1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2019 The Bitcoin Core developers
3 // Distributed under the MIT software license, see the accompanying
4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5 
6 #include <stdexcept>
7 
8 #include <flatfile.h>
9 #include <logging.h>
10 #include <tinyformat.h>
11 #include <util/system.h>
12 
13 FlatFileSeq::FlatFileSeq(fs::path dir, const char* prefix, size_t chunk_size) :
14     m_dir(std::move(dir)),
15     m_prefix(prefix),
16     m_chunk_size(chunk_size)
17 {
18     if (chunk_size == 0) {
19         throw std::invalid_argument("chunk_size must be positive");
20     }
21 }
22 
23 std::string FlatFilePos::ToString() const
24 {
25     return strprintf("FlatFilePos(nFile=%i, nPos=%i)", nFile, nPos);
26 }
27 
28 fs::path FlatFileSeq::FileName(const FlatFilePos& pos) const
29 {
30     return m_dir / strprintf("%s%05u.dat", m_prefix, pos.nFile);
31 }
32 
33 FILE* FlatFileSeq::Open(const FlatFilePos& pos, bool read_only)
34 {
35     if (pos.IsNull()) {
36         return nullptr;
37     }
38     fs::path path = FileName(pos);
39     fs::create_directories(path.parent_path());
40     FILE* file = fsbridge::fopen(path, read_only ? "rb": "rb+");
41     if (!file && !read_only)
42         file = fsbridge::fopen(path, "wb+");
43     if (!file) {
44         LogPrintf("Unable to open file %s\n", path.string());
45         return nullptr;
46     }
47     if (pos.nPos && fseek(file, pos.nPos, SEEK_SET)) {
48         LogPrintf("Unable to seek to position %u of %s\n", pos.nPos, path.string());
49         fclose(file);
50         return nullptr;
51     }
52     return file;
53 }
54 
55 size_t FlatFileSeq::Allocate(const FlatFilePos& pos, size_t add_size, bool& out_of_space)
56 {
57     out_of_space = false;
58 
59     unsigned int n_old_chunks = (pos.nPos + m_chunk_size - 1) / m_chunk_size;
60     unsigned int n_new_chunks = (pos.nPos + add_size + m_chunk_size - 1) / m_chunk_size;
61     if (n_new_chunks > n_old_chunks) {
62         size_t old_size = pos.nPos;
63         size_t new_size = n_new_chunks * m_chunk_size;
64         size_t inc_size = new_size - old_size;
65 
66         if (CheckDiskSpace(m_dir, inc_size)) {
67             FILE *file = Open(pos);
68             if (file) {
69                 LogPrint(BCLog::VALIDATION, "Pre-allocating up to position 0x%x in %s%05u.dat\n", new_size, m_prefix, pos.nFile);
70                 AllocateFileRange(file, pos.nPos, inc_size);
71                 fclose(file);
72                 return inc_size;
73             }
74         } else {
75             out_of_space = true;
76         }
77     }
78     return 0;
79 }
80 
81 bool FlatFileSeq::Flush(const FlatFilePos& pos, bool finalize)
82 {
83     FILE* file = Open(FlatFilePos(pos.nFile, 0)); // Avoid fseek to nPos
84     if (!file) {
85         return error("%s: failed to open file %d", __func__, pos.nFile);
86     }
87     if (finalize && !TruncateFile(file, pos.nPos)) {
88         fclose(file);
89         return error("%s: failed to truncate file %d", __func__, pos.nFile);
90     }
91     if (!FileCommit(file)) {
92         fclose(file);
93         return error("%s: failed to commit file %d", __func__, pos.nFile);
94     }
95     DirectoryCommit(m_dir);
96 
97     fclose(file);
98     return true;
99 }
100