evolution/camel/camel-data-wrapper.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-data-wrapper.c : Abstract class for a data_wrapper */

/** THIS IS MOSTLY AN ABSTRACT CLASS THAT SHOULD HAVE BEEN AN
    INTERFACE. **/

/*
 *
 * Author :
 *  Bertrand Guiheneuf <bertrand@helixcode.com>
 *
 * Copyright 1999, 2000 Helix Code, Inc. (http://www.helixcode.com)
 *
 * 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
 */
#include <config.h>
#include "camel-data-wrapper.h"

static GtkObjectClass *parent_class = NULL;

/* Returns the class for a CamelDataWrapper */
#define CDW_CLASS(so) CAMEL_DATA_WRAPPER_CLASS (GTK_OBJECT (so)->klass)


static void set_input_stream (CamelDataWrapper *data_wrapper,
			      CamelStream *stream);
static CamelStream *get_input_stream (CamelDataWrapper *data_wrapper);
static void set_output_stream (CamelDataWrapper *data_wrapper,
			       CamelStream *stream);
static CamelStream *get_output_stream (CamelDataWrapper *data_wrapper);

static void construct_from_stream (CamelDataWrapper *data_wrapper,
				   CamelStream *stream);
static void write_to_stream (CamelDataWrapper *data_wrapper,
			     CamelStream *stream);
static void set_mime_type (CamelDataWrapper *data_wrapper,
			   const gchar *mime_type);
static gchar *get_mime_type (CamelDataWrapper *data_wrapper);
static GMimeContentField *get_mime_type_field (CamelDataWrapper *data_wrapper);
static void set_mime_type_field (CamelDataWrapper *data_wrapper,
				 GMimeContentField *mime_type);
static void finalize (GtkObject *object);

static void
camel_data_wrapper_class_init (CamelDataWrapperClass *camel_data_wrapper_class)
{
	GtkObjectClass *gtk_object_class =
		GTK_OBJECT_CLASS (camel_data_wrapper_class);

	parent_class = gtk_type_class (gtk_object_get_type ());

	/* virtual method definition */
	camel_data_wrapper_class->write_to_stream = write_to_stream;
	camel_data_wrapper_class->construct_from_stream = construct_from_stream;
	camel_data_wrapper_class->set_mime_type = set_mime_type;
	camel_data_wrapper_class->get_mime_type = get_mime_type;
	camel_data_wrapper_class->get_mime_type_field = get_mime_type_field;
	camel_data_wrapper_class->set_mime_type_field = set_mime_type_field;

	camel_data_wrapper_class->set_input_stream = set_input_stream;
	camel_data_wrapper_class->get_input_stream = get_input_stream;
	camel_data_wrapper_class->set_output_stream = set_output_stream;
	camel_data_wrapper_class->get_output_stream = get_output_stream;

	/* virtual method overload */
	gtk_object_class->finalize = finalize;
}

static void
camel_data_wrapper_init (gpointer object, gpointer klass)
{
	CamelDataWrapper *camel_data_wrapper = CAMEL_DATA_WRAPPER (object);

	camel_data_wrapper->mime_type = gmime_content_field_new (NULL, NULL);
}



GtkType
camel_data_wrapper_get_type (void)
{
	static GtkType camel_data_wrapper_type = 0;

	if (!camel_data_wrapper_type) {
		GtkTypeInfo camel_data_wrapper_info =
		{
			"CamelDataWrapper",
			sizeof (CamelDataWrapper),
			sizeof (CamelDataWrapperClass),
			(GtkClassInitFunc) camel_data_wrapper_class_init,
			(GtkObjectInitFunc) camel_data_wrapper_init,
				/* reserved_1 */ NULL,
				/* reserved_2 */ NULL,
			(GtkClassInitFunc) NULL,
		};

		camel_data_wrapper_type = gtk_type_unique (gtk_object_get_type (), &camel_data_wrapper_info);
	}

	return camel_data_wrapper_type;
}


static void
finalize (GtkObject *object)
{
	CamelDataWrapper *camel_data_wrapper = CAMEL_DATA_WRAPPER (object);

	if (camel_data_wrapper->mime_type)
		gmime_content_field_unref (camel_data_wrapper->mime_type);

	if (camel_data_wrapper->input_stream)
		gtk_object_unref (GTK_OBJECT (camel_data_wrapper->input_stream));

	if (camel_data_wrapper->output_stream)
		gtk_object_unref (GTK_OBJECT (camel_data_wrapper->output_stream));

	parent_class->finalize (object);
}


static void
set_input_stream (CamelDataWrapper *data_wrapper, CamelStream *stream)
{
	if (data_wrapper->input_stream)
		gtk_object_unref (GTK_OBJECT (data_wrapper->input_stream));

	data_wrapper->input_stream = stream;

	if (!data_wrapper->output_stream && stream)
		set_output_stream (data_wrapper, stream);

	if (stream) {
		gtk_object_ref (GTK_OBJECT (stream));
		gtk_object_sink (GTK_OBJECT (stream));
	}
}

/**
 * camel_data_wrapper_set_input_stream:
 * @data_wrapper: a data wrapper
 * @stream: a stream that can be read from, or %NULL
 *
 * This sets the data wrapper's input stream from @stream, most likely
 * causing @data_wrapper to initialize itself from that stream.
 * @data_wrapper may or may not notice future changes to @stream, and
 * if @stream is closed before @data_wrapper is destroyed, it could
 * be arbitrarily bad. This function may fail, but there is no way
 * for the caller to know this.
 *
 * If @data_wrapper has no output stream, its output stream will also
 * be set to @stream.
 **/
void
camel_data_wrapper_set_input_stream (CamelDataWrapper *data_wrapper,
				     CamelStream *stream)
{
	g_return_if_fail (CAMEL_IS_DATA_WRAPPER (data_wrapper));
	g_return_if_fail (stream == NULL || CAMEL_IS_STREAM (stream));

	CDW_CLASS (data_wrapper)->set_input_stream (data_wrapper, stream);
}


static CamelStream *
get_input_stream (CamelDataWrapper *data_wrapper)
{
	return data_wrapper->input_stream;
}

/**
 * camel_data_wrapper_get_input_stream:
 * @data_wrapper: a data wrapper
 *
 * Return value: @data_wrapper's input stream
 **/
CamelStream *
camel_data_wrapper_get_input_stream (CamelDataWrapper *data_wrapper)
{
	g_return_val_if_fail (CAMEL_IS_DATA_WRAPPER (data_wrapper), NULL);

	return CDW_CLASS (data_wrapper)->get_input_stream (data_wrapper);
}


static void
set_output_stream (CamelDataWrapper *data_wrapper, CamelStream *stream)
{
	if (data_wrapper->output_stream)
		gtk_object_unref (GTK_OBJECT (data_wrapper->output_stream));

	data_wrapper->output_stream = stream;
	if (stream) {
		gtk_object_ref (GTK_OBJECT (stream));
		gtk_object_sink (GTK_OBJECT (stream));
	}
}

/**
 * camel_data_wrapper_set_output_stream:
 * @data_wrapper: a data wrapper
 * @stream: a stream that can be read from
 *
 * This sets the data wrapper's output stream to @stream. Unlike
 * camel_data_wrapper_set_input_stream(), this function has no side
 * effects.
 *
 * The output stream should theoretically be a stream that, if read
 * from, produces the data wrapper's contents. However, while certain
 * pieces of code assume this, nothing enforces it.
 **/
void
camel_data_wrapper_set_output_stream (CamelDataWrapper *data_wrapper,
				      CamelStream *stream)
{
	g_return_if_fail (CAMEL_IS_DATA_WRAPPER (data_wrapper));
	g_return_if_fail (CAMEL_IS_STREAM (stream));

	CDW_CLASS (data_wrapper)->set_output_stream (data_wrapper, stream);
}


static CamelStream *
get_output_stream (CamelDataWrapper *data_wrapper)
{
	return data_wrapper->output_stream;
}

/**
 * camel_data_wrapper_get_output_stream:
 * @data_wrapper: a data wrapper
 *
 * Return value: @data_wrapper's output stream
 **/
CamelStream *
camel_data_wrapper_get_output_stream (CamelDataWrapper *data_wrapper)
{
	g_return_val_if_fail (CAMEL_IS_DATA_WRAPPER (data_wrapper), NULL);

	return CDW_CLASS (data_wrapper)->get_output_stream (data_wrapper);
}


static void
write_to_stream (CamelDataWrapper *data_wrapper, CamelStream *stream)
{
	gchar tmp_buf[4096];
	gint nb_read;
	gint nb_written;
	CamelStream *output_stream;

	output_stream = camel_data_wrapper_get_output_stream (data_wrapper);
	if (!output_stream)
		return;

	camel_stream_reset (output_stream);

	while (!camel_stream_eos (output_stream)) {
		nb_read = camel_stream_read (output_stream, tmp_buf, 4096);
		nb_written = 0;
		while (nb_written < nb_read)
			nb_written += camel_stream_write (stream, tmp_buf + nb_written, nb_read - nb_written);
	}
}


/**
 * camel_data_wrapper_write_to_stream:
 * @data_wrapper: a data wrapper
 * @stream: stream for data to be written to
 *
 * Writes the data content to @stream in a machine-independent format
 * appropriate for the data. It should be possible to construct an
 * equivalent data wrapper object later by passing this stream to
 * camel_data_construct_from_stream().
 *
 * Of course, this operation might fail, and of course, there's no
 * way for you to find out about it.
 **/
void
camel_data_wrapper_write_to_stream (CamelDataWrapper *data_wrapper,
				    CamelStream *stream)
{
	g_return_if_fail (CAMEL_IS_DATA_WRAPPER (data_wrapper));
	g_return_if_fail (CAMEL_IS_STREAM (stream));

	CDW_CLASS (data_wrapper)->write_to_stream (data_wrapper, stream);
}


static void
construct_from_stream (CamelDataWrapper *data_wrapper, CamelStream *stream)
{
	/* nothing */
}

/**
 * camel_data_wrapper_construct_from_stream:
 * @data_wrapper: a data wrapper
 * @stream: a stream that can be read from
 *
 * This constructs a data wrapper object from a stream. It is not clear
 * how this differs from camel_data_wrapper_set_input_stream(), nor is
 * it clear how it affects the data wrapper's input and output streams.
 *
 * This could fail, but you can't know if it did.
 **/
void
camel_data_wrapper_construct_from_stream (CamelDataWrapper *data_wrapper,
					  CamelStream *stream)
{
	g_return_if_fail (CAMEL_IS_DATA_WRAPPER (data_wrapper));
	g_return_if_fail (CAMEL_IS_STREAM (stream));

	CDW_CLASS (data_wrapper)->construct_from_stream (data_wrapper, stream);
}


static void
set_mime_type (CamelDataWrapper *data_wrapper, const gchar *mime_type)
{
	gmime_content_field_construct_from_string (data_wrapper->mime_type,
						   mime_type);
}

/**
 * camel_data_wrapper_set_mime_type:
 * @data_wrapper: a data wrapper
 * @mime_type: the text representation of a MIME type
 *
 * This sets the data wrapper's MIME type.
 * It might fail, but you won't know. It will allow you to set
 * Content-Type parameters on the data wrapper, which are meaningless.
 * You should not be allowed to change the MIME type of a data wrapper
 * that contains data, or at least, if you do, it should invalidate the
 * data.
 **/
void
camel_data_wrapper_set_mime_type (CamelDataWrapper *data_wrapper,
				  const gchar *mime_type)
{
	g_return_if_fail (CAMEL_IS_DATA_WRAPPER (data_wrapper));
	g_return_if_fail (mime_type != NULL);

	CDW_CLASS (data_wrapper)->set_mime_type (data_wrapper, mime_type);
}

static gchar *
get_mime_type (CamelDataWrapper *data_wrapper)
{
	return gmime_content_field_get_mime_type (data_wrapper->mime_type);
}

/**
 * camel_data_wrapper_get_mime_type:
 * @data_wrapper: a data wrapper
 *
 * Return value: the text form of the data wrapper's MIME type
 **/
gchar *
camel_data_wrapper_get_mime_type (CamelDataWrapper *data_wrapper)
{
	g_return_val_if_fail (CAMEL_IS_DATA_WRAPPER (data_wrapper), NULL);

	return CDW_CLASS (data_wrapper)->get_mime_type (data_wrapper);
}


static GMimeContentField *
get_mime_type_field (CamelDataWrapper *data_wrapper)
{
	return data_wrapper->mime_type;
}

/**
 * camel_data_wrapper_get_mime_type_field:
 * @data_wrapper: a data wrapper
 *
 * Return value: the parsed form of the data wrapper's MIME type
 **/
GMimeContentField *
camel_data_wrapper_get_mime_type_field (CamelDataWrapper *data_wrapper)
{
	g_return_val_if_fail (CAMEL_IS_DATA_WRAPPER (data_wrapper), NULL);

	return CDW_CLASS (data_wrapper)->get_mime_type_field (data_wrapper);
}


/**
 * camel_data_wrapper_set_mime_type_field:
 * @data_wrapper: a data wrapper
 * @mime_type: the parsed representation of a MIME type
 *
 * This sets the data wrapper's MIME type. It suffers from the same
 * flaws as camel_data_wrapper_set_mime_type.
 **/
static void
set_mime_type_field (CamelDataWrapper *data_wrapper,
		     GMimeContentField *mime_type)
{
	g_return_if_fail (CAMEL_IS_DATA_WRAPPER (data_wrapper));
	g_return_if_fail (mime_type != NULL);

	if (data_wrapper->mime_type)
		gmime_content_field_unref (data_wrapper->mime_type);
	data_wrapper->mime_type = mime_type;
}

void
camel_data_wrapper_set_mime_type_field (CamelDataWrapper *data_wrapper,
					GMimeContentField *mime_type)
{
	CDW_CLASS (data_wrapper)->set_mime_type_field (data_wrapper,
						       mime_type);
}