1// Copyright (c) 2009-2010 Satoshi Nakamoto
2// Copyright (c) 2009-present 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 <flatfile.h>
7
8#include <tinyformat.h>
9#include <util/fs_helpers.h>
10#include <util/log.h>
11#include <util/overflow.h>
12
13#include <stdexcept>
14
15FlatFileSeq::FlatFileSeq(fs::path dir, const char* prefix, size_t chunk_size) :
16    m_dir(std::move(dir)),
17    m_prefix(prefix),
18    m_chunk_size(chunk_size)
19{
20    if (chunk_size == 0) {
21        throw std::invalid_argument("chunk_size must be positive");
22    }
23}
24
25std::string FlatFilePos::ToString() const
26{
27    return strprintf("FlatFilePos(nFile=%i, nPos=%i)", nFile, nPos);
28}
29
30fs::path FlatFileSeq::FileName(const FlatFilePos& pos) const
31{
32    return m_dir / fs::u8path(strprintf("%s%05u.dat", m_prefix, pos.nFile));
33}
34
35FILE* FlatFileSeq::Open(const FlatFilePos& pos, bool read_only) const
36{
37    if (pos.IsNull()) {
38        return nullptr;
39    }
40    fs::path path = FileName(pos);
41    fs::create_directories(path.parent_path());
42    FILE* file = fsbridge::fopen(path, read_only ? "rb": "rb+");
43    if (!file && !read_only)
44        file = fsbridge::fopen(path, "wb+");
45    if (!file) {
46        LogError("Unable to open file %s", fs::PathToString(path));
47        return nullptr;
48    }
49    if (pos.nPos && FileSeek64(file, pos.nPos, SEEK_SET)) {
50        LogError("Unable to seek to position %u of %s", pos.nPos, fs::PathToString(path));
51        if (fclose(file) != 0) {
52            LogError("Unable to close file %s", fs::PathToString(path));
53        }
54        return nullptr;
55    }
56    return file;
57}
58
59size_t FlatFileSeq::Allocate(const FlatFilePos& pos, size_t add_size, bool& out_of_space) const
60{
61    out_of_space = false;
62
63    uint64_t n_old_chunks = CeilDiv(pos.nPos, uint64_t{m_chunk_size});
64    uint64_t n_new_chunks = CeilDiv(pos.nPos + add_size, uint64_t{m_chunk_size});
65    if (n_new_chunks > n_old_chunks) {
66        uint64_t old_size = pos.nPos;
67        uint64_t new_size = n_new_chunks * m_chunk_size;
68        size_t inc_size = new_size - old_size;
69
70        if (CheckDiskSpace(m_dir, inc_size)) {
71            FILE *file = Open(pos);
72            if (file) {
73                LogDebug(BCLog::VALIDATION, "Pre-allocating up to position 0x%x in %s%05u.dat\n", new_size, m_prefix, pos.nFile);
74                AllocateFileRange(file, pos.nPos, inc_size);
75                if (fclose(file) != 0) {
76                    LogError("Cannot close file %s%05u.dat after extending it with %u bytes", m_prefix, pos.nFile, new_size);
77                    return 0;
78                }
79                return inc_size;
80            }
81        } else {
82            out_of_space = true;
83        }
84    }
85    return 0;
86}
87
88bool FlatFileSeq::Flush(const FlatFilePos& pos, bool finalize) const
89{
90    FILE* file = Open(FlatFilePos(pos.nFile, 0)); // Avoid fseek to nPos
91    if (!file) {
92        LogError("%s: failed to open file %d\n", __func__, pos.nFile);
93        return false;
94    }
95    if (finalize && !TruncateFile(file, pos.nPos)) {
96        LogError("%s: failed to truncate file %d\n", __func__, pos.nFile);
97        if (fclose(file) != 0) {
98            LogError("Failed to close file %d", pos.nFile);
99        }
100        return false;
101    }
102    if (!FileCommit(file)) {
103        LogError("%s: failed to commit file %d\n", __func__, pos.nFile);
104        if (fclose(file) != 0) {
105            LogError("Failed to close file %d", pos.nFile);
106        }
107        return false;
108    }
109    DirectoryCommit(m_dir);
110
111    if (fclose(file) != 0) {
112        LogError("Failed to close file %d after flush", pos.nFile);
113        return false;
114    }
115    return true;
116}
117