Clarified role of burn_source

ZeroFourZero
Thomas Schmitt 15 years ago
parent fc6163732e
commit 769ea039a1
  1. 2
      cdrskin/cdrskin_timestamp.h
  2. 77
      libburn/libburn.h

@ -1 +1 @@
#define Cdrskin_timestamP "2007.10.02.120659"
#define Cdrskin_timestamP "2007.10.02.135538"

@ -318,38 +318,77 @@ struct burn_toc_entry
};
/** Data source for tracks */
/** Data source interface for tracks.
Objects compliant to this interface are either provided by the application
or by API calls of libburn. If provided by the application then the
functions (*read), (*get_size), (*set_size), (*free_data) MUST be
implemented by the application and attached to the object at creation time.
Function (*read_sub) MUST either be NULL or provided by the application.
*/
struct burn_source {
/** Reference count for the data source. Should be 1 when a new source
is created. Increment it to take a reference for yourself. Use
burn_source_free to destroy your reference to it. */
int refcount;
/** Read data from the source */
int (*read)(struct burn_source *,
unsigned char *buffer,
int size);
/** Reference count for the data source. MUST be 1 when a new source
is created. Increment it to take more references for yourself. Use
burn_source_free() to destroy your references to it. */
int refcount;
/** Read subchannel data from the source (NULL if lib generated) */
int (*read_sub)(struct burn_source *,
unsigned char *buffer,
int size);
/** Read data from the source. Semantics like with read(2), but MUST
either deliver the full buffer as defined by size or MUST deliver
EOF (return -1) at the following call.
*/
int (*read)(struct burn_source *, unsigned char *buffer, int size);
/** Get the size of the source's data */
off_t (*get_size)(struct burn_source *);
/** Read subchannel data from the source (NULL if lib generated)
WARNING: This is an obscure feature with CD raw write modes.
Unless you checked the libburn code for correctness in that aspect
you should not rely on raw writing with own subchannels.
ADVICE: Set this pointer to NULL.
*/
int (*read_sub)(struct burn_source *, unsigned char *buffer, int size);
/** Set the size of the source's data */
/** Get the size of the source's data. Return 0 means unpredictable
size. If application provided (*get_size) allows return 0, then
the application MUST provide a fully functional (*set_size).
*/
off_t (*get_size)(struct burn_source *);
/** Program the reply of (*get_size) to a fixed value. It is advised
to implement this by a attribute off_t fixed_size; in *data .
The read() function does not have to take into respect this fake
setting. It is rather a note of libburn to itself. Eventually
necessary truncation or padding is done in libburn. Truncation
is usually considered a misburn. Padding is considered ok.
libburn is supposed to work even if (*get_size) ignores the
setting by (*set_size). But your application will not be able to
enforce fixed track sizes by burn_track_set_size() and possibly
even padding might be left out.
*/
int (*set_size)(struct burn_source *source, off_t size);
/** Clean up the source specific data */
/** Clean up the source specific data. This function will be called
once by burn_source_free() when the last referer disposes the
source.
*/
void (*free_data)(struct burn_source *);
/** Next source, for when a source runs dry and padding is disabled
THIS IS AUTOMATICALLY HANDLED, DO NOT TOUCH
WARNING: This is an obscure feature. Set to NULL at creation and
from then on leave untouched and uninterpreted.
*/
struct burn_source *next;
/** Source specific data */
/** Source specific data. Here the various source classes express their
specific properties and the instance objects store their individual
management data. E.g. a struct like this:
struct app_burn_source
{
struct my_app *app_handle;
... other individual source parameters ...
off_t fixed_size;
};
*/
void *data;
};

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