/*-

 * Copyright (c) 2003-2007 Tim Kientzle

 * 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: head/lib/libarchive/archive_write_set_compression_gzip.c 201081 2009-12-28 02:04:42Z kientzle $");

#ifdef HAVE_ERRNO_H

#include <errno.h>

#endif

#ifdef HAVE_STDLIB_H

#include <stdlib.h>

#endif

#ifdef HAVE_STRING_H

#include <string.h>

#endif

#include <time.h>

#ifdef HAVE_ZLIB_H

#include <zlib.h>

#endif

#include "archive.h"

#include "archive_private.h"

#include "archive_string.h"

#include "archive_write_private.h"

#if ARCHIVE_VERSION_NUMBER < 4000000

int

archive_write_set_compression_gzip(struct archive *a)

{

	__archive_write_filters_free(a);

	return (archive_write_add_filter_gzip(a));

}

#endif

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

struct private_data {

	int		 compression_level;

	int		 timestamp;

#ifdef HAVE_ZLIB_H

	z_stream	 stream;

	int64_t		 total_in;

	unsigned char	*compressed;

	size_t		 compressed_buffer_size;

	unsigned long	 crc;

#else

	struct archive_write_program_data *pdata;

#endif

};

/*

 * Yuck.  zlib.h is not const-correct, so I need this one bit

 * of ugly hackery to convert a const * pointer to a non-const pointer.

 */

#define	SET_NEXT_IN(st,src)					\

	(st)->stream.next_in = (Bytef *)(uintptr_t)(const void *)(src)

static int archive_compressor_gzip_options(struct archive_write_filter *,

		    const char *, const char *);

static int archive_compressor_gzip_open(struct archive_write_filter *);

static int archive_compressor_gzip_write(struct archive_write_filter *,

		    const void *, size_t);

static int archive_compressor_gzip_close(struct archive_write_filter *);

static int archive_compressor_gzip_free(struct archive_write_filter *);

#ifdef HAVE_ZLIB_H

static int drive_compressor(struct archive_write_filter *,

		    struct private_data *, int finishing);

#endif

/*

 * Add a gzip compression filter to this write handle.

 */

int

archive_write_add_filter_gzip(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_gzip");

	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_gzip_open;

	f->options = &archive_compressor_gzip_options;

	f->close = &archive_compressor_gzip_close;

	f->free = &archive_compressor_gzip_free;

	f->code = ARCHIVE_FILTER_GZIP;

	f->name = "gzip";

#ifdef HAVE_ZLIB_H

	data->compression_level = Z_DEFAULT_COMPRESSION;

	return (ARCHIVE_OK);

#else

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

	if (data->pdata == NULL) {

		free(data);

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

		return (ARCHIVE_FATAL);

	}

	data->compression_level = 0;

	archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,

	    "Using external gzip program");

	return (ARCHIVE_WARN);

#endif

}

static int

archive_compressor_gzip_free(struct archive_write_filter *f)

{

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

#ifdef HAVE_ZLIB_H

	free(data->compressed);

#else

	__archive_write_program_free(data->pdata);

#endif

	free(data);

	f->data = NULL;

	return (ARCHIVE_OK);

}

/*

 * Set write options.

 */

static int

archive_compressor_gzip_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) {

		if (value == NULL || !(value[0] >= '0' && value[0] <= '9') ||

		    value[1] != '\0')

			return (ARCHIVE_WARN);

		data->compression_level = value[0] - '0';

		return (ARCHIVE_OK);

	}

	if (strcmp(key, "timestamp") == 0) {

		data->timestamp = (value == NULL)?-1:1;

		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);

}

#ifdef HAVE_ZLIB_H

/*

 * Setup callback.

 */

static int

archive_compressor_gzip_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->compressed == NULL) {

		size_t bs = 65536, 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->compressed_buffer_size = bs;

		data->compressed

		    = (unsigned char *)malloc(data->compressed_buffer_size);

		if (data->compressed == NULL) {

			archive_set_error(f->archive, ENOMEM,

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

			return (ARCHIVE_FATAL);

		}

	}

	data->crc = crc32(0L, NULL, 0);

	data->stream.next_out = data->compressed;

	data->stream.avail_out = (uInt)data->compressed_buffer_size;

	/* Prime output buffer with a gzip header. */

	data->compressed[0] = 0x1f; /* GZip signature bytes */

	data->compressed[1] = 0x8b;

	data->compressed[2] = 0x08; /* "Deflate" compression */

	data->compressed[3] = 0; /* No options */

	if (data->timestamp >= 0) {

		time_t t = time(NULL);

		data->compressed[4] = (uint8_t)(t)&0xff;  /* Timestamp */

		data->compressed[5] = (uint8_t)(t>>8)&0xff;

		data->compressed[6] = (uint8_t)(t>>16)&0xff;

		data->compressed[7] = (uint8_t)(t>>24)&0xff;

	} else

		memset(&data->compressed[4], 0, 4);

    if (data->compression_level == 9)

	    data->compressed[8] = 2;

    else if(data->compression_level == 1)

	    data->compressed[8] = 4;

    else

	    data->compressed[8] = 0;

	data->compressed[9] = 3; /* OS=Unix */

	data->stream.next_out += 10;

	data->stream.avail_out -= 10;

	f->write = archive_compressor_gzip_write;

	/* Initialize compression library. */

	ret = deflateInit2(&(data->stream),

	    data->compression_level,

	    Z_DEFLATED,

	    -15 /* < 0 to suppress zlib header */,

	    8,

	    Z_DEFAULT_STRATEGY);

	if (ret == Z_OK) {

		f->data = data;

		return (ARCHIVE_OK);

	}

	/* Library setup failed: clean up. */

	archive_set_error(f->archive, ARCHIVE_ERRNO_MISC, "Internal error "

	    "initializing compression library");

	/* Override the error message if we know what really went wrong. */

	switch (ret) {

	case Z_STREAM_ERROR:

		archive_set_error(f->archive, ARCHIVE_ERRNO_MISC,

		    "Internal error initializing "

		    "compression library: invalid setup parameter");

		break;

	case Z_MEM_ERROR:

		archive_set_error(f->archive, ENOMEM,

		    "Internal error initializing compression library");

		break;

	case Z_VERSION_ERROR:

		archive_set_error(f->archive, ARCHIVE_ERRNO_MISC,

		    "Internal error initializing "

		    "compression library: invalid library version");

		break;

	}

	return (ARCHIVE_FATAL);

}

/*

 * Write data to the compressed stream.

 */

static int

archive_compressor_gzip_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->crc = crc32(data->crc, (const Bytef *)buff, (uInt)length);

	data->total_in += length;

	/* Compress input data to output buffer */

	SET_NEXT_IN(data, buff);

	data->stream.avail_in = (uInt)length;

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

		return (ret);

	return (ARCHIVE_OK);

}

/*

 * Finish the compression...

 */

static int

archive_compressor_gzip_close(struct archive_write_filter *f)

{

	unsigned char trailer[8];

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

	int ret, r1;

	/* Finish compression cycle */

	ret = drive_compressor(f, data, 1);

	if (ret == ARCHIVE_OK) {

		/* Write the last compressed data. */

		ret = __archive_write_filter(f->next_filter,

		    data->compressed,

		    data->compressed_buffer_size - data->stream.avail_out);

	}

	if (ret == ARCHIVE_OK) {

		/* Build and write out 8-byte trailer. */

		trailer[0] = (uint8_t)(data->crc)&0xff;

		trailer[1] = (uint8_t)(data->crc >> 8)&0xff;

		trailer[2] = (uint8_t)(data->crc >> 16)&0xff;

		trailer[3] = (uint8_t)(data->crc >> 24)&0xff;

		trailer[4] = (uint8_t)(data->total_in)&0xff;

		trailer[5] = (uint8_t)(data->total_in >> 8)&0xff;

		trailer[6] = (uint8_t)(data->total_in >> 16)&0xff;

		trailer[7] = (uint8_t)(data->total_in >> 24)&0xff;

		ret = __archive_write_filter(f->next_filter, trailer, 8);

	}

	switch (deflateEnd(&(data->stream))) {

	case Z_OK:

		break;

	default:

		archive_set_error(f->archive, ARCHIVE_ERRNO_MISC,

		    "Failed to clean up compressor");

		ret = ARCHIVE_FATAL;

	}

	r1 = __archive_write_close_filter(f->next_filter);

	return (r1 < ret ? r1 : ret);

}

/*

 * 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)

{

	int ret;

	for (;;) {

		if (data->stream.avail_out == 0) {

			ret = __archive_write_filter(f->next_filter,

			    data->compressed,

			    data->compressed_buffer_size);

			if (ret != ARCHIVE_OK)

				return (ARCHIVE_FATAL);

			data->stream.next_out = data->compressed;

			data->stream.avail_out =

			    (uInt)data->compressed_buffer_size;

		}

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

		if (!finishing && data->stream.avail_in == 0)

			return (ARCHIVE_OK);

		ret = deflate(&(data->stream),

		    finishing ? Z_FINISH : Z_NO_FLUSH );

		switch (ret) {

		case Z_OK:

			/* In non-finishing case, check if compressor

			 * consumed everything */

			if (!finishing && data->stream.avail_in == 0)

				return (ARCHIVE_OK);

			/* In finishing case, this return always means

			 * there's more work */

			break;

		case Z_STREAM_END:

			/* This return can only occur in finishing case. */

			return (ARCHIVE_OK);

		default:

			/* Any other return value indicates an error. */

			archive_set_error(f->archive, ARCHIVE_ERRNO_MISC,

			    "GZip compression failed:"

			    " deflate() call returned status %d",

			    ret);

			return (ARCHIVE_FATAL);

		}

	}

}

#else /* HAVE_ZLIB_H */

static int

archive_compressor_gzip_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_strcpy(&as, "gzip");

	/* Specify compression level. */

	if (data->compression_level > 0) {

		archive_strcat(&as, " -");

		archive_strappend_char(&as, '0' + data->compression_level);

	}

	if (data->timestamp < 0)

		/* Do not save timestamp. */

		archive_strcat(&as, " -n");

	else if (data->timestamp > 0)

		/* Save timestamp. */

		archive_strcat(&as, " -N");

	f->write = archive_compressor_gzip_write;

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

	archive_string_free(&as);

	return (r);

}

static int

archive_compressor_gzip_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_gzip_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_ZLIB_H */