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

/*  slibtool: a skinny libtool implementation, written in C        */

/*  Copyright (C) 2016--2021  SysDeer Technologies, LLC            */

/*  Released under the Standard MIT License; see COPYING.SLIBTOOL. */

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

#include <fcntl.h>

#include <errno.h>

#include <unistd.h>

#include <stdint.h>

#include <stdlib.h>

#include <string.h>

#include <sys/mman.h>

#include <sys/stat.h>

#include "slibtool_errinfo_impl.h"

#include "slibtool_mapfile_impl.h"

static void slbt_munmap(void * addr, size_t size)

{

	if (addr) {

		munmap(addr,size);

	}

}

struct slbt_map_info * slbt_map_file(

	int		fdat,

	const char *	path,

	uint32_t	flags)

{

	int 			fd;

	void *			addr;

	struct stat		st;

	uint32_t		oflag;

	uint32_t		mprot;

	struct slbt_map_info *	mapinfo;

	if ((flags & SLBT_MAP_INPUT) && (flags & SLBT_MAP_OUTPUT))  {

		oflag = O_RDWR;

		mprot = PROT_READ|PROT_WRITE;

	} else if (flags & SLBT_MAP_INPUT) {

		oflag = O_RDONLY;

		mprot = PROT_READ;

	} else if (flags & SLBT_MAP_OUTPUT) {

		oflag = O_WRONLY;

		mprot = PROT_WRITE;

	} else {

		errno = EINVAL;

		return 0;

	}

	if ((fd = openat(fdat,path,oflag,0)) < 0)

		return 0;

	if (fstat(fd,&st) < 0) {

		close(fd);

		return 0;

	}

	addr = st.st_size

		? mmap(0,st.st_size,mprot,MAP_SHARED,fd,0)

		: 0;

	if (addr == MAP_FAILED) {

		close(fd);

		return 0;

	}

	if (!(mapinfo = malloc(sizeof(*mapinfo)))) {

		close(fd);

		slbt_munmap(addr,st.st_size);

		return 0;

	}

	close(fd);

	mapinfo->addr = addr;

	mapinfo->size = st.st_size;

	mapinfo->mark = addr;

	mapinfo->cap  = &mapinfo->mark[st.st_size];

	return mapinfo;

}

void slbt_unmap_file(struct slbt_map_info * mapinfo)

{

	slbt_munmap(mapinfo->addr,mapinfo->size);

	free(mapinfo);

}

int  slbt_mapped_readline(

	const struct slbt_driver_ctx *	dctx,

	struct slbt_map_info *		mapinfo,

	char *				buf,

	size_t				buflen)

{

	const char * ch;

	const char * cap;

	const char * mark;

	const char * newline;

	size_t       len;

	mark = mapinfo->mark;

	cap  = mapinfo->cap;

	for (ch=mark, newline=0; ch

		if (*ch == '\n')

			newline = ch;

	len = ch - mark;

	if (newline && (buflen <= len))

		return SLBT_CUSTOM_ERROR(dctx,SLBT_ERR_FLOW_ERROR);

	if (!newline)

		return SLBT_CUSTOM_ERROR(dctx,SLBT_ERR_BAD_DATA);

	memcpy(buf,mark,len);

	buf[len] = 0;

	mapinfo->mark += len;

	return 0;

}