source: trunk/third/bonobo/bonobo/bonobo-stream-memory.c @ 15579

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/**
 * bonobo-stream-memory.c: Memory based stream
 *
 * Author:
 *   Miguel de Icaza (miguel@gnu.org)
 *
 * Copyright 1999, 2000 Helix Code, Inc.
 */
#include <config.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <libgnome/gnome-defs.h>
#include <libgnome/gnome-util.h>
#include <bonobo/bonobo-stream-memory.h>
#include <errno.h>

static BonoboStreamClass *bonobo_stream_mem_parent_class;

static Bonobo_StorageInfo*
mem_get_info (BonoboStream                  *stream,
              const Bonobo_StorageInfoFields mask,
              CORBA_Environment             *ev)
{
        Bonobo_StorageInfo *si;
        BonoboStreamMem    *smem = BONOBO_STREAM_MEM (stream);

        si = Bonobo_StorageInfo__alloc ();

        si->size = smem->size;
        si->type = Bonobo_STORAGE_TYPE_REGULAR;
        si->name = CORBA_string_dup ("");
        si->content_type = CORBA_string_dup ("application/octet-stream");

        return si;
}

static void
mem_set_info (BonoboStream *stream,
              const Bonobo_StorageInfo *info,
              const Bonobo_StorageInfoFields mask,
              CORBA_Environment *ev)
{
        BonoboStreamMem *smem = BONOBO_STREAM_MEM (stream);

        if (smem->read_only)
                CORBA_exception_set (
                        ev, CORBA_USER_EXCEPTION,
                        ex_Bonobo_Stream_NoPermission, NULL);
        else
                CORBA_exception_set (
                        ev, CORBA_USER_EXCEPTION,
                        ex_Bonobo_Stream_NotSupported, NULL);
}

static void
mem_truncate (BonoboStream *stream,
              const CORBA_long new_size, 
              CORBA_Environment *ev)
{
        BonoboStreamMem *smem = BONOBO_STREAM_MEM (stream);
        void *newp;
        
        if (smem->read_only)
                return;

        newp = g_realloc (smem->buffer, new_size);
        if (!newp) {
                CORBA_exception_set (ev, CORBA_USER_EXCEPTION,
                                     ex_Bonobo_Stream_NoPermission, NULL);
                return;
        }

        smem->buffer = newp;
        smem->size = new_size;

        if (smem->pos > new_size)
                smem->pos = new_size;
}

static void
mem_write (BonoboStream *stream, const Bonobo_Stream_iobuf *buffer,
           CORBA_Environment *ev)
{
        BonoboStreamMem *smem = BONOBO_STREAM_MEM (stream);
        long len = buffer->_length;

        if (smem->read_only){
                g_warning ("Should signal an exception here");
                return;
        }

        if (smem->pos + len > smem->size){
                if (smem->resizable){
                        smem->size = smem->pos + len;
                        smem->buffer = g_realloc (smem->buffer, smem->size);
                } else {
                        mem_truncate (stream, smem->pos + len, ev);
                        g_warning ("Should check for an exception here");
                }
        }

        if (smem->pos + len > smem->size)
                len = smem->size - smem->pos;
        
        memcpy (smem->buffer + smem->pos, buffer->_buffer, len);
        smem->pos += len;
                
        return;
}

static void
mem_read (BonoboStream *stream, CORBA_long count,
          Bonobo_Stream_iobuf ** buffer,
          CORBA_Environment *ev)
{
        BonoboStreamMem *smem = BONOBO_STREAM_MEM (stream);

        if (smem->pos + count > smem->size)
                count = smem->size - smem->pos;
            
        *buffer = Bonobo_Stream_iobuf__alloc ();
        CORBA_sequence_set_release (*buffer, TRUE);
        (*buffer)->_buffer = CORBA_sequence_CORBA_octet_allocbuf (count);
        (*buffer)->_length = count;
        
        memcpy ((*buffer)->_buffer, smem->buffer + smem->pos, count);

        smem->pos += count;
}

static CORBA_long
mem_seek (BonoboStream *stream,
          CORBA_long offset, Bonobo_Stream_SeekType whence,
          CORBA_Environment *ev)
{
        BonoboStreamMem *smem = BONOBO_STREAM_MEM (stream);
        int pos = 0;
        
        switch (whence){
        case Bonobo_Stream_SEEK_SET:
                pos = offset;
                break;

        case Bonobo_Stream_SEEK_CUR:
                pos = smem->pos + offset;
                break;

        case Bonobo_Stream_SEEK_END:
                pos = smem->size + offset;
                break;

        default:
                g_warning ("Signal exception");
        }

        if (pos > smem->size){
                if (smem->resizable){
                        smem->buffer = g_realloc (smem->buffer, pos);
                        memset (smem->buffer + smem->size, 0,
                                pos - smem->size);
                        smem->size = pos;
                } else
                        mem_truncate (stream, pos, ev);
        }
        smem->pos = pos;
        return pos;
}

static void
mem_copy_to  (BonoboStream *stream,
              const CORBA_char *dest,
              const CORBA_long bytes,
              CORBA_long *read,
              CORBA_long *written,
              CORBA_Environment *ev)
{
        BonoboStreamMem *smem = BONOBO_STREAM_MEM (stream);
        gint fd_out;
        gint w;
        
        *read = smem->size - smem->pos;
        *written = 0;
        
        /* create the output file */
        fd_out = creat(dest, 0666);
        if (fd_out == -1) {
                g_warning ("unable to create output file");
                return;
        }
        
        /* write the memory stream buffer to the output file */
        do {
                w = write (fd_out, smem->buffer, *read);
        } while (w == -1 && errno == EINTR);
        
        if (w != -1)
                *written = w;
        else if (errno != EINTR) {
                /* should probably do something to signal an error here */
                g_warning ("ouput file write failed");
        }
        
        
        close(fd_out);

}

static void
mem_commit (BonoboStream *stream,
            CORBA_Environment *ev)
{
        CORBA_exception_set (ev, CORBA_USER_EXCEPTION,
                             ex_Bonobo_Stream_NotSupported, NULL);
}

static void
mem_revert (BonoboStream *stream,
            CORBA_Environment *ev)
{
        CORBA_exception_set (ev, CORBA_USER_EXCEPTION,
                             ex_Bonobo_Stream_NotSupported, NULL);
}

static void
mem_destroy (GtkObject *object)
{
        BonoboStreamMem *smem = BONOBO_STREAM_MEM (object);
        
        if (smem->buffer)
                g_free (smem->buffer);
        
        GTK_OBJECT_CLASS (bonobo_stream_mem_parent_class)->destroy (object);
}

static char *
mem_get_buffer (BonoboStreamMem *stream_mem)
{
        g_return_val_if_fail (BONOBO_IS_STREAM_MEM (stream_mem), NULL);

        return stream_mem->buffer;
}

static size_t
mem_get_size (BonoboStreamMem *stream_mem)
{
        g_return_val_if_fail (BONOBO_IS_STREAM_MEM (stream_mem), 0);

        return stream_mem->size;
}

static void
bonobo_stream_mem_class_init (BonoboStreamMemClass *klass)
{
        GtkObjectClass *object_class = (GtkObjectClass *) klass;
        BonoboStreamClass *sclass = BONOBO_STREAM_CLASS (klass);
        
        bonobo_stream_mem_parent_class = gtk_type_class (bonobo_stream_get_type ());

        object_class->destroy = mem_destroy;
        
        sclass->get_info  = mem_get_info;
        sclass->set_info  = mem_set_info;
        sclass->write     = mem_write;
        sclass->read      = mem_read;
        sclass->seek      = mem_seek;
        sclass->truncate  = mem_truncate;
        sclass->copy_to   = mem_copy_to;
        sclass->commit    = mem_commit;
        sclass->revert    = mem_revert;

        klass->get_buffer = mem_get_buffer;
        klass->get_size   = mem_get_size;
}

/**
 * bonobo_stream_mem_get_type:
 *
 * Returns: the GtkType of the BonoboStreamMem class.
 */
GtkType
bonobo_stream_mem_get_type (void)
{
        static GtkType type = 0;

        if (!type){
                GtkTypeInfo info = {
                        "BonoboStreamMem",
                        sizeof (BonoboStreamMem),
                        sizeof (BonoboStreamMemClass),
                        (GtkClassInitFunc) bonobo_stream_mem_class_init,
                        (GtkObjectInitFunc) NULL,
                        NULL, /* reserved 1 */
                        NULL, /* reserved 2 */
                        (GtkClassInitFunc) NULL
                };

                type = gtk_type_unique (bonobo_stream_get_type (), &info);
        }

        return type;
}

BonoboStreamMem *
bonobo_stream_mem_construct (BonoboStreamMem *stream_mem,
                             Bonobo_Stream    corba_stream,
                             const char      *buffer,
                             size_t           size,
                             gboolean         read_only,
                             gboolean         resizable)
{
        g_return_val_if_fail (corba_stream != CORBA_OBJECT_NIL, NULL);
        g_return_val_if_fail (BONOBO_IS_STREAM_MEM (stream_mem), NULL);

        if (buffer == NULL) {
                stream_mem->buffer = g_malloc (size);
                memset (stream_mem->buffer, 0, size);
        } else
                stream_mem->buffer = g_memdup (buffer, size);

        stream_mem->size = size;
        stream_mem->pos = 0;
        stream_mem->read_only = read_only;
        stream_mem->resizable = resizable;

        return BONOBO_STREAM_MEM (
                bonobo_object_construct (BONOBO_OBJECT (stream_mem),
                                         corba_stream));
}

/**
 * bonobo_stream_mem_create:
 * @buffer: The data for which a BonoboStreamMem object is to be created.
 * @size: The size in bytes of @buffer.
 * @read_only: Specifies whether or not the returned BonoboStreamMem
 * object should allow write() operations.
 * @resizable: Whether or not the buffer should be resized as needed.
 *
 * Creates a new BonoboStreamMem object.
 *
 * If @buffer is non-%NULL, @size bytes are copied from it into a new
 * buffer. If @buffer is %NULL, a new buffer of size @size is created
 * and filled with zero bytes.
 *
 * When data is read out of or (if @read_only is FALSE) written into
 * the returned BonoboStream object, the read() and write() operations
 * operate on the new buffer. If @resizable is TRUE, writing or seeking
 * past the end of the buffer will cause the buffer to be expanded (with
 * the new space zero-filled for a seek).
 *
 * Returns: the constructed BonoboStream object
 **/
BonoboStream *
bonobo_stream_mem_create (const char *buffer, size_t size,
                          gboolean read_only, gboolean resizable)
{
        BonoboStreamMem *stream_mem;
        Bonobo_Stream corba_stream;

        stream_mem = gtk_type_new (bonobo_stream_mem_get_type ());
        if (stream_mem == NULL)
                return NULL;


        corba_stream = bonobo_stream_corba_object_create (
                BONOBO_OBJECT (stream_mem));

        if (corba_stream == CORBA_OBJECT_NIL) {
                bonobo_object_unref (BONOBO_OBJECT (stream_mem));
                return NULL;
        }

        return BONOBO_STREAM (bonobo_stream_mem_construct (
                stream_mem, corba_stream, buffer, size,
                read_only, resizable));
}

/**
 * bonobo_stream_mem_get_buffer:
 * @stream_mem: a BonoboStreamMem
 *
 * Returns the buffer associated with a BonoboStreamMem. If the stream
 * is set to automatically resize itself, this buffer is only guaranteed
 * to stay valid until the next write operation on the stream.
 *
 * Return value: a buffer containing the data written to the stream (or
 * the data the stream was initialized with if nothing has been written).
 **/
const char *
bonobo_stream_mem_get_buffer (BonoboStreamMem *stream_mem)
{
        return BONOBO_STREAM_MEM_CLASS(
                GTK_OBJECT(stream_mem)->klass)->get_buffer (stream_mem);
}

/**
 * bonobo_stream_mem_get_size:
 * @stream_mem: a BonoboStreamMem
 *
 * Returns the size of the data associated with a BonoboStreamMem
 * see bonobo_stream_mem_get_buffer
 *
 * Return value: the size.
 **/
size_t
bonobo_stream_mem_get_size (BonoboStreamMem *stream_mem)
{
        return BONOBO_STREAM_MEM_CLASS(
                GTK_OBJECT(stream_mem)->klass)->get_size (stream_mem);
}