path: root/camel/camel-stream-fs.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-stream-fs.c : file system based stream */

/* inspired by gnome-stream-fs.c in bonobo by Miguel de Icaza */
/* 
 *
 * Copyright (C) 1999 Bertrand Guiheneuf <Bertrand.Guiheneuf@inria.fr> .
 *
 * 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-stream-fs.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include "camel-log.h"

static CamelStreamClass *parent_class=NULL;


/* Returns the class for a CamelStreamFS */
#define CS_CLASS(so) CAMEL_STREAM_FS_CLASS (GTK_OBJECT(so)->klass)

static gint _read (CamelStream *stream, gchar *buffer, gint n);
static gint _write (CamelStream *stream, const gchar *buffer, gint n);
static void _flush (CamelStream *stream);
static gint _available (CamelStream *stream);
static gboolean _eos (CamelStream *stream);
static void _close (CamelStream *stream);
static gint _seek (CamelStream *stream, gint offset, CamelStreamSeekPolicy policy);

static void _finalize (GtkObject *object);
static void _destroy (GtkObject *object);

static void
camel_stream_fs_class_init (CamelStreamFsClass *camel_stream_fs_class)
{
    CamelStreamClass *camel_stream_class = CAMEL_STREAM_CLASS (camel_stream_fs_class);
    GtkObjectClass *gtk_object_class = GTK_OBJECT_CLASS (camel_stream_fs_class);

    parent_class = gtk_type_class (gtk_object_get_type ());
    
    /* virtual method definition */

    /* virtual method overload */
    camel_stream_class->read = _read;
    camel_stream_class->write = _write;
    camel_stream_class->flush = _flush;
    camel_stream_class->available = _available;
    camel_stream_class->eos = _eos;
    camel_stream_class->close = _close;
    camel_stream_class->seek = _seek;

    gtk_object_class->finalize = _finalize;
    gtk_object_class->destroy = _destroy;

}



GtkType
camel_stream_fs_get_type (void)
{
    static GtkType camel_stream_fs_type = 0;
    
    if (!camel_stream_fs_type)  {
        GtkTypeInfo camel_stream_fs_info =  
        {
            "CamelStreamFs",
            sizeof (CamelStreamFs),
            sizeof (CamelStreamFsClass),
            (GtkClassInitFunc) camel_stream_fs_class_init,
            (GtkObjectInitFunc) NULL,
                /* reserved_1 */ NULL,
                /* reserved_2 */ NULL,
            (GtkClassInitFunc) NULL,
        };
        
        camel_stream_fs_type = gtk_type_unique (camel_stream_get_type (), &camel_stream_fs_info);
    }
    
    return camel_stream_fs_type;
}


static void           
_destroy (GtkObject *object)
{
    CamelStreamFs *stream_fs = CAMEL_STREAM_FS (object);
    gint close_error;
    
    CAMEL_LOG_FULL_DEBUG ("Entering CamelStreamFs::destroy\n");
    
    close_error = close (stream_fs->fd);
    if (close_error) {
        CAMEL_LOG_FULL_DEBUG ("CamelStreamFs::destroy Error while closing file descriptor\n");
        CAMEL_LOG_FULL_DEBUG ( "  Full error text is : %s\n", strerror(errno));
    }
    GTK_OBJECT_CLASS (parent_class)->destroy (object);
    g_free (object);
    CAMEL_LOG_FULL_DEBUG ("Leaving CamelStreamFs::destroy\n");
}


static void           
_finalize (GtkObject *object)
{
    CamelStreamFs *stream_fs = CAMEL_STREAM_FS (object);


    CAMEL_LOG_FULL_DEBUG ("Entering CamelStreamFs::finalize\n");
    
    if (stream_fs->name) g_free (stream_fs->name);

    GTK_OBJECT_CLASS (parent_class)->finalize (object);
    CAMEL_LOG_FULL_DEBUG ("Leaving CamelStreamFs::finalize\n");
}


CamelStream *
camel_stream_fs_new_with_name (gchar *name, CamelStreamFsMode mode)
{
    struct stat s;
    int v, fd;
    int flags;
    CamelStreamFs *stream_fs;

    g_assert (name);
    CAMEL_LOG_FULL_DEBUG ( "Entering CamelStream::new_with_name, name=\"%s\", mode=%d\n", name, mode); 
    v = stat (name, &s);
    
    if (mode & CAMEL_STREAM_FS_READ){
        if (mode & CAMEL_STREAM_FS_WRITE)
            flags = O_RDWR | O_CREAT;
        else
            flags = O_RDONLY;
    } else {
        if (mode & CAMEL_STREAM_FS_WRITE)
            flags = O_WRONLY | O_CREAT;
        else
            return NULL;
    }
    if ( (mode & CAMEL_STREAM_FS_READ) && !(mode & CAMEL_STREAM_FS_WRITE) )
        if (v == -1) return NULL;

    fd = open (name, flags, 0600);
    if (fd==-1) {
        CAMEL_LOG_WARNING ( "CamelStreamFs::new_with_name can not obtain fd for file \"%s\"\n", name);
        CAMEL_LOG_FULL_DEBUG ( "  Full error text is : %s\n", strerror(errno));
        return NULL;
    }
    
    stream_fs = CAMEL_STREAM_FS (camel_stream_fs_new_with_fd (fd));
    stream_fs->name = name;

    return CAMEL_STREAM (stream_fs);
    
}

CamelStream *
camel_stream_fs_new_with_fd (int fd)
{
    CamelStreamFs *stream_fs;
    
    CAMEL_LOG_FULL_DEBUG ( "Entering CamelStream::new_with_fd  fd=%d\n",fd);
    stream_fs = gtk_type_new (camel_stream_fs_get_type ());
    stream_fs->fd = fd;
    return CAMEL_STREAM (stream_fs);
}

/**
 * _read: read bytes from a stream
 * @stream: stream
 * @buffer: buffer where bytes are stored
 * @n: max number of bytes to read
 * 
 * 
 * 
 * Return value: number of bytes actually read.
 **/
static gint
_read (CamelStream *stream, gchar *buffer, gint n)
{
    gint v;
    do {
        v = read ( (CAMEL_STREAM_FS (stream))->fd, buffer, n);
    } while (v == -1 && errno == EINTR);
    if (v<0)
        CAMEL_LOG_FULL_DEBUG ("CamelStreamFs::read v=%d\n", v);
    return v;
}


/**
 * _write: read bytes to a stream
 * @stream: the stream
 * @buffer: byte buffer
 * @n: number of bytes to write
 * 
 * 
 * 
 * Return value: the number of bytes actually written
 *  in the stream.
 **/
static gint
_write (CamelStream *stream, const gchar *buffer, gint n)
{
    int v;
    g_assert (stream);
    g_assert ((CAMEL_STREAM_FS (stream))->fd);
    CAMEL_LOG_FULL_DEBUG ( "CamelStreamFs:: entering write. n=%d\n", n);
    do {
        v = write ( (CAMEL_STREAM_FS (stream))->fd, buffer, n);
    } while (v == -1 && errno == EINTR);
    
#if HARD_LOG_LEVEL >= FULL_DEBUG
    if (v==-1) {
        perror("");
        CAMEL_LOG_FULL_DEBUG ( "CamelStreamFs::write could not write bytes in stream\n");
    }
#endif
    return v;

}



/**
 * _flush: flush pending changes 
 * @stream: the stream
 * 
 * 
 **/
static void
_flush (CamelStream *stream)
{
    fsync ((CAMEL_STREAM_FS (stream))->fd);
}



/**
 * _available: return the number of bytes available for reading
 * @stream: the stream
 * 
 * Return the number of bytes available without blocking.
 * 
 * Return value: the number of bytes available
 **/
static gint 
_available (CamelStream *stream)
{
    g_warning ("Not implemented yet");
}


/**
 * _eos: test if there are bytes left to read
 * @stream: the stream
 * 
 * 
 * 
 * Return value: true if all stream has been read
 **/
static gboolean
_eos (CamelStream *stream)
{
    g_warning ("Not implemented yet");
}


/**
 * _close: close a stream
 * @stream: the stream
 * 
 * 
 **/
static void
_close (CamelStream *stream)
{
    close ((CAMEL_STREAM_FS (stream))->fd);
}


static gint
_seek (CamelStream *stream, gint offset, CamelStreamSeekPolicy policy)
{
    int whence;
    switch  (policy) {
    case CAMEL_STREAM_SET:
        whence = SEEK_SET;
        break;
    case CAMEL_STREAM_CUR:
        whence = SEEK_CUR;
        break;
    case CAMEL_STREAM_END:
        whence = SEEK_END;
        break;
    default:
        return -1;
    }
        
        
    return lseek ((CAMEL_STREAM_FS (stream))->fd, offset, whence);
}