1 /* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- */ 2 // vim: ft=cpp:expandtab:ts=8:sw=4:softtabstop=4: 3 #ident "$Id$" 4 /*====== 5 This file is part of PerconaFT. 6 7 8 Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved. 9 10 PerconaFT is free software: you can redistribute it and/or modify 11 it under the terms of the GNU General Public License, version 2, 12 as published by the Free Software Foundation. 13 14 PerconaFT is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with PerconaFT. If not, see <http://www.gnu.org/licenses/>. 21 22 ---------------------------------------- 23 24 PerconaFT is free software: you can redistribute it and/or modify 25 it under the terms of the GNU Affero General Public License, version 3, 26 as published by the Free Software Foundation. 27 28 PerconaFT is distributed in the hope that it will be useful, 29 but WITHOUT ANY WARRANTY; without even the implied warranty of 30 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 31 GNU Affero General Public License for more details. 32 33 You should have received a copy of the GNU Affero General Public License 34 along with PerconaFT. If not, see <http://www.gnu.org/licenses/>. 35 ======= */ 36 37 #ident "Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved." 38 39 #pragma once 40 41 #include <toku_portability.h> 42 43 #include <util/mempool.h> 44 #include <util/omt.h> 45 46 #include "ft/txn/txn_manager.h" 47 #include "ft/serialize/rbuf.h" 48 #include "ft/msg.h" 49 50 /* 51 Memory format of packed leaf entry 52 CONSTANTS: 53 num_uxrs 54 keylen 55 Run-time-constants 56 voffset of val/vallen??? (for le_any_val) This must be small if it is interpreted as voffset = realoffset_of_val - keylen 57 GOOD performance optimization. 58 ALSO good for simplicity (no having to scan packed version) 59 key[] 60 variable length 61 62 63 Memory format of packed dup leaf entry 64 CONSTANTS: 65 num_uxrs 66 keylen 67 vallen 68 Run-time-constants 69 key[] 70 val[] 71 */ 72 73 enum cursor_read_type { 74 C_READ_ANY = 0, 75 C_READ_SNAPSHOT = 1, 76 C_READ_COMMITTED = 2 77 }; 78 79 // 80 // enum of possible values for LEAFENTRY->type field 81 // LE_CLEAN means that there is a single committed value in a format that saves disk space 82 // LE_MVCC means that there may be multiple committed values or there are provisional values 83 // 84 enum { LE_CLEAN = 0, LE_MVCC = 1 }; 85 86 // This is an on-disk format. static_asserts verify everything is packed and aligned correctly. 87 struct leafentry { 88 struct leafentry_clean { 89 uint32_t vallen; 90 uint8_t val[0]; //actual val 91 }; // For the case where LEAFENTRY->type is LE_CLEAN 92 static_assert(4 == sizeof(leafentry::leafentry_clean), "leafentry_clean size is wrong"); 93 static_assert(4 == __builtin_offsetof(leafentry::leafentry_clean, val), "val is in the wrong place"); 94 struct __attribute__ ((__packed__)) leafentry_mvcc { 95 uint32_t num_cxrs; // number of committed transaction records 96 uint8_t num_pxrs; // number of provisional transaction records 97 uint8_t xrs[0]; //then TXNIDs of XRs relevant for reads: 98 // if provisional XRs exist, store OUTERMOST TXNID 99 // store committed TXNIDs, from most recently committed to least recently committed (newest first) 100 //then lengths of XRs relevant for reads (length is at most 1<<31, MSB is 1 for insert, 0 for delete): 101 // if provisional XRs exist (num_pxrs>0), store length and insert/delete flag associated with INNERMOST TXNID 102 // store length and insert/delete flag associated with each committed TXNID, in same order as above (newest first) 103 //then data of XRs relevant for reads 104 // if provisional XRs exist (num_pxrs>0), store data associated with INNERMOST provisional TXNID 105 // store data associated with committed TXNIDs (all committed data, newest committed values first) 106 //if provisional XRs still exist (that is, num_puxrs > 1, so INNERMOST provisional TXNID != OUTERMOST provisional TXNID): 107 // for OUTERMOST provisional XR: 108 // 1 byte: store type (insert/delete/placeholder) 109 // 4 bytes: length (if type is INSERT, no length stored if placeholder or delete) 110 // data 111 // for rest of provisional stack (if num_pxrs > 2), from second-outermost to second-innermost (outermost is stored above, innermost is stored separately): 112 // 8 bytes: TXNID 113 // 1 byte: store type (insert/delete/placeholder) 114 // 4 bytes: length (if type is INSERT) 115 // data 116 // for INNERMOST provisional XR: 117 // 8 bytes: TXNID 118 // (innermost data and length with insert/delete flag are stored above, cannot be a placeholder) 119 }; // For the case where LEAFENTRY->type is LE_MVCC 120 static_assert(5 == sizeof(leafentry::leafentry_mvcc), "leafentry_mvcc size is wrong"); 121 static_assert(5 == __builtin_offsetof(leafentry::leafentry_mvcc, xrs), "xrs is in the wrong place"); 122 123 uint8_t type; // type is LE_CLEAN or LE_MVCC 124 //uint32_t keylen; 125 union __attribute__ ((__packed__)) { 126 struct leafentry_clean clean; 127 struct leafentry_mvcc mvcc; 128 } u; 129 }; 130 static_assert(6 == sizeof(leafentry), "leafentry size is wrong"); 131 static_assert(1 == __builtin_offsetof(leafentry, u), "union is in the wrong place"); 132 133 #define LE_CLEAN_MEMSIZE(_vallen) \ 134 (sizeof(((LEAFENTRY)NULL)->type) /* type */ \ 135 +sizeof(((LEAFENTRY)NULL)->u.clean.vallen) /* vallen */ \ 136 +(_vallen)) /* actual val */ 137 138 #define LE_MVCC_COMMITTED_HEADER_MEMSIZE \ 139 (sizeof(((LEAFENTRY)NULL)->type) /* type */ \ 140 +sizeof(((LEAFENTRY)NULL)->u.mvcc.num_cxrs) /* committed */ \ 141 +sizeof(((LEAFENTRY)NULL)->u.mvcc.num_pxrs) /* provisional */ \ 142 +sizeof(TXNID) /* transaction */ \ 143 +sizeof(uint32_t) /* length+bit */ \ 144 +sizeof(uint32_t)) /* length+bit */ 145 146 #define LE_MVCC_COMMITTED_MEMSIZE(_vallen) \ 147 (LE_MVCC_COMMITTED_HEADER_MEMSIZE \ 148 +(_vallen)) /* actual val */ 149 150 151 typedef struct leafentry *LEAFENTRY; 152 typedef struct leafentry_13 *LEAFENTRY_13; 153 154 // 155 // TODO: consistency among names is very poor. 156 // 157 158 // TODO: rename this helper function for deserialization 159 size_t leafentry_rest_memsize(uint32_t num_puxrs, uint32_t num_cuxrs, uint8_t* start); 160 size_t leafentry_memsize (LEAFENTRY le); // the size of a leafentry in memory. 161 size_t leafentry_disksize (LEAFENTRY le); // this is the same as logsizeof_LEAFENTRY. The size of a leafentry on disk. 162 void wbuf_nocrc_LEAFENTRY(struct wbuf *w, LEAFENTRY le); 163 int print_klpair (FILE *outf, const void* key, uint32_t keylen, LEAFENTRY v); // Print a leafentry out in human-readable form. 164 165 int le_latest_is_del(LEAFENTRY le); // Return true if it is a provisional delete. 166 int le_val_is_del(LEAFENTRY le, enum cursor_read_type read_type, TOKUTXN txn); // Returns true if the value that is to be read is empty 167 bool le_is_clean(LEAFENTRY le); //Return how many xids exist (0 does not count) 168 bool le_has_xids(LEAFENTRY le, XIDS xids); // Return true transaction represented by xids is still provisional in this leafentry (le's xid stack is a superset or equal to xids) 169 void* le_latest_val (LEAFENTRY le); // Return the latest val (return NULL for provisional deletes) 170 uint32_t le_latest_vallen (LEAFENTRY le); // Return the latest vallen. Returns 0 for provisional deletes. 171 void* le_latest_val_and_len (LEAFENTRY le, uint32_t *len); 172 173 uint64_t le_outermost_uncommitted_xid (LEAFENTRY le); 174 175 //Callback contract: 176 // Function checks to see if id is accepted by context. 177 // Returns: 178 // 0: context ignores this entry, id. 179 // TOKUDB_ACCEPT: context accepts id 180 // r|r!=0&&r!=TOKUDB_ACCEPT: Quit early, return r, because something unexpected went wrong (error case) 181 typedef int(*LE_ITERATE_CALLBACK)(TXNID id, TOKUTXN context, bool is_provisional); 182 183 int le_iterate_val( 184 LEAFENTRY le, 185 LE_ITERATE_CALLBACK f, 186 void** valpp, 187 uint32_t* vallenp, 188 TOKUTXN context); 189 190 void le_extract_val( 191 LEAFENTRY le, 192 // should we return the entire leafentry as the val? 193 bool is_leaf_mode, 194 enum cursor_read_type read_type, 195 TOKUTXN ttxn, 196 uint32_t* vallen, 197 void** val); 198 199 size_t leafentry_disksize_13(LEAFENTRY_13 le); 200 201 int toku_le_upgrade_13_14( 202 // NULL if there was no stored data. 203 LEAFENTRY_13 old_leafentry, 204 void** keyp, 205 uint32_t* keylen, 206 size_t* new_leafentry_memorysize, 207 LEAFENTRY *new_leafentry_p); 208 209 class bn_data; 210 211 int64_t toku_le_apply_msg( 212 const ft_msg &msg, 213 // NULL if there was no stored data. 214 LEAFENTRY old_leafentry, 215 // bn_data storing leafentry, if NULL, means there is no bn_data 216 bn_data* data_buffer, 217 // index in data_buffer where leafentry is stored (and should be replaced 218 uint32_t idx, 219 uint32_t old_keylen, 220 txn_gc_info* gc_info, 221 LEAFENTRY *new_leafentry_p, 222 int64_t* numbytes_delta_p); 223 224 bool toku_le_worth_running_garbage_collection( 225 LEAFENTRY le, 226 txn_gc_info* gc_info); 227 228 void toku_le_garbage_collect( 229 LEAFENTRY old_leaf_entry, 230 bn_data* data_buffer, 231 uint32_t idx, 232 void* keyp, 233 uint32_t keylen, 234 txn_gc_info* gc_info, 235 LEAFENTRY* new_leaf_entry, 236 int64_t* numbytes_delta_p); 237