/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */

/* gnome-vfs-utils.c - Private utility functions for the GNOME Virtual
   File System.
   gnome_vfs_read_entire_file() extraction for Captive

   Copyright (C) 1999 Free Software Foundation
   Copyright (C) 2000, 2001 Eazel, Inc.

   The Gnome Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The Gnome Library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the Gnome Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.

   Authors: Ettore Perazzoli <ettore@comm2000.it>
   	    John Sullivan <sullivan@eazel.com> 
            Darin Adler <darin@eazel.com>
*/


#include "config.h"

#include <glib/gmem.h>
#include <libgnomevfs/gnome-vfs-result.h>
#include <libgnomevfs/gnome-vfs-handle.h>
#include <libgnomevfs/gnome-vfs-ops.h>


#define READ_CHUNK_SIZE 8192


/**
 * gnome_vfs_read_entire_file:
 * @uri: URI of the file to read
 * @file_size: after reading the file, contains the size of the file read
 * @file_contents: contains the file_size bytes, the contents of the file at @uri.
 * 
 * Reads an entire file into memory for convenience. Beware accidentally
 * loading large files into memory with this function.
 *
 * Return value: An integer representing the result of the operation
 *
 * Since: 2.2
 */

GnomeVFSResult
gnome_vfs_read_entire_file (const char *uri,
			    int *file_size,
			    char **file_contents)
{
	GnomeVFSResult result;
	GnomeVFSHandle *handle;
	char *buffer;
	GnomeVFSFileSize total_bytes_read;
	GnomeVFSFileSize bytes_read;

	*file_size = 0;
	*file_contents = NULL;

	/* Open the file. */
	result = gnome_vfs_open (&handle, uri, GNOME_VFS_OPEN_READ);
	if (result != GNOME_VFS_OK) {
		return result;
	}

	/* Read the whole thing. */
	buffer = NULL;
	total_bytes_read = 0;
	do {
		buffer = g_realloc (buffer, total_bytes_read + READ_CHUNK_SIZE);
		result = gnome_vfs_read (handle,
					 buffer + total_bytes_read,
					 READ_CHUNK_SIZE,
					 &bytes_read);
		if (result != GNOME_VFS_OK && result != GNOME_VFS_ERROR_EOF) {
			g_free (buffer);
			gnome_vfs_close (handle);
			return result;
		}

		/* Check for overflow. */
		if (total_bytes_read + bytes_read < total_bytes_read) {
			g_free (buffer);
			gnome_vfs_close (handle);
			return GNOME_VFS_ERROR_TOO_BIG;
		}

		total_bytes_read += bytes_read;
	} while (result == GNOME_VFS_OK);

	/* Close the file. */
	result = gnome_vfs_close (handle);
	if (result != GNOME_VFS_OK) {
		g_free (buffer);
		return result;
	}

	/* Return the file. */
	*file_size = total_bytes_read;
	*file_contents = g_realloc (buffer, total_bytes_read);
	return GNOME_VFS_OK;
}