READ THE CODE

Inside Bitcoin

The code behind the network, with room to understand it.

Stable release v32.1bitcoin/bitcoin · f0de87f04062 ↗3,020 source files · 47.5 MB stored on the server340 file guides

Release published 2026-10-28 · Snapshot fetched 2026-11-01. Latest stable release at fetch time; development branches and Git history are excluded. Only the selected code window and visible folders load here.

20,252 bytes · SHA-256 acabcfa484a698e4… · View upstream ↗

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 <logging.h>
7#include <memusage.h>
8#include <util/check.h>
9#include <util/fs.h>
10#include <util/string.h>
11#include <util/threadnames.h>
12#include <util/time.h>
13
14#include <array>
15#include <cstring>
16#include <map>
17#include <optional>
18#include <utility>
19
20using util::Join;
21using util::RemovePrefixView;
22
23const char * const DEFAULT_DEBUGLOGFILE = "debug.log";
24constexpr auto MAX_USER_SETABLE_SEVERITY_LEVEL{BCLog::Level::Info};
25
26BCLog::Logger& LogInstance()
27{
28/**
29 * NOTE: the logger instances is leaked on exit. This is ugly, but will be
30 * cleaned up by the OS/libc. Defining a logger as a global object doesn't work
31 * since the order of destruction of static/global objects is undefined.
32 * Consider if the logger gets destroyed, and then some later destructor calls
33 * LogInfo, maybe indirectly, and you get a core dump at shutdown trying to
34 * access the logger. When the shutdown sequence is fully audited and tested,
35 * explicit destruction of these objects can be implemented by changing this
36 * from a raw pointer to a std::unique_ptr.
37 * Since the ~Logger() destructor is never called, the Logger class and all
38 * its subclasses must have implicitly-defined destructors.
39 *
40 * This method of initialization was originally introduced in
41 * ee3374234c60aba2cc4c5cd5cac1c0aefc2d817c.
42 */
43    static BCLog::Logger* g_logger{new BCLog::Logger()};
44    return *g_logger;
45}
46
47bool fLogIPs = DEFAULT_LOGIPS;
48
49static int FileWriteStr(std::string_view str, FILE *fp)
50{
51    return fwrite(str.data(), 1, str.size(), fp);
52}
53
54bool BCLog::Logger::StartLogging()
55{
56    STDLOCK(m_cs);
57
58    assert(m_buffering);
59    assert(m_fileout == nullptr);
60
61    if (m_print_to_file) {
62        assert(!m_file_path.empty());
63        m_fileout = fsbridge::fopen(m_file_path, "a");
64        if (!m_fileout) {
65            return false;
66        }
67
68        setbuf(m_fileout, nullptr); // unbuffered
69
70        // Add newlines to the logfile to distinguish this execution from the
71        // last one.
72        FileWriteStr("\n\n\n\n\n", m_fileout);
73    }
74
75    // dump buffered messages from before we opened the log
76    m_buffering = false;
77    if (m_buffer_lines_discarded > 0) {
78        LogPrint_({
79            .category = BCLog::ALL,
80            .level = Level::Info,
81            .should_ratelimit = false,
82            .source_loc = SourceLocation{__func__},
83            .message = strprintf("Early logging buffer overflowed, %d log lines discarded.", m_buffer_lines_discarded),
84        });
85    }
86    while (!m_msgs_before_open.empty()) {
87        const auto& buflog = m_msgs_before_open.front();
88        std::string s{Format(buflog)};
89        m_msgs_before_open.pop_front();
90
91        if (m_print_to_file) FileWriteStr(s, m_fileout);
92        if (m_print_to_console) fwrite(s.data(), 1, s.size(), stdout);
93        for (const auto& cb : m_print_callbacks) {
94            cb(s);
95        }
96    }
97    m_cur_buffer_memusage = 0;
98    if (m_print_to_console) fflush(stdout);
99
100    return true;
101}
102
103void BCLog::Logger::DisconnectTestLogger()
104{
105    STDLOCK(m_cs);
106    m_buffering = true;
107    if (m_fileout != nullptr) fclose(m_fileout);
108    m_fileout = nullptr;
109    m_print_callbacks.clear();
110    m_max_buffer_memusage = DEFAULT_MAX_LOG_BUFFER;
111    m_cur_buffer_memusage = 0;
112    m_buffer_lines_discarded = 0;
113    m_msgs_before_open.clear();
114}
115
116void BCLog::Logger::DisableLogging()
117{
118    {
119        STDLOCK(m_cs);
120        assert(m_buffering);
121        assert(m_print_callbacks.empty());
122    }
123    m_print_to_file = false;
124    m_print_to_console = false;
125    StartLogging();
126}
127
128void BCLog::Logger::EnableCategory(BCLog::LogFlags flag)
129{
130    m_categories |= flag;
131}
132
133bool BCLog::Logger::EnableCategory(std::string_view str)
134{
135    if (const auto flag{GetLogCategory(str)}) {
136        EnableCategory(*flag);
137        return true;
138    }
139    return false;
140}
141
142void BCLog::Logger::DisableCategory(BCLog::LogFlags flag)
143{
144    m_categories &= ~flag;
145}
146
147bool BCLog::Logger::DisableCategory(std::string_view str)
148{
149    if (const auto flag{GetLogCategory(str)}) {
150        DisableCategory(*flag);
151        return true;
152    }
153    return false;
154}
155
156bool BCLog::Logger::WillLogCategory(BCLog::LogFlags category) const
157{
158    return (m_categories.load(std::memory_order_relaxed) & category) != 0;
159}
160
161bool BCLog::Logger::WillLogCategoryLevel(BCLog::LogFlags category, BCLog::Level level) const
162{
163    // Log messages at Info, Warning and Error level unconditionally, so that
164    // important troubleshooting information doesn't get lost.
165    if (level >= BCLog::Level::Info) return true;
166
167    if (!WillLogCategory(category)) return false;
168
169    STDLOCK(m_cs);
170    const auto it{m_category_log_levels.find(category)};
171    return level >= (it == m_category_log_levels.end() ? LogLevel() : it->second);
172}
173
174bool BCLog::Logger::DefaultShrinkDebugFile() const
175{
176    return m_categories == BCLog::NONE;
177}
178
179static const std::map<std::string, BCLog::LogFlags, std::less<>> LOG_CATEGORIES_BY_STR{
180    {"net", BCLog::NET},
181    {"tor", BCLog::TOR},
182    {"mempool", BCLog::MEMPOOL},
183    {"http", BCLog::HTTP},
184    {"bench", BCLog::BENCH},
185    {"zmq", BCLog::ZMQ},
186    {"walletdb", BCLog::WALLETDB},
187    {"rpc", BCLog::RPC},
188    {"estimatefee", BCLog::ESTIMATEFEE},
189    {"addrman", BCLog::ADDRMAN},
190    {"selectcoins", BCLog::SELECTCOINS},
191    {"reindex", BCLog::REINDEX},
192    {"cmpctblock", BCLog::CMPCTBLOCK},
193    {"rand", BCLog::RAND},
194    {"prune", BCLog::PRUNE},
195    {"proxy", BCLog::PROXY},
196    {"mempoolrej", BCLog::MEMPOOLREJ},
197    {"coindb", BCLog::COINDB},
198    {"qt", BCLog::QT},
199    {"leveldb", BCLog::LEVELDB},
200    {"validation", BCLog::VALIDATION},
201    {"i2p", BCLog::I2P},
202    {"ipc", BCLog::IPC},
203#ifdef DEBUG_LOCKCONTENTION
204    {"lock", BCLog::LOCK},
205#endif
206    {"blockstorage", BCLog::BLOCKSTORAGE},
207    {"txreconciliation", BCLog::TXRECONCILIATION},
208    {"scan", BCLog::SCAN},
209    {"txpackages", BCLog::TXPACKAGES},
210    {"kernel", BCLog::KERNEL},
211    {"privatebroadcast", BCLog::PRIVBROADCAST},
212    {"mining", BCLog::MINING},
213};
214
215static const std::unordered_map<BCLog::LogFlags, std::string> LOG_CATEGORIES_BY_FLAG{
216    // Swap keys and values from LOG_CATEGORIES_BY_STR.
217    [](const auto& in) {
218        std::unordered_map<BCLog::LogFlags, std::string> out;
219        for (const auto& [k, v] : in) {
220            const bool inserted{out.emplace(v, k).second};
221            assert(inserted);
222        }
223        return out;
224    }(LOG_CATEGORIES_BY_STR)
225};
226
227std::optional<BCLog::LogFlags> BCLog::Logger::GetLogCategory(std::string_view str)
228{
229    if (str.empty() || str == "1" || str == "all") {
230        return BCLog::ALL;
231    }
232    auto it = LOG_CATEGORIES_BY_STR.find(str);
233    if (it != LOG_CATEGORIES_BY_STR.end()) {
234        return it->second;
235    }
236    if (str == "libevent") {
237       LogWarning("The logging category `%s` is deprecated, does nothing, and will be removed in a future version", str);
238       return BCLog::NONE;
239    }
240    return std::nullopt;
241}
242
243std::string BCLog::Logger::LogLevelToStr(BCLog::Level level)
244{
245    switch (level) {
246    case BCLog::Level::Trace:
247        return "trace";
248    case BCLog::Level::Debug:
249        return "debug";
250    case BCLog::Level::Info:

src/wallet/receive.cpp

src/wallet/coinselection.cpp

src/consensus/validation.h

src/primitives/transaction.cpp

src/script/descriptor.cpp

src/bitcoin-cli.cpp

src/rpc/blockchain.cpp

src/rpc/rawtransaction.cpp

src/init.cpp

src/crypto/sha256.cpp

src/consensus/merkle.h

src/consensus/tx_check.h

src/consensus/tx_verify.h

src/policy/feerate.h

src/policy/feerate.cpp

src/primitives/transaction_identifier.h

src/chainparamsbase.h

src/chainparamsbase.cpp

src/util/moneystr.cpp

src/crypto/ripemd160.h

src/crypto/sha1.h

src/crypto/sha512.h

src/crypto/hmac_sha256.h

src/crypto/hmac_sha512.h

src/crypto/hmac_sha256.cpp

src/crypto/hmac_sha512.cpp

src/crypto/hkdf_sha256_32.h

src/crypto/hkdf_sha256_32.cpp

src/support/cleanse.h

src/support/cleanse.cpp

src/crypto/siphash.cpp

src/crypto/muhash.h

src/crypto/chacha20.h

src/crypto/poly1305.h

src/crypto/chacha20poly1305.h

src/crypto/chacha20poly1305.cpp

src/util/chaintype.cpp

src/util/obfuscation.h

src/util/byte_units.h

src/util/overflow.h

src/blockencodings.cpp

src/net_permissions.cpp

src/policy/packages.cpp

src/policy/rbf.cpp

src/policy/truc_policy.cpp

src/policy/ephemeral_policy.cpp

src/policy/settings.cpp

src/policy/policy.cpp

src/node/transaction.cpp

src/node/coin.cpp

src/rpc/client.cpp

src/rpc/external_signer.cpp

src/rpc/request.cpp

src/rpc/server_util.cpp

src/rpc/fees.cpp

src/rpc/output_script.cpp

src/rpc/rawtransaction_util.cpp

src/rpc/rawtransaction_util.h

src/rpc/register.h

src/rpc/request.h

src/rpc/server_util.h

src/rpc/protocol.h

src/rpc/server.h

src/rpc/signmessage.cpp

src/rpc/txoutproof.cpp

src/rpc/util.cpp

src/rpc/util.h

src/wallet/rpc/addresses.cpp

src/wallet/rpc/backup.cpp

src/wallet/rpc/coins.cpp

src/wallet/rpc/encrypt.cpp

src/wallet/rpc/signmessage.cpp

src/wallet/rpc/util.cpp

src/wallet/rpc/util.h

src/wallet/coincontrol.cpp

src/wallet/coincontrol.h

src/wallet/context.cpp

src/wallet/context.h

src/wallet/crypter.cpp

src/wallet/crypter.h

src/wallet/db.cpp

src/wallet/export.cpp

src/wallet/external_signer_scriptpubkeyman.cpp

src/wallet/rpc/spend.cpp

src/wallet/rpc/transactions.cpp

src/wallet/rpc/wallet.cpp

src/wallet/feebumper.cpp

src/wallet/feebumper.h

src/index/base.h

src/index/base.cpp

src/index/txindex.h

src/index/txindex.cpp

src/index/txindex_key.h

src/index/txospenderindex.h

src/index/txospenderindex.cpp

src/index/blockfilterindex.h

src/index/blockfilterindex.cpp

src/index/coinstatsindex.h

src/index/coinstatsindex.cpp

src/index/db_key.h

src/index/disktxpos.h

src/kernel/chain.cpp

src/kernel/chain.h

src/kernel/checks.cpp

src/kernel/checks.h

src/kernel/context.cpp

src/kernel/context.h

src/kernel/cs_main.cpp

src/kernel/cs_main.h

src/kernel/disconnected_transactions.cpp

src/kernel/disconnected_transactions.h

src/kernel/mempool_removal_reason.cpp

src/kernel/mempool_removal_reason.h

src/kernel/coinstats.cpp

src/kernel/coinstats.h

src/kernel/chainparams.cpp

src/kernel/chainparams.h

src/wallet/sqlite.cpp

src/wallet/sqlite.h

src/wallet/transaction.cpp

src/wallet/transaction.h

src/wallet/dump.cpp

src/wallet/dump.h

src/wallet/init.cpp

src/wallet/walletutil.cpp

src/wallet/walletutil.h

src/wallet/wallettool.cpp

src/wallet/wallettool.h

src/wallet/export.h

src/wallet/migrate.cpp

src/wallet/migrate.h

src/wallet/db.h

src/wallet/walletdb.cpp

src/wallet/interfaces.cpp

src/wallet/scriptpubkeyman.cpp

src/wallet/scriptpubkeyman.h

src/kernel/bitcoinkernel.cpp

src/kernel/bitcoinkernel.h

src/kernel/bitcoinkernel_wrapper.h

src/node/chainstate.cpp

src/node/chainstate.h

src/node/blockstorage.cpp

src/node/blockstorage.h

src/node/mempool_persist.cpp

src/node/mempool_persist.h

src/node/utxo_snapshot.cpp

src/node/utxo_snapshot.h

src/node/kernel_notifications.cpp

src/node/kernel_notifications.h

src/node/blockmanager_args.cpp

src/kernel/blockmanager_opts.h

src/util/expected.cpp

src/policy/settings.h

src/util/types.h

src/kernel/messagestartchars.h

src/kernel/warning.h

src/util/exception.h

src/common/license_info.h

src/node/coins_view_args.h

src/node/database_args.h

src/util/batchpriority.h

src/util/ui_change_type.h

src/node/coins_view_args.cpp

src/node/peerman_args.h

src/util/serfloat.h

src/node/blockmanager_args.h

src/node/database_args.cpp

src/util/overloaded.h

src/interfaces/types.h

src/node/chainstatemanager_args.h

src/node/minisketchwrapper.h

src/util/macros.h

src/util/syserror.h

src/common/run_command.h

src/util/bytevectorhash.cpp

src/node/mempool_persist_args.cpp

src/util/exec.h

src/util/rbf.h

src/crypto/hex_base.h

src/node/mempool_persist_args.h

src/interfaces/echo.h

src/util/any.h

src/util/batchpriority.cpp

src/util/threadnames.h

src/node/coin.h

src/node/mempool_args.h

src/util/asmap.h

src/util/bytevectorhash.h

src/node/context.cpp

src/util/insert.h

src/util/readwritefile.h

src/node/peerman_args.cpp

src/node/interface_ui.cpp

src/interfaces/handler.h

src/node/mining_args.h

src/util/hasher.cpp

src/common/init.h

src/kernel/mempool_limits.h

src/common/system.h

src/crypto/sha3.h

src/util/threadinterrupt.cpp

src/node/protocol_version.h

src/util/exception.cpp

src/common/messages.h

src/node/connection_types.cpp

src/util/bip32.h

src/common/license_info.cpp

src/util/stdmutex.h

src/common/run_command.cpp

src/util/check.cpp

src/util/golombrice.h

src/node/types.h

src/node/timeoffsets.h

src/util/readwritefile.cpp

src/util/fastrange.h

src/util/signalinterrupt.h

src/util/task_runner.h

src/util/syserror.cpp

src/common/interfaces.cpp

src/common/types.h

src/util/threadinterrupt.h

src/kernel/chainstatemanager_opts.h

src/node/psbt.h

src/policy/ephemeral_policy.h

src/util/trace.h

src/common/url.cpp

src/kernel/mempool_options.h

src/util/serfloat.cpp

src/kernel/notifications_interface.h

src/node/timeoffsets.cpp

src/node/warnings.cpp

src/util/hash_type.h

src/crypto/hex_base.cpp

src/node/eviction.h

src/util/tokenbucket.h

src/crypto/aes.h

src/common/pcp.h

src/util/feefrac.cpp

src/node/transaction.h

src/util/threadnames.cpp

src/common/signmessage.h

src/util/exec.cpp

src/util/signalinterrupt.cpp

Independent explanations by MyBitcoinExplorer. Not affiliated with or endorsed by Bitcoin Core. Guides are educational and do not replace the source or its tests.

Bitcoin Core source © its contributors, distributed under the MIT license. Original notices and bundled third-party licenses are retained in the source tree.