Bitcoin Core  27.99.0
P2P Digital Currency
utxo_snapshot.cpp
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1 // Copyright (c) 2022 The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 
5 #include <node/utxo_snapshot.h>
6 
7 #include <logging.h>
8 #include <streams.h>
9 #include <sync.h>
10 #include <tinyformat.h>
11 #include <txdb.h>
12 #include <uint256.h>
13 #include <util/fs.h>
14 #include <validation.h>
15 
16 #include <cassert>
17 #include <cstdio>
18 #include <optional>
19 #include <string>
20 
21 namespace node {
22 
23 bool WriteSnapshotBaseBlockhash(Chainstate& snapshot_chainstate)
24 {
26  assert(snapshot_chainstate.m_from_snapshot_blockhash);
27 
28  const std::optional<fs::path> chaindir = snapshot_chainstate.CoinsDB().StoragePath();
29  assert(chaindir); // Sanity check that chainstate isn't in-memory.
30  const fs::path write_to = *chaindir / node::SNAPSHOT_BLOCKHASH_FILENAME;
31 
32  FILE* file{fsbridge::fopen(write_to, "wb")};
33  AutoFile afile{file};
34  if (afile.IsNull()) {
35  LogPrintf("[snapshot] failed to open base blockhash file for writing: %s\n",
36  fs::PathToString(write_to));
37  return false;
38  }
39  afile << *snapshot_chainstate.m_from_snapshot_blockhash;
40 
41  if (afile.fclose() != 0) {
42  LogPrintf("[snapshot] failed to close base blockhash file %s after writing\n",
43  fs::PathToString(write_to));
44  return false;
45  }
46  return true;
47 }
48 
49 std::optional<uint256> ReadSnapshotBaseBlockhash(fs::path chaindir)
50 {
51  if (!fs::exists(chaindir)) {
52  LogPrintf("[snapshot] cannot read base blockhash: no chainstate dir "
53  "exists at path %s\n", fs::PathToString(chaindir));
54  return std::nullopt;
55  }
56  const fs::path read_from = chaindir / node::SNAPSHOT_BLOCKHASH_FILENAME;
57  const std::string read_from_str = fs::PathToString(read_from);
58 
59  if (!fs::exists(read_from)) {
60  LogPrintf("[snapshot] snapshot chainstate dir is malformed! no base blockhash file "
61  "exists at path %s. Try deleting %s and calling loadtxoutset again?\n",
62  fs::PathToString(chaindir), read_from_str);
63  return std::nullopt;
64  }
65 
66  uint256 base_blockhash;
67  FILE* file{fsbridge::fopen(read_from, "rb")};
68  AutoFile afile{file};
69  if (afile.IsNull()) {
70  LogPrintf("[snapshot] failed to open base blockhash file for reading: %s\n",
71  read_from_str);
72  return std::nullopt;
73  }
74  afile >> base_blockhash;
75 
76  if (std::fgetc(afile.Get()) != EOF) {
77  LogPrintf("[snapshot] warning: unexpected trailing data in %s\n", read_from_str);
78  } else if (std::ferror(afile.Get())) {
79  LogPrintf("[snapshot] warning: i/o error reading %s\n", read_from_str);
80  }
81  return base_blockhash;
82 }
83 
84 std::optional<fs::path> FindSnapshotChainstateDir(const fs::path& data_dir)
85 {
86  fs::path possible_dir =
87  data_dir / fs::u8path(strprintf("chainstate%s", SNAPSHOT_CHAINSTATE_SUFFIX));
88 
89  if (fs::exists(possible_dir)) {
90  return possible_dir;
91  }
92  return std::nullopt;
93 }
94 
95 } // namespace node
Non-refcounted RAII wrapper for FILE*.
Definition: streams.h:389
std::optional< fs::path > StoragePath()
Definition: txdb.h:77
Chainstate stores and provides an API to update our local knowledge of the current best chain.
Definition: validation.h:490
CCoinsViewDB & CoinsDB() EXCLUSIVE_LOCKS_REQUIRED(
Definition: validation.h:604
const std::optional< uint256 > m_from_snapshot_blockhash
The blockhash which is the base of the snapshot this chainstate was created from.
Definition: validation.h:577
Path class wrapper to block calls to the fs::path(std::string) implicit constructor and the fs::path:...
Definition: fs.h:33
256-bit opaque blob.
Definition: uint256.h:106
RecursiveMutex cs_main
Mutex to guard access to validation specific variables, such as reading or changing the chainstate.
Definition: cs_main.cpp:8
#define LogPrintf(...)
Definition: logging.h:244
static path u8path(const std::string &utf8_str)
Definition: fs.h:75
static bool exists(const path &p)
Definition: fs.h:89
static std::string PathToString(const path &path)
Convert path object to a byte string.
Definition: fs.h:151
FILE * fopen(const fs::path &p, const char *mode)
Definition: fs.cpp:26
Definition: messages.h:20
const fs::path SNAPSHOT_BLOCKHASH_FILENAME
The file in the snapshot chainstate dir which stores the base blockhash.
bool WriteSnapshotBaseBlockhash(Chainstate &snapshot_chainstate)
std::optional< uint256 > ReadSnapshotBaseBlockhash(fs::path chaindir)
bool WriteSnapshotBaseBlockhash(Chainstate &snapshot_chainstate) EXCLUSIVE_LOCKS_REQUIRED(std::optional< uint256 > constexpr ReadSnapshotBaseBlockhash(fs::path chaindir) EXCLUSIVE_LOCKS_REQUIRED(std::string_view SNAPSHOT_CHAINSTATE_SUFFIX
Write out the blockhash of the snapshot base block that was used to construct this chainstate.
std::optional< fs::path > FindSnapshotChainstateDir(const fs::path &data_dir)
Return a path to the snapshot-based chainstate dir, if one exists.
#define strprintf
Format arguments and return the string or write to given std::ostream (see tinyformat::format doc for...
Definition: tinyformat.h:1162
AssertLockHeld(pool.cs)
assert(!tx.IsCoinBase())