streams.cpp raw
1 // Copyright (c) 2009-present The Limenka developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or https://opensource.org/license/mit/.
4
5 #include <memusage.h>
6 #include <span.h>
7 #include <streams.h>
8 #include <util/fs_helpers.h>
9 #include <util/ioprio.h>
10 #include <util/obfuscation.h>
11
12 #include <array>
13
14 AutoFile::AutoFile(std::FILE* file, const Obfuscation& obfuscation) : m_file{file}, m_obfuscation{obfuscation}
15 {
16 if (!IsNull()) {
17 auto pos{std::ftell(m_file)};
18 if (pos >= 0) m_position = pos;
19 }
20 }
21
22 std::size_t AutoFile::detail_fread(Span<std::byte> dst)
23 {
24 if (!m_file) throw std::ios_base::failure("AutoFile::read: file handle is nullptr");
25 size_t ret = std::fread(dst.data(), 1, dst.size(), m_file);
26 if (m_obfuscation) {
27 if (!m_position.has_value()) throw std::ios_base::failure("AutoFile::read: position unknown");
28 m_obfuscation(dst.subspan(0, ret), *m_position);
29 }
30 if (m_position.has_value()) *m_position += ret;
31 return ret;
32 }
33
34 void AutoFile::seek(int64_t offset, int origin)
35 {
36 if (IsNull()) {
37 throw std::ios_base::failure("AutoFile::seek: file handle is nullptr");
38 }
39 if (std::fseek(m_file, offset, origin) != 0) {
40 throw std::ios_base::failure(feof() ? "AutoFile::seek: end of file" : "AutoFile::seek: fseek failed");
41 }
42 if (origin == SEEK_SET) {
43 m_position = offset;
44 } else if (origin == SEEK_CUR && m_position.has_value()) {
45 *m_position += offset;
46 } else {
47 int64_t r{std::ftell(m_file)};
48 if (r < 0) {
49 throw std::ios_base::failure("AutoFile::seek: ftell failed");
50 }
51 m_position = r;
52 }
53 }
54
55 int64_t AutoFile::tell()
56 {
57 if (!m_position.has_value()) throw std::ios_base::failure("AutoFile::tell: position unknown");
58 return *m_position;
59 }
60
61 void AutoFile::read(Span<std::byte> dst)
62 {
63 if (detail_fread(dst) != dst.size()) {
64 throw std::ios_base::failure(feof() ? "AutoFile::read: end of file" : "AutoFile::read: fread failed");
65 }
66 }
67
68 void AutoFile::ignore(size_t nSize)
69 {
70 if (!m_file) throw std::ios_base::failure("AutoFile::ignore: file handle is nullptr");
71 unsigned char data[4096];
72 while (nSize > 0) {
73 size_t nNow = std::min<size_t>(nSize, sizeof(data));
74 if (std::fread(data, 1, nNow, m_file) != nNow) {
75 throw std::ios_base::failure(feof() ? "AutoFile::ignore: end of file" : "AutoFile::ignore: fread failed");
76 }
77 nSize -= nNow;
78 if (m_position.has_value()) *m_position += nNow;
79 }
80 }
81
82 void AutoFile::write(Span<const std::byte> src)
83 {
84 if (!m_file) throw std::ios_base::failure("AutoFile::write: file handle is nullptr");
85 if (!m_obfuscation) {
86 if (std::fwrite(src.data(), 1, src.size(), m_file) != src.size()) {
87 throw std::ios_base::failure("AutoFile::write: write failed");
88 }
89 m_was_written = true;
90 if (m_position.has_value()) *m_position += src.size();
91 } else {
92 std::array<std::byte, 4096> buf;
93 while (src.size() > 0) {
94 auto buf_now{Span{buf}.first(std::min<size_t>(src.size(), buf.size()))};
95 std::copy_n(src.begin(), buf_now.size(), buf_now.begin());
96 write_buffer(buf_now);
97 src = src.subspan(buf_now.size());
98 }
99 }
100 }
101
102 void AutoFile::write_buffer(std::span<std::byte> src)
103 {
104 if (!m_file) throw std::ios_base::failure("AutoFile::write_buffer: file handle is nullptr");
105 if (m_obfuscation) {
106 if (!m_position) throw std::ios_base::failure("AutoFile::write_buffer: obfuscation position unknown");
107 m_obfuscation(src, *m_position); // obfuscate in-place
108 }
109 if (std::fwrite(src.data(), 1, src.size(), m_file) != src.size()) {
110 throw std::ios_base::failure("AutoFile::write_buffer: write failed");
111 }
112 m_was_written = true;
113 if (m_position) *m_position += src.size();
114 }
115
116 bool AutoFile::Commit()
117 {
118 return ::FileCommit(m_file);
119 }
120
121 void AutoFile::SetIdlePriority()
122 {
123 ioprio_set_file_idle(m_file);
124 }
125
126 bool AutoFile::Truncate(unsigned size)
127 {
128 m_was_written = true;
129 return ::TruncateFile(m_file, size);
130 }
131
132 size_t DataStream::GetMemoryUsage() const noexcept
133 {
134 return sizeof(*this) + memusage::DynamicUsage(vch);
135 }
136