claunia/libcdio-osx
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Document some of the interfaces.

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This commit is contained in:
rocky
2003-04-06 23:40:21 +00:00
parent f54f7824e2
commit 689abfbb93
3 changed files with 164 additions and 51 deletions
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54
lib/_cdio_stream.c
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@@ -1,5 +1,5 @@
/*
$Id: _cdio_stream.c,v 1.3 2003/04/06 17:57:20 rocky Exp $
$Id: _cdio_stream.c,v 1.4 2003/04/06 23:40:21 rocky Exp $
Copyright (C) 2000 Herbert Valerio Riedel <hvr@gnu.org>
@@ -34,7 +34,7 @@
#include "util.h"
#include "_cdio_stream.h"
static const char _rcsid[] = "$Id: _cdio_stream.c,v 1.3 2003/04/06 17:57:20 rocky Exp $";
static const char _rcsid[] = "$Id: _cdio_stream.c,v 1.4 2003/04/06 23:40:21 rocky Exp $";
/*
* DataSource implementations
@@ -47,6 +47,10 @@ struct _CdioDataSource {
long position;
};
/*
Open if not already open.
Return false if we hit an error. Errno should be set for that error.
*/
static bool
_cdio_stream_open_if_necessary(CdioDataSource *obj)
{
@@ -65,12 +69,31 @@ _cdio_stream_open_if_necessary(CdioDataSource *obj)
return true;
}
/*!
Like 3 fseek and in fact may be the same.
This function sets the file position indicator for the stream
pointed to by stream. The new position, measured in bytes, is obtained
by adding offset bytes to the position specified by whence. If whence
is set to SEEK_SET, SEEK_CUR, or SEEK_END, the offset is relative to
the start of the file, the current position indicator, or end-of-file,
respectively. A successful call to the fseek function clears the end-
of-file indicator for the stream and undoes any effects of the
ungetc(3) function on the same stream.
RETURN VALUE
Upon successful completion, return 0,
Otherwise, -1 is returned and the global variable errno is set to indi-
cate the error.
*/
long
cdio_stream_seek(CdioDataSource* obj, long offset, int whence)
{
cdio_assert (obj != NULL);
if (!_cdio_stream_open_if_necessary(obj)) return 0;
if (!_cdio_stream_open_if_necessary(obj))
/* errno is set by _cdio_stream_open_if necessary. */
return -1;
if (obj->position != offset) {
#ifdef STREAM_DEBUG
@@ -96,6 +119,23 @@ cdio_stream_new(void *user_data, const cdio_stream_io_functions *funcs)
return new_obj;
}
/*!
Like fread(3) and in fact may be the same.
DESCRIPTION:
The function fread reads nmemb elements of data, each size bytes long,
from the stream pointed to by stream, storing them at the location
given by ptr.
RETURN VALUE:
return the number of items successfully read or written (i.e.,
not the number of characters). If an error occurs, or the
end-of-file is reached, the return value is a short item count
(or zero).
We do not distinguish between end-of-file and error, and callers
must use feof(3) and ferror(3) to determine which occurred.
*/
long
cdio_stream_read(CdioDataSource* obj, void *ptr, long size, long nmemb)
{
@@ -111,12 +151,16 @@ cdio_stream_read(CdioDataSource* obj, void *ptr, long size, long nmemb)
return read_bytes;
}
long
/*!
Return whatever size of stream reports, I guess unit size is bytes.
On error return -1;
*/
long int
cdio_stream_stat(CdioDataSource* obj)
{
cdio_assert (obj != NULL);
if (!_cdio_stream_open_if_necessary(obj)) return 0;
if (!_cdio_stream_open_if_necessary(obj)) return -1;
return obj->op.stat(obj->user_data);
}