/*
 * Copyright (c) 2002, The Tendra Project <http://www.ten15.org/>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 *    		 Crown Copyright (c) 1997
 *
 *    This TenDRA(r) Computer Program is subject to Copyright
 *    owned by the United Kingdom Secretary of State for Defence
 *    acting through the Defence Evaluation and Research Agency
 *    (DERA).  It is made available to Recipients with a
 *    royalty-free licence for its use, reproduction, transfer
 *    to other parties and amendment for any purpose not excluding
 *    product development provided that any such use et cetera
 *    shall be deemed to be acceptance of the following conditions:-
 *
 *        (1) Its Recipients shall ensure that this Notice is
 *        reproduced upon any copies or amended versions of it;
 *
 *        (2) Any amended version of it shall be clearly marked to
 *        show both the nature of and the organisation responsible
 *        for the relevant amendment or amendments;
 *
 *        (3) Its onward transfer from a recipient to another
 *        party shall be deemed to be that party's acceptance of
 *        these conditions;
 *
 *        (4) DERA gives no warranty or assurance as to its
 *        quality or suitability for any purpose and DERA accepts
 *        no liability whatsoever in relation to any use to which
 *        it may be put.
 *
 * $TenDRA: tendra/src/tools/tld/bistream.c,v 1.11 2005/10/18 15:31:05 stefanf Exp $
 */


/**** bistream.c --- Binary input stream handling.
 *
 ** Author: Steve Folkes <smf@hermes.mod.uk>
 *
 **** Commentary:
 *
 * This file implements the binary input stream facility specified in the file
 * "bistream.h".  See that file for more details.
 *
 **** Change Log:*/

/****************************************************************************/

#include "bistream.h"
#include "cstring.h"

/*--------------------------------------------------------------------------*/

ExceptionP XX_bistream_read_error = EXCEPTION ("error reading from binary stream");

/*--------------------------------------------------------------------------*/

void
bistream_init(BIStreamP bistream)
{
	bistream->name = NULL;
}

BoolT
bistream_open(BIStreamP bistream, char *name)
{
#ifdef FS_BINARY_STDIO
	if ((bistream->file = fopen (name, "rb")) == NIL (FILE *)) {
		return (FALSE);
	}
#else
	if ((bistream->file = fopen (name, "r")) == NIL (FILE *)) {
		return (FALSE);
	}
#endif /* defined (FS_BINARY_STDIO) */
	bistream->bytes = 0;
	bistream->name  = name;
	return (TRUE);
}

void
bistream_assign(BIStreamP to, BIStreamP from)
{
	to->file  = from->file;
	to->bytes = from->bytes;
	to->name  = from->name;
}

BoolT
bistream_is_open(BIStreamP bistream)
{
	return (bistream->name != NULL);
}

unsigned
bistream_read_chars(BIStreamP bistream, unsigned length, char *chars)
{
	unsigned bytes_read = (unsigned) fread ((void *) chars, sizeof (char),
											(size_t) length, bistream->file);

	if ((bytes_read == 0) && (ferror (bistream->file))) {
		char *name = string_copy (bistream->name);

		THROW_VALUE (XX_bistream_read_error, name);
		UNREACHED;
	}
	bistream->bytes += bytes_read;
	return (bytes_read);
}

unsigned
bistream_read_bytes(BIStreamP bistream, unsigned length, ByteP bytes)
{
	unsigned bytes_read = (unsigned) fread ((void *) bytes, sizeof (ByteT),
											(size_t) length, bistream->file);

	if ((bytes_read == 0) && (ferror (bistream->file))) {
		char *name = string_copy (bistream->name);

		THROW_VALUE (XX_bistream_read_error, name);
		UNREACHED;
	}
	bistream->bytes += bytes_read;
	return (bytes_read);
}

BoolT
bistream_read_byte(BIStreamP bistream, ByteT *byte_ref)
{
	int byte = fgetc (bistream->file);

	if (byte == EOF) {
		if (ferror (bistream->file)) {
			char *name = string_copy (bistream->name);

			THROW_VALUE (XX_bistream_read_error, name);
			UNREACHED;
		} else if (feof (bistream->file)) {
			return (FALSE);
		}
	}
	bistream->bytes ++;
	*byte_ref = (ByteT) byte;
	return (TRUE);
}

unsigned
bistream_byte(BIStreamP bistream)
{
	return (bistream->bytes);
}

char *
bistream_name(BIStreamP bistream)
{
	return (bistream->name);
}

void
bistream_rewind(BIStreamP bistream)
{
#ifdef FS_ANSI_ENVIRON
	rewind (bistream->file);
#else
	(void) fseek (bistream->file, (long) 0, SEEK_SET);
#endif /* defined (FS_REWIND) */
}

void
bistream_close(BIStreamP bistream)
{
	(void) fclose (bistream->file);
	bistream_init (bistream);
}