giochannel.c

嵌入式下基于MiniGUI的Web Browser

/* GLIB - Library of useful routines for C programming
 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * giochannel.c: IO Channel abstraction
 * Copyright 1998 Owen Taylor
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/*
 * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
 * file for a list of people on the GLib Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GLib at ftp://ftp.gtk.org/pub/gtk/. 
 */

/* 
 * MT safe
 */

#include "glibconfig.h"
#include "giochannel.h"

#include <string.h>
#include <errno.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#undef G_DISABLE_DEPRECATED

#include "glib.h"

#include "glibintl.h"

#define G_IO_NICE_BUF_SIZE	1024

/* This needs to be as wide as the largest character in any possible encoding */
#define MAX_CHAR_SIZE		10

/* Some simplifying macros, which reduce the need to worry whether the
 * buffers have been allocated. These also make USE_BUF () an lvalue,
 * which is used in g_io_channel_read_to_end ().
 */
#define USE_BUF(channel)	((channel)->encoding ? (channel)->encoded_read_buf \
				 : (channel)->read_buf)
#define BUF_LEN(string)		((string) ? (string)->len : 0)

static void		g_io_channel_purge		(GIOChannel  *channel);

void
g_io_channel_init (GIOChannel *channel)
{
  channel->ref_count = 1;
  channel->encoding = g_strdup ("UTF-8");
  channel->line_term = NULL;
  channel->line_term_len = 0;
  channel->buf_size = G_IO_NICE_BUF_SIZE;
  channel->read_cd = (GIConv) -1;
  channel->write_cd = (GIConv) -1;
  channel->read_buf = NULL; /* Lazy allocate buffers */
  channel->encoded_read_buf = NULL;
  channel->write_buf = NULL;
  channel->partial_write_buf[0] = '\0';
  channel->use_buffer = TRUE;
  channel->do_encode = FALSE;
  channel->close_on_unref = FALSE;
}

void 
g_io_channel_ref (GIOChannel *channel)
{
  g_return_if_fail (channel != NULL);

  channel->ref_count++;
}

void 
g_io_channel_unref (GIOChannel *channel)
{
  g_return_if_fail (channel != NULL);

  channel->ref_count--;
  if (channel->ref_count == 0)
    {
      if (channel->close_on_unref)
        g_io_channel_shutdown (channel, TRUE, NULL);
      else
        g_io_channel_purge (channel);
      g_free (channel->encoding);
#if 0
      if (channel->read_cd != (GIConv) -1)
        g_iconv_close (channel->read_cd);
      if (channel->write_cd != (GIConv) -1)
        g_iconv_close (channel->write_cd);
#endif
      if (channel->line_term)
        g_free (channel->line_term);
      if (channel->read_buf)
        g_string_free (channel->read_buf, TRUE);
      if (channel->write_buf)
        g_string_free (channel->write_buf, TRUE);
      if (channel->encoded_read_buf)
        g_string_free (channel->encoded_read_buf, TRUE);
      channel->funcs->io_free (channel);
    }
}

/**
 * g_io_channel_read:
 * @channel: a #GIOChannel. 
 * @buf: a buffer to read the data into (which should be at least count bytes long).
 * @count: the number of bytes to read from the #GIOChannel.
 * @bytes_read: returns the number of bytes actually read. 
 * 
 * Reads data from a #GIOChannel. This function is deprecated. New code should
 * use g_io_channel_read_chars() instead.
 * 
 * Return value: %G_IO_ERROR_NONE if the operation was successful. 
 **/
#ifdef changebysunny

GIOError 
g_io_channel_read (GIOChannel *channel, 
		   gchar      *buf, 
		   gsize       count,
		   gsize      *bytes_read)
{
  GError *err = NULL;
  GIOError error;
  GIOStatus status;

  g_return_val_if_fail (channel != NULL, G_IO_ERROR_UNKNOWN);
  g_return_val_if_fail (bytes_read != NULL, G_IO_ERROR_UNKNOWN);

  status = channel->funcs->io_read (channel, buf, count, bytes_read, &err);

  error = g_io_error_get_from_g_error (status, err);

  if (err)
    g_error_free (err);

  return error;
}
#endif
/**
 * g_io_channel_write:
 * @channel:  a #GIOChannel.
 * @buf: the buffer containing the data to write. 
 * @count: the number of bytes to write.
 * @bytes_written:  the number of bytes actually written.
 * 
 * Writes data to a #GIOChannel. This function is deprecated. New code should
 * use g_io_channel_write_chars() instead.
 * 
 * Return value:  %G_IO_ERROR_NONE if the operation was successful.
 **/
#ifdef changebysunny

GIOError 
g_io_channel_write (GIOChannel  *channel, 
		    const gchar *buf, 
		    gsize        count,
		    gsize       *bytes_written)
{
  GError *err = NULL;
  GIOError error;
  GIOStatus status;

  g_return_val_if_fail (channel != NULL, G_IO_ERROR_UNKNOWN);
  g_return_val_if_fail (bytes_written != NULL, G_IO_ERROR_UNKNOWN);

  status = channel->funcs->io_write (channel, buf, count, bytes_written, &err);

  error = g_io_error_get_from_g_error (status, err);

  if (err)
    g_error_free (err);

  return error;
}
#endif
/**
 * g_io_channel_seek:
 * @channel: a #GIOChannel. 
 * @offset: an offset, in bytes, which is added to the position specified by @type
 * @type: the position in the file, which can be %G_SEEK_CUR (the current
 *        position), %G_SEEK_SET (the start of the file), or %G_SEEK_END (the end of the
 *        file).
 * 
 * Sets the current position in the #GIOChannel, similar to the standard library
 * function <function>fseek()</function>. This function is deprecated. New 
 * code should use g_io_channel_seek_position() instead.
 * 
 * Return value: %G_IO_ERROR_NONE if the operation was successful.
 **/
#ifdef changebysunny

GIOError 
g_io_channel_seek  (GIOChannel   *channel,
		    gint64        offset, 
		    GSeekType     type)
{
  GError *err = NULL;
  GIOError error;
  GIOStatus status;

  g_return_val_if_fail (channel != NULL, G_IO_ERROR_UNKNOWN);
  g_return_val_if_fail (channel->is_seekable, G_IO_ERROR_UNKNOWN);

  switch (type)
    {
      case G_SEEK_CUR:
      case G_SEEK_SET:
      case G_SEEK_END:
        break;
      default:
        g_warning ("g_io_channel_seek: unknown seek type");
        return G_IO_ERROR_UNKNOWN;
    }

  status = channel->funcs->io_seek (channel, offset, type, &err);

  error = g_io_error_get_from_g_error (status, err);

  if (err)
    g_error_free (err);

  return error;
}
#endif
/* The function g_io_channel_new_file() is prototyped in both
 * giounix.c and giowin32.c, so we stick its documentation here.
 */

/**
 * g_io_channel_new_file:
 * @filename: A string containing the name of a file.
 * @mode: One of "r", "w", "a", "r+", "w+", "a+". These have
 *        the same meaning as in <function>fopen()</function>.
 * @error: A location to return an error of type %G_FILE_ERROR.
 *
 * Open a file @filename as a #GIOChannel using mode @mode. This
 * channel will be closed when the last reference to it is dropped,
 * so there is no need to call g_io_channel_close() (though doing
 * so will not cause problems, as long as no attempt is made to
 * access the channel after it is closed).
 *
 * Return value: A #GIOChannel on success, %NULL on failure.
 **/

/**
 * g_io_channel_close:
 * @channel: A #GIOChannel
 * 
 * Close an IO channel. Any pending data to be written will be
 * flushed, ignoring errors. The channel will not be freed until the
 * last reference is dropped using g_io_channel_unref(). This
 * function is deprecated: you should use g_io_channel_shutdown()
 * instead.
 **/
void
g_io_channel_close (GIOChannel *channel)
{
  GError *err = NULL;
  
  g_return_if_fail (channel != NULL);

  g_io_channel_purge (channel);

  channel->funcs->io_close (channel, &err);

  if (err)
    { /* No way to return the error */
      g_warning ("Error closing channel: %s", err->message);
      g_error_free (err);
    }
  
  channel->close_on_unref = FALSE; /* Because we already did */
  channel->is_readable = FALSE;
  channel->is_writeable = FALSE;
  channel->is_seekable = FALSE;
}

/**
 * g_io_channel_shutdown:
 * @channel: a #GIOChannel
 * @flush: if %TRUE, flush pending
 * @err: location to store a #GIOChannelError
 * 
 * Close an IO channel. Any pending data to be written will be
 * flushed if @flush is %TRUE. The channel will not be freed until the
 * last reference is dropped using g_io_channel_unref().
 *
 * Return value: the status of the operation.
 **/
GIOStatus //used
g_io_channel_shutdown (GIOChannel *channel,
		       gboolean    flush,
		       GError    **err)
{
  GIOStatus status, result;
  GError *tmperr = NULL;
  
  g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
  g_return_val_if_fail (err == NULL || *err == NULL, G_IO_STATUS_ERROR);

  if (channel->write_buf && channel->write_buf->len > 0)
    {
      if (flush)
        {
          GIOFlags flags;
      
          /* Set the channel to blocking, to avoid a busy loop
           */
          flags = g_io_channel_get_flags (channel);
          /* Ignore any errors here, they're irrelevant */
          g_io_channel_set_flags (channel, flags & ~G_IO_FLAG_NONBLOCK, NULL);

          result = g_io_channel_flush (channel, &tmperr);
        }
      else
        result = G_IO_STATUS_NORMAL;

      g_string_truncate(channel->write_buf, 0);
    }
  else
    result = G_IO_STATUS_NORMAL;

  if (channel->partial_write_buf[0] != '\0')
    {
      if (flush)
        g_warning ("Partial character at end of write buffer not flushed.\n");
      channel->partial_write_buf[0] = '\0';
    }

  status = channel->funcs->io_close (channel, err);

  channel->close_on_unref = FALSE; /* Because we already did */
  channel->is_readable = FALSE;
  channel->is_writeable = FALSE;
  channel->is_seekable = FALSE;

  if (status != G_IO_STATUS_NORMAL)
    {
      g_clear_error (&tmperr);
      return status;
    }
  else if (result != G_IO_STATUS_NORMAL)
    {
      g_propagate_error (err, tmperr);
      return result;
    }
  else
    return G_IO_STATUS_NORMAL;
}

/* This function is used for the final flush on close or unref */
static void //used
g_io_channel_purge (GIOChannel *channel)
{
  GError *err = NULL;
  GIOStatus status;

  g_return_if_fail (channel != NULL);

  if (channel->write_buf && channel->write_buf->len > 0)
    {
      GIOFlags flags;
      
      /* Set the channel to blocking, to avoid a busy loop
       */
      flags = g_io_channel_get_flags (channel);
      g_io_channel_set_flags (channel, flags & ~G_IO_FLAG_NONBLOCK, NULL);

      status = g_io_channel_flush (channel, &err);

      if (err)
	{ /* No way to return the error */
	  g_warning ("Error flushing string: %s", err->message);
	  g_error_free (err);
	}
    }

  /* Flush these in case anyone tries to close without unrefing */

  if (channel->read_buf)
    g_string_truncate (channel->read_buf, 0);
  if (channel->write_buf)
    g_string_truncate (channel->write_buf, 0);
  if (channel->encoding)
    {
      if (channel->encoded_read_buf)
        g_string_truncate (channel->encoded_read_buf, 0);

      if (channel->partial_write_buf[0] != '\0')
        {
          g_warning ("Partial character at end of write buffer not flushed.\n");
          channel->partial_write_buf[0] = '\0';
        }
    }
}

GSource *   //used
g_io_create_watch (GIOChannel  *channel,
		   GIOCondition condition)
{
  g_return_val_if_fail (channel != NULL, NULL);

  return channel->funcs->io_create_watch (channel, condition);
}

guint 
g_io_add_watch_full (GIOChannel    *channel,
		     gint           priority,
		     GIOCondition   condition,
		     GIOFunc        func,
		     gpointer       user_data,
		     GDestroyNotify notify)
{
  GSource *source;
  guint id;