, or the empty blob if something failed or if length is zero or offset is beyond the end of parent 's data. Destroy with hb_blob_destroy().

Since 1.0

hb_blob_destroy ()

void
hb_blob_destroy (hb_blob_t *blob);

Descreases the reference count on blob , and if it reaches zero, destroys blob , freeing all memory, possibly calling the destroy-callback the blob was created for if it has not been called already.

See TODO:link object types for more information.

Parameters

blob

a blob.

Since 1.0

hb_blob_get_data ()

const char *
hb_blob_get_data (hb_blob_t *blob,
                  unsigned int *length);

Parameters

blob	a blob.
length	.	[out]

Returns

[transfer none][array length=length]

Since 1.0

hb_blob_get_data_writable ()

char *
hb_blob_get_data_writable (hb_blob_t *blob,
                           unsigned int *length);

Tries to make blob data writable (possibly copying it) and return pointer to data.

Fails if blob has been made immutable, or if memory allocation fails.

Parameters

blob	a blob.
length	output length of the writable data.	[out]

Returns

Writable blob data, or NULL if failed.

[transfer none][array length=length]

Since 1.0

hb_blob_get_empty ()

hb_blob_t *
hb_blob_get_empty (void);

Returns the singleton empty blob.

See TODO:link object types for more information.

Returns

the empty blob.

[transfer full]

Since 1.0

hb_blob_get_length ()

unsigned int
hb_blob_get_length (hb_blob_t *blob);

Parameters

blob

a blob.

Returns

the length of blob data in bytes.

Since 1.0

hb_blob_get_user_data ()

void *
hb_blob_get_user_data (hb_blob_t *blob,
                       hb_user_data_key_t *key);

Parameters

blob	a blob.
key	key for data to get.

Returns

[transfer none]

Since 1.0

hb_blob_is_immutable ()

hb_bool_t
hb_blob_is_immutable (hb_blob_t *blob);

Parameters

blob

a blob.

Returns

TODO

Since 1.0

hb_blob_make_immutable ()

void
hb_blob_make_immutable (hb_blob_t *blob);

Parameters

blob

a blob.

Since 1.0

hb_blob_reference ()

hb_blob_t *
hb_blob_reference (hb_blob_t *blob);

Increases the reference count on blob .

See TODO:link object types for more information.

Parameters

blob

a blob.

Returns

blob .

Since 1.0

hb_blob_set_user_data ()

hb_bool_t
hb_blob_set_user_data (hb_blob_t *blob,
                       hb_user_data_key_t *key,
                       void *data,
                       hb_destroy_func_t destroy,
                       hb_bool_t replace);

Parameters

blob	a blob.
key	key for data to set.
data	data to set.
destroy	callback to call when `data` is not needed anymore.
replace	whether to replace an existing data with the same key.

Returns

Since 1.0

Types and Values

hb_blob_t

typedef struct hb_blob_t hb_blob_t;

enum hb_memory_mode_t

Members

HB_MEMORY_MODE_DUPLICATE
HB_MEMORY_MODE_READONLY
HB_MEMORY_MODE_WRITABLE
HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE