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| -rw-r--r-- | storage/rocksdb/rdb_utils.h | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/storage/rocksdb/rdb_utils.h b/storage/rocksdb/rdb_utils.h new file mode 100644 index 00000000..0ef74b9f --- /dev/null +++ b/storage/rocksdb/rdb_utils.h @@ -0,0 +1,335 @@ +/* + Copyright (c) 2016, Facebook, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA */ +#pragma once + +#include "rdb_mariadb_port.h" + +/* C++ standard header files */ +#include <chrono> +#include <string> +#include <vector> +#include <functional> + +/* MySQL header files */ +#include "../sql/log.h" +#include "./my_stacktrace.h" +#include "./sql_string.h" + +/* RocksDB header files */ +#include "rocksdb/slice.h" +#include "rocksdb/status.h" + +#ifdef HAVE_JEMALLOC +#include <jemalloc/jemalloc.h> +#endif + +namespace myrocks { + +/* + Guess what? + An interface is a class where all members are public by default. +*/ + +#ifndef interface +#define interface struct +#endif // interface + +/* + Introduce C-style pseudo-namespaces, a handy way to make code more readble + when calling into a legacy API, which does not have any namespace defined. + Since we cannot or don't want to change the API in any way, we can use this + mechanism to define readability tokens that look like C++ namespaces, but are + not enforced in any way by the compiler, since the pre-compiler strips them + out. However, on the calling side, code looks like my_core::thd_get_ha_data() + rather than plain a thd_get_ha_data() call. This technique adds an immediate + visible cue on what type of API we are calling into. +*/ + +#ifndef my_core +// C-style pseudo-namespace for MySQL Core API, to be used in decorating calls +// to non-obvious MySQL functions, like the ones that do not start with well +// known prefixes: "my_", "sql_", and "mysql_". +#define my_core +#endif // my_core + +/* + The intent behind a SHIP_ASSERT() macro is to have a mechanism for validating + invariants in retail builds. Traditionally assertions (such as macros defined + in <cassert>) are evaluated for performance reasons only in debug builds and + become NOOP in retail builds when DBUG_OFF is defined. + + This macro is intended to validate the invariants which are critical for + making sure that data corruption and data loss won't take place. Proper + intended usage can be described as "If a particular condition is not true then + stop everything what's going on and terminate the process because continued + execution will cause really bad things to happen". + + Use the power of SHIP_ASSERT() wisely. +*/ + +#ifndef SHIP_ASSERT +#define SHIP_ASSERT(expr) \ + do { \ + if (!(expr)) { \ + my_safe_printf_stderr("\nShip assert failure: \'%s\'\n", #expr); \ + abort(); \ + } \ + } while (0) +#endif // SHIP_ASSERT + +/* + Assert a implies b. + If a is true, then b must be true. + If a is false, then the value is b does not matter. +*/ +#ifndef DBUG_ASSERT_IMP +#define DBUG_ASSERT_IMP(a, b) DBUG_ASSERT(!(a) || (b)) +#endif + +/* + Assert a if and only if b. + a and b must be both true or both false. +*/ +#ifndef DBUG_ASSERT_IFF +#define DBUG_ASSERT_IFF(a, b) \ + DBUG_ASSERT(static_cast<bool>(a) == static_cast<bool>(b)) +#endif + + +/* + Portability: use __PRETTY_FUNCTION__ when available, otherwise use __func__ + which is in the standard. +*/ + +#ifdef __GNUC__ +# define __MYROCKS_PORTABLE_PRETTY_FUNCTION__ __PRETTY_FUNCTION__ +#else +# define __MYROCKS_PORTABLE_PRETTY_FUNCTION__ __func__ +#endif + +/* + Intent behind this macro is to avoid manually typing the function name every + time we want to add the debugging statement and use the compiler for this + work. This avoids typical refactoring problems when one renames a function, + but the tracing message doesn't get updated. + + We could use __func__ or __FUNCTION__ macros, but __PRETTY_FUNCTION__ + contains the signature of the function as well as its bare name and provides + therefore more context when interpreting the logs. +*/ +#define DBUG_ENTER_FUNC() DBUG_ENTER(__MYROCKS_PORTABLE_PRETTY_FUNCTION__) + +/* + Error handling pattern used across MySQL abides by the following rules: "All + functions that can report an error (usually an allocation error), should + return 0/FALSE/false on success, 1/TRUE/true on failure." + + https://dev.mysql.com/doc/internals/en/additional-suggestions.html has more + details. + + To increase the comprehension and readability of MyRocks codebase we'll use + constants similar to ones from C standard (EXIT_SUCCESS and EXIT_FAILURE) to + make sure that both failure and success paths are clearly identifiable. The + definitions of FALSE and TRUE come from <my_global.h>. +*/ +#define HA_EXIT_SUCCESS FALSE +#define HA_EXIT_FAILURE TRUE + +/* + Macros to better convey the intent behind checking the results from locking + and unlocking mutexes. +*/ +#define RDB_MUTEX_LOCK_CHECK(m) \ + rdb_check_mutex_call_result(__MYROCKS_PORTABLE_PRETTY_FUNCTION__, true, \ + mysql_mutex_lock(&m)) +#define RDB_MUTEX_UNLOCK_CHECK(m) \ + rdb_check_mutex_call_result(__MYROCKS_PORTABLE_PRETTY_FUNCTION__, false, \ + mysql_mutex_unlock(&m)) + +/* + Generic constant. +*/ +const size_t RDB_MAX_HEXDUMP_LEN = 1000; + +/* + Helper function to get an NULL terminated uchar* out of a given MySQL String. +*/ + +inline uchar *rdb_mysql_str_to_uchar_str(my_core::String *str) { + DBUG_ASSERT(str != nullptr); + return reinterpret_cast<uchar *>(str->c_ptr()); +} + +/* + Helper function to get plain (not necessary NULL terminated) uchar* out of a + given STL string. +*/ + +inline const uchar *rdb_std_str_to_uchar_ptr(const std::string &str) { + return reinterpret_cast<const uchar *>(str.data()); +} + +/* + Helper function to convert seconds to milliseconds. +*/ + +constexpr int rdb_convert_sec_to_ms(int sec) { + return std::chrono::milliseconds(std::chrono::seconds(sec)).count(); +} + +/* + Helper function to get plain (not necessary NULL terminated) uchar* out of a + given RocksDB item. +*/ + +inline const uchar *rdb_slice_to_uchar_ptr(const rocksdb::Slice *item) { + DBUG_ASSERT(item != nullptr); + return reinterpret_cast<const uchar *>(item->data()); +} + +/* + Call this function in cases when you can't rely on garbage collector and need + to explicitly purge all unused dirty pages. This should be a relatively rare + scenario for cases where it has been verified that this intervention has + noticeable benefits. +*/ +inline int purge_all_jemalloc_arenas() { +#ifdef HAVE_JEMALLOC + unsigned narenas = 0; + size_t sz = sizeof(unsigned); + char name[25] = {0}; + + // Get the number of arenas first. Please see `jemalloc` documentation for + // all the various options. + int result = mallctl("arenas.narenas", &narenas, &sz, nullptr, 0); + + // `mallctl` returns 0 on success and we really want caller to know if all the + // trickery actually works. + if (result) { + return result; + } + + // Form the command to be passed to `mallctl` and purge all the unused dirty + // pages. + snprintf(name, sizeof(name) / sizeof(char), "arena.%d.purge", narenas); + result = mallctl(name, nullptr, nullptr, nullptr, 0); + + return result; +#else + return EXIT_SUCCESS; +#endif +} + +/* + Helper function to check the result of locking or unlocking a mutex. We'll + intentionally abort in case of a failure because it's better to terminate + the process instead of continuing in an undefined state and corrupting data + as a result. +*/ +inline void rdb_check_mutex_call_result(const char *function_name, + const bool attempt_lock, + const int result) { + if (unlikely(result)) { + /* NO_LINT_DEBUG */ + sql_print_error( + "%s a mutex inside %s failed with an " + "error code %d.", + attempt_lock ? "Locking" : "Unlocking", function_name, result); + + // This will hopefully result in a meaningful stack trace which we can use + // to efficiently debug the root cause. + abort(); + } +} + +void rdb_log_status_error(const rocksdb::Status &s, const char *msg = nullptr); + +// return true if the marker file exists which indicates that the corruption +// has been detected +bool rdb_check_rocksdb_corruption(); + +// stores a marker file in the data directory so that after restart server +// is still aware that rocksdb data is corrupted +void rdb_persist_corruption_marker(); + +/* + Helper functions to parse strings. +*/ + +const char *rdb_skip_spaces(const struct charset_info_st *const cs, + const char *str) + MY_ATTRIBUTE((__nonnull__, __warn_unused_result__)); + +bool rdb_compare_strings_ic(const char *const str1, const char *const str2) + MY_ATTRIBUTE((__nonnull__, __warn_unused_result__)); + +const char *rdb_find_in_string(const char *str, const char *pattern, + bool *const succeeded) + MY_ATTRIBUTE((__nonnull__, __warn_unused_result__)); + +const char *rdb_check_next_token(const struct charset_info_st *const cs, + const char *str, const char *const pattern, + bool *const succeeded) + MY_ATTRIBUTE((__nonnull__, __warn_unused_result__)); + +const char *rdb_parse_id(const struct charset_info_st *const cs, + const char *str, std::string *const id) + MY_ATTRIBUTE((__nonnull__(1, 2), __warn_unused_result__)); + +const char *rdb_skip_id(const struct charset_info_st *const cs, const char *str) + MY_ATTRIBUTE((__nonnull__, __warn_unused_result__)); + +const std::vector<std::string> parse_into_tokens(const std::string &s, + const char delim); + +/* + Helper functions to populate strings. +*/ + +std::string rdb_hexdump(const char *data, const std::size_t data_len, + const std::size_t maxsize = 0) + MY_ATTRIBUTE((__nonnull__)); + +/* + Helper function to see if a database exists + */ +bool rdb_database_exists(const std::string &db_name); + +const char *get_rocksdb_supported_compression_types(); + +/* + Helper class to make sure cleanup always happens. Helpful for complicated + logic where there can be multiple exits/returns requiring cleanup + */ +class Ensure_cleanup { + public: + explicit Ensure_cleanup(std::function<void()> cleanup) + : m_cleanup(cleanup), m_skip_cleanup(false) {} + + ~Ensure_cleanup() { + if (!m_skip_cleanup) { + m_cleanup(); + } + } + + // If you want to skip cleanup (such as when the operation is successful) + void skip() { m_skip_cleanup = true; } + + private: + std::function<void()> m_cleanup; + bool m_skip_cleanup; +}; +} // namespace myrocks |