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

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-stream-mem.c : memory buffer based stream
 * inspired by gnome-stream-mem.c in bonobo by Miguel de Icaza
 *
 * Authors: Bertrand Guiheneuf <bertrand@helixcode.com>
 *      Michael Zucchi <notzed@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-stream-mem.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>

static CamelStreamClass *parent_class=NULL;

/* Returns the class for a CamelStreamMEM */
#define CSM_CLASS(so) CAMEL_STREAM_MEM_CLASS (GTK_OBJECT(so)->klass)

static gint stream_read (CamelStream *stream, gchar *buffer, gint n);
static gint stream_write (CamelStream *stream, const gchar *buffer, gint n);
static void stream_flush (CamelStream *stream);
static gboolean stream_eos (CamelStream *stream);
static void stream_close (CamelStream *stream);
static off_t stream_seek (CamelSeekableStream *stream, off_t offset, CamelStreamSeekPolicy policy);

static void finalize (GtkObject *object);

static void
camel_stream_mem_class_init (CamelStreamMemClass *camel_stream_mem_class)
{
    CamelSeekableStreamClass *camel_seekable_stream_class = CAMEL_SEEKABLE_STREAM_CLASS (camel_stream_mem_class);
    CamelStreamClass *camel_stream_class = CAMEL_STREAM_CLASS (camel_stream_mem_class);
    GtkObjectClass *gtk_object_class = GTK_OBJECT_CLASS (camel_stream_mem_class);
    
    parent_class = gtk_type_class (gtk_object_get_type ());
    
    /* virtual method definition */
    
    /* virtual method overload */
    camel_stream_class->read = stream_read;
    camel_stream_class->write = stream_write;
    camel_stream_class->flush = stream_flush;
    camel_stream_class->eos = stream_eos;
    camel_stream_class->close = stream_close;

    camel_seekable_stream_class->seek = stream_seek;
    
    gtk_object_class->finalize = finalize;
}

static void
camel_stream_mem_init (gpointer   object,  gpointer   klass)
{
    CamelStreamMem *stream_mem = CAMEL_STREAM_MEM (object);
    stream_mem->owner = FALSE;
    stream_mem->buffer = 0;
}

GtkType
camel_stream_mem_get_type (void)
{
    static GtkType camel_stream_mem_type = 0;
    
    if (!camel_stream_mem_type) {
        GtkTypeInfo camel_stream_mem_info = 
        {
            "CamelStreamMem",
            sizeof (CamelStreamMem),
            sizeof (CamelStreamMemClass),
            (GtkClassInitFunc) camel_stream_mem_class_init,
            (GtkObjectInitFunc) camel_stream_mem_init,
                /* reserved_1 */ NULL,
                /* reserved_2 */ NULL,
            (GtkClassInitFunc) NULL,
        };
        
        camel_stream_mem_type = gtk_type_unique (camel_seekable_stream_get_type (), &camel_stream_mem_info);
    }
    
    return camel_stream_mem_type;
}


CamelStream *
camel_stream_mem_new (void)
{
    return camel_stream_mem_new_with_byte_array (g_byte_array_new ());
}

CamelStream *
camel_stream_mem_new_with_buffer (const char *buffer, unsigned int len)
{
    GByteArray *ba;

    ba = g_byte_array_new ();
    g_byte_array_append (ba, (const guint8 *)buffer, len);
    return camel_stream_mem_new_with_byte_array (ba);
}

CamelStream *
camel_stream_mem_new_with_byte_array (GByteArray *byte_array)
{
    CamelStreamMem *stream_mem;
    
    stream_mem = gtk_type_new (camel_stream_mem_get_type ());
    stream_mem->buffer = byte_array;
    stream_mem->owner = TRUE;
    
    return CAMEL_STREAM (stream_mem);
}

/* note: with these functions the caller is the 'owner' of the buffer */
void camel_stream_mem_set_byte_array (CamelStreamMem *s, GByteArray *buffer)
{
    if (s->buffer && s->owner)
        g_byte_array_free(s->buffer, TRUE);
    s->owner = FALSE;
    s->buffer = buffer;
}

void camel_stream_mem_set_buffer (CamelStreamMem *s, const char *buffer, size_t len)
{
    GByteArray *ba;

    ba = g_byte_array_new ();
    g_byte_array_append (ba, (const guint8 *)buffer, len);
    camel_stream_mem_set_byte_array(s, ba);
}

static void           
finalize (GtkObject *object)
{
    CamelStreamMem *stream_mem = CAMEL_STREAM_MEM (object);

    if (stream_mem->buffer && stream_mem->owner)
        g_byte_array_free (stream_mem->buffer, TRUE);

    GTK_OBJECT_CLASS (parent_class)->finalize (object);
}

static gint
stream_read (CamelStream *stream, gchar *buffer, gint n)
{
    CamelStreamMem *camel_stream_mem = CAMEL_STREAM_MEM (stream);
    CamelSeekableStream *seekable = (CamelSeekableStream *)stream;

    g_assert (stream);

    if (seekable->bound_end != CAMEL_STREAM_UNBOUND) {
        n = MIN(seekable->bound_end - seekable->position, n);
    }

    n = MIN (n, camel_stream_mem->buffer->len - seekable->position);
    if (n>0) {
        memcpy (buffer, (camel_stream_mem->buffer)->data + seekable->position, n);
        seekable->position += n;
    } else {
        n = -1;
    }

    return n;
}

static gint
stream_write (CamelStream *stream, const gchar *buffer, gint n)
{
    CamelStreamMem *stream_mem = CAMEL_STREAM_MEM (stream);
    CamelSeekableStream *seekable = (CamelSeekableStream *)stream;

    g_assert (stream);

    if (seekable->bound_end != CAMEL_STREAM_UNBOUND) {
        n = MIN(seekable->bound_end - seekable->position, n);
    }

#warning "g_byte_arrays use g_malloc and so are totally unsuitable for this object"
    if (seekable->position == stream_mem->buffer->len) {
        stream_mem->buffer = g_byte_array_append (stream_mem->buffer, (const guint8 *)buffer, n);
    } else {
        g_byte_array_set_size(stream_mem->buffer, n+stream_mem->buffer->len);
        memcpy(stream_mem->buffer->data + seekable->position, buffer, n);
    }
    seekable->position += n;
    
    return n;
}

static void
stream_flush (CamelStream *stream)
{
    /* Nothing to do. */
    return;
}

static gboolean
stream_eos (CamelStream *stream)
{
    return ((CamelStreamMem *)stream)->buffer->len <= ((CamelSeekableStream *)stream)->position;
}

static void
stream_close (CamelStream *stream)
{
    CamelStreamMem *stream_mem = CAMEL_STREAM_MEM (stream);

    if (stream_mem->buffer && stream_mem->owner)
        g_byte_array_free (stream_mem->buffer, TRUE);
    stream_mem->buffer = NULL;
}

static off_t
stream_seek (CamelSeekableStream *stream, off_t offset, CamelStreamSeekPolicy policy)
{
    off_t position;
    CamelStreamMem *stream_mem = (CamelStreamMem *)stream;

    switch  (policy) {
    case CAMEL_STREAM_SET:
        position = offset;
        break;
    case CAMEL_STREAM_CUR:
        position = stream->position + offset;
        break;
    case CAMEL_STREAM_END:
        position = (stream_mem->buffer)->len + offset;
        break;
    default:
        errno = EINVAL;
        return -1;
    }

    if (stream->bound_end == CAMEL_STREAM_UNBOUND) {
        position = MIN (position, stream->bound_end);
    }
    if (stream->bound_start == CAMEL_STREAM_UNBOUND) {
        position = MAX (position, 0);
    } else {
        position = MAX (position, stream->bound_start);
    }

    if (position > stream_mem->buffer->len) {
        int oldlen = stream_mem->buffer->len;
        g_byte_array_set_size(stream_mem->buffer, position);
        memset(stream_mem->buffer->data + oldlen, 0, position - oldlen);
    }

    stream->position = position;

    return position;
}