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
|
// file : libbutl/lz4.hxx -*- C++ -*-
// license : MIT; see accompanying LICENSE file
#pragma once
#include <cstdint>
#include <libbutl/optional.mxx>
#include <libbutl/fdstream.mxx>
#include <libbutl/export.hxx>
namespace butl
{
namespace lz4
{
//@@ TODO: allow (re-)using external buffers, contexts?
// Read the content from the input stream, compress it using the specified
// compression level and block size, and write the compressed content to
// the output stream. If content size is specified, then include it into
// the compressed content header. Return the compressed content size.
//
// This function may throw std::bad_alloc as well as exceptions thrown by
// fdstream read/write functions. It may also throw invalid_argument in
// case of argument inconsistencies (e.g., content size does not match
// actual) with what() returning the error description. The input stream
// is expected to throw on badbit (but not failbit). The output stream is
// expected to throw on badbit or failbit.
//
// The output and most likely the input streams must be in the binary
// mode.
//
// Valid values for the compressions level are between 1 (fastest) and
// 12 (best compression level).
//
// Valid block sizes and their IDs:
//
// 4: 64KB
// 5: 256KB
// 6: 1MB
// 7: 4MB
//
// This function produces compressed content identical to:
//
// lz4 -z -<compression_level> -B<block_size_id> -BD [--content-size]
//
LIBBUTL_SYMEXPORT std::uint64_t
compress (ofdstream&,
ifdstream&,
int compression_level,
int block_size_id,
optional<std::uint64_t> content_size);
// Read the compressed content from the input stream, decompress it, and
// write the decompressed content to the output stream. Return the
// decompressed content size.
//
// This function may throw std::bad_alloc as well as exceptions thrown by
// fdstream read/write functions. It may also throw invalid_argument if
// the compressed content is invalid with what() returning the error
// description. The input stream is expected to throw on badbit (but not
// failbit). The output stream is expected to throw on badbit or failbit.
//
// The input and most likely the output streams must be in the binary
// mode.
//
// Note that this function does not require the input stream to reach EOF
// at the end of compressed content. So if you have this a requirement,
// you will need to enforce it yourself.
//
LIBBUTL_SYMEXPORT std::uint64_t
decompress (ofdstream&, ifdstream&);
}
}
|
