aboutsummaryrefslogtreecommitdiff
path: root/debug/known_sizes.c
blob: ef7472de21f1cb784d9f258f8e133ca62b9e5e00 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
///////////////////////////////////////////////////////////////////////////////
//
/// \file       known_sizes.c
/// \brief      Encodes .lzma Stream with sizes known in Block Header
///
/// The input file is encoded in RAM, and the known Compressed Size
/// and/or Uncompressed Size values are stored in the Block Header.
/// As of writing there's no such Stream encoder in liblzma.
//
//  Copyright (C) 2008 Lasse Collin
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Lesser General Public
//  License as published by the Free Software Foundation; either
//  version 2.1 of the License, or (at your option) any later version.
//
//  This library is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//  Lesser General Public License for more details.
//
///////////////////////////////////////////////////////////////////////////////

#include "sysdefs.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/unistd.h>
#include <stdio.h>


// Support file sizes up to 1 MiB. We use this for output space too, so files
// close to 1 MiB had better compress at least a little or we have a buffer
// overflow.
#define BUFFER_SIZE (1U << 20)


int
main(void)
{
	// Allocate the buffers.
	uint8_t *in = malloc(BUFFER_SIZE);
	uint8_t *out = malloc(BUFFER_SIZE);
	if (in == NULL || out == NULL)
		return 1;

	// Fill the input buffer.
	const size_t in_size = fread(in, 1, BUFFER_SIZE, stdin);

	// Filter setup
	lzma_options_lzma opt_lzma;
	if (lzma_lzma_preset(&opt_lzma, 0))
		return 1;
	
	lzma_filter filters[] = {
		{
			.id = LZMA_FILTER_LZMA2,
			.options = &opt_lzma
		},
		{
			.id = LZMA_VLI_UNKNOWN
		}
	};

	lzma_block block = {
		.check = LZMA_CHECK_CRC32,
		.compressed_size = BUFFER_SIZE, // Worst case reserve
		.uncompressed_size = in_size,
		.filters = filters,
	};

	lzma_stream strm = LZMA_STREAM_INIT;
	if (lzma_block_encoder(&strm, &block) != LZMA_OK)
		return 1;

	// Reserve space for Stream Header and Block Header. We need to
	// calculate the size of the Block Header first.
	if (lzma_block_header_size(&block) != LZMA_OK)
		return 1;

	size_t out_size = LZMA_STREAM_HEADER_SIZE + block.header_size;

	strm.next_in = in;
	strm.avail_in = in_size;
	strm.next_out = out + out_size;
	strm.avail_out = BUFFER_SIZE - out_size;

	if (lzma_code(&strm, LZMA_FINISH) != LZMA_STREAM_END)
		return 1;

	out_size += strm.total_out;

	if (lzma_block_header_encode(&block, out + LZMA_STREAM_HEADER_SIZE)
			!= LZMA_OK)
		return 1;

	lzma_index *idx = lzma_index_init(NULL, NULL);
	if (idx == NULL)
		return 1;

	if (lzma_index_append(idx, NULL, block.header_size + strm.total_out,
			strm.total_in) != LZMA_OK)
		return 1;

	if (lzma_index_encoder(&strm, idx) != LZMA_OK)
		return 1;

	if (lzma_code(&strm, LZMA_RUN) != LZMA_STREAM_END)
		return 1;

	out_size += strm.total_out;

	lzma_end(&strm);

	lzma_index_end(idx, NULL);

	// Encode the Stream Header and Stream Footer. backwards_size is
	// needed only for the Stream Footer.
	lzma_stream_flags sf = {
		.backward_size = strm.total_out,
		.check = block.check,
	};

	if (lzma_stream_header_encode(&sf, out) != LZMA_OK)
		return 1;

	if (lzma_stream_footer_encode(&sf, out + out_size) != LZMA_OK)
		return 1;

	out_size += LZMA_STREAM_HEADER_SIZE;

	// Write out the file.
	fwrite(out, 1, out_size, stdout);

	return 0;
}