/* * Copyright (C) 2003-2010 The Music Player Daemon Project * http://www.musicpd.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., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #ifndef MPD_INPUT_STREAM_H #define MPD_INPUT_STREAM_H #include "check.h" #include <glib.h> #include <stddef.h> #include <stdbool.h> #include <sys/types.h> #if !GLIB_CHECK_VERSION(2,14,0) typedef gint64 goffset; #endif struct input_stream { /** * the plugin which implements this input stream */ const struct input_plugin *plugin; /** * The absolute URI which was used to open this stream. May * be NULL if this is unknown. */ char *uri; /** * indicates whether the stream is ready for reading and * whether the other attributes in this struct are valid */ bool ready; /** * if true, then the stream is fully seekable */ bool seekable; /** * the size of the resource, or -1 if unknown */ goffset size; /** * the current offset within the stream */ goffset offset; /** * the MIME content type of the resource, or NULL if unknown */ char *mime; }; static inline void input_stream_init(struct input_stream *is, const struct input_plugin *plugin, const char *uri) { is->plugin = plugin; is->uri = g_strdup(uri); is->ready = false; is->seekable = false; is->size = -1; is->offset = 0; is->mime = NULL; } static inline void input_stream_deinit(struct input_stream *is) { g_free(is->uri); g_free(is->mime); } /** * Opens a new input stream. You may not access it until the "ready" * flag is set. * * @return an #input_stream object on success, NULL on error */ struct input_stream * input_stream_open(const char *uri, GError **error_r); /** * Close the input stream and free resources. */ void input_stream_close(struct input_stream *is); /** * Seeks to the specified position in the stream. This will most * likely fail if the "seekable" flag is false. * * @param is the input_stream object * @param offset the relative offset * @param whence the base of the seek, one of SEEK_SET, SEEK_CUR, SEEK_END */ bool input_stream_seek(struct input_stream *is, goffset offset, int whence, GError **error_r); /** * Returns true if the stream has reached end-of-file. */ bool input_stream_eof(struct input_stream *is); /** * Reads the tag from the stream. * * @return a tag object which must be freed with tag_free(), or NULL * if the tag has not changed since the last call */ struct tag * input_stream_tag(struct input_stream *is); /** * Reads some of the stream into its buffer. The following return * codes are defined: -1 = error, 1 = something was buffered, 0 = * nothing was buffered. * * The semantics of this function are not well-defined, and it will * eventually be removed. */ int input_stream_buffer(struct input_stream *is, GError **error_r); /** * Reads data from the stream into the caller-supplied buffer. * Returns 0 on error or eof (check with input_stream_eof()). * * @param is the input_stream object * @param ptr the buffer to read into * @param size the maximum number of bytes to read * @return the number of bytes read */ size_t input_stream_read(struct input_stream *is, void *ptr, size_t size, GError **error_r); #endif