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Overview
Comment: | Reorder the fields in private structures in an effort to reduce alignment gaps and thus make the structures smaller, and to put frequently accessed fields first. Also update some obsolete comments. Valgrind shows a very slight performance improvement. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
378a1d13af4a6f4cb2bfa65944b3b0d4 |
User & Date: | drh 2011-01-07 02:50:40.000 |
Context
2011-01-10
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21:01 | Update pager requirements to account for the ZIPVFS extension. (check-in: d94e59b514 user: drh tags: trunk) | |
2011-01-07
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02:50 | Reorder the fields in private structures in an effort to reduce alignment gaps and thus make the structures smaller, and to put frequently accessed fields first. Also update some obsolete comments. Valgrind shows a very slight performance improvement. (check-in: 378a1d13af user: drh tags: trunk) | |
2011-01-06
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15:51 | Enhance the showdb tool to show overflow page pointers at the end of overflow cells. (check-in: cda5eab18f user: drh tags: trunk) | |
Changes
Changes to src/btreeInt.h.
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410 411 412 413 414 415 416 417 418 419 420 | u8 secureDelete; /* True if secure_delete is enabled */ u8 initiallyEmpty; /* Database is empty at start of transaction */ u8 openFlags; /* Flags to sqlite3BtreeOpen() */ #ifndef SQLITE_OMIT_AUTOVACUUM u8 autoVacuum; /* True if auto-vacuum is enabled */ u8 incrVacuum; /* True if incr-vacuum is enabled */ #endif u16 maxLocal; /* Maximum local payload in non-LEAFDATA tables */ u16 minLocal; /* Minimum local payload in non-LEAFDATA tables */ u16 maxLeaf; /* Maximum local payload in a LEAFDATA table */ u16 minLeaf; /* Minimum local payload in a LEAFDATA table */ | > > < < | 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 | u8 secureDelete; /* True if secure_delete is enabled */ u8 initiallyEmpty; /* Database is empty at start of transaction */ u8 openFlags; /* Flags to sqlite3BtreeOpen() */ #ifndef SQLITE_OMIT_AUTOVACUUM u8 autoVacuum; /* True if auto-vacuum is enabled */ u8 incrVacuum; /* True if incr-vacuum is enabled */ #endif u8 inTransaction; /* Transaction state */ u8 doNotUseWAL; /* If true, do not open write-ahead-log file */ u16 maxLocal; /* Maximum local payload in non-LEAFDATA tables */ u16 minLocal; /* Minimum local payload in non-LEAFDATA tables */ u16 maxLeaf; /* Maximum local payload in a LEAFDATA table */ u16 minLeaf; /* Minimum local payload in a LEAFDATA table */ u32 pageSize; /* Total number of bytes on a page */ u32 usableSize; /* Number of usable bytes on each page */ int nTransaction; /* Number of open transactions (read + write) */ u32 nPage; /* Number of pages in the database */ void *pSchema; /* Pointer to space allocated by sqlite3BtreeSchema() */ void (*xFreeSchema)(void*); /* Destructor for BtShared.pSchema */ sqlite3_mutex *mutex; /* Non-recursive mutex required to access this struct */ |
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442 443 444 445 446 447 448 | /* ** An instance of the following structure is used to hold information ** about a cell. The parseCellPtr() function fills in this structure ** based on information extract from the raw disk page. */ typedef struct CellInfo CellInfo; struct CellInfo { | < > | 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 | /* ** An instance of the following structure is used to hold information ** about a cell. The parseCellPtr() function fills in this structure ** based on information extract from the raw disk page. */ typedef struct CellInfo CellInfo; struct CellInfo { i64 nKey; /* The key for INTKEY tables, or number of bytes in key */ u8 *pCell; /* Pointer to the start of cell content */ u32 nData; /* Number of bytes of data */ u32 nPayload; /* Total amount of payload */ u16 nHeader; /* Size of the cell content header in bytes */ u16 nLocal; /* Amount of payload held locally */ u16 iOverflow; /* Offset to overflow page number. Zero if no overflow */ u16 nSize; /* Size of the cell content on the main b-tree page */ }; |
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485 486 487 488 489 490 491 492 493 494 495 | Btree *pBtree; /* The Btree to which this cursor belongs */ BtShared *pBt; /* The BtShared this cursor points to */ BtCursor *pNext, *pPrev; /* Forms a linked list of all cursors */ struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */ Pgno pgnoRoot; /* The root page of this tree */ sqlite3_int64 cachedRowid; /* Next rowid cache. 0 means not valid */ CellInfo info; /* A parse of the cell we are pointing at */ u8 wrFlag; /* True if writable */ u8 atLast; /* Cursor pointing to the last entry */ u8 validNKey; /* True if info.nKey is valid */ u8 eState; /* One of the CURSOR_XXX constants (see below) */ | > > > < < < < > < > | 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 | Btree *pBtree; /* The Btree to which this cursor belongs */ BtShared *pBt; /* The BtShared this cursor points to */ BtCursor *pNext, *pPrev; /* Forms a linked list of all cursors */ struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */ Pgno pgnoRoot; /* The root page of this tree */ sqlite3_int64 cachedRowid; /* Next rowid cache. 0 means not valid */ CellInfo info; /* A parse of the cell we are pointing at */ i64 nKey; /* Size of pKey, or last integer key */ void *pKey; /* Saved key that was cursor's last known position */ int skipNext; /* Prev() is noop if negative. Next() is noop if positive */ u8 wrFlag; /* True if writable */ u8 atLast; /* Cursor pointing to the last entry */ u8 validNKey; /* True if info.nKey is valid */ u8 eState; /* One of the CURSOR_XXX constants (see below) */ #ifndef SQLITE_OMIT_INCRBLOB Pgno *aOverflow; /* Cache of overflow page locations */ u8 isIncrblobHandle; /* True if this cursor is an incr. io handle */ #endif i16 iPage; /* Index of current page in apPage */ u16 aiIdx[BTCURSOR_MAX_DEPTH]; /* Current index in apPage[i] */ MemPage *apPage[BTCURSOR_MAX_DEPTH]; /* Pages from root to current page */ }; /* ** Potential values for BtCursor.eState. ** ** CURSOR_VALID: ** Cursor points to a valid entry. getPayload() etc. may be called. |
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Changes to src/vdbeInt.h.
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35 36 37 38 39 40 41 | ** The cursor can seek to a BTree entry with a particular key, or ** loop over all entries of the Btree. You can also insert new BTree ** entries or retrieve the key or data from the entry that the cursor ** is currently pointing to. ** ** Every cursor that the virtual machine has open is represented by an ** instance of the following structure. | < < < < < > > > | < < < < < < > > > | 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 | ** The cursor can seek to a BTree entry with a particular key, or ** loop over all entries of the Btree. You can also insert new BTree ** entries or retrieve the key or data from the entry that the cursor ** is currently pointing to. ** ** Every cursor that the virtual machine has open is represented by an ** instance of the following structure. */ struct VdbeCursor { BtCursor *pCursor; /* The cursor structure of the backend */ Btree *pBt; /* Separate file holding temporary table */ KeyInfo *pKeyInfo; /* Info about index keys needed by index cursors */ int iDb; /* Index of cursor database in db->aDb[] (or -1) */ int pseudoTableReg; /* Register holding pseudotable content. */ int nField; /* Number of fields in the header */ Bool zeroed; /* True if zeroed out and ready for reuse */ Bool rowidIsValid; /* True if lastRowid is valid */ Bool atFirst; /* True if pointing to first entry */ Bool useRandomRowid; /* Generate new record numbers semi-randomly */ Bool nullRow; /* True if pointing to a row with no data */ Bool deferredMoveto; /* A call to sqlite3BtreeMoveto() is needed */ Bool isTable; /* True if a table requiring integer keys */ Bool isIndex; /* True if an index containing keys only - no data */ Bool isOrdered; /* True if the underlying table is BTREE_UNORDERED */ sqlite3_vtab_cursor *pVtabCursor; /* The cursor for a virtual table */ const sqlite3_module *pModule; /* Module for cursor pVtabCursor */ i64 seqCount; /* Sequence counter */ i64 movetoTarget; /* Argument to the deferred sqlite3BtreeMoveto() */ i64 lastRowid; /* Last rowid from a Next or NextIdx operation */ /* Result of last sqlite3BtreeMoveto() done by an OP_NotExists or ** OP_IsUnique opcode on this cursor. */ int seekResult; /* Cached information about the header for the data record that the ** cursor is currently pointing to. Only valid if cacheStatus matches |
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133 134 135 136 137 138 139 | ** A value for VdbeCursor.cacheValid that means the cache is always invalid. */ #define CACHE_STALE 0 /* ** Internally, the vdbe manipulates nearly all SQL values as Mem ** structures. Each Mem struct may cache multiple representations (string, | | < < < < < < > > > | < < < | 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 | ** A value for VdbeCursor.cacheValid that means the cache is always invalid. */ #define CACHE_STALE 0 /* ** Internally, the vdbe manipulates nearly all SQL values as Mem ** structures. Each Mem struct may cache multiple representations (string, ** integer etc.) of the same value. */ struct Mem { sqlite3 *db; /* The associated database connection */ char *z; /* String or BLOB value */ double r; /* Real value */ union { i64 i; /* Integer value used when MEM_Int is set in flags */ int nZero; /* Used when bit MEM_Zero is set in flags */ FuncDef *pDef; /* Used only when flags==MEM_Agg */ RowSet *pRowSet; /* Used only when flags==MEM_RowSet */ VdbeFrame *pFrame; /* Used when flags==MEM_Frame */ } u; int n; /* Number of characters in string value, excluding '\0' */ u16 flags; /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */ u8 type; /* One of SQLITE_NULL, SQLITE_TEXT, SQLITE_INTEGER, etc */ u8 enc; /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */ #ifdef SQLITE_DEBUG Mem *pScopyFrom; /* This Mem is a shallow copy of pScopyFrom */ void *pFiller; /* So that sizeof(Mem) is a multiple of 8 */ |
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175 176 177 178 179 180 181 | ** No other flags may be set in this case. ** ** If the MEM_Str flag is set then Mem.z points at a string representation. ** Usually this is encoded in the same unicode encoding as the main ** database (see below for exceptions). If the MEM_Term flag is also ** set, then the string is nul terminated. The MEM_Int and MEM_Real ** flags may coexist with the MEM_Str flag. | < < < | 164 165 166 167 168 169 170 171 172 173 174 175 176 177 | ** No other flags may be set in this case. ** ** If the MEM_Str flag is set then Mem.z points at a string representation. ** Usually this is encoded in the same unicode encoding as the main ** database (see below for exceptions). If the MEM_Term flag is also ** set, then the string is nul terminated. The MEM_Int and MEM_Real ** flags may coexist with the MEM_Str flag. */ #define MEM_Null 0x0001 /* Value is NULL */ #define MEM_Str 0x0002 /* Value is a string */ #define MEM_Int 0x0004 /* Value is an integer */ #define MEM_Real 0x0008 /* Value is a real number */ #define MEM_Blob 0x0010 /* Value is a BLOB */ #define MEM_RowSet 0x0020 /* Value is a RowSet object */ |
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260 261 262 263 264 265 266 | VdbeFunc *pVdbeFunc; /* Auxilary data, if created. */ Mem s; /* The return value is stored here */ Mem *pMem; /* Memory cell used to store aggregate context */ int isError; /* Error code returned by the function. */ CollSeq *pColl; /* Collating sequence */ }; | < < < < < < < < < < < < | < < < | < < > > > > > > > > > < < < < < | > | | < > | | > > | | 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 | VdbeFunc *pVdbeFunc; /* Auxilary data, if created. */ Mem s; /* The return value is stored here */ Mem *pMem; /* Memory cell used to store aggregate context */ int isError; /* Error code returned by the function. */ CollSeq *pColl; /* Collating sequence */ }; /* ** An instance of the virtual machine. This structure contains the complete ** state of the virtual machine. ** ** The "sqlite3_stmt" structure pointer that is returned by sqlite3_prepare() ** is really a pointer to an instance of this structure. ** ** The Vdbe.inVtabMethod variable is set to non-zero for the duration of ** any virtual table method invocations made by the vdbe program. It is ** set to 2 for xDestroy method calls and 1 for all other methods. This ** variable is used for two purposes: to allow xDestroy methods to execute ** "DROP TABLE" statements and to prevent some nasty side effects of ** malloc failure when SQLite is invoked recursively by a virtual table ** method function. */ struct Vdbe { sqlite3 *db; /* The database connection that owns this statement */ Op *aOp; /* Space to hold the virtual machine's program */ Mem *aMem; /* The memory locations */ Mem **apArg; /* Arguments to currently executing user function */ Mem *aColName; /* Column names to return */ Mem *pResultSet; /* Pointer to an array of results */ int nMem; /* Number of memory locations currently allocated */ int nOp; /* Number of instructions in the program */ int nOpAlloc; /* Number of slots allocated for aOp[] */ int nLabel; /* Number of labels used */ int nLabelAlloc; /* Number of slots allocated in aLabel[] */ int *aLabel; /* Space to hold the labels */ u16 nResColumn; /* Number of columns in one row of the result set */ u16 nCursor; /* Number of slots in apCsr[] */ u32 magic; /* Magic number for sanity checking */ char *zErrMsg; /* Error message written here */ Vdbe *pPrev,*pNext; /* Linked list of VDBEs with the same Vdbe.db */ VdbeCursor **apCsr; /* One element of this array for each open cursor */ Mem *aVar; /* Values for the OP_Variable opcode. */ char **azVar; /* Name of variables */ ynVar nVar; /* Number of entries in aVar[] */ u32 cacheCtr; /* VdbeCursor row cache generation counter */ int pc; /* The program counter */ int rc; /* Value to return */ u8 errorAction; /* Recovery action to do in case of an error */ u8 okVar; /* True if azVar[] has been initialized */ u8 explain; /* True if EXPLAIN present on SQL command */ u8 changeCntOn; /* True to update the change-counter */ u8 expired; /* True if the VM needs to be recompiled */ u8 runOnlyOnce; /* Automatically expire on reset */ u8 minWriteFileFormat; /* Minimum file format for writable database files */ u8 inVtabMethod; /* See comments above */ u8 usesStmtJournal; /* True if uses a statement journal */ u8 readOnly; /* True for read-only statements */ u8 isPrepareV2; /* True if prepared with prepare_v2() */ int nChange; /* Number of db changes made since last reset */ int btreeMask; /* Bitmask of db->aDb[] entries referenced */ int iStatement; /* Statement number (or 0 if has not opened stmt) */ int aCounter[3]; /* Counters used by sqlite3_stmt_status() */ BtreeMutexArray aMutex; /* An array of Btree used here and needing locks */ #ifndef SQLITE_OMIT_TRACE i64 startTime; /* Time when query started - used for profiling */ #endif i64 nFkConstraint; /* Number of imm. FK constraints this VM */ i64 nStmtDefCons; /* Number of def. constraints when stmt started */ char *zSql; /* Text of the SQL statement that generated this */ void *pFree; /* Free this when deleting the vdbe */ #ifdef SQLITE_DEBUG FILE *trace; /* Write an execution trace here, if not NULL */ #endif VdbeFrame *pFrame; /* Parent frame */ VdbeFrame *pDelFrame; /* List of frame objects to free on VM reset */ int nFrame; /* Number of frames in pFrame list */ u32 expmask; /* Binding to these vars invalidates VM */ |
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Changes to src/vdbeapi.c.
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681 682 683 684 685 686 687 | ** this assert() from failing, when building with SQLITE_DEBUG defined ** using gcc, force nullMem to be 8-byte aligned using the magical ** __attribute__((aligned(8))) macro. */ static const Mem nullMem #if defined(SQLITE_DEBUG) && defined(__GNUC__) __attribute__((aligned(8))) #endif | | | 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 | ** this assert() from failing, when building with SQLITE_DEBUG defined ** using gcc, force nullMem to be 8-byte aligned using the magical ** __attribute__((aligned(8))) macro. */ static const Mem nullMem #if defined(SQLITE_DEBUG) && defined(__GNUC__) __attribute__((aligned(8))) #endif = {0, "", (double)0, {0}, 0, MEM_Null, SQLITE_NULL, 0, 0, 0 }; if( pVm && ALWAYS(pVm->db) ){ sqlite3_mutex_enter(pVm->db->mutex); sqlite3Error(pVm->db, SQLITE_RANGE, 0); } pOut = (Mem*)&nullMem; } |
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