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

/*  tpax: a topological pax implementation                    */

/*  Copyright (C) 2020--2024  SysDeer Technologies, LLC       */

/*  Released under GPLv2 and GPLv3; see COPYING.TPAX.         */

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

#include <stdint.h>

#include <stdlib.h>

#include <tpax/tpax.h>

#include "tpax_driver_impl.h"

#include "tpax_errinfo_impl.h"

#include "tpax_visibility_impl.h"

#define TPAX_MAX_DEPTH 512

tpax_hidden const char * tpax_queue_item_full_path(

	const struct tpax_driver_ctx *  dctx,

	const struct tpax_dirent *      cdent)

{

	char *                          ch;

	char *                          pathbuf;

	const struct tpax_dirent *      pparent;

	const struct tpax_dirent **     pdirent;

	const struct tpax_dirent *      dirstck[TPAX_MAX_DEPTH];

	if (cdent->depth >= TPAX_MAX_DEPTH)

		return 0;

	ch = pathbuf = (tpax_get_driver_ictx(dctx))->dirbuff;

	for (pparent=cdent,pdirent=dirstck; pparent; pparent=pparent->parent)

		*pdirent++ = pparent;

	*pdirent-- = 0;

	if (pdirent[0]->prefix)

		ch += sprintf(ch,"%s",pdirent[0]->prefix);

	for (; pdirent > dirstck; ) {

		if (!(pdirent[0]->flags & TPAX_ITEM_SYMLINK))

			ch += sprintf(ch,"%s/",pdirent[0]->dirent.d_name);

		pdirent--;

	}

	if (pdirent[0]->flags & TPAX_ITEM_SYMLINK) {

		*--ch = '\0';

	} else {

		sprintf(ch,"%s",pdirent[0]->dirent.d_name);

	}

	return pathbuf;

}

static int tpax_cpio_dirent_compare(const void * a, const void * b)

{

	const struct tpax_dirent * direnta;

	const struct tpax_dirent * direntb;

	direnta = *(const struct tpax_dirent **)a;

	direntb = *(const struct tpax_dirent **)b;

	return (direnta->stdev == direntb->stdev)

		? direnta->stino - direntb->stino

		: direnta->stdev - direntb->stdev;

}

static int tpax_update_cpio_queue_vector(const struct tpax_driver_ctx * dctx)

{

	struct tpax_driver_ctx_impl *   ictx;

	struct tpax_dirent **           cpiov;

	struct tpax_dirent **           direntv;

	struct tpax_dirent *            cdent;

	dev_t                           stdev;

	ino_t                           stino;

	int                             cpdev;

	int                             cpino;

	int                             nlink;

	int                             idx;

	/* driver */

	ictx = tpax_get_driver_ictx(dctx);

	/* not needed? */

	if (ictx->nqueued == 0)

		return 0;

	/* vector copy */

	direntv = ictx->direntv;

	cpiov   = ictx->cpiov;

	for (; *direntv; )

		*cpiov++ = *direntv++;

	/* sort by real st_dev, st_ino */

	qsort(ictx->cpiov,ictx->nqueued,sizeof(*cpiov),tpax_cpio_dirent_compare);

	/* set the cpio internal c_dev, c_ino, and c_nlink fields (U+1F620) */

	cpiov = ictx->cpiov;

	cdent = cpiov[0];

	cpiov++;

	cpdev = 1;

	cpino = 1;

	nlink = 1;

	stdev = cdent->stdev;

	stino = cdent->stino;

	cdent->cpdev = cpdev;

	cdent->cpino = cpino;

	cdent->nlink = nlink;

	for (; *cpiov; ) {

		cdent = *cpiov;

		if (cdent->srdev > 0777777)

			return TPAX_CUSTOM_ERROR(

				dctx,

				TPAX_ERR_FLOW_ERROR);

		if ((cdent->stdev == stdev) && (cdent->stino == stino)) {

			nlink++;

		} else if (cdent->stdev > stdev) {

			if (nlink > 1)

				for (idx=2; idx<=nlink; idx++)

					cpiov[-idx]->nlink = nlink;

			cpdev++;

			cpino = 1;

			nlink = 1;

			stdev = cdent->stdev;

			stino = cdent->stino;

			if (cpdev > 0777777)

				return TPAX_CUSTOM_ERROR(

					dctx,

					TPAX_ERR_FLOW_ERROR);

		} else if (cdent->stino > stino) {

			if (nlink > 1)

				for (idx=2; idx<=nlink; idx++)

					cpiov[-idx]->nlink = nlink;

			cpino++;

			stino = cdent->stino;

			nlink = 1;

			if (cpino > 0777777)

				return TPAX_CUSTOM_ERROR(

					dctx,

					TPAX_ERR_FLOW_ERROR);

		}

		cdent->cpdev = cpdev;

		cdent->cpino = cpino;

		cdent->nlink = nlink;

		cpiov++;

	}

	return 0;

}

tpax_hidden int tpax_update_queue_vector(const struct tpax_driver_ctx * dctx)

{

	uintptr_t                       addr;

	struct tpax_driver_ctx_impl *   ictx;

	struct tpax_dirent_buffer *     dentbuf;

	struct tpax_dirent **           direntv;

	struct tpax_dirent *            cdent;

	struct tpax_dirent *            cnext;

	size_t                          arrsize;

	/* driver */

	ictx = tpax_get_driver_ictx(dctx);

	/* vector alloc */

	if (ictx->direntv) {

		free(ictx->direntv);

		free(ictx->cpiov);

		ictx->direntv = 0;

		ictx->cpiov   = 0;

	}

	arrsize = ictx->nqueued + 1;

	if (!(ictx->direntv = calloc(arrsize,sizeof(struct tpax_dirent *))))

		return TPAX_SYSTEM_ERROR(dctx);

	if (dctx->cctx->drvflags & TPAX_DRIVER_WRITE_FORMAT_CPIO)

		if (!(ictx->cpiov = calloc(arrsize,sizeof(struct tpax_dirent *))))

			return TPAX_SYSTEM_ERROR(dctx);

	/* queue vector */

	dentbuf = tpax_get_driver_dirents(dctx);

	cdent   = ictx->nqueued ? dentbuf->dbuf : 0;

	for (direntv=ictx->direntv; cdent; direntv++) {

		*direntv = cdent;

		addr  = (uintptr_t)cdent;

		addr += cdent->nsize;

		cnext = (struct tpax_dirent *)addr;

		if (cnext == dentbuf->cdent) {

			dentbuf = dentbuf->next;

			cnext   = dentbuf ? dentbuf->dbuf : 0;

		}

		cdent = cnext;

	}

	if (dctx->cctx->drvflags & TPAX_DRIVER_WRITE_FORMAT_CPIO)

		if (tpax_update_cpio_queue_vector(dctx) < 0)

			return TPAX_NESTED_ERROR(dctx);

	return 0;

}