glib/giochannel.h

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 /*
  21  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  22  * file for a list of people on the GLib Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 #if defined(G_DISABLE_SINGLE_INCLUDES) && !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
  28 #error "Only <glib.h> can be included directly."
  29 #endif
  30
  31 #ifndef __G_IOCHANNEL_H__
  32 #define __G_IOCHANNEL_H__
  33
  34 #include <glib/gconvert.h>
  35 #include <glib/gmain.h>
  36 #include <glib/gstring.h>
  37
  38 G_BEGIN_DECLS
  39
  40 /* GIOChannel
  41  */
  42
  43 typedef struct _GIOChannel      GIOChannel;
  44 typedef struct _GIOFuncs        GIOFuncs;
  45
  46 typedef enum
  47 {
  48   G_IO_ERROR_NONE,
  49   G_IO_ERROR_AGAIN,
  50   G_IO_ERROR_INVAL,
  51   G_IO_ERROR_UNKNOWN
  52 } GIOError;
  53
  54 #define G_IO_CHANNEL_ERROR g_io_channel_error_quark()
  55
  56 typedef enum
  57 {
  58   /* Derived from errno */
  59   G_IO_CHANNEL_ERROR_FBIG,
  60   G_IO_CHANNEL_ERROR_INVAL,
  61   G_IO_CHANNEL_ERROR_IO,
  62   G_IO_CHANNEL_ERROR_ISDIR,
  63   G_IO_CHANNEL_ERROR_NOSPC,
  64   G_IO_CHANNEL_ERROR_NXIO,
  65   G_IO_CHANNEL_ERROR_OVERFLOW,
  66   G_IO_CHANNEL_ERROR_PIPE,
  67   /* Other */
  68   G_IO_CHANNEL_ERROR_FAILED
  69 } GIOChannelError;
  70
  71 typedef enum
  72 {
  73   G_IO_STATUS_ERROR,
  74   G_IO_STATUS_NORMAL,
  75   G_IO_STATUS_EOF,
  76   G_IO_STATUS_AGAIN
  77 } GIOStatus;
  78
  79 typedef enum
  80 {
  81   G_SEEK_CUR,
  82   G_SEEK_SET,
  83   G_SEEK_END
  84 } GSeekType;
  85
  86 typedef enum
  87 {
  88   G_IO_IN       GLIB_SYSDEF_POLLIN,
  89   G_IO_OUT      GLIB_SYSDEF_POLLOUT,
  90   G_IO_PRI      GLIB_SYSDEF_POLLPRI,
  91   G_IO_ERR      GLIB_SYSDEF_POLLERR,
  92   G_IO_HUP      GLIB_SYSDEF_POLLHUP,
  93   G_IO_NVAL     GLIB_SYSDEF_POLLNVAL
  94 } GIOCondition;
  95
  96 typedef enum
  97 {
  98   G_IO_FLAG_APPEND = 1 << 0,
  99   G_IO_FLAG_NONBLOCK = 1 << 1,
 100   G_IO_FLAG_IS_READABLE = 1 << 2,       /* Read only flag */
 101   G_IO_FLAG_IS_WRITEABLE = 1 << 3,      /* Read only flag */
 102   G_IO_FLAG_IS_SEEKABLE = 1 << 4,       /* Read only flag */
 103   G_IO_FLAG_MASK = (1 << 5) - 1,
 104   G_IO_FLAG_GET_MASK = G_IO_FLAG_MASK,
 105   G_IO_FLAG_SET_MASK = G_IO_FLAG_APPEND | G_IO_FLAG_NONBLOCK
 106 } GIOFlags;
 107
 108 struct _GIOChannel
 109 {
 110   /*< private >*/
 111   gint ref_count;
 112   GIOFuncs *funcs;
 113
 114   gchar *encoding;
 115   GIConv read_cd;
 116   GIConv write_cd;
 117   gchar *line_term;             /* String which indicates the end of a line of text */
 118   guint line_term_len;          /* So we can have null in the line term */
 119
 120   gsize buf_size;
 121   GString *read_buf;            /* Raw data from the channel */
 122   GString *encoded_read_buf;    /* Channel data converted to UTF-8 */
 123   GString *write_buf;           /* Data ready to be written to the file */
 124   gchar partial_write_buf[6];   /* UTF-8 partial characters, null terminated */
 125
 126   /* Group the flags together, immediately after partial_write_buf, to save memory */
 127
 128   guint use_buffer     : 1;     /* The encoding uses the buffers */
 129   guint do_encode      : 1;     /* The encoding uses the GIConv coverters */
 130   guint close_on_unref : 1;     /* Close the channel on final unref */
 131   guint is_readable    : 1;     /* Cached GIOFlag */
 132   guint is_writeable   : 1;     /* ditto */
 133   guint is_seekable    : 1;     /* ditto */
 134
 135   gpointer reserved1;
 136   gpointer reserved2;
 137 };
 138
 139 typedef gboolean (*GIOFunc) (GIOChannel   *source,
 140                              GIOCondition  condition,
 141                              gpointer      data);
 142 struct _GIOFuncs
 143 {
 144   GIOStatus (*io_read)           (GIOChannel   *channel,
 145                                   gchar        *buf,
 146                                   gsize         count,
 147                                   gsize        *bytes_read,
 148                                   GError      **err);
 149   GIOStatus (*io_write)          (GIOChannel   *channel,
 150                                   const gchar  *buf,
 151                                   gsize         count,
 152                                   gsize        *bytes_written,
 153                                   GError      **err);
 154   GIOStatus (*io_seek)           (GIOChannel   *channel,
 155                                   gint64        offset,
 156                                   GSeekType     type,
 157                                   GError      **err);
 158   GIOStatus  (*io_close)         (GIOChannel   *channel,
 159                                   GError      **err);
 160   GSource*   (*io_create_watch)  (GIOChannel   *channel,
 161                                   GIOCondition  condition);
 162   void       (*io_free)          (GIOChannel   *channel);
 163   GIOStatus  (*io_set_flags)     (GIOChannel   *channel,
 164                                   GIOFlags      flags,
 165                                   GError      **err);
 166   GIOFlags   (*io_get_flags)     (GIOChannel   *channel);
 167 };
 168
 169 void        g_io_channel_init   (GIOChannel    *channel);
 170 GIOChannel *g_io_channel_ref    (GIOChannel    *channel);
 171 void        g_io_channel_unref  (GIOChannel    *channel);
 172
 173 #ifndef G_DISABLE_DEPRECATED
 174 GIOError    g_io_channel_read   (GIOChannel    *channel,
 175                                  gchar         *buf,
 176                                  gsize          count,
 177                                  gsize         *bytes_read);
 178 GIOError  g_io_channel_write    (GIOChannel    *channel,
 179                                  const gchar   *buf,
 180                                  gsize          count,
 181                                  gsize         *bytes_written);
 182 GIOError  g_io_channel_seek     (GIOChannel    *channel,
 183                                  gint64         offset,
 184                                  GSeekType      type);
 185 void      g_io_channel_close    (GIOChannel    *channel);
 186 #endif /* G_DISABLE_DEPRECATED */
 187
 188 GIOStatus g_io_channel_shutdown (GIOChannel      *channel,
 189                                  gboolean         flush,
 190                                  GError         **err);
 191 guint     g_io_add_watch_full   (GIOChannel      *channel,
 192                                  gint             priority,
 193                                  GIOCondition     condition,
 194                                  GIOFunc          func,
 195                                  gpointer         user_data,
 196                                  GDestroyNotify   notify);
 197 GSource * g_io_create_watch     (GIOChannel      *channel,
 198                                  GIOCondition     condition);
 199 guint     g_io_add_watch        (GIOChannel      *channel,
 200                                  GIOCondition     condition,
 201                                  GIOFunc          func,
 202                                  gpointer         user_data);
 203
 204 /* character encoding conversion involved functions.
 205  */
 206
 207 void                  g_io_channel_set_buffer_size      (GIOChannel   *channel,
 208                                                          gsize         size);
 209 gsize                 g_io_channel_get_buffer_size      (GIOChannel   *channel);
 210 GIOCondition          g_io_channel_get_buffer_condition (GIOChannel   *channel);
 211 GIOStatus             g_io_channel_set_flags            (GIOChannel   *channel,
 212                                                          GIOFlags      flags,
 213                                                          GError      **error);
 214 GIOFlags              g_io_channel_get_flags            (GIOChannel   *channel);
 215 void                  g_io_channel_set_line_term        (GIOChannel   *channel,
 216                                                          const gchar  *line_term,
 217                                                          gint          length);
 218 G_CONST_RETURN gchar* g_io_channel_get_line_term        (GIOChannel   *channel,
 219                                                          gint         *length);
 220 void                  g_io_channel_set_buffered         (GIOChannel   *channel,
 221                                                          gboolean      buffered);
 222 gboolean              g_io_channel_get_buffered         (GIOChannel   *channel);
 223 GIOStatus             g_io_channel_set_encoding         (GIOChannel   *channel,
 224                                                          const gchar  *encoding,
 225                                                          GError      **error);
 226 G_CONST_RETURN gchar* g_io_channel_get_encoding         (GIOChannel   *channel);
 227 void                  g_io_channel_set_close_on_unref   (GIOChannel   *channel,
 228                                                          gboolean      do_close);
 229 gboolean              g_io_channel_get_close_on_unref   (GIOChannel   *channel);
 230
 231
 232 GIOStatus   g_io_channel_flush            (GIOChannel   *channel,
 233                                            GError      **error);
 234 GIOStatus   g_io_channel_read_line        (GIOChannel   *channel,
 235                                            gchar       **str_return,
 236                                            gsize        *length,
 237                                            gsize        *terminator_pos,
 238                                            GError      **error);
 239 GIOStatus   g_io_channel_read_line_string (GIOChannel   *channel,
 240                                            GString      *buffer,
 241                                            gsize        *terminator_pos,
 242                                            GError      **error);
 243 GIOStatus   g_io_channel_read_to_end      (GIOChannel   *channel,
 244                                            gchar       **str_return,
 245                                            gsize        *length,
 246                                            GError      **error);
 247 GIOStatus   g_io_channel_read_chars       (GIOChannel   *channel,
 248                                            gchar        *buf,
 249                                            gsize         count,
 250                                            gsize        *bytes_read,
 251                                            GError      **error);
 252 GIOStatus   g_io_channel_read_unichar     (GIOChannel   *channel,
 253                                            gunichar     *thechar,
 254                                            GError      **error);
 255 GIOStatus   g_io_channel_write_chars      (GIOChannel   *channel,
 256                                            const gchar  *buf,
 257                                            gssize        count,
 258                                            gsize        *bytes_written,
 259                                            GError      **error);
 260 GIOStatus   g_io_channel_write_unichar    (GIOChannel   *channel,
 261                                            gunichar      thechar,
 262                                            GError      **error);
 263 GIOStatus   g_io_channel_seek_position    (GIOChannel   *channel,
 264                                            gint64        offset,
 265                                            GSeekType     type,
 266                                            GError      **error);
 267 #ifdef G_OS_WIN32
 268 #define g_io_channel_new_file g_io_channel_new_file_utf8
 269 #endif
 270
 271 GIOChannel* g_io_channel_new_file         (const gchar  *filename,
 272                                            const gchar  *mode,
 273                                            GError      **error);
 274
 275 /* Error handling */
 276
 277 GQuark          g_io_channel_error_quark      (void);
 278 GIOChannelError g_io_channel_error_from_errno (gint en);
 279
 280 /* On Unix, IO channels created with this function for any file
 281  * descriptor or socket.
 282  *
 283  * On Win32, this can be used either for files opened with the MSVCRT
 284  * (the Microsoft run-time C library) _open() or _pipe, including file
 285  * descriptors 0, 1 and 2 (corresponding to stdin, stdout and stderr),
 286  * or for Winsock SOCKETs. If the parameter is a legal file
 287  * descriptor, it is assumed to be such, otherwise it should be a
 288  * SOCKET. This relies on SOCKETs and file descriptors not
 289  * overlapping. If you want to be certain, call either
 290  * g_io_channel_win32_new_fd() or g_io_channel_win32_new_socket()
 291  * instead as appropriate.
 292  *
 293  * The term file descriptor as used in the context of Win32 refers to
 294  * the emulated Unix-like file descriptors MSVCRT provides. The native
 295  * corresponding concept is file HANDLE. There isn't as of yet a way to
 296  * get GIOChannels for Win32 file HANDLEs.
 297  */
 298 GIOChannel* g_io_channel_unix_new    (int         fd);
 299 gint        g_io_channel_unix_get_fd (GIOChannel *channel);
 300
 301
 302 /* Hook for GClosure / GSource integration. Don't touch */
 303 GLIB_VAR GSourceFuncs g_io_watch_funcs;
 304
 305 #ifdef G_OS_WIN32
 306
 307 /* You can use this "pseudo file descriptor" in a GPollFD to add
 308  * polling for Windows messages. GTK applications should not do that.
 309  */
 310
 311 #define G_WIN32_MSG_HANDLE 19981206
 312
 313 /* Use this to get a GPollFD from a GIOChannel, so that you can call
 314  * g_io_channel_win32_poll(). After calling this you should only use
 315  * g_io_channel_read() to read from the GIOChannel, i.e. never read()
 316  * from the underlying file descriptor. For SOCKETs, it is possible to call
 317  * recv().
 318  */
 319 void        g_io_channel_win32_make_pollfd (GIOChannel   *channel,
 320                                             GIOCondition  condition,
 321                                             GPollFD      *fd);
 322
 323 /* This can be used to wait a until at least one of the channels is readable.
 324  * On Unix you would do a select() on the file descriptors of the channels.
 325  */
 326 gint        g_io_channel_win32_poll   (GPollFD    *fds,
 327                                        gint        n_fds,
 328                                        gint        timeout_);
 329
 330 /* Create an IO channel for Windows messages for window handle hwnd. */
 331 GIOChannel *g_io_channel_win32_new_messages (guint hwnd);
 332
 333 /* Create an IO channel for C runtime (emulated Unix-like) file
 334  * descriptors. After calling g_io_add_watch() on a IO channel
 335  * returned by this function, you shouldn't call read() on the file
 336  * descriptor. This is because adding polling for a file descriptor is
 337  * implemented on Win32 by starting a thread that sits blocked in a
 338  * read() from the file descriptor most of the time. All reads from
 339  * the file descriptor should be done by this internal GLib
 340  * thread. Your code should call only g_io_channel_read_chars().
 341  */
 342 GIOChannel* g_io_channel_win32_new_fd (gint         fd);
 343
 344 /* Get the C runtime file descriptor of a channel. */
 345 gint        g_io_channel_win32_get_fd (GIOChannel *channel);
 346
 347 /* Create an IO channel for a winsock socket. The parameter should be
 348  * a SOCKET. Contrary to IO channels for file descriptors (on *Win32),
 349  * you can use normal recv() or recvfrom() on sockets even if GLib
 350  * is polling them.
 351  */
 352 GIOChannel *g_io_channel_win32_new_socket (gint socket);
 353
 354 #endif
 355
 356 G_END_DECLS
 357
 358 #endif /* __G_IOCHANNEL_H__ */