/*-

 * Copyright (c) 2017 Sean Purcell

 * 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.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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(S) 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 "archive_platform.h"

__FBSDID("$FreeBSD$");

#ifdef HAVE_ERRNO_H

#include <errno.h>

#endif

#ifdef HAVE_STDLIB_H

#include <stdlib.h>

#endif

#ifdef HAVE_STRING_H

#include <string.h>

#endif

#ifdef HAVE_ZSTD_H

#include <zstd.h>

#endif

#include "archive.h"

#include "archive_private.h"

#include "archive_string.h"

#include "archive_write_private.h"

/* Don't compile this if we don't have zstd.h */

struct private_data {

	int		 compression_level;

#if HAVE_ZSTD_H && HAVE_LIBZSTD

	ZSTD_CStream	*cstream;

	int64_t		 total_in;

	ZSTD_outBuffer	 out;

#else

	struct archive_write_program_data *pdata;

#endif

};

static int archive_compressor_zstd_options(struct archive_write_filter *,

		    const char *, const char *);

static int archive_compressor_zstd_open(struct archive_write_filter *);

static int archive_compressor_zstd_write(struct archive_write_filter *,

		    const void *, size_t);

static int archive_compressor_zstd_close(struct archive_write_filter *);

static int archive_compressor_zstd_free(struct archive_write_filter *);

#if HAVE_ZSTD_H && HAVE_LIBZSTD

static int drive_compressor(struct archive_write_filter *,

		    struct private_data *, int, const void *, size_t);

#endif

/*

 * Add a zstd compression filter to this write handle.

 */

int

archive_write_add_filter_zstd(struct archive *_a)

{

	struct archive_write *a = (struct archive_write *)_a;

	struct archive_write_filter *f = __archive_write_allocate_filter(_a);

	struct private_data *data;

	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,

	    ARCHIVE_STATE_NEW, "archive_write_add_filter_zstd");

	data = calloc(1, sizeof(*data));

	if (data == NULL) {

		archive_set_error(&a->archive, ENOMEM, "Out of memory");

		return (ARCHIVE_FATAL);

	}

	f->data = data;

	f->open = &archive_compressor_zstd_open;

	f->options = &archive_compressor_zstd_options;

	f->close = &archive_compressor_zstd_close;

	f->free = &archive_compressor_zstd_free;

	f->code = ARCHIVE_FILTER_ZSTD;

	f->name = "zstd";

	data->compression_level = 3; /* Default level used by the zstd CLI */

#if HAVE_ZSTD_H && HAVE_LIBZSTD

	data->cstream = ZSTD_createCStream();

	if (data->cstream == NULL) {

		free(data);

		archive_set_error(&a->archive, ENOMEM,

		    "Failed to allocate zstd compressor object");

		return (ARCHIVE_FATAL);

	}

	return (ARCHIVE_OK);

#else

	data->pdata = __archive_write_program_allocate("zstd");

	if (data->pdata == NULL) {

		free(data);

		archive_set_error(&a->archive, ENOMEM, "Out of memory");

		return (ARCHIVE_FATAL);

	}

	archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,

	    "Using external zstd program");

	return (ARCHIVE_WARN);

#endif

}

static int

archive_compressor_zstd_free(struct archive_write_filter *f)

{

	struct private_data *data = (struct private_data *)f->data;

#if HAVE_ZSTD_H && HAVE_LIBZSTD

	ZSTD_freeCStream(data->cstream);

	free(data->out.dst);

#else

	__archive_write_program_free(data->pdata);

#endif

	free(data);

	f->data = NULL;

	return (ARCHIVE_OK);

}

/*

 * Set write options.

 */

static int

archive_compressor_zstd_options(struct archive_write_filter *f, const char *key,

    const char *value)

{

	struct private_data *data = (struct private_data *)f->data;

	if (strcmp(key, "compression-level") == 0) {

		int level = atoi(value);

#if HAVE_ZSTD_H && HAVE_LIBZSTD

		if (level < 1 || level > ZSTD_maxCLevel()) {

#else

		/* If we don't have the library, hard-code the max level */

		if (level < 1 || level > 22) {

#endif

			return (ARCHIVE_WARN);

		}

		data->compression_level = level;

		return (ARCHIVE_OK);

	}

	/* Note: The "warn" return is just to inform the options

	 * supervisor that we didn't handle it.  It will generate

	 * a suitable error if no one used this option. */

	return (ARCHIVE_WARN);

}

#if HAVE_ZSTD_H && HAVE_LIBZSTD

/*

 * Setup callback.

 */

static int

archive_compressor_zstd_open(struct archive_write_filter *f)

{

	struct private_data *data = (struct private_data *)f->data;

	int ret;

	ret = __archive_write_open_filter(f->next_filter);

	if (ret != ARCHIVE_OK)

		return (ret);

	if (data->out.dst == NULL) {

		size_t bs = ZSTD_CStreamOutSize(), bpb;

		if (f->archive->magic == ARCHIVE_WRITE_MAGIC) {

			/* Buffer size should be a multiple number of

			 * the of bytes per block for performance. */

			bpb = archive_write_get_bytes_per_block(f->archive);

			if (bpb > bs)

				bs = bpb;

			else if (bpb != 0)

				bs -= bs % bpb;

		}

		data->out.size = bs;

		data->out.pos = 0;

		data->out.dst

		    = (unsigned char *)malloc(data->out.size);

		if (data->out.dst == NULL) {

			archive_set_error(f->archive, ENOMEM,

			    "Can't allocate data for compression buffer");

			return (ARCHIVE_FATAL);

		}

	}

	f->write = archive_compressor_zstd_write;

	if (ZSTD_isError(ZSTD_initCStream(data->cstream,

	    data->compression_level))) {

		archive_set_error(f->archive, ARCHIVE_ERRNO_MISC,

		    "Internal error initializing zstd compressor object");

		return (ARCHIVE_FATAL);

	}

	return (ARCHIVE_OK);

}

/*

 * Write data to the compressed stream.

 */

static int

archive_compressor_zstd_write(struct archive_write_filter *f, const void *buff,

    size_t length)

{

	struct private_data *data = (struct private_data *)f->data;

	int ret;

	/* Update statistics */

	data->total_in += length;

	if ((ret = drive_compressor(f, data, 0, buff, length)) != ARCHIVE_OK)

		return (ret);

	return (ARCHIVE_OK);

}

/*

 * Finish the compression...

 */

static int

archive_compressor_zstd_close(struct archive_write_filter *f)

{

	struct private_data *data = (struct private_data *)f->data;

	int r1, r2;

	/* Finish zstd frame */

	r1 = drive_compressor(f, data, 1, NULL, 0);

	r2 = __archive_write_close_filter(f->next_filter);

	return r1 < r2 ? r1 : r2;

}

/*

 * Utility function to push input data through compressor,

 * writing full output blocks as necessary.

 *

 * Note that this handles both the regular write case (finishing ==

 * false) and the end-of-archive case (finishing == true).

 */

static int

drive_compressor(struct archive_write_filter *f,

    struct private_data *data, int finishing, const void *src, size_t length)

{

	ZSTD_inBuffer in = (ZSTD_inBuffer) { src, length, 0 };

	for (;;) {

		if (data->out.pos == data->out.size) {

			const int ret = __archive_write_filter(f->next_filter,

			    data->out.dst, data->out.size);

			if (ret != ARCHIVE_OK)

				return (ARCHIVE_FATAL);

			data->out.pos = 0;

		}

		/* If there's nothing to do, we're done. */

		if (!finishing && in.pos == in.size)

			return (ARCHIVE_OK);

		{

			const size_t zstdret = !finishing ?

			    ZSTD_compressStream(data->cstream, &data->out, &in)

			    : ZSTD_endStream(data->cstream, &data->out);

			if (ZSTD_isError(zstdret)) {

				archive_set_error(f->archive,

				    ARCHIVE_ERRNO_MISC,

				    "Zstd compression failed: %s",

				    ZSTD_getErrorName(zstdret));

				return (ARCHIVE_FATAL);

			}

			/* If we're finishing, 0 means nothing left to flush */

			if (finishing && zstdret == 0) {

				const int ret = __archive_write_filter(f->next_filter,

				    data->out.dst, data->out.pos);

				return (ret);

			}

		}

	}

}

#else /* HAVE_ZSTD_H && HAVE_LIBZSTD */

static int

archive_compressor_zstd_open(struct archive_write_filter *f)

{

	struct private_data *data = (struct private_data *)f->data;

	struct archive_string as;

	int r;

	archive_string_init(&as);

	archive_string_sprintf(&as, "zstd -%d", data->compression_level);

	f->write = archive_compressor_zstd_write;

	r = __archive_write_program_open(f, data->pdata, as.s);

	archive_string_free(&as);

	return (r);

}

static int

archive_compressor_zstd_write(struct archive_write_filter *f, const void *buff,

    size_t length)

{

	struct private_data *data = (struct private_data *)f->data;

	return __archive_write_program_write(f, data->pdata, buff, length);

}

static int

archive_compressor_zstd_close(struct archive_write_filter *f)

{

	struct private_data *data = (struct private_data *)f->data;

	return __archive_write_program_close(f, data->pdata);

}

#endif /* HAVE_ZSTD_H && HAVE_LIBZSTD */