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Diffstat (limited to 'contrib/libcdio/_cdio_stream.c')
| -rw-r--r-- | contrib/libcdio/_cdio_stream.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/contrib/libcdio/_cdio_stream.c b/contrib/libcdio/_cdio_stream.c new file mode 100644 index 000000000..fc1f7fce7 --- /dev/null +++ b/contrib/libcdio/_cdio_stream.c @@ -0,0 +1,200 @@ +/* + $Id: _cdio_stream.c,v 1.2 2004/04/11 12:20:31 miguelfreitas Exp $ + + Copyright (C) 2000, 2004 Herbert Valerio Riedel <hvr@gnu.org> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <stdarg.h> +#include "cdio_assert.h" + +/* #define STREAM_DEBUG */ + +#include <cdio/logging.h> +#include <cdio/util.h> +#include "_cdio_stream.h" + +static const char _rcsid[] = "$Id: _cdio_stream.c,v 1.2 2004/04/11 12:20:31 miguelfreitas Exp $"; + +/* + * DataSource implementations + */ + +struct _CdioDataSource { + void* user_data; + cdio_stream_io_functions op; + int is_open; + 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) +{ + cdio_assert (obj != NULL); + + if (!obj->is_open) { + if (obj->op.open(obj->user_data)) { + cdio_warn ("could not open input stream..."); + return false; + } else { + cdio_debug ("opened source..."); + obj->is_open = 1; + obj->position = 0; + } + } + 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)) + /* errno is set by _cdio_stream_open_if necessary. */ + return -1; + + if (obj->position != offset) { +#ifdef STREAM_DEBUG + cdio_warn("had to reposition DataSource from %ld to %ld!", obj->position, offset); +#endif + obj->position = offset; + return obj->op.seek(obj->user_data, offset, whence); + } + + return 0; +} + +CdioDataSource* +cdio_stream_new(void *user_data, const cdio_stream_io_functions *funcs) +{ + CdioDataSource *new_obj; + + new_obj = _cdio_malloc (sizeof (CdioDataSource)); + + new_obj->user_data = user_data; + memcpy(&(new_obj->op), funcs, sizeof(cdio_stream_io_functions)); + + 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) +{ + long read_bytes; + + cdio_assert (obj != NULL); + + if (!_cdio_stream_open_if_necessary(obj)) return 0; + + read_bytes = obj->op.read(obj->user_data, ptr, size*nmemb); + obj->position += read_bytes; + + return read_bytes; +} + +/*! + 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 -1; + + return obj->op.stat(obj->user_data); +} + +void +cdio_stream_close(CdioDataSource* obj) +{ + cdio_assert (obj != NULL); + + if (obj->is_open) { + cdio_debug ("closed source..."); + obj->op.close(obj->user_data); + obj->is_open = 0; + obj->position = 0; + } +} + +void +cdio_stream_destroy(CdioDataSource* obj) +{ + cdio_assert (obj != NULL); + + cdio_stream_close(obj); + + obj->op.free(obj->user_data); + + free(obj); +} + + +/* + * Local variables: + * c-file-style: "gnu" + * tab-width: 8 + * indent-tabs-mode: nil + * End: + */ |