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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43
lib/_cdio_stdio.c
View File

@@ -1,5 +1,5 @@
/*
$Id: _cdio_stdio.c,v 1.2 2003/03/29 17:32:00 rocky Exp $
$Id: _cdio_stdio.c,v 1.3 2003/04/06 23:40:21 rocky Exp $
Copyright (C) 2000 Herbert Valerio Riedel <hvr@gnu.org>
Copyright (C) 2003 Rocky Bernstein <rocky@panix.com>
@@ -35,7 +35,7 @@
#include "_cdio_stream.h"
#include "_cdio_stdio.h"
static const char _rcsid[] = "$Id: _cdio_stdio.c,v 1.2 2003/03/29 17:32:00 rocky Exp $";
static const char _rcsid[] = "$Id: _cdio_stdio.c,v 1.3 2003/04/06 23:40:21 rocky Exp $";
#define CDIO_STDIO_BUFSIZE (128*1024)
@@ -90,18 +90,36 @@ _stdio_free(void *user_data)
free(ud);
}
/*!
Like fseek(3) 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.
*/
static long
_stdio_seek(void *user_data, long offset, int whence)
{
_UserData *const ud = user_data;
if (fseek (ud->fd, offset, whence))
if ( (offset=fseek (ud->fd, offset, whence)) ) {
cdio_error ("fseek (): %s", strerror (errno));
}
return offset;
}
static long
static long int
_stdio_stat(void *user_data)
{
const _UserData *const ud = user_data;
@@ -109,6 +127,23 @@ _stdio_stat(void *user_data)
return ud->st_size;
}
/*!
Like fread(3) and in fact is about 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.
*/
static long
_stdio_read(void *user_data, void *buf, long count)
{

54
lib/_cdio_stream.c
View File

@@ -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);
}

118
lib/_cdio_stream.h
View File

@@ -1,5 +1,5 @@
/*
$Id: _cdio_stream.h,v 1.3 2003/04/03 12:16:27 rocky Exp $
$Id: _cdio_stream.h,v 1.4 2003/04/06 23:40:21 rocky Exp $
Copyright (C) 2000 Herbert Valerio Riedel <hvr@gnu.org>
Copyright (C) 2003 Rocky Bernstein <rocky@panix.com>
@@ -29,52 +29,86 @@
extern "C" {
#endif /* __cplusplus */
/* typedef'ed IO functions prototypes */
/* typedef'ed IO functions prototypes */
typedef int(*cdio_data_open_t)(void *user_data);
typedef long(*cdio_data_read_t)(void *user_data, void *buf, long count);
typedef long(*cdio_data_seek_t)(void *user_data, long offset, int whence);
typedef long(*cdio_data_stat_t)(void *user_data);
typedef int(*cdio_data_close_t)(void *user_data);
typedef void(*cdio_data_free_t)(void *user_data);
/* abstract data source */
typedef struct _CdioDataSource CdioDataSource;
typedef struct {
cdio_data_open_t open;
cdio_data_seek_t seek;
cdio_data_stat_t stat;
cdio_data_read_t read;
cdio_data_close_t close;
cdio_data_free_t free;
} cdio_stream_io_functions;
CdioDataSource*
cdio_stream_new(void *user_data, const cdio_stream_io_functions *funcs);
typedef int(*cdio_data_open_t)(void *user_data);
/*!
Like fread(3) and in fact may be the same.
typedef long(*cdio_data_read_t)(void *user_data, void *buf, long count);
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.
typedef long(*cdio_data_seek_t)(void *user_data, long offset, int whence);
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).
typedef long(*cdio_data_stat_t)(void *user_data);
typedef int(*cdio_data_close_t)(void *user_data);
typedef void(*cdio_data_free_t)(void *user_data);
/* abstract data source */
typedef struct _CdioDataSource CdioDataSource;
typedef struct {
cdio_data_open_t open;
cdio_data_seek_t seek;
cdio_data_stat_t stat;
cdio_data_read_t read;
cdio_data_close_t close;
cdio_data_free_t free;
} cdio_stream_io_functions;
CdioDataSource*
cdio_stream_new(void *user_data, const cdio_stream_io_functions *funcs);
long
cdio_stream_read(CdioDataSource* obj, void *ptr, long size, long nmemb);
long
cdio_stream_seek(CdioDataSource* obj, long offset, int whence);
long
cdio_stream_stat(CdioDataSource* obj);
void
cdio_stream_destroy(CdioDataSource* obj);
void
cdio_stream_close(CdioDataSource* obj);
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);
/*!
Like fseek(3) 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);
/*!
Return whatever size of stream reports, I guess unit size is bytes.
On error return -1;
*/
long cdio_stream_stat(CdioDataSource* obj);
void cdio_stream_destroy(CdioDataSource* obj);
void cdio_stream_close(CdioDataSource* obj);
#ifdef __cplusplus
}
#endif /* __cplusplus */