/*************************************************************************
* (C) 2011 AITNET ltd - Sofia/Bulgaria - <misho@aitnet.org>
*  by Michael Pounov <misho@elwix.org>
*
* $Author: misho $
* $Id: bufio.c,v 1.10 2016/08/18 09:06:31 misho Exp $
*
**************************************************************************
The ELWIX and AITNET software is distributed under the following
terms:

All of the documentation and software included in the ELWIX and AITNET
Releases is copyrighted by ELWIX - Sofia/Bulgaria <info@elwix.org>

Copyright 2004 - 2016
	by Michael Pounov <misho@elwix.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, 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.
3. All advertising materials mentioning features or use of this software
   must display the following acknowledgement:
This product includes software developed by Michael Pounov <misho@elwix.org>
ELWIX - Embedded LightWeight unIX and its contributors.
4. Neither the name of AITNET nor the names of its contributors
   may be used to endorse or promote products derived from this software
   without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY AITNET AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*/
#include "global.h"


static void
unmap_cf(struct tagBufIO *buf)
{
	if (buf)
		munmap(buf->buf_base, buf->buf_size);
}

static int
cf_(struct tagBufIO *buf)
{
	if (!buf) {
		io_SetErr(EINVAL, "Invalid arguments ...");
		return -1;
	}

	if (buf->buf_mode == BUFIO_MODE_INFINIT)
		e_free(buf->buf_base);
	else if (buf->buf_unmap)
		buf->buf_unmap(buf);

	e_free(buf);
	return 0;
}

#ifndef __linux__
#ifdef __NetBSD__
static off_t
sf_lim(struct tagBufIO *buf, off_t pos, int w)
#else
static fpos_t
sf_lim(struct tagBufIO *buf, fpos_t pos, int w)
#endif
#else
static off_t
sf_lim(struct tagBufIO *buf, off64_t *ppos, int w)
#endif
{
#ifdef __linux__
	off_t pos = (off_t) *ppos;
#endif

	if (!buf)
		goto err;

	switch (w) {
		case SEEK_SET:
			if (buf->buf_size < pos || pos < 0)
				goto err;
			buf->buf_offset = pos;
			break;
		case SEEK_CUR:
			if (buf->buf_size < (buf->buf_offset + pos) || (buf->buf_offset + pos) < 0)
				goto err;
			buf->buf_offset += pos;
			break;
		case SEEK_END:
			if (buf->buf_size < (buf->buf_size + pos) || (buf->buf_size + pos) < 0)
				goto err;
			buf->buf_offset = buf->buf_size + pos;
			break;
		default:
			goto err;
	}

	return buf->buf_offset;
err:
	io_SetErr(EINVAL, "Invalid arguments ...");
	return -1;
}

static int
rf_lim(struct tagBufIO *buf, char *dat, int siz)
{
	if (!buf || !dat) {
		io_SetErr(EINVAL, "Invalid arguments ...");
		return -1;
	}

	if (buf->buf_offset + siz > buf->buf_size)
		siz = buf->buf_size - buf->buf_offset;

	memcpy(dat, buf->buf_base + buf->buf_offset, siz);
	buf->buf_offset += siz;
	return siz;
}

static int
wf_lim(struct tagBufIO *buf, const char *dat, int siz)
{
	if (!buf || !dat) {
		io_SetErr(EINVAL, "Invalid arguments ...");
		return -1;
	}

	if (buf->buf_offset + siz > buf->buf_size)
		siz = buf->buf_size - buf->buf_offset;

	memcpy(buf->buf_base + buf->buf_offset, dat, siz);
	buf->buf_offset += siz;
	return siz;
}

#ifndef __linux__
#ifdef __NetBSD__
static off_t
sf_inf(struct tagBufIO *buf, off_t pos, int w)
#else
static fpos_t
sf_inf(struct tagBufIO *buf, fpos_t pos, int w)
#endif
#else
static off_t
sf_inf(struct tagBufIO *buf, off64_t *ppos, int w)
#endif
{
	void *b;
#ifdef __linux__
	off_t pos = (off_t) *ppos;
#endif

	if (!buf)
		goto err;

	switch (w) {
		case SEEK_SET:
			if (pos < 0)
				goto err;
			if (buf->buf_size < pos) {
				b = e_realloc(buf->buf_base, pos);
				if (!b) {
					LOGERR;
					return -1;
				} else {
					buf->buf_base = b;
					memset(buf->buf_base + buf->buf_size, 0, pos - buf->buf_size);
					buf->buf_size = pos;
				}
			}
			buf->buf_offset = pos;
			break;
		case SEEK_CUR:
			if ((buf->buf_offset + pos) < 0)
				goto err;
			if (buf->buf_size < (buf->buf_offset + pos)) {
				b = e_realloc(buf->buf_base, buf->buf_offset + pos);
				if (!b) {
					LOGERR;
					return -1;
				} else {
					buf->buf_base = b;
					memset(buf->buf_base + buf->buf_size, 0, 
							buf->buf_offset + pos - buf->buf_size);
					buf->buf_size = buf->buf_offset + pos;
				}
			}
			buf->buf_offset += pos;
			break;
		case SEEK_END:
			if ((buf->buf_size + pos) < 0)
				goto err;
			if (buf->buf_size < (buf->buf_size + pos)) {
				b = e_realloc(buf->buf_base, buf->buf_size + pos);
				if (!b) {
					LOGERR;
					return -1;
				} else {
					buf->buf_base = b;
					memset(buf->buf_base + buf->buf_size, 0, pos);
					buf->buf_size += pos;
					buf->buf_offset = buf->buf_size;
				}
			} else
				buf->buf_offset = buf->buf_size + pos;
			break;
		default:
			goto err;
	}

	return buf->buf_offset;
err:
	io_SetErr(EINVAL, "Invalid arguments ...");
	return -1;
}

static int
wf_inf(struct tagBufIO *buf, const char *dat, int siz)
{
	void *b;

	if (!buf || !dat) {
		io_SetErr(EINVAL, "Invalid arguments ...");
		return -1;
	}

	if (buf->buf_offset + siz > buf->buf_size) {
		b = e_realloc(buf->buf_base, buf->buf_offset + siz);
		if (!b) {
			LOGERR;
			return -1;
		} else {
			buf->buf_base = b;
			memset(buf->buf_base + buf->buf_size, 0, 
					buf->buf_offset + siz - buf->buf_size);
			buf->buf_size = buf->buf_offset + siz;
		}
	}

	memcpy(buf->buf_base + buf->buf_offset, dat, siz);
	buf->buf_offset += siz;
	return siz;
}


/*
 * io_fmemopen() - File buffered stream operations over memory block
 *
 * @base = Base address of memory block, if =NULL Infinit length(auto-grow)
 * @basesize = Size of memory block
 * return: NULL error or !=NULL Opened file resource
 */
FILE *
io_fmemopen(void ** __restrict base, off_t basesize)
{
	FILE *f = NULL;
	struct tagBufIO *buf;
#ifdef __linux__
	cookie_io_functions_t cookie;
#endif

	if (!base) {
		io_SetErr(EINVAL, "Invalid base argument ...");
		return NULL;
	}

	buf = e_malloc(sizeof(struct tagBufIO));
	if (!buf) {
		LOGERR;
		return NULL;
	} else
		memset(buf, 0, sizeof(struct tagBufIO));

	if (!*base) {
		*base = e_malloc(basesize);
		if (!*base) {
			LOGERR;
			e_free(buf);
			return NULL;
		} else
			memset(*base, 0, basesize);

		buf->buf_mode = BUFIO_MODE_INFINIT;
	} else
		buf->buf_mode = BUFIO_MODE_LIMIT;

	buf->buf_base = *base;
	buf->buf_size = basesize;

#ifndef __linux__
#ifdef __NetBSD__
	if (buf->buf_mode == BUFIO_MODE_INFINIT)
		f = funopen(buf, (int (*)(void *, char *, int)) rf_lim, 
				(int (*)(void *, char const *, int)) wf_inf, 
				(off_t (*)(void *, off_t, int)) sf_inf, 
				(int (*)(void *)) cf_);
	else
		f = funopen(buf, (int (*)(void *, char *, int)) rf_lim, 
				(int (*)(void *, char const *, int)) wf_lim, 
				(off_t (*)(void *, off_t, int)) sf_lim, 
				(int (*)(void *)) cf_);
#else
	if (buf->buf_mode == BUFIO_MODE_INFINIT)
		f = funopen(buf, (int (*)(void *, char *, int)) rf_lim, 
				(int (*)(void *, char const *, int)) wf_inf, 
				(fpos_t (*)(void *, fpos_t, int)) sf_inf, 
				(int (*)(void *)) cf_);
	else
		f = funopen(buf, (int (*)(void *, char *, int)) rf_lim, 
				(int (*)(void *, char const *, int)) wf_lim, 
				(fpos_t (*)(void *, fpos_t, int)) sf_lim, 
				(int (*)(void *)) cf_);
#endif
#else
	if (buf->buf_mode == BUFIO_MODE_INFINIT) {
		cookie.read = (cookie_read_function_t*) rf_lim;
		cookie.write = (cookie_write_function_t*) wf_inf;
		cookie.seek = (cookie_seek_function_t*) sf_inf;
		cookie.close = (cookie_close_function_t*) cf_;
	} else {
		cookie.read = (cookie_read_function_t*) rf_lim;
		cookie.write = (cookie_write_function_t*) wf_lim;
		cookie.seek = (cookie_seek_function_t*) sf_lim;
		cookie.close = (cookie_close_function_t*) cf_;
	}

	f = fopencookie(buf, "r+", cookie);
#endif
	if (!f) {
		LOGERR;
		if (buf->buf_mode == BUFIO_MODE_INFINIT) {
			e_free(*base);
			*base = NULL;
		}
		e_free(buf);
		return NULL;
	}

	return f;
}

/*
 * io_fmapopen() - File buffered stream operations over MMAP block
 *
 * @csFile = Filename for MMAP, if =NULL private MMAP block
 * @mode = File open mode
 * @perm = If file not exists will be created with this access permissions
 * @prot = MMAP protection
 * @flags = MMAP mode flags
 * @offset = Map from file offset, if csFile==NULL then this is size of MMAP private block
 * return: NULL error or !=NULL Opened file resource
 */
FILE *
io_fmapopen(const char *csFile, int mode, int perm, int prot, int flags, off_t offset)
{
	FILE *f;
	struct tagBufIO *buf;
	void *base;
	off_t basesize;
	int fd = -1;
#ifdef __linux__
	cookie_io_functions_t cookie = {
		.read = (cookie_read_function_t*) rf_lim, 
		.write = (cookie_write_function_t*) wf_lim, 
		.seek = (cookie_seek_function_t*) sf_lim, 
		.close = (cookie_close_function_t*) cf_
	};
#endif

	if (csFile) {
		fd = open(csFile, mode, perm);
		if (fd == -1) {
			LOGERR;
			return NULL;
		}
		basesize = lseek(fd, 0, SEEK_END);
		if (basesize == -1) {
			LOGERR;
			close(fd);
			return NULL;
		} else
			lseek(fd, 0, SEEK_SET);

		base = mmap(NULL, basesize, prot, flags | MAP_FILE, fd, offset);
		if (base == MAP_FAILED) {
			LOGERR;
			close(fd);
			return NULL;
		} else
			close(fd);
	} else if (offset) {
		basesize = offset;
		base = mmap(NULL, basesize, prot, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
		if (base == MAP_FAILED) {
			LOGERR;
			return NULL;
		}
	} else {
		io_SetErr(EINVAL, "Invalid base argument ...");
		return NULL;
	}


	buf = e_malloc(sizeof(struct tagBufIO));
	if (!buf) {
		LOGERR;
		munmap(base, basesize);
		return NULL;
	} else
		memset(buf, 0, sizeof(struct tagBufIO));

	buf->buf_mode = BUFIO_MODE_LIMIT;
	buf->buf_base = base;
	buf->buf_size = basesize;
	buf->buf_unmap = unmap_cf;

#ifndef __linux__
#ifdef __NetBSD__
	f = funopen(buf, (int (*)(void *, char *, int)) rf_lim, 
			(int (*)(void *, char const *, int)) wf_lim, 
			(off_t (*)(void *, off_t, int)) sf_lim, 
			(int (*)(void *)) cf_);
#else
	f = funopen(buf, (int (*)(void *, char *, int)) rf_lim, 
			(int (*)(void *, char const *, int)) wf_lim, 
			(fpos_t (*)(void *, fpos_t, int)) sf_lim, 
			(int (*)(void *)) cf_);
#endif
#else
	f = fopencookie(buf, "r+", cookie);
#endif
	if (!f) {
		LOGERR;
		e_free(buf);
		munmap(base, basesize);
		return NULL;
	}

	return f;
}

/*
 * io_dumbFile() - Create empry or dumb file with fixed size
 *
 * @csFile = Filename for create
 * @mode = File access permissions
 * @size = File size
 * return: -1 error or open file handle
 */
int
io_dumbFile(const char *csFile, int mode, off_t size)
{
	int fd;

	fd = open(csFile, O_RDWR | O_CREAT, mode);
	if (fd == -1) {
		LOGERR;
		return -1;
	}

	if (lseek(fd, size - 1, SEEK_SET) == -1)
		goto err;
	if (write(fd, "", 1) != 1)
		goto err;
	else
		lseek(fd, 0, SEEK_SET);

	return fd;
err:
	LOGERR;
	close(fd);
	return -1;
}

/*
 * io_fd2buf() - Convert open file handle to buffered file I/O
 *
 * @fd = File handle
 * @mode = Permissions for new buffered file I/O
 * return: NULL error or open buffered file
 */
FILE *
io_fd2buf(int fd, const char *mode)
{
	FILE *f;

	f = fdopen(fd, mode);
	if (!f)
		LOGERR;

	return f;
}