| 1 | /* |
| 2 | Copyright (c) 2016, Facebook, Inc. |
| 3 | |
| 4 | This program is free software; you can redistribute it and/or modify |
| 5 | it under the terms of the GNU General Public License as published by |
| 6 | the Free Software Foundation; version 2 of the License. |
| 7 | |
| 8 | This program is distributed in the hope that it will be useful, |
| 9 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | GNU General Public License for more details. |
| 12 | |
| 13 | You should have received a copy of the GNU General Public License |
| 14 | along with this program; if not, write to the Free Software |
| 15 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ |
| 16 | #pragma once |
| 17 | |
| 18 | #include "rdb_mariadb_port.h" |
| 19 | |
| 20 | /* C++ standard header files */ |
| 21 | #include <chrono> |
| 22 | #include <string> |
| 23 | #include <vector> |
| 24 | |
| 25 | /* MySQL header files */ |
| 26 | #include "../sql/log.h" |
| 27 | #include "./my_stacktrace.h" |
| 28 | #include "./sql_string.h" |
| 29 | |
| 30 | /* RocksDB header files */ |
| 31 | #include "rocksdb/slice.h" |
| 32 | #include "rocksdb/status.h" |
| 33 | |
| 34 | #ifdef HAVE_JEMALLOC |
| 35 | #include <jemalloc/jemalloc.h> |
| 36 | #endif |
| 37 | |
| 38 | namespace myrocks { |
| 39 | |
| 40 | /* |
| 41 | Guess what? |
| 42 | An interface is a class where all members are public by default. |
| 43 | */ |
| 44 | |
| 45 | #ifndef interface |
| 46 | #define interface struct |
| 47 | #endif // interface |
| 48 | |
| 49 | /* |
| 50 | Introduce C-style pseudo-namespaces, a handy way to make code more readble |
| 51 | when calling into a legacy API, which does not have any namespace defined. |
| 52 | Since we cannot or don't want to change the API in any way, we can use this |
| 53 | mechanism to define readability tokens that look like C++ namespaces, but are |
| 54 | not enforced in any way by the compiler, since the pre-compiler strips them |
| 55 | out. However, on the calling side, code looks like my_core::thd_ha_data() |
| 56 | rather than plain a thd_ha_data() call. This technique adds an immediate |
| 57 | visible cue on what type of API we are calling into. |
| 58 | */ |
| 59 | |
| 60 | #ifndef my_core |
| 61 | // C-style pseudo-namespace for MySQL Core API, to be used in decorating calls |
| 62 | // to non-obvious MySQL functions, like the ones that do not start with well |
| 63 | // known prefixes: "my_", "sql_", and "mysql_". |
| 64 | #define my_core |
| 65 | #endif // my_core |
| 66 | |
| 67 | /* |
| 68 | The intent behind a SHIP_ASSERT() macro is to have a mechanism for validating |
| 69 | invariants in retail builds. Traditionally assertions (such as macros defined |
| 70 | in <cassert>) are evaluated for performance reasons only in debug builds and |
| 71 | become NOOP in retail builds when NDEBUG is defined. |
| 72 | |
| 73 | This macro is intended to validate the invariants which are critical for |
| 74 | making sure that data corruption and data loss won't take place. Proper |
| 75 | intended usage can be described as "If a particular condition is not true then |
| 76 | stop everything what's going on and terminate the process because continued |
| 77 | execution will cause really bad things to happen". |
| 78 | |
| 79 | Use the power of SHIP_ASSERT() wisely. |
| 80 | */ |
| 81 | |
| 82 | #ifndef SHIP_ASSERT |
| 83 | #define SHIP_ASSERT(expr) \ |
| 84 | do { \ |
| 85 | if (!(expr)) { \ |
| 86 | my_safe_printf_stderr("\nShip assert failure: \'%s\'\n", #expr); \ |
| 87 | abort(); \ |
| 88 | } \ |
| 89 | } while (0) |
| 90 | #endif // SHIP_ASSERT |
| 91 | |
| 92 | /* |
| 93 | Assert a implies b. |
| 94 | If a is true, then b must be true. |
| 95 | If a is false, then the value is b does not matter. |
| 96 | */ |
| 97 | #ifndef DBUG_ASSERT_IMP |
| 98 | #define DBUG_ASSERT_IMP(a, b) DBUG_ASSERT(!(a) || (b)) |
| 99 | #endif |
| 100 | |
| 101 | /* |
| 102 | Assert a if and only if b. |
| 103 | a and b must be both true or both false. |
| 104 | */ |
| 105 | #ifndef DBUG_ASSERT_IFF |
| 106 | #define DBUG_ASSERT_IFF(a, b) \ |
| 107 | DBUG_ASSERT(static_cast<bool>(a) == static_cast<bool>(b)) |
| 108 | #endif |
| 109 | |
| 110 | |
| 111 | /* |
| 112 | Portability: use __PRETTY_FUNCTION__ when available, otherwise use __func__ |
| 113 | which is in the standard. |
| 114 | */ |
| 115 | |
| 116 | #ifdef __GNUC__ |
| 117 | # define __MYROCKS_PORTABLE_PRETTY_FUNCTION__ __PRETTY_FUNCTION__ |
| 118 | #else |
| 119 | # define __MYROCKS_PORTABLE_PRETTY_FUNCTION__ __func__ |
| 120 | #endif |
| 121 | |
| 122 | /* |
| 123 | Intent behind this macro is to avoid manually typing the function name every |
| 124 | time we want to add the debugging statement and use the compiler for this |
| 125 | work. This avoids typical refactoring problems when one renames a function, |
| 126 | but the tracing message doesn't get updated. |
| 127 | |
| 128 | We could use __func__ or __FUNCTION__ macros, but __PRETTY_FUNCTION__ |
| 129 | contains the signature of the function as well as its bare name and provides |
| 130 | therefore more context when interpreting the logs. |
| 131 | */ |
| 132 | #define DBUG_ENTER_FUNC() DBUG_ENTER(__MYROCKS_PORTABLE_PRETTY_FUNCTION__) |
| 133 | |
| 134 | /* |
| 135 | Error handling pattern used across MySQL abides by the following rules: "All |
| 136 | functions that can report an error (usually an allocation error), should |
| 137 | return 0/FALSE/false on success, 1/TRUE/true on failure." |
| 138 | |
| 139 | https://dev.mysql.com/doc/internals/en/additional-suggestions.html has more |
| 140 | details. |
| 141 | |
| 142 | To increase the comprehension and readability of MyRocks codebase we'll use |
| 143 | constants similar to ones from C standard (EXIT_SUCCESS and EXIT_FAILURE) to |
| 144 | make sure that both failure and success paths are clearly identifiable. The |
| 145 | definitions of FALSE and TRUE come from <my_global.h>. |
| 146 | */ |
| 147 | #define HA_EXIT_SUCCESS FALSE |
| 148 | #define HA_EXIT_FAILURE TRUE |
| 149 | |
| 150 | /* |
| 151 | Macros to better convey the intent behind checking the results from locking |
| 152 | and unlocking mutexes. |
| 153 | */ |
| 154 | #define RDB_MUTEX_LOCK_CHECK(m) \ |
| 155 | rdb_check_mutex_call_result(__MYROCKS_PORTABLE_PRETTY_FUNCTION__, true, \ |
| 156 | mysql_mutex_lock(&m)) |
| 157 | #define RDB_MUTEX_UNLOCK_CHECK(m) \ |
| 158 | rdb_check_mutex_call_result(__MYROCKS_PORTABLE_PRETTY_FUNCTION__, false, \ |
| 159 | mysql_mutex_unlock(&m)) |
| 160 | |
| 161 | /* |
| 162 | Generic constant. |
| 163 | */ |
| 164 | const size_t RDB_MAX_HEXDUMP_LEN = 1000; |
| 165 | |
| 166 | /* |
| 167 | Helper function to get an NULL terminated uchar* out of a given MySQL String. |
| 168 | */ |
| 169 | |
| 170 | inline uchar *rdb_mysql_str_to_uchar_str(my_core::String *str) { |
| 171 | DBUG_ASSERT(str != nullptr); |
| 172 | return reinterpret_cast<uchar *>(str->c_ptr()); |
| 173 | } |
| 174 | |
| 175 | /* |
| 176 | Helper function to get plain (not necessary NULL terminated) uchar* out of a |
| 177 | given STL string. |
| 178 | */ |
| 179 | |
| 180 | inline const uchar *rdb_std_str_to_uchar_ptr(const std::string &str) { |
| 181 | return reinterpret_cast<const uchar *>(str.data()); |
| 182 | } |
| 183 | |
| 184 | /* |
| 185 | Helper function to convert seconds to milliseconds. |
| 186 | */ |
| 187 | |
| 188 | constexpr int rdb_convert_sec_to_ms(int sec) { |
| 189 | return std::chrono::milliseconds(std::chrono::seconds(sec)).count(); |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | Helper function to get plain (not necessary NULL terminated) uchar* out of a |
| 194 | given RocksDB item. |
| 195 | */ |
| 196 | |
| 197 | inline const uchar *rdb_slice_to_uchar_ptr(const rocksdb::Slice *item) { |
| 198 | DBUG_ASSERT(item != nullptr); |
| 199 | return reinterpret_cast<const uchar *>(item->data()); |
| 200 | } |
| 201 | |
| 202 | /* |
| 203 | Call this function in cases when you can't rely on garbage collector and need |
| 204 | to explicitly purge all unused dirty pages. This should be a relatively rare |
| 205 | scenario for cases where it has been verified that this intervention has |
| 206 | noticeable benefits. |
| 207 | */ |
| 208 | inline int purge_all_jemalloc_arenas() { |
| 209 | #ifdef HAVE_JEMALLOC |
| 210 | unsigned narenas = 0; |
| 211 | size_t sz = sizeof(unsigned); |
| 212 | char name[25] = {0}; |
| 213 | |
| 214 | // Get the number of arenas first. Please see `jemalloc` documentation for |
| 215 | // all the various options. |
| 216 | int result = mallctl("arenas.narenas" , &narenas, &sz, nullptr, 0); |
| 217 | |
| 218 | // `mallctl` returns 0 on success and we really want caller to know if all the |
| 219 | // trickery actually works. |
| 220 | if (result) { |
| 221 | return result; |
| 222 | } |
| 223 | |
| 224 | // Form the command to be passed to `mallctl` and purge all the unused dirty |
| 225 | // pages. |
| 226 | snprintf(name, sizeof(name) / sizeof(char), "arena.%d.purge" , narenas); |
| 227 | result = mallctl(name, nullptr, nullptr, nullptr, 0); |
| 228 | |
| 229 | return result; |
| 230 | #else |
| 231 | return EXIT_SUCCESS; |
| 232 | #endif |
| 233 | } |
| 234 | |
| 235 | /* |
| 236 | Helper function to check the result of locking or unlocking a mutex. We'll |
| 237 | intentionally abort in case of a failure because it's better to terminate |
| 238 | the process instead of continuing in an undefined state and corrupting data |
| 239 | as a result. |
| 240 | */ |
| 241 | inline void rdb_check_mutex_call_result(const char *function_name, |
| 242 | const bool attempt_lock, |
| 243 | const int result) { |
| 244 | if (unlikely(result)) { |
| 245 | /* NO_LINT_DEBUG */ |
| 246 | sql_print_error("%s a mutex inside %s failed with an " |
| 247 | "error code %d." , |
| 248 | attempt_lock ? "Locking" : "Unlocking" , function_name, |
| 249 | result); |
| 250 | |
| 251 | // This will hopefully result in a meaningful stack trace which we can use |
| 252 | // to efficiently debug the root cause. |
| 253 | abort(); |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | void rdb_log_status_error(const rocksdb::Status &s, const char *msg = nullptr); |
| 258 | |
| 259 | // return true if the marker file exists which indicates that the corruption |
| 260 | // has been detected |
| 261 | bool rdb_check_rocksdb_corruption(); |
| 262 | |
| 263 | // stores a marker file in the data directory so that after restart server |
| 264 | // is still aware that rocksdb data is corrupted |
| 265 | void rdb_persist_corruption_marker(); |
| 266 | |
| 267 | /* |
| 268 | Helper functions to parse strings. |
| 269 | */ |
| 270 | |
| 271 | const char *rdb_skip_spaces(const struct charset_info_st *const cs, |
| 272 | const char *str) |
| 273 | MY_ATTRIBUTE((__nonnull__, __warn_unused_result__)); |
| 274 | |
| 275 | bool rdb_compare_strings_ic(const char *const str1, const char *const str2) |
| 276 | MY_ATTRIBUTE((__nonnull__, __warn_unused_result__)); |
| 277 | |
| 278 | const char *rdb_find_in_string(const char *str, const char *pattern, |
| 279 | bool *const succeeded) |
| 280 | MY_ATTRIBUTE((__nonnull__, __warn_unused_result__)); |
| 281 | |
| 282 | const char *rdb_check_next_token(const struct charset_info_st *const cs, |
| 283 | const char *str, const char *const pattern, |
| 284 | bool *const succeeded) |
| 285 | MY_ATTRIBUTE((__nonnull__, __warn_unused_result__)); |
| 286 | |
| 287 | const char *rdb_parse_id(const struct charset_info_st *const cs, |
| 288 | const char *str, std::string *const id) |
| 289 | MY_ATTRIBUTE((__nonnull__(1, 2), __warn_unused_result__)); |
| 290 | |
| 291 | const char *rdb_skip_id(const struct charset_info_st *const cs, const char *str) |
| 292 | MY_ATTRIBUTE((__nonnull__, __warn_unused_result__)); |
| 293 | |
| 294 | const std::vector<std::string> parse_into_tokens(const std::string& s, |
| 295 | const char delim); |
| 296 | |
| 297 | /* |
| 298 | Helper functions to populate strings. |
| 299 | */ |
| 300 | |
| 301 | std::string rdb_hexdump(const char *data, const std::size_t data_len, |
| 302 | const std::size_t maxsize = 0) |
| 303 | MY_ATTRIBUTE((__nonnull__)); |
| 304 | |
| 305 | /* |
| 306 | Helper function to see if a database exists |
| 307 | */ |
| 308 | bool rdb_database_exists(const std::string &db_name); |
| 309 | |
| 310 | const char *get_rocksdb_supported_compression_types(); |
| 311 | |
| 312 | } // namespace myrocks |
| 313 | |