NAME¶
zip_source_function - create data source from function
LIBRARY¶
libzip (-lzip)
SYNOPSIS¶
#include <zip.h>
struct zip_source * zip_source_function(struct zip *archive, zip_source_callback
fn, void *userdata);
DESCRIPTION¶
The function zip_source_function creates a zip source from the user-provided
function
fn, which must be of the following type: typedef zip_int64_t
(*zip_source_callback)(void *state,
void *data, zip_uint64_t len, enum zip_source_cmd cmd);
When called by the library, the first argument is the
userdata argument
supplied to zip_source_function. The next two arguments are a buffer
data of size
len when data is expected to be returned, or else
NULL and 0. The last argument,
cmd, specifies which action the
function should perform:
- ZIP_SOURCE_OPEN
- Prepare for reading. Return 0 on success, -1 on error.
- ZIP_SOURCE_READ
- Read data into the buffer data of size len.
Return the number of bytes placed into data on success, -1 on
error.
- ZIP_SOURCE_CLOSE
- Reading is done. Return 0.
- ZIP_SOURCE_STAT
- Get meta information for the input data. data points
to an initialized which should be filled in. (See zip_stat_init(3). )
Information only available after the source has been read (e.g. size) can
be omitted in an earlier call. Return sizeof(struct zip_stat) on success,
-1 on error.
- ZIP_SOURCE_ERROR
- Get error information. data points to an array of
two ints, which should be filled with the libzip error code and the
corresponding system error code for the error that occurred. See
zip_errors(3) for details on the error codes. Return return(2 *
sizeof(int)).
- ZIP_SOURCE_FREE
- Clean up and free all resources. Return 0.
The library will always issue
ZIP_SOURCE_OPEN before issuing
ZIP_SOURCE_READ. When it no longer wishes to read from this source, it
will issue
ZIP_SOURCE_CLOSE. If the library wishes to read the data
again, it will issue
ZIP_SOURCE_OPEN a second time. If the function is
unable to provide the data again, it should return -1.
ZIP_SOURCE_STAT can be issued at any time.
ZIP_SOURCE_ERROR will
only be issued in response to the function returning -1.
ZIP_SOURCE_FREE will be the last command issued; if
ZIP_SOURCE_OPEN was called and succeeded,
ZIP_SOURCE_CLOSE will
be called before
ZIP_SOURCE_FREE.
RETURN VALUES¶
Upon successful completion, the created source is returned. Otherwise,
NULL is returned and the error code in
archive is set to
indicate the error.
ERRORS¶
zip_source_function fails if:
- [ZIP_ER_MEMORY]
- Required memory could not be allocated.
SEE ALSO¶
libzip(3),
zip_add(3),
zip_replace(3),
zip_source_buffer(3),
zip_source_file(3),
zip_source_filep(3),
zip_source_free(3),
zip_source_zip(3),
zip_stat_init(3)
AUTHORS¶
Dieter Baron <dillo@nih.at> and Thomas Klausner
<tk@giga.or.at>