path: root/mail/em-sync-stream.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 *  Authors: Jeffrey Stedfast <fejj@ximian.com>
 *       Michael Zucchi <notzed@ximian.com>
 *
 *  Copyright 2001 Ximian, Inc. (www.ximian.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * 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 <string.h>
#include <stdio.h>
#include <camel/camel-stream.h>
#include <camel/camel-object.h>
#include <gtk/gtkmain.h>
#include "em-sync-stream.h"

#include "mail-mt.h"

/*#define LOG_STREAM*/

#define d(x) 

#define EMSS_CLASS(x) ((EMSyncStreamClass *)(((CamelObject *)(x))->klass))

struct _EMSyncStreamPrivate {
    /* FIXME: use a single data port/gui channel for all instances */
    /* TODO: possibly just use one of the mail-mt ports ... */
    struct _EMsgPort *data_port, *reply_port;
    struct _GIOChannel *gui_channel;
    guint gui_watch;

    char *buf_data;
    int buf_used;
    int buf_size;
};

/* Should probably expose messages to outside world ... so subclasses can extend */
enum _write_msg_t {
    EMSS_WRITE,
    EMSS_FLUSH,
    EMSS_CLOSE,
};

struct _write_msg {
    EMsg msg;

    enum _write_msg_t op;

    const char *data;
    size_t n;
};

static void em_sync_stream_class_init (EMSyncStreamClass *klass);
static void em_sync_stream_init (CamelObject *object);
static void em_sync_stream_finalize (CamelObject *object);

static ssize_t stream_write(CamelStream *stream, const char *buffer, size_t n);
static int stream_close(CamelStream *stream);
static int stream_flush(CamelStream *stream);

static CamelStreamClass *parent_class = NULL;

CamelType
em_sync_stream_get_type (void)
{
    static CamelType type = CAMEL_INVALID_TYPE;
    
    if (type == CAMEL_INVALID_TYPE) {
        type = camel_type_register (CAMEL_STREAM_TYPE,
                        "EMSyncStream",
                        sizeof (EMSyncStream),
                        sizeof (EMSyncStreamClass),
                        (CamelObjectClassInitFunc) em_sync_stream_class_init,
                        NULL,
                        (CamelObjectInitFunc) em_sync_stream_init,
                        (CamelObjectFinalizeFunc) em_sync_stream_finalize);
    }
    
    return type;
}

static void
em_sync_stream_class_init (EMSyncStreamClass *klass)
{
    CamelStreamClass *stream_class = CAMEL_STREAM_CLASS (klass);
    
    parent_class = (CamelStreamClass *) CAMEL_STREAM_TYPE;
    
    /* virtual method overload */
    stream_class->write = stream_write;
    stream_class->flush = stream_flush;
    stream_class->close = stream_close;
}

static gboolean
emcs_gui_received(GIOChannel *source, GIOCondition cond, void *data)
{
    EMSyncStream *emss = data;
    struct _EMSyncStreamPrivate *p = emss->priv;
    struct _write_msg *msg;

    d(printf("%p: gui sync op job waiting\n", emss));

    msg = (struct _write_msg *)e_msgport_get(p->data_port);
    /* Should never happen ... */
    if (msg == NULL)
        return TRUE;

    d(printf("%p: running sync op %d\n", emss, msg->op));

    /* force out any pending data before doing anything else */
    if (p->buf_used > 0) {
        EMSS_CLASS(emss)->sync_write((CamelStream *)emss, p->buf_data, p->buf_used);
        p->buf_used = 0;
    }

    /* FIXME: need to handle return values */

    switch (msg->op) {
    case EMSS_WRITE:
        EMSS_CLASS(emss)->sync_write((CamelStream *)emss, msg->data, msg->n);
        break;
    case EMSS_FLUSH:
        EMSS_CLASS(emss)->sync_flush((CamelStream *)emss);
        break;
    case EMSS_CLOSE:
        EMSS_CLASS(emss)->sync_close((CamelStream *)emss);
        break;
    }
    
    e_msgport_reply((EMsg *)msg);
    d(printf("%p: gui sync op jobs done\n", emss));

    return TRUE;
}

static void
em_sync_stream_init (CamelObject *object)
{
    EMSyncStream *emss = (EMSyncStream *)object;
    struct _EMSyncStreamPrivate *p;

    p = emss->priv = g_malloc0(sizeof(*p));

    p->data_port = e_msgport_new();
    p->reply_port = e_msgport_new();

    p->gui_channel = g_io_channel_unix_new(e_msgport_fd(p->data_port));
    p->gui_watch = g_io_add_watch(p->gui_channel, G_IO_IN, emcs_gui_received, emss);

    d(printf("%p: new emss\n", emss));
}

static void
sync_op(EMSyncStream *emss, enum _write_msg_t op, const char *data, size_t n)
{
    struct _EMSyncStreamPrivate *p = emss->priv;
    struct _write_msg msg;

    d(printf("%p: launching sync op %d\n", emss, op));

    /* we do everything synchronous, we should never have any locks, and
       this prevents overflow from banked up data */

    msg.msg.reply_port = p->reply_port;
    msg.op = op;
    msg.data = data;
    msg.n = n;

    e_msgport_put(p->data_port, &msg.msg);
    e_msgport_wait(p->reply_port);

    g_assert(e_msgport_get(msg.msg.reply_port) == &msg.msg);
    d(printf("%p: returned sync op %d\n", emss, op));
}

static void
em_sync_stream_finalize (CamelObject *object)
{
    EMSyncStream *emss = (EMSyncStream *)object;
    struct _EMSyncStreamPrivate *p = emss->priv;

    /* TODO: is this stuff safe to do in another thread? */
    g_source_remove(p->gui_watch);
    g_io_channel_unref(p->gui_channel);

    e_msgport_destroy(p->data_port);
    e_msgport_destroy(p->reply_port);

    p->data_port = NULL;
    p->reply_port = NULL;

    g_free(p->buf_data);
    g_free(p);
}

static ssize_t
stream_write (CamelStream *stream, const char *buffer, size_t n)
{
    EMSyncStream *emss = EM_SYNC_STREAM (stream);
    struct _EMSyncStreamPrivate *p = emss->priv;

    if (emss->cancel)
        return -1;

    if (pthread_self() == mail_gui_thread)
        EMSS_CLASS(emss)->sync_write(stream, buffer, n);
    else if (p->buf_size > 0) {
        size_t left = p->buf_size-p->buf_used;

        if (n >= left) {
            sync_op(emss, EMSS_WRITE, buffer, n);
        } else {
            memcpy(p->buf_data + p->buf_used, buffer, n);
            p->buf_used += n;
        }
    } else {
        sync_op(emss, EMSS_WRITE, buffer, n);
    }

    return (ssize_t) n;
}

static int
stream_flush(CamelStream *stream)
{
    EMSyncStream *emss = (EMSyncStream *)stream;

    if (emss->cancel)
        return -1;

    if (pthread_self() == mail_gui_thread)
        return ((EMSyncStreamClass *)(((CamelObject *)emss)->klass))->sync_flush(stream);
    else
        sync_op(emss, EMSS_FLUSH, NULL, 0);

    return 0;
}

static int
stream_close(CamelStream *stream)
{
    EMSyncStream *emss = (EMSyncStream *)stream;

    if (emss->cancel)
        return -1;

    d(printf("%p: closing stream\n", stream));

    if (pthread_self() == mail_gui_thread)
        return ((EMSyncStreamClass *)(((CamelObject *)emss)->klass))->sync_close(stream);
    else
        sync_op(emss, EMSS_CLOSE, NULL, 0);

    return 0;
}

void
em_sync_stream_set_buffer_size(EMSyncStream *emss, size_t size)
{
    struct _EMSyncStreamPrivate *p = emss->priv;

    g_free(p->buf_data);
    p->buf_data = g_malloc(size);
    p->buf_size = size;
    p->buf_used = 0;
}