/*
* I/O streams.
* Copyright (c) 1998 New Generation Software (NGS) Oy
*
* Author: Markku Rossi <mtr@ngs.fi>
*/
/*
* This 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.
*
* This 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 this library; if not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA
*/
/*
* $Source: /tmp/cvsroot-15-2-2007/clamav-devel/libclamav/js/iostream.c,v $
* $Id: iostream.c,v 1.2 2006/10/28 11:27:44 njh Exp $
*/
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#ifdef CL_EXPERIMENTAL
#include "jsint.h"
/*
* Types and definitions.
*/
#define DEFAULT_BUFFER_SIZE 4096
/*
* Global functions.
*/
JSIOStream *
js_iostream_new ()
{
JSIOStream *stream;
stream = js_calloc (NULL, 1, sizeof (*stream));
if (stream == NULL)
return NULL;
stream->buflen = DEFAULT_BUFFER_SIZE;
stream->buffer = js_malloc (NULL, stream->buflen);
if (stream->buffer == NULL)
{
js_free (stream);
return NULL;
}
return stream;
}
/* The `FILE *' stream. */
static int
file_read (void *context, unsigned char *buffer, unsigned int todo,
int *error_return)
{
int got;
errno = 0;
got = fread (buffer, 1, todo, (FILE *) context);
*error_return = errno;
return got;
}
static int
file_write (void *context, unsigned char *buffer, unsigned int todo,
int *error_return)
{
int wrote;
errno = 0;
wrote = fwrite (buffer, 1, todo, (FILE *) context);
*error_return = errno;
return wrote;
}
static int
file_seek (void *context, long offset, int whence)
{
return fseek ((FILE *) context, offset, whence);
}
static long
file_get_position (void *context)
{
return ftell ((FILE *) context);
}
static long
file_get_length (void *context)
{
FILE *fp = (FILE *) context;
long cpos;
long result = -1;
/* Save current position. */
cpos = ftell (fp);
if (cpos >= 0)
{
/* Seek to the end of the file. */
if (fseek (fp, 0, SEEK_END) >= 0)
{
/* Fetch result. */
result = ftell (fp);
/* Seek back. */
if (fseek (fp, cpos, SEEK_SET) < 0)
/* Couldn't revert the fp to the original position. */
result = -1;
}
}
return result;
}
static void
file_close (void *context)
{
fclose ((FILE *) context);
}
JSIOStream *
js_iostream_file (FILE *fp, int readp, int writep, int do_close)
{
JSIOStream *stream;
if (fp == NULL)
return NULL;
stream = js_iostream_new ();
if (stream == NULL)
return NULL;
if (readp)
stream->read = file_read;
if (writep)
stream->write = file_write;
stream->seek = file_seek;
stream->get_position = file_get_position;
stream->get_length = file_get_length;
if (do_close)
stream->close = file_close;
stream->context = fp;
return stream;
}
static void
close_pipe (void *context)
{
pclose ((FILE *) context);
}
JSIOStream *
js_iostream_pipe (FILE *fp, int readp)
{
JSIOStream *stream;
if (fp == NULL)
return NULL;
stream = js_iostream_new ();
if (stream == NULL)
return NULL;
if (readp)
stream->read = file_read;
else
stream->write = file_write;
stream->seek = file_seek;
stream->get_position = file_get_position;
stream->get_length = file_get_length;
stream->close = close_pipe;
stream->context = fp;
return stream;
}
size_t
js_iostream_read (JSIOStream *stream, void *v, size_t size)
{
unsigned char *ptr = (unsigned char *)v;
size_t total = 0;
int got;
if (stream->writep)
{
/* We have buffered output data. */
if (js_iostream_flush (stream) == EOF)
return 0;
assert (stream->writep == 0);
}
while (size > 0)
{
/* First, take everything from the buffer. */
if (stream->bufpos < stream->data_in_buf)
{
got = stream->data_in_buf - stream->bufpos;
if (size < got)
got = size;
memcpy (ptr, stream->buffer + stream->bufpos, got);
stream->bufpos += got;
size -= got;
ptr += got;
total += got;
}
else
{
if (stream->at_eof)
/* EOF seen, can't read more. */
break;
js_iostream_fill_buffer (stream);
}
}
return total;
}
size_t
js_iostream_write (JSIOStream *stream, void *v, size_t size)
{
int space;
size_t total = 0;
unsigned char *ptr = (unsigned char *)v;
if (stream->write == NULL)
{
stream->error = EBADF;
return 0;
}
if (!stream->writep && stream->bufpos < stream->data_in_buf)
{
/*
* We have some buffered data in the stream => the actual stream
* position in stream->context is not in sync with stream->bufpos.
* Seek back.
*/
if ((*stream->seek) (stream->context, SEEK_CUR,
stream->bufpos - stream->data_in_buf) < 0)
/* XXX Error value. */
return 0;
stream->bufpos = 0;
stream->data_in_buf = 0;
}
while (size > 0)
{
space = stream->buflen - stream->data_in_buf;
if (size < space)
space = size;
/* Append data to the buffer. */
memcpy (stream->buffer + stream->data_in_buf, ptr, space);
stream->data_in_buf += space;
total += space;
size -= space;
ptr += space;
/* Now the buffer contains buffered write data. */
stream->writep = 1;
if (size > 0)
{
/* Still some data left. Must flush */
if (js_iostream_flush (stream) == EOF)
return total;
}
}
/* Autoflush. */
if (stream->autoflush && stream->writep)
if (js_iostream_flush (stream) == EOF)
/* Failed. Just return something smaller than <size> */
return total - stream->data_in_buf;
return total;
}
int
js_iostream_flush (JSIOStream *stream)
{
if (stream == NULL || stream->write == NULL || !stream->writep)
return 0;
stream->writep = 0;
assert (stream->bufpos == 0);
if (stream->data_in_buf > 0)
{
int to_write = stream->data_in_buf;
stream->data_in_buf = 0;
if ((*stream->write) (stream->context, stream->buffer,
to_write, &stream->error) < to_write)
{
stream->error = errno;
return EOF;
}
}
return 0;
}
int
js_iostream_unget (JSIOStream *stream, int byte)
{
if (stream->writep)
{
/* We have buffered output data. */
if (js_iostream_flush (stream) == EOF)
return EOF;
assert (stream->writep == 0);
}
if (stream->bufpos > 0)
{
/* It fits. */
stream->buffer[--stream->bufpos] = byte;
}
else if (stream->data_in_buf < stream->buflen)
{
move:
memmove (stream->buffer + 1, stream->buffer, stream->data_in_buf);
stream->data_in_buf++;
stream->buffer[0] = byte;
}
else
{
/* Allocate a bigger buffer. */
unsigned char *new_buffer = js_realloc (NULL, stream->buffer,
stream->buflen + 1);
if (new_buffer == NULL)
{
stream->error = errno;
return EOF;
}
stream->buflen++;
stream->buffer = new_buffer;
goto move;
}
/* Upon successful completion, we must return the byte. */
return byte;
}
int
js_iostream_close (JSIOStream *stream)
{
int result = 0;
if (stream == NULL)
return result;
if (js_iostream_flush (stream) == EOF)
result = EOF;
if (stream->close)
(*stream->close) (stream->context);
js_free (stream->buffer);
js_free (stream);
return result;
}
int
js_iostream_seek (JSIOStream *stream, long offset, int whence)
{
int result;
if (js_iostream_flush (stream) == EOF)
return -1;
result = (*stream->seek) (stream->context, offset, whence);
if (result == 0)
/* Successful. Clear the eof flag. */
stream->at_eof = 0;
return result;
}
long
js_iostream_get_position (JSIOStream *stream)
{
long pos;
/* Flush the possible buffered output. */
if (js_iostream_flush (stream) == EOF)
return -1;
pos = (*stream->get_position) (stream->context);
if (pos < 0)
return pos;
/*
* The logical position if at <bufpos>, the context's idea is at
* <data_in_buf>. Adjust.
*/
return pos - (stream->data_in_buf - stream->bufpos);
}
long
js_iostream_get_length (JSIOStream *stream)
{
/* Flush the possible buffered output. */
if (js_iostream_flush (stream) == EOF)
return -1;
return (*stream->get_length) (stream->context);
}
void
js_iostream_fill_buffer (JSIOStream *stream)
{
if (stream->read == NULL)
{
stream->at_eof = 1;
return;
}
stream->data_in_buf = (*stream->read) (stream->context, stream->buffer,
stream->buflen, &stream->error);
stream->bufpos = 0;
if (stream->data_in_buf == 0)
stream->at_eof = 1;
}
#endif /*CL_EXPERIMENTAL*/