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 */
/* 
 *
 * Author : 
 *  Bertrand Guiheneuf <bertrand@helixcode.com>
 *
 * Copyright 1999, 2000 HelixCode (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-stream-fs.h"
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include "camel-log.h"

static CamelSeekableStreamClass *parent_class=NULL;


/* Returns the class for a CamelStreamFS */
#define CSFS_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 gboolean _available (CamelStream *stream);
static gboolean _eos (CamelStream *stream);
static void _close (CamelStream *stream);
static gint _seek (CamelSeekableStream *stream, gint offset, CamelStreamSeekPolicy policy);

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

static void _init_with_fd (CamelStreamFs *stream_fs, int fd);
static void _init_with_fd_and_bounds (CamelStreamFs *stream_fs, int fd, guint32 inf_bound, gint32 sup_bound);
static void _init_with_name (CamelStreamFs *stream_fs, const gchar *name, CamelStreamFsMode mode);
static void _init_with_name_and_bounds (CamelStreamFs *stream_fs, const gchar *name, CamelStreamFsMode mode,
                    guint32 inf_bound, gint32 sup_bound);

static void
camel_stream_fs_class_init (CamelStreamFsClass *camel_stream_fs_class)
{
    CamelSeekableStreamClass *camel_seekable_stream_class = CAMEL_SEEKABLE_STREAM_CLASS (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 (camel_seekable_stream_get_type ());
    
    /* virtual method definition */
    camel_stream_fs_class->init_with_fd = _init_with_fd;
    camel_stream_fs_class->init_with_fd_and_bounds = _init_with_fd_and_bounds;
    camel_stream_fs_class->init_with_name = _init_with_name;
    camel_stream_fs_class->init_with_name_and_bounds = _init_with_name_and_bounds;
    
    /* 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_seekable_stream_class->seek = _seek;

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

}

static void
camel_stream_fs_init (gpointer   object,  gpointer   klass)
{
    CamelStreamFs *stream = CAMEL_STREAM_FS (object);

    stream->name = NULL;
    stream->eof = FALSE;
}


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) camel_stream_fs_init,
                /* reserved_1 */ NULL,
                /* reserved_2 */ NULL,
            (GtkClassInitFunc) NULL,
        };
        
        camel_stream_fs_type = gtk_type_unique (camel_seekable_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);
    
    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");
    
    g_free (stream_fs->name);

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



static void 
_set_bounds (CamelStreamFs *stream_fs, guint32 inf_bound, guint32 sup_bound)
{
    
    printf ("sup_bounds = %u\n", sup_bound);
    /* store the bounds */
    stream_fs->inf_bound = inf_bound;
    stream_fs->sup_bound = sup_bound;

    /* go to the first position */
    lseek (stream_fs->fd, inf_bound, SEEK_SET);

    CAMEL_SEEKABLE_STREAM (stream_fs)->cur_pos = inf_bound;
    
    CAMEL_LOG_FULL_DEBUG ("In CamelStreamFs::_set_bounds, "
                  "setting inf bound to %u, "
                  "sup bound to %ld, current postion to %u from %u\n", 
                  stream_fs->inf_bound, stream_fs->sup_bound,
                  CAMEL_SEEKABLE_STREAM (stream_fs)->cur_pos, inf_bound);
    
}




static void
_init_with_fd (CamelStreamFs *stream_fs, int fd)
{
    stream_fs->fd = fd;
    stream_fs->inf_bound = 0;
    stream_fs->sup_bound = -1;
    CAMEL_SEEKABLE_STREAM (stream_fs)->cur_pos = 0;
}




static void
_init_with_fd_and_bounds (CamelStreamFs *stream_fs, int fd, guint32 inf_bound, gint32 sup_bound)
{
    
    CSFS_CLASS (stream_fs)->init_with_fd (stream_fs, fd);
    _set_bounds (stream_fs, inf_bound, sup_bound);
    
}



static void
_init_with_name (CamelStreamFs *stream_fs, const gchar *name, CamelStreamFsMode mode)
{
    struct stat s;
    int v, fd;
    int flags;
    
    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 | O_NONBLOCK;
        else
            flags = O_RDONLY | O_NONBLOCK;
    } else {
        if (mode & CAMEL_STREAM_FS_WRITE)
            flags = O_WRONLY | O_CREAT | O_NONBLOCK;
        else
            return;
    }

    if ( (mode & CAMEL_STREAM_FS_READ) && !(mode & CAMEL_STREAM_FS_WRITE) )
        if (v == -1) {
            stream_fs->fd = -1;
            return;
        }
    

    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;
    }
    
    stream_fs->name = g_strdup (name);
    CSFS_CLASS (stream_fs)->init_with_fd (stream_fs, fd);
    
    gtk_signal_emit_by_name (GTK_OBJECT (stream_fs), "data_available");
    
}



static void
_init_with_name_and_bounds (CamelStreamFs *stream_fs, const gchar *name, CamelStreamFsMode mode,
                guint32 inf_bound, gint32 sup_bound)
{
    CSFS_CLASS (stream_fs)->init_with_name (stream_fs, name, mode);
    _set_bounds (stream_fs, inf_bound, (gint32)sup_bound);
    CAMEL_LOG_FULL_DEBUG ("In CamelStreamFs::init_with_name_and_bounds, "
                  "setting inf bound to %u, "
                  "sup bound to %ld, current postion to %u\n", 
                  stream_fs->inf_bound, stream_fs->sup_bound,
                  CAMEL_SEEKABLE_STREAM (stream_fs)->cur_pos);
}




CamelStream *
camel_stream_fs_new_with_name (const gchar *name, CamelStreamFsMode mode)
{
    CamelStreamFs *stream_fs;
    stream_fs = gtk_type_new (camel_stream_fs_get_type ());
    CSFS_CLASS (stream_fs)->init_with_name (stream_fs, name, mode);
    if (stream_fs->fd == -1) {
        gtk_object_destroy (GTK_OBJECT (stream_fs));
        return NULL;
    }
    
    return CAMEL_STREAM (stream_fs);
}
 

CamelStream *
camel_stream_fs_new_with_name_and_bounds (const gchar *name, CamelStreamFsMode mode,
                      guint32 inf_bound, gint32 sup_bound)
{
    CamelStreamFs *stream_fs;
    stream_fs = gtk_type_new (camel_stream_fs_get_type ());
    CSFS_CLASS (stream_fs)->init_with_name_and_bounds (stream_fs, name, mode, inf_bound, sup_bound);
    
    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 ());
    CSFS_CLASS (stream_fs)->init_with_fd (stream_fs, fd);

    
    return CAMEL_STREAM (stream_fs);
}



CamelStream *
camel_stream_fs_new_with_fd_and_bounds (int fd, guint32 inf_bound, gint32 sup_bound)
{
    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 ());
    CSFS_CLASS (stream_fs)->init_with_fd_and_bounds (stream_fs, fd, inf_bound, sup_bound);
    
    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)
{
    CamelStreamFs *stream_fs = CAMEL_STREAM_FS (stream);
    gint v;
    gint nb_to_read;
    
    if (stream_fs->sup_bound != -1)
        nb_to_read = MIN (stream_fs->sup_bound - CAMEL_SEEKABLE_STREAM (stream)->cur_pos, n);
    else 
        nb_to_read = n;
    
    do {
        v = read ( (CAMEL_STREAM_FS (stream))->fd, buffer, nb_to_read);
    } while (v == -1 && errno == EINTR);

    if (v<0)
        CAMEL_LOG_FULL_DEBUG ("CamelStreamFs::read v=%d\n", v);
    else 
        CAMEL_SEEKABLE_STREAM (stream)->cur_pos += v;

    if (v == 0)
        stream_fs->eof = TRUE;

    return v;
}


/**
 * _write: write 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)
{
    CamelStreamFs *stream_fs = CAMEL_STREAM_FS (stream);
    int v;
    gint nb_to_write;
    gint nb_bytes_written = 0;
    
    if (n <= 0)
        return 0;

    g_assert (stream);
    g_assert (stream_fs->fd);
    CAMEL_LOG_FULL_DEBUG ( "CamelStreamFs:: entering write. n=%d\n", n);

    /* we do not take the end bounds into account as it does not
       really make any sense in the case of a write operation */
    do {
        v = write ( stream_fs->fd, buffer, n);
        if (v>0) nb_bytes_written += v;
    } 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

    if (nb_bytes_written>0)
        CAMEL_SEEKABLE_STREAM (stream)->cur_pos += nb_bytes_written;

    return nb_bytes_written;

}



/**
 * _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 gboolean
_available (CamelStream *stream)
{
    g_warning ("Not implemented yet");
    return FALSE;
}


/**
 * _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)
{
    CamelStreamFs *stream_fs = CAMEL_STREAM_FS (stream);

    g_assert (stream_fs);
    return stream_fs->eof;
}


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


static gint
_seek (CamelSeekableStream *stream, gint offset, CamelStreamSeekPolicy policy)
{
    int whence;
    gint return_position;
    gint real_offset; 
    CamelStreamFs *stream_fs = CAMEL_STREAM_FS (stream);


    switch  (policy) {
    case CAMEL_STREAM_SET:
        real_offset = MAX (stream_fs->inf_bound + offset, stream_fs->inf_bound);
        if (stream_fs->sup_bound > 0)
            real_offset = MIN (real_offset, stream_fs->sup_bound);
        whence = SEEK_SET;      
        break;

    case CAMEL_STREAM_CUR:
        if ((stream_fs->sup_bound != -1) && ((CAMEL_SEEKABLE_STREAM (stream)->cur_pos + offset) > stream_fs->sup_bound)) {
            real_offset = stream_fs->sup_bound;
            whence = SEEK_SET;  
        } else if ((CAMEL_SEEKABLE_STREAM (stream)->cur_pos + offset) < stream_fs->inf_bound) {
            real_offset = stream_fs->inf_bound;
            whence = SEEK_SET;  
        } else 
            {
                real_offset = offset;
                whence = SEEK_CUR;
            }
        break;

    case CAMEL_STREAM_END:
        if (stream_fs->sup_bound != -1) {
            real_offset = stream_fs->sup_bound - offset;
            whence = SEEK_SET;
        } else {
            real_offset = offset;
            whence = SEEK_END;
        }
        
        
        break;
    default:
        return -1;
    }
        
    
        
    printf ("***** Seeking : real_offset=%d, whence=%d\n", real_offset, whence);
    return_position =  lseek (stream_fs->fd, real_offset, whence) - stream_fs->inf_bound;
    if (CAMEL_SEEKABLE_STREAM (stream)->cur_pos != return_position)
        stream_fs->eof = FALSE;

    CAMEL_SEEKABLE_STREAM (stream)->cur_pos = return_position;
    
    
    return return_position;
}