1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 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 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828
|
#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
#define __SQLITESESSION_H_ 1
/*
** Make sure we can call this stuff from C++.
*/
#ifdef __cplusplus
extern "C" {
#endif
#include "sqlite3.h"
/*
** CAPI3REF: Session Object Handle
**
** An instance of this object is a [session] that can be used to
** record changes to a database.
*/
typedef struct sqlite3_session sqlite3_session;
/*
** CAPI3REF: Changeset Iterator Handle
**
** An instance of this object acts as a cursor for iterating
** over the elements of a [changeset] or [patchset].
*/
typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
/*
** CAPI3REF: Create A New Session Object
** CONSTRUCTOR: sqlite3_session
**
** Create a new session object attached to database handle db. If successful,
** a pointer to the new object is written to *ppSession and SQLITE_OK is
** returned. If an error occurs, *ppSession is set to NULL and an SQLite
** error code (e.g. SQLITE_NOMEM) is returned.
**
** It is possible to create multiple session objects attached to a single
** database handle.
**
** Session objects created using this function should be deleted using the
** [sqlite3session_delete()] function before the database handle that they
** are attached to is itself closed. If the database handle is closed before
** the session object is deleted, then the results of calling any session
** module function, including [sqlite3session_delete()] on the session object
** are undefined.
**
** Because the session module uses the [sqlite3_preupdate_hook()] API, it
** is not possible for an application to register a pre-update hook on a
** database handle that has one or more session objects attached. Nor is
** it possible to create a session object attached to a database handle for
** which a pre-update hook is already defined. The results of attempting
** either of these things are undefined.
**
** The session object will be used to create changesets for tables in
** database zDb, where zDb is either "main", or "temp", or the name of an
** attached database. It is not an error if database zDb is not attached
** to the database when the session object is created.
*/
int sqlite3session_create(
sqlite3 *db, /* Database handle */
const char *zDb, /* Name of db (e.g. "main") */
sqlite3_session **ppSession /* OUT: New session object */
);
/*
** CAPI3REF: Delete A Session Object
** DESTRUCTOR: sqlite3_session
**
** Delete a session object previously allocated using
** [sqlite3session_create()]. Once a session object has been deleted, the
** results of attempting to use pSession with any other session module
** function are undefined.
**
** Session objects must be deleted before the database handle to which they
** are attached is closed. Refer to the documentation for
** [sqlite3session_create()] for details.
*/
void sqlite3session_delete(sqlite3_session *pSession);
/*
** CAPI3REF: Configure a Session Object
** METHOD: sqlite3_session
**
** This method is used to configure a session object after it has been
** created. At present the only valid values for the second parameter are
** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
**
*/
int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
/*
** CAPI3REF: Options for sqlite3session_object_config
**
** The following values may passed as the the 2nd parameter to
** sqlite3session_object_config().
**
** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
** This option is used to set, clear or query the flag that enables
** the [sqlite3session_changeset_size()] API. Because it imposes some
** computational overhead, this API is disabled by default. Argument
** pArg must point to a value of type (int). If the value is initially
** 0, then the sqlite3session_changeset_size() API is disabled. If it
** is greater than 0, then the same API is enabled. Or, if the initial
** value is less than zero, no change is made. In all cases the (int)
** variable is set to 1 if the sqlite3session_changeset_size() API is
** enabled following the current call, or 0 otherwise.
**
** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
** the first table has been attached to the session object.
**
** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
** This option is used to set, clear or query the flag that enables
** collection of data for tables with no explicit PRIMARY KEY.
**
** Normally, tables with no explicit PRIMARY KEY are simply ignored
** by the sessions module. However, if this flag is set, it behaves
** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
** as their leftmost columns.
**
** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
** the first table has been attached to the session object.
*/
#define SQLITE_SESSION_OBJCONFIG_SIZE 1
#define SQLITE_SESSION_OBJCONFIG_ROWID 2
/*
** CAPI3REF: Enable Or Disable A Session Object
** METHOD: sqlite3_session
**
** Enable or disable the recording of changes by a session object. When
** enabled, a session object records changes made to the database. When
** disabled - it does not. A newly created session object is enabled.
** Refer to the documentation for [sqlite3session_changeset()] for further
** details regarding how enabling and disabling a session object affects
** the eventual changesets.
**
** Passing zero to this function disables the session. Passing a value
** greater than zero enables it. Passing a value less than zero is a
** no-op, and may be used to query the current state of the session.
**
** The return value indicates the final state of the session object: 0 if
** the session is disabled, or 1 if it is enabled.
*/
int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
/*
** CAPI3REF: Set Or Clear the Indirect Change Flag
** METHOD: sqlite3_session
**
** Each change recorded by a session object is marked as either direct or
** indirect. A change is marked as indirect if either:
**
** <ul>
** <li> The session object "indirect" flag is set when the change is
** made, or
** <li> The change is made by an SQL trigger or foreign key action
** instead of directly as a result of a users SQL statement.
** </ul>
**
** If a single row is affected by more than one operation within a session,
** then the change is considered indirect if all operations meet the criteria
** for an indirect change above, or direct otherwise.
**
** This function is used to set, clear or query the session object indirect
** flag. If the second argument passed to this function is zero, then the
** indirect flag is cleared. If it is greater than zero, the indirect flag
** is set. Passing a value less than zero does not modify the current value
** of the indirect flag, and may be used to query the current state of the
** indirect flag for the specified session object.
**
** The return value indicates the final state of the indirect flag: 0 if
** it is clear, or 1 if it is set.
*/
int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
/*
** CAPI3REF: Attach A Table To A Session Object
** METHOD: sqlite3_session
**
** If argument zTab is not NULL, then it is the name of a table to attach
** to the session object passed as the first argument. All subsequent changes
** made to the table while the session object is enabled will be recorded. See
** documentation for [sqlite3session_changeset()] for further details.
**
** Or, if argument zTab is NULL, then changes are recorded for all tables
** in the database. If additional tables are added to the database (by
** executing "CREATE TABLE" statements) after this call is made, changes for
** the new tables are also recorded.
**
** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
** defined as part of their CREATE TABLE statement. It does not matter if the
** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
** KEY may consist of a single column, or may be a composite key.
**
** It is not an error if the named table does not exist in the database. Nor
** is it an error if the named table does not have a PRIMARY KEY. However,
** no changes will be recorded in either of these scenarios.
**
** Changes are not recorded for individual rows that have NULL values stored
** in one or more of their PRIMARY KEY columns.
**
** SQLITE_OK is returned if the call completes without error. Or, if an error
** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
**
** <h3>Special sqlite_stat1 Handling</h3>
**
** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
** <pre>
** CREATE TABLE sqlite_stat1(tbl,idx,stat)
** </pre>
**
** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
** are recorded for rows for which (idx IS NULL) is true. However, for such
** rows a zero-length blob (SQL value X'') is stored in the changeset or
** patchset instead of a NULL value. This allows such changesets to be
** manipulated by legacy implementations of sqlite3changeset_invert(),
** concat() and similar.
**
** The sqlite3changeset_apply() function automatically converts the
** zero-length blob back to a NULL value when updating the sqlite_stat1
** table. However, if the application calls sqlite3changeset_new(),
** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
** iterator directly (including on a changeset iterator passed to a
** conflict-handler callback) then the X'' value is returned. The application
** must translate X'' to NULL itself if required.
**
** Legacy (older than 3.22.0) versions of the sessions module cannot capture
** changes made to the sqlite_stat1 table. Legacy versions of the
** sqlite3changeset_apply() function silently ignore any modifications to the
** sqlite_stat1 table that are part of a changeset or patchset.
*/
int sqlite3session_attach(
sqlite3_session *pSession, /* Session object */
const char *zTab /* Table name */
);
/*
** CAPI3REF: Set a table filter on a Session Object.
** METHOD: sqlite3_session
**
** The second argument (xFilter) is the "filter callback". For changes to rows
** in tables that are not attached to the Session object, the filter is called
** to determine whether changes to the table's rows should be tracked or not.
** If xFilter returns 0, changes are not tracked. Note that once a table is
** attached, xFilter will not be called again.
*/
void sqlite3session_table_filter(
sqlite3_session *pSession, /* Session object */
int(*xFilter)(
void *pCtx, /* Copy of third arg to _filter_table() */
const char *zTab /* Table name */
),
void *pCtx /* First argument passed to xFilter */
);
/*
** CAPI3REF: Generate A Changeset From A Session Object
** METHOD: sqlite3_session
**
** Obtain a changeset containing changes to the tables attached to the
** session object passed as the first argument. If successful,
** set *ppChangeset to point to a buffer containing the changeset
** and *pnChangeset to the size of the changeset in bytes before returning
** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
** zero and return an SQLite error code.
**
** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
** each representing a change to a single row of an attached table. An INSERT
** change contains the values of each field of a new database row. A DELETE
** contains the original values of each field of a deleted database row. An
** UPDATE change contains the original values of each field of an updated
** database row along with the updated values for each updated non-primary-key
** column. It is not possible for an UPDATE change to represent a change that
** modifies the values of primary key columns. If such a change is made, it
** is represented in a changeset as a DELETE followed by an INSERT.
**
** Changes are not recorded for rows that have NULL values stored in one or
** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
** no corresponding change is present in the changesets returned by this
** function. If an existing row with one or more NULL values stored in
** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
** only an INSERT is appears in the changeset. Similarly, if an existing row
** with non-NULL PRIMARY KEY values is updated so that one or more of its
** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
** DELETE change only.
**
** The contents of a changeset may be traversed using an iterator created
** using the [sqlite3changeset_start()] API. A changeset may be applied to
** a database with a compatible schema using the [sqlite3changeset_apply()]
** API.
**
** Within a changeset generated by this function, all changes related to a
** single table are grouped together. In other words, when iterating through
** a changeset or when applying a changeset to a database, all changes related
** to a single table are processed before moving on to the next table. Tables
** are sorted in the same order in which they were attached (or auto-attached)
** to the sqlite3_session object. The order in which the changes related to
** a single table are stored is undefined.
**
** Following a successful call to this function, it is the responsibility of
** the caller to eventually free the buffer that *ppChangeset points to using
** [sqlite3_free()].
**
** <h3>Changeset Generation</h3>
**
** Once a table has been attached to a session object, the session object
** records the primary key values of all new rows inserted into the table.
** It also records the original primary key and other column values of any
** deleted or updated rows. For each unique primary key value, data is only
** recorded once - the first time a row with said primary key is inserted,
** updated or deleted in the lifetime of the session.
**
** There is one exception to the previous paragraph: when a row is inserted,
** updated or deleted, if one or more of its primary key columns contain a
** NULL value, no record of the change is made.
**
** The session object therefore accumulates two types of records - those
** that consist of primary key values only (created when the user inserts
** a new record) and those that consist of the primary key values and the
** original values of other table columns (created when the users deletes
** or updates a record).
**
** When this function is called, the requested changeset is created using
** both the accumulated records and the current contents of the database
** file. Specifically:
**
** <ul>
** <li> For each record generated by an insert, the database is queried
** for a row with a matching primary key. If one is found, an INSERT
** change is added to the changeset. If no such row is found, no change
** is added to the changeset.
**
** <li> For each record generated by an update or delete, the database is
** queried for a row with a matching primary key. If such a row is
** found and one or more of the non-primary key fields have been
** modified from their original values, an UPDATE change is added to
** the changeset. Or, if no such row is found in the table, a DELETE
** change is added to the changeset. If there is a row with a matching
** primary key in the database, but all fields contain their original
** values, no change is added to the changeset.
** </ul>
**
** This means, amongst other things, that if a row is inserted and then later
** deleted while a session object is active, neither the insert nor the delete
** will be present in the changeset. Or if a row is deleted and then later a
** row with the same primary key values inserted while a session object is
** active, the resulting changeset will contain an UPDATE change instead of
** a DELETE and an INSERT.
**
** When a session object is disabled (see the [sqlite3session_enable()] API),
** it does not accumulate records when rows are inserted, updated or deleted.
** This may appear to have some counter-intuitive effects if a single row
** is written to more than once during a session. For example, if a row
** is inserted while a session object is enabled, then later deleted while
** the same session object is disabled, no INSERT record will appear in the
** changeset, even though the delete took place while the session was disabled.
** Or, if one field of a row is updated while a session is disabled, and
** another field of the same row is updated while the session is enabled, the
** resulting changeset will contain an UPDATE change that updates both fields.
*/
int sqlite3session_changeset(
sqlite3_session *pSession, /* Session object */
int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
void **ppChangeset /* OUT: Buffer containing changeset */
);
/*
** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
** METHOD: sqlite3_session
**
** By default, this function always returns 0. For it to return
** a useful result, the sqlite3_session object must have been configured
** to enable this API using sqlite3session_object_config() with the
** SQLITE_SESSION_OBJCONFIG_SIZE verb.
**
** When enabled, this function returns an upper limit, in bytes, for the size
** of the changeset that might be produced if sqlite3session_changeset() were
** called. The final changeset size might be equal to or smaller than the
** size in bytes returned by this function.
*/
sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
/*
** CAPI3REF: Load The Difference Between Tables Into A Session
** METHOD: sqlite3_session
**
** If it is not already attached to the session object passed as the first
** argument, this function attaches table zTbl in the same manner as the
** [sqlite3session_attach()] function. If zTbl does not exist, or if it
** does not have a primary key, this function is a no-op (but does not return
** an error).
**
** Argument zFromDb must be the name of a database ("main", "temp" etc.)
** attached to the same database handle as the session object that contains
** a table compatible with the table attached to the session by this function.
** A table is considered compatible if it:
**
** <ul>
** <li> Has the same name,
** <li> Has the same set of columns declared in the same order, and
** <li> Has the same PRIMARY KEY definition.
** </ul>
**
** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
** are compatible but do not have any PRIMARY KEY columns, it is not an error
** but no changes are added to the session object. As with other session
** APIs, tables without PRIMARY KEYs are simply ignored.
**
** This function adds a set of changes to the session object that could be
** used to update the table in database zFrom (call this the "from-table")
** so that its content is the same as the table attached to the session
** object (call this the "to-table"). Specifically:
**
** <ul>
** <li> For each row (primary key) that exists in the to-table but not in
** the from-table, an INSERT record is added to the session object.
**
** <li> For each row (primary key) that exists in the to-table but not in
** the from-table, a DELETE record is added to the session object.
**
** <li> For each row (primary key) that exists in both tables, but features
** different non-PK values in each, an UPDATE record is added to the
** session.
** </ul>
**
** To clarify, if this function is called and then a changeset constructed
** using [sqlite3session_changeset()], then after applying that changeset to
** database zFrom the contents of the two compatible tables would be
** identical.
**
** It an error if database zFrom does not exist or does not contain the
** required compatible table.
**
** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
** may be set to point to a buffer containing an English language error
** message. It is the responsibility of the caller to free this buffer using
** sqlite3_free().
*/
int sqlite3session_diff(
sqlite3_session *pSession,
const char *zFromDb,
const char *zTbl,
char **pzErrMsg
);
/*
** CAPI3REF: Generate A Patchset From A Session Object
** METHOD: sqlite3_session
**
** The differences between a patchset and a changeset are that:
**
** <ul>
** <li> DELETE records consist of the primary key fields only. The
** original values of other fields are omitted.
** <li> The original values of any modified fields are omitted from
** UPDATE records.
** </ul>
**
** A patchset blob may be used with up to date versions of all
** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
** attempting to use a patchset blob with old versions of the
** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
**
** Because the non-primary key "old.*" fields are omitted, no
** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
** is passed to the sqlite3changeset_apply() API. Other conflict types work
** in the same way as for changesets.
**
** Changes within a patchset are ordered in the same way as for changesets
** generated by the sqlite3session_changeset() function (i.e. all changes for
** a single table are grouped together, tables appear in the order in which
** they were attached to the session object).
*/
int sqlite3session_patchset(
sqlite3_session *pSession, /* Session object */
int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
void **ppPatchset /* OUT: Buffer containing patchset */
);
/*
** CAPI3REF: Test if a changeset has recorded any changes.
**
** Return non-zero if no changes to attached tables have been recorded by
** the session object passed as the first argument. Otherwise, if one or
** more changes have been recorded, return zero.
**
** Even if this function returns zero, it is possible that calling
** [sqlite3session_changeset()] on the session handle may still return a
** changeset that contains no changes. This can happen when a row in
** an attached table is modified and then later on the original values
** are restored. However, if this function returns non-zero, then it is
** guaranteed that a call to sqlite3session_changeset() will return a
** changeset containing zero changes.
*/
int sqlite3session_isempty(sqlite3_session *pSession);
/*
** CAPI3REF: Query for the amount of heap memory used by a session object.
**
** This API returns the total amount of heap memory in bytes currently
** used by the session object passed as the only argument.
*/
sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
/*
** CAPI3REF: Create An Iterator To Traverse A Changeset
** CONSTRUCTOR: sqlite3_changeset_iter
**
** Create an iterator used to iterate through the contents of a changeset.
** If successful, *pp is set to point to the iterator handle and SQLITE_OK
** is returned. Otherwise, if an error occurs, *pp is set to zero and an
** SQLite error code is returned.
**
** The following functions can be used to advance and query a changeset
** iterator created by this function:
**
** <ul>
** <li> [sqlite3changeset_next()]
** <li> [sqlite3changeset_op()]
** <li> [sqlite3changeset_new()]
** <li> [sqlite3changeset_old()]
** </ul>
**
** It is the responsibility of the caller to eventually destroy the iterator
** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
** changeset (pChangeset) must remain valid until after the iterator is
** destroyed.
**
** Assuming the changeset blob was created by one of the
** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
** [sqlite3changeset_invert()] functions, all changes within the changeset
** that apply to a single table are grouped together. This means that when
** an application iterates through a changeset using an iterator created by
** this function, all changes that relate to a single table are visited
** consecutively. There is no chance that the iterator will visit a change
** the applies to table X, then one for table Y, and then later on visit
** another change for table X.
**
** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
** may be modified by passing a combination of
** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
**
** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
** and therefore subject to change.
*/
int sqlite3changeset_start(
sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
int nChangeset, /* Size of changeset blob in bytes */
void *pChangeset /* Pointer to blob containing changeset */
);
int sqlite3changeset_start_v2(
sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
int nChangeset, /* Size of changeset blob in bytes */
void *pChangeset, /* Pointer to blob containing changeset */
int flags /* SESSION_CHANGESETSTART_* flags */
);
/*
** CAPI3REF: Flags for sqlite3changeset_start_v2
**
** The following flags may passed via the 4th parameter to
** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
**
** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
** Invert the changeset while iterating through it. This is equivalent to
** inverting a changeset using sqlite3changeset_invert() before applying it.
** It is an error to specify this flag with a patchset.
*/
#define SQLITE_CHANGESETSTART_INVERT 0x0002
/*
** CAPI3REF: Advance A Changeset Iterator
** METHOD: sqlite3_changeset_iter
**
** This function may only be used with iterators created by the function
** [sqlite3changeset_start()]. If it is called on an iterator passed to
** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
** is returned and the call has no effect.
**
** Immediately after an iterator is created by sqlite3changeset_start(), it
** does not point to any change in the changeset. Assuming the changeset
** is not empty, the first call to this function advances the iterator to
** point to the first change in the changeset. Each subsequent call advances
** the iterator to point to the next change in the changeset (if any). If
** no error occurs and the iterator points to a valid change after a call
** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
** Otherwise, if all changes in the changeset have already been visited,
** SQLITE_DONE is returned.
**
** If an error occurs, an SQLite error code is returned. Possible error
** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
** SQLITE_NOMEM.
*/
int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
/*
** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
** METHOD: sqlite3_changeset_iter
**
** The pIter argument passed to this function may either be an iterator
** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
** created by [sqlite3changeset_start()]. In the latter case, the most recent
** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
** is not the case, this function returns [SQLITE_MISUSE].
**
** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
** outputs are set through these pointers:
**
** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
** depending on the type of change that the iterator currently points to;
**
** *pnCol is set to the number of columns in the table affected by the change; and
**
** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
** the name of the table affected by the current change. The buffer remains
** valid until either sqlite3changeset_next() is called on the iterator
** or until the conflict-handler function returns.
**
** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
** is an indirect change, or false (0) otherwise. See the documentation for
** [sqlite3session_indirect()] for a description of direct and indirect
** changes.
**
** If no error occurs, SQLITE_OK is returned. If an error does occur, an
** SQLite error code is returned. The values of the output variables may not
** be trusted in this case.
*/
int sqlite3changeset_op(
sqlite3_changeset_iter *pIter, /* Iterator object */
const char **pzTab, /* OUT: Pointer to table name */
int *pnCol, /* OUT: Number of columns in table */
int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
int *pbIndirect /* OUT: True for an 'indirect' change */
);
/*
** CAPI3REF: Obtain The Primary Key Definition Of A Table
** METHOD: sqlite3_changeset_iter
**
** For each modified table, a changeset includes the following:
**
** <ul>
** <li> The number of columns in the table, and
** <li> Which of those columns make up the tables PRIMARY KEY.
** </ul>
**
** This function is used to find which columns comprise the PRIMARY KEY of
** the table modified by the change that iterator pIter currently points to.
** If successful, *pabPK is set to point to an array of nCol entries, where
** nCol is the number of columns in the table. Elements of *pabPK are set to
** 0x01 if the corresponding column is part of the tables primary key, or
** 0x00 if it is not.
**
** If argument pnCol is not NULL, then *pnCol is set to the number of columns
** in the table.
**
** If this function is called when the iterator does not point to a valid
** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
** SQLITE_OK is returned and the output variables populated as described
** above.
*/
int sqlite3changeset_pk(
sqlite3_changeset_iter *pIter, /* Iterator object */
unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
int *pnCol /* OUT: Number of entries in output array */
);
/*
** CAPI3REF: Obtain old.* Values From A Changeset Iterator
** METHOD: sqlite3_changeset_iter
**
** The pIter argument passed to this function may either be an iterator
** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
** created by [sqlite3changeset_start()]. In the latter case, the most recent
** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
** Furthermore, it may only be called if the type of change that the iterator
** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
**
** Argument iVal must be greater than or equal to 0, and less than the number
** of columns in the table affected by the current change. Otherwise,
** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
**
** If successful, this function sets *ppValue to point to a protected
** sqlite3_value object containing the iVal'th value from the vector of
** original row values stored as part of the UPDATE or DELETE change and
** returns SQLITE_OK. The name of the function comes from the fact that this
** is similar to the "old.*" columns available to update or delete triggers.
**
** If some other error occurs (e.g. an OOM condition), an SQLite error code
** is returned and *ppValue is set to NULL.
*/
int sqlite3changeset_old(
sqlite3_changeset_iter *pIter, /* Changeset iterator */
int iVal, /* Column number */
sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
);
/*
** CAPI3REF: Obtain new.* Values From A Changeset Iterator
** METHOD: sqlite3_changeset_iter
**
** The pIter argument passed to this function may either be an iterator
** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
** created by [sqlite3changeset_start()]. In the latter case, the most recent
** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
** Furthermore, it may only be called if the type of change that the iterator
** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
**
** Argument iVal must be greater than or equal to 0, and less than the number
** of columns in the table affected by the current change. Otherwise,
** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
**
** If successful, this function sets *ppValue to point to a protected
** sqlite3_value object containing the iVal'th value from the vector of
** new row values stored as part of the UPDATE or INSERT change and
** returns SQLITE_OK. If the change is an UPDATE and does not include
** a new value for the requested column, *ppValue is set to NULL and
** SQLITE_OK returned. The name of the function comes from the fact that
** this is similar to the "new.*" columns available to update or delete
** triggers.
**
** If some other error occurs (e.g. an OOM condition), an SQLite error code
** is returned and *ppValue is set to NULL.
*/
int sqlite3changeset_new(
sqlite3_changeset_iter *pIter, /* Changeset iterator */
int iVal, /* Column number */
sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
);
/*
** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
** METHOD: sqlite3_changeset_iter
**
** This function should only be used with iterator objects passed to a
** conflict-handler callback by [sqlite3changeset_apply()] with either
** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
** is set to NULL.
**
** Argument iVal must be greater than or equal to 0, and less than the number
** of columns in the table affected by the current change. Otherwise,
** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
**
** If successful, this function sets *ppValue to point to a protected
** sqlite3_value object containing the iVal'th value from the
** "conflicting row" associated with the current conflict-handler callback
** and returns SQLITE_OK.
**
** If some other error occurs (e.g. an OOM condition), an SQLite error code
** is returned and *ppValue is set to NULL.
*/
int sqlite3changeset_conflict(
sqlite3_changeset_iter *pIter, /* Changeset iterator */
int iVal, /* Column number */
sqlite3_value **ppValue /* OUT: Value from conflicting row */
);
/*
** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
** METHOD: sqlite3_changeset_iter
**
** This function may only be called with an iterator passed to an
** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
** it sets the output variable to the total number of known foreign key
** violations in the destination database and returns SQLITE_OK.
**
** In all other cases this function returns SQLITE_MISUSE.
*/
int sqlite3changeset_fk_conflicts(
sqlite3_changeset_iter *pIter, /* Changeset iterator */
int *pnOut /* OUT: Number of FK violations */
);
/*
** CAPI3REF: Finalize A Changeset Iterator
** METHOD: sqlite3_changeset_iter
**
** This function is used to finalize an iterator allocated with
** [sqlite3changeset_start()].
**
** This function should only be called on iterators created using the
** [sqlite3changeset_start()] function. If an application calls this
** function with an iterator passed to a conflict-handler by
** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
** call has no effect.
**
** If an error was encountered within a call to an sqlite3changeset_xxx()
** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
** to that error is returned by this function. Otherwise, SQLITE_OK is
** returned. This is to allow the following pattern (pseudo-code):
**
** <pre>
** sqlite3changeset_start();
** while( SQLITE_ROW==sqlite3changeset_next() ){
** // Do something with change.
** }
** rc = sqlite3changeset_finalize();
** if( rc!=SQLITE_OK ){
** // An error has occurred
** }
** </pre>
*/
int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
/*
** CAPI3REF: Invert A Changeset
**
** This function is used to "invert" a changeset object. Applying an inverted
** changeset to a database reverses the effects of applying the uninverted
** changeset. Specifically:
**
** <ul>
** <li> Each DELETE change is changed to an INSERT, and
** <li> Each INSERT change is changed to a DELETE, and
** <li> For each UPDATE change, the old.* and new.* values are exchanged.
** </ul>
**
** This function does not change the order in which changes appear within
** the changeset. It merely reverses the sense of each individual change.
**
** If successful, a pointer to a buffer containing the inverted changeset
** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
** zeroed and an SQLite error code returned.
**
** It is the responsibility of the caller to eventually call sqlite3_free()
** on the *ppOut pointer to free the buffer allocation following a successful
** call to this function.
**
** WARNING/TODO: This function currently assumes that the input is a valid
** changeset. If it is not, the results are undefined.
*/
int sqlite3changeset_invert(
int nIn, const void *pIn, /* Input changeset */
int *pnOut, void **ppOut /* OUT: Inverse of input */
);
/*
** CAPI3REF: Concatenate Two Changeset Objects
**
** This function is used to concatenate two changesets, A and B, into a
** single changeset. The result is a changeset equivalent to applying
** changeset A followed by changeset B.
**
** This function combines the two input changesets using an
** sqlite3_changegroup object. Calling it produces similar results as the
** following code fragment:
**
** <pre>
** sqlite3_changegroup *pGrp;
** rc = sqlite3_changegroup_new(&pGrp);
** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
** if( rc==SQLITE_OK ){
** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
** }else{
** *ppOut = 0;
** *pnOut = 0;
** }
** </pre>
**
** Refer to the sqlite3_changegroup documentation below for details.
*/
int sqlite3changeset_concat(
int nA, /* Number of bytes in buffer pA */
void *pA, /* Pointer to buffer containing changeset A */
int nB, /* Number of bytes in buffer pB */
void *pB, /* Pointer to buffer containing changeset B */
int *pnOut, /* OUT: Number of bytes in output changeset */
void **ppOut /* OUT: Buffer containing output changeset */
);
/*
** CAPI3REF: Upgrade the Schema of a Changeset/Patchset
*/
int sqlite3changeset_upgrade(
sqlite3 *db,
const char *zDb,
int nIn, const void *pIn, /* Input changeset */
int *pnOut, void **ppOut /* OUT: Inverse of input */
);
/*
** CAPI3REF: Changegroup Handle
**
** A changegroup is an object used to combine two or more
** [changesets] or [patchsets]
*/
typedef struct sqlite3_changegroup sqlite3_changegroup;
/*
** CAPI3REF: Create A New Changegroup Object
** CONSTRUCTOR: sqlite3_changegroup
**
** An sqlite3_changegroup object is used to combine two or more changesets
** (or patchsets) into a single changeset (or patchset). A single changegroup
** object may combine changesets or patchsets, but not both. The output is
** always in the same format as the input.
**
** If successful, this function returns SQLITE_OK and populates (*pp) with
** a pointer to a new sqlite3_changegroup object before returning. The caller
** should eventually free the returned object using a call to
** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
**
** The usual usage pattern for an sqlite3_changegroup object is as follows:
**
** <ul>
** <li> It is created using a call to sqlite3changegroup_new().
**
** <li> Zero or more changesets (or patchsets) are added to the object
** by calling sqlite3changegroup_add().
**
** <li> The result of combining all input changesets together is obtained
** by the application via a call to sqlite3changegroup_output().
**
** <li> The object is deleted using a call to sqlite3changegroup_delete().
** </ul>
**
** Any number of calls to add() and output() may be made between the calls to
** new() and delete(), and in any order.
**
** As well as the regular sqlite3changegroup_add() and
** sqlite3changegroup_output() functions, also available are the streaming
** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
*/
int sqlite3changegroup_new(sqlite3_changegroup **pp);
/*
** CAPI3REF: Add a Schema to a Changegroup
** METHOD: sqlite3_changegroup_schema
**
** This method may be used to optionally enforce the rule that the changesets
** added to the changegroup handle must match the schema of database zDb
** ("main", "temp", or the name of an attached database). If
** sqlite3changegroup_add() is called to add a changeset that is not compatible
** with the configured schema, SQLITE_SCHEMA is returned and the changegroup
** object is left in an undefined state.
**
** A changeset schema is considered compatible with the database schema in
** the same way as for sqlite3changeset_apply(). Specifically, for each
** table in the changeset, there exists a database table with:
**
** <ul>
** <li> The name identified by the changeset, and
** <li> at least as many columns as recorded in the changeset, and
** <li> the primary key columns in the same position as recorded in
** the changeset.
** </ul>
**
** The output of the changegroup object always has the same schema as the
** database nominated using this function. In cases where changesets passed
** to sqlite3changegroup_add() have fewer columns than the corresponding table
** in the database schema, these are filled in using the default column
** values from the database schema. This makes it possible to combined
** changesets that have different numbers of columns for a single table
** within a changegroup, provided that they are otherwise compatible.
*/
int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb);
/*
** CAPI3REF: Add A Changeset To A Changegroup
** METHOD: sqlite3_changegroup
**
** Add all changes within the changeset (or patchset) in buffer pData (size
** nData bytes) to the changegroup.
**
** If the buffer contains a patchset, then all prior calls to this function
** on the same changegroup object must also have specified patchsets. Or, if
** the buffer contains a changeset, so must have the earlier calls to this
** function. Otherwise, SQLITE_ERROR is returned and no changes are added
** to the changegroup.
**
** Rows within the changeset and changegroup are identified by the values in
** their PRIMARY KEY columns. A change in the changeset is considered to
** apply to the same row as a change already present in the changegroup if
** the two rows have the same primary key.
**
** Changes to rows that do not already appear in the changegroup are
** simply copied into it. Or, if both the new changeset and the changegroup
** contain changes that apply to a single row, the final contents of the
** changegroup depends on the type of each change, as follows:
**
** <table border=1 style="margin-left:8ex;margin-right:8ex">
** <tr><th style="white-space:pre">Existing Change </th>
** <th style="white-space:pre">New Change </th>
** <th>Output Change
** <tr><td>INSERT <td>INSERT <td>
** The new change is ignored. This case does not occur if the new
** changeset was recorded immediately after the changesets already
** added to the changegroup.
** <tr><td>INSERT <td>UPDATE <td>
** The INSERT change remains in the changegroup. The values in the
** INSERT change are modified as if the row was inserted by the
** existing change and then updated according to the new change.
** <tr><td>INSERT <td>DELETE <td>
** The existing INSERT is removed from the changegroup. The DELETE is
** not added.
** <tr><td>UPDATE <td>INSERT <td>
** The new change is ignored. This case does not occur if the new
** changeset was recorded immediately after the changesets already
** added to the changegroup.
** <tr><td>UPDATE <td>UPDATE <td>
** The existing UPDATE remains within the changegroup. It is amended
** so that the accompanying values are as if the row was updated once
** by the existing change and then again by the new change.
** <tr><td>UPDATE <td>DELETE <td>
** The existing UPDATE is replaced by the new DELETE within the
** changegroup.
** <tr><td>DELETE <td>INSERT <td>
** If one or more of the column values in the row inserted by the
** new change differ from those in the row deleted by the existing
** change, the existing DELETE is replaced by an UPDATE within the
** changegroup. Otherwise, if the inserted row is exactly the same
** as the deleted row, the existing DELETE is simply discarded.
** <tr><td>DELETE <td>UPDATE <td>
** The new change is ignored. This case does not occur if the new
** changeset was recorded immediately after the changesets already
** added to the changegroup.
** <tr><td>DELETE <td>DELETE <td>
** The new change is ignored. This case does not occur if the new
** changeset was recorded immediately after the changesets already
** added to the changegroup.
** </table>
**
** If the new changeset contains changes to a table that is already present
** in the changegroup, then the number of columns and the position of the
** primary key columns for the table must be consistent. If this is not the
** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup
** object has been configured with a database schema using the
** sqlite3changegroup_schema() API, then it is possible to combine changesets
** with different numbers of columns for a single table, provided that
** they are otherwise compatible.
**
** If the input changeset appears to be corrupt and the corruption is
** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition
** occurs during processing, this function returns SQLITE_NOMEM.
**
** In all cases, if an error occurs the state of the final contents of the
** changegroup is undefined. If no error occurs, SQLITE_OK is returned.
*/
int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
/*
** CAPI3REF: Add A Single Change To A Changegroup
** METHOD: sqlite3_changegroup
**
** This function adds the single change currently indicated by the iterator
** passed as the second argument to the changegroup object. The rules for
** adding the change are just as described for [sqlite3changegroup_add()].
**
** If the change is successfully added to the changegroup, SQLITE_OK is
** returned. Otherwise, an SQLite error code is returned.
**
** The iterator must point to a valid entry when this function is called.
** If it does not, SQLITE_ERROR is returned and no change is added to the
** changegroup. Additionally, the iterator must not have been opened with
** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also
** returned.
*/
int sqlite3changegroup_add_change(
sqlite3_changegroup*,
sqlite3_changeset_iter*
);
/*
** CAPI3REF: Obtain A Composite Changeset From A Changegroup
** METHOD: sqlite3_changegroup
**
** Obtain a buffer containing a changeset (or patchset) representing the
** current contents of the changegroup. If the inputs to the changegroup
** were themselves changesets, the output is a changeset. Or, if the
** inputs were patchsets, the output is also a patchset.
**
** As with the output of the sqlite3session_changeset() and
** sqlite3session_patchset() functions, all changes related to a single
** table are grouped together in the output of this function. Tables appear
** in the same order as for the very first changeset added to the changegroup.
** If the second or subsequent changesets added to the changegroup contain
** changes for tables that do not appear in the first changeset, they are
** appended onto the end of the output changeset, again in the order in
** which they are first encountered.
**
** If an error occurs, an SQLite error code is returned and the output
** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
** is returned and the output variables are set to the size of and a
** pointer to the output buffer, respectively. In this case it is the
** responsibility of the caller to eventually free the buffer using a
** call to sqlite3_free().
*/
int sqlite3changegroup_output(
sqlite3_changegroup*,
int *pnData, /* OUT: Size of output buffer in bytes */
void **ppData /* OUT: Pointer to output buffer */
);
/*
** CAPI3REF: Delete A Changegroup Object
** DESTRUCTOR: sqlite3_changegroup
*/
void sqlite3changegroup_delete(sqlite3_changegroup*);
/*
** CAPI3REF: Apply A Changeset To A Database
**
** Apply a changeset or patchset to a database. These functions attempt to
** update the "main" database attached to handle db with the changes found in
** the changeset passed via the second and third arguments.
**
** The fourth argument (xFilter) passed to these functions is the "filter
** callback". If it is not NULL, then for each table affected by at least one
** change in the changeset, the filter callback is invoked with
** the table name as the second argument, and a copy of the context pointer
** passed as the sixth argument as the first. If the "filter callback"
** returns zero, then no attempt is made to apply any changes to the table.
** Otherwise, if the return value is non-zero or the xFilter argument to
** is NULL, all changes related to the table are attempted.
**
** For each table that is not excluded by the filter callback, this function
** tests that the target database contains a compatible table. A table is
** considered compatible if all of the following are true:
**
** <ul>
** <li> The table has the same name as the name recorded in the
** changeset, and
** <li> The table has at least as many columns as recorded in the
** changeset, and
** <li> The table has primary key columns in the same position as
** recorded in the changeset.
** </ul>
**
** If there is no compatible table, it is not an error, but none of the
** changes associated with the table are applied. A warning message is issued
** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
** one such warning is issued for each table in the changeset.
**
** For each change for which there is a compatible table, an attempt is made
** to modify the table contents according to the UPDATE, INSERT or DELETE
** change. If a change cannot be applied cleanly, the conflict handler
** function passed as the fifth argument to sqlite3changeset_apply() may be
** invoked. A description of exactly when the conflict handler is invoked for
** each type of change is below.
**
** Unlike the xFilter argument, xConflict may not be passed NULL. The results
** of passing anything other than a valid function pointer as the xConflict
** argument are undefined.
**
** Each time the conflict handler function is invoked, it must return one
** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
** if the second argument passed to the conflict handler is either
** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
** returns an illegal value, any changes already made are rolled back and
** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
** actions are taken by sqlite3changeset_apply() depending on the value
** returned by each invocation of the conflict-handler function. Refer to
** the documentation for the three
** [SQLITE_CHANGESET_OMIT|available return values] for details.
**
** <dl>
** <dt>DELETE Changes<dd>
** For each DELETE change, the function checks if the target database
** contains a row with the same primary key value (or values) as the
** original row values stored in the changeset. If it does, and the values
** stored in all non-primary key columns also match the values stored in
** the changeset the row is deleted from the target database.
**
** If a row with matching primary key values is found, but one or more of
** the non-primary key fields contains a value different from the original
** row value stored in the changeset, the conflict-handler function is
** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
** database table has more columns than are recorded in the changeset,
** only the values of those non-primary key fields are compared against
** the current database contents - any trailing database table columns
** are ignored.
**
** If no row with matching primary key values is found in the database,
** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
** passed as the second argument.
**
** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
** (which can only happen if a foreign key constraint is violated), the
** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
** passed as the second argument. This includes the case where the DELETE
** operation is attempted because an earlier call to the conflict handler
** function returned [SQLITE_CHANGESET_REPLACE].
**
** <dt>INSERT Changes<dd>
** For each INSERT change, an attempt is made to insert the new row into
** the database. If the changeset row contains fewer fields than the
** database table, the trailing fields are populated with their default
** values.
**
** If the attempt to insert the row fails because the database already
** contains a row with the same primary key values, the conflict handler
** function is invoked with the second argument set to
** [SQLITE_CHANGESET_CONFLICT].
**
** If the attempt to insert the row fails because of some other constraint
** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
** This includes the case where the INSERT operation is re-attempted because
** an earlier call to the conflict handler function returned
** [SQLITE_CHANGESET_REPLACE].
**
** <dt>UPDATE Changes<dd>
** For each UPDATE change, the function checks if the target database
** contains a row with the same primary key value (or values) as the
** original row values stored in the changeset. If it does, and the values
** stored in all modified non-primary key columns also match the values
** stored in the changeset the row is updated within the target database.
**
** If a row with matching primary key values is found, but one or more of
** the modified non-primary key fields contains a value different from an
** original row value stored in the changeset, the conflict-handler function
** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
** UPDATE changes only contain values for non-primary key fields that are
** to be modified, only those fields need to match the original values to
** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
**
** If no row with matching primary key values is found in the database,
** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
** passed as the second argument.
**
** If the UPDATE operation is attempted, but SQLite returns
** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
** This includes the case where the UPDATE operation is attempted after
** an earlier call to the conflict handler function returned
** [SQLITE_CHANGESET_REPLACE].
** </dl>
**
** It is safe to execute SQL statements, including those that write to the
** table that the callback related to, from within the xConflict callback.
** This can be used to further customize the application's conflict
** resolution strategy.
**
** All changes made by these functions are enclosed in a savepoint transaction.
** If any other error (aside from a constraint failure when attempting to
** write to the target database) occurs, then the savepoint transaction is
** rolled back, restoring the target database to its original state, and an
** SQLite error code returned.
**
** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
** may set (*ppRebase) to point to a "rebase" that may be used with the
** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
** is set to the size of the buffer in bytes. It is the responsibility of the
** caller to eventually free any such buffer using sqlite3_free(). The buffer
** is only allocated and populated if one or more conflicts were encountered
** while applying the patchset. See comments surrounding the sqlite3_rebaser
** APIs for further details.
**
** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
** may be modified by passing a combination of
** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
**
** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
** and therefore subject to change.
*/
int sqlite3changeset_apply(
sqlite3 *db, /* Apply change to "main" db of this handle */
int nChangeset, /* Size of changeset in bytes */
void *pChangeset, /* Changeset blob */
int(*xFilter)(
void *pCtx, /* Copy of sixth arg to _apply() */
const char *zTab /* Table name */
),
int(*xConflict)(
void *pCtx, /* Copy of sixth arg to _apply() */
int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
sqlite3_changeset_iter *p /* Handle describing change and conflict */
),
void *pCtx /* First argument passed to xConflict */
);
int sqlite3changeset_apply_v2(
sqlite3 *db, /* Apply change to "main" db of this handle */
int nChangeset, /* Size of changeset in bytes */
void *pChangeset, /* Changeset blob */
int(*xFilter)(
void *pCtx, /* Copy of sixth arg to _apply() */
const char *zTab /* Table name */
),
int(*xConflict)(
void *pCtx, /* Copy of sixth arg to _apply() */
int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
sqlite3_changeset_iter *p /* Handle describing change and conflict */
),
void *pCtx, /* First argument passed to xConflict */
void **ppRebase, int *pnRebase, /* OUT: Rebase data */
int flags /* SESSION_CHANGESETAPPLY_* flags */
);
/*
** CAPI3REF: Flags for sqlite3changeset_apply_v2
**
** The following flags may passed via the 9th parameter to
** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
**
** <dl>
** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
** Usually, the sessions module encloses all operations performed by
** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
** SAVEPOINT is committed if the changeset or patchset is successfully
** applied, or rolled back if an error occurs. Specifying this flag
** causes the sessions module to omit this savepoint. In this case, if the
** caller has an open transaction or savepoint when apply_v2() is called,
** it may revert the partially applied changeset by rolling it back.
**
** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
** Invert the changeset before applying it. This is equivalent to inverting
** a changeset using sqlite3changeset_invert() before applying it. It is
** an error to specify this flag with a patchset.
**
** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
** Do not invoke the conflict handler callback for any changes that
** would not actually modify the database even if they were applied.
** Specifically, this means that the conflict handler is not invoked
** for:
** <ul>
** <li>a delete change if the row being deleted cannot be found,
** <li>an update change if the modified fields are already set to
** their new values in the conflicting row, or
** <li>an insert change if all fields of the conflicting row match
** the row being inserted.
** </ul>
**
** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd>
** If this flag it set, then all foreign key constraints in the target
** database behave as if they were declared with "ON UPDATE NO ACTION ON
** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL
** or SET DEFAULT.
*/
#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
#define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
#define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008
/*
** CAPI3REF: Constants Passed To The Conflict Handler
**
** Values that may be passed as the second argument to a conflict-handler.
**
** <dl>
** <dt>SQLITE_CHANGESET_DATA<dd>
** The conflict handler is invoked with CHANGESET_DATA as the second argument
** when processing a DELETE or UPDATE change if a row with the required
** PRIMARY KEY fields is present in the database, but one or more other
** (non primary-key) fields modified by the update do not contain the
** expected "before" values.
**
** The conflicting row, in this case, is the database row with the matching
** primary key.
**
** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
** argument when processing a DELETE or UPDATE change if a row with the
** required PRIMARY KEY fields is not present in the database.
**
** There is no conflicting row in this case. The results of invoking the
** sqlite3changeset_conflict() API are undefined.
**
** <dt>SQLITE_CHANGESET_CONFLICT<dd>
** CHANGESET_CONFLICT is passed as the second argument to the conflict
** handler while processing an INSERT change if the operation would result
** in duplicate primary key values.
**
** The conflicting row in this case is the database row with the matching
** primary key.
**
** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
** If foreign key handling is enabled, and applying a changeset leaves the
** database in a state containing foreign key violations, the conflict
** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
** exactly once before the changeset is committed. If the conflict handler
** returns CHANGESET_OMIT, the changes, including those that caused the
** foreign key constraint violation, are committed. Or, if it returns
** CHANGESET_ABORT, the changeset is rolled back.
**
** No current or conflicting row information is provided. The only function
** it is possible to call on the supplied sqlite3_changeset_iter handle
** is sqlite3changeset_fk_conflicts().
**
** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
** If any other constraint violation occurs while applying a change (i.e.
** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
** invoked with CHANGESET_CONSTRAINT as the second argument.
**
** There is no conflicting row in this case. The results of invoking the
** sqlite3changeset_conflict() API are undefined.
**
** </dl>
*/
#define SQLITE_CHANGESET_DATA 1
#define SQLITE_CHANGESET_NOTFOUND 2
#define SQLITE_CHANGESET_CONFLICT 3
#define SQLITE_CHANGESET_CONSTRAINT 4
#define SQLITE_CHANGESET_FOREIGN_KEY 5
/*
** CAPI3REF: Constants Returned By The Conflict Handler
**
** A conflict handler callback must return one of the following three values.
**
** <dl>
** <dt>SQLITE_CHANGESET_OMIT<dd>
** If a conflict handler returns this value no special action is taken. The
** change that caused the conflict is not applied. The session module
** continues to the next change in the changeset.
**
** <dt>SQLITE_CHANGESET_REPLACE<dd>
** This value may only be returned if the second argument to the conflict
** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
** is not the case, any changes applied so far are rolled back and the
** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
**
** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
** handler, then the conflicting row is either updated or deleted, depending
** on the type of change.
**
** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
** handler, then the conflicting row is removed from the database and a
** second attempt to apply the change is made. If this second attempt fails,
** the original row is restored to the database before continuing.
**
** <dt>SQLITE_CHANGESET_ABORT<dd>
** If this value is returned, any changes applied so far are rolled back
** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
** </dl>
*/
#define SQLITE_CHANGESET_OMIT 0
#define SQLITE_CHANGESET_REPLACE 1
#define SQLITE_CHANGESET_ABORT 2
/*
** CAPI3REF: Rebasing changesets
** EXPERIMENTAL
**
** Suppose there is a site hosting a database in state S0. And that
** modifications are made that move that database to state S1 and a
** changeset recorded (the "local" changeset). Then, a changeset based
** on S0 is received from another site (the "remote" changeset) and
** applied to the database. The database is then in state
** (S1+"remote"), where the exact state depends on any conflict
** resolution decisions (OMIT or REPLACE) made while applying "remote".
** Rebasing a changeset is to update it to take those conflict
** resolution decisions into account, so that the same conflicts
** do not have to be resolved elsewhere in the network.
**
** For example, if both the local and remote changesets contain an
** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
**
** local: INSERT INTO t1 VALUES(1, 'v1');
** remote: INSERT INTO t1 VALUES(1, 'v2');
**
** and the conflict resolution is REPLACE, then the INSERT change is
** removed from the local changeset (it was overridden). Or, if the
** conflict resolution was "OMIT", then the local changeset is modified
** to instead contain:
**
** UPDATE t1 SET b = 'v2' WHERE a=1;
**
** Changes within the local changeset are rebased as follows:
**
** <dl>
** <dt>Local INSERT<dd>
** This may only conflict with a remote INSERT. If the conflict
** resolution was OMIT, then add an UPDATE change to the rebased
** changeset. Or, if the conflict resolution was REPLACE, add
** nothing to the rebased changeset.
**
** <dt>Local DELETE<dd>
** This may conflict with a remote UPDATE or DELETE. In both cases the
** only possible resolution is OMIT. If the remote operation was a
** DELETE, then add no change to the rebased changeset. If the remote
** operation was an UPDATE, then the old.* fields of change are updated
** to reflect the new.* values in the UPDATE.
**
** <dt>Local UPDATE<dd>
** This may conflict with a remote UPDATE or DELETE. If it conflicts
** with a DELETE, and the conflict resolution was OMIT, then the update
** is changed into an INSERT. Any undefined values in the new.* record
** from the update change are filled in using the old.* values from
** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
** the UPDATE change is simply omitted from the rebased changeset.
**
** If conflict is with a remote UPDATE and the resolution is OMIT, then
** the old.* values are rebased using the new.* values in the remote
** change. Or, if the resolution is REPLACE, then the change is copied
** into the rebased changeset with updates to columns also updated by
** the conflicting remote UPDATE removed. If this means no columns would
** be updated, the change is omitted.
** </dl>
**
** A local change may be rebased against multiple remote changes
** simultaneously. If a single key is modified by multiple remote
** changesets, they are combined as follows before the local changeset
** is rebased:
**
** <ul>
** <li> If there has been one or more REPLACE resolutions on a
** key, it is rebased according to a REPLACE.
**
** <li> If there have been no REPLACE resolutions on a key, then
** the local changeset is rebased according to the most recent
** of the OMIT resolutions.
** </ul>
**
** Note that conflict resolutions from multiple remote changesets are
** combined on a per-field basis, not per-row. This means that in the
** case of multiple remote UPDATE operations, some fields of a single
** local change may be rebased for REPLACE while others are rebased for
** OMIT.
**
** In order to rebase a local changeset, the remote changeset must first
** be applied to the local database using sqlite3changeset_apply_v2() and
** the buffer of rebase information captured. Then:
**
** <ol>
** <li> An sqlite3_rebaser object is created by calling
** sqlite3rebaser_create().
** <li> The new object is configured with the rebase buffer obtained from
** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
** If the local changeset is to be rebased against multiple remote
** changesets, then sqlite3rebaser_configure() should be called
** multiple times, in the same order that the multiple
** sqlite3changeset_apply_v2() calls were made.
** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
** <li> The sqlite3_rebaser object is deleted by calling
** sqlite3rebaser_delete().
** </ol>
*/
typedef struct sqlite3_rebaser sqlite3_rebaser;
/*
** CAPI3REF: Create a changeset rebaser object.
** EXPERIMENTAL
**
** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
** point to the new object and return SQLITE_OK. Otherwise, if an error
** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
** to NULL.
*/
int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
/*
** CAPI3REF: Configure a changeset rebaser object.
** EXPERIMENTAL
**
** Configure the changeset rebaser object to rebase changesets according
** to the conflict resolutions described by buffer pRebase (size nRebase
** bytes), which must have been obtained from a previous call to
** sqlite3changeset_apply_v2().
*/
int sqlite3rebaser_configure(
sqlite3_rebaser*,
int nRebase, const void *pRebase
);
/*
** CAPI3REF: Rebase a changeset
** EXPERIMENTAL
**
** Argument pIn must point to a buffer containing a changeset nIn bytes
** in size. This function allocates and populates a buffer with a copy
** of the changeset rebased according to the configuration of the
** rebaser object passed as the first argument. If successful, (*ppOut)
** is set to point to the new buffer containing the rebased changeset and
** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
** responsibility of the caller to eventually free the new buffer using
** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
** are set to zero and an SQLite error code returned.
*/
int sqlite3rebaser_rebase(
sqlite3_rebaser*,
int nIn, const void *pIn,
int *pnOut, void **ppOut
);
/*
** CAPI3REF: Delete a changeset rebaser object.
** EXPERIMENTAL
**
** Delete the changeset rebaser object and all associated resources. There
** should be one call to this function for each successful invocation
** of sqlite3rebaser_create().
*/
void sqlite3rebaser_delete(sqlite3_rebaser *p);
/*
** CAPI3REF: Streaming Versions of API functions.
**
** The six streaming API xxx_strm() functions serve similar purposes to the
** corresponding non-streaming API functions:
**
** <table border=1 style="margin-left:8ex;margin-right:8ex">
** <tr><th>Streaming function<th>Non-streaming equivalent</th>
** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
** </table>
**
** Non-streaming functions that accept changesets (or patchsets) as input
** require that the entire changeset be stored in a single buffer in memory.
** Similarly, those that return a changeset or patchset do so by returning
** a pointer to a single large buffer allocated using sqlite3_malloc().
** Normally this is convenient. However, if an application running in a
** low-memory environment is required to handle very large changesets, the
** large contiguous memory allocations required can become onerous.
**
** In order to avoid this problem, instead of a single large buffer, input
** is passed to a streaming API functions by way of a callback function that
** the sessions module invokes to incrementally request input data as it is
** required. In all cases, a pair of API function parameters such as
**
** <pre>
** int nChangeset,
** void *pChangeset,
** </pre>
**
** Is replaced by:
**
** <pre>
** int (*xInput)(void *pIn, void *pData, int *pnData),
** void *pIn,
** </pre>
**
** Each time the xInput callback is invoked by the sessions module, the first
** argument passed is a copy of the supplied pIn context pointer. The second
** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
** error occurs the xInput method should copy up to (*pnData) bytes of data
** into the buffer and set (*pnData) to the actual number of bytes copied
** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
** should be set to zero to indicate this. Or, if an error occurs, an SQLite
** error code should be returned. In all cases, if an xInput callback returns
** an error, all processing is abandoned and the streaming API function
** returns a copy of the error code to the caller.
**
** In the case of sqlite3changeset_start_strm(), the xInput callback may be
** invoked by the sessions module at any point during the lifetime of the
** iterator. If such an xInput callback returns an error, the iterator enters
** an error state, whereby all subsequent calls to iterator functions
** immediately fail with the same error code as returned by xInput.
**
** Similarly, streaming API functions that return changesets (or patchsets)
** return them in chunks by way of a callback function instead of via a
** pointer to a single large buffer. In this case, a pair of parameters such
** as:
**
** <pre>
** int *pnChangeset,
** void **ppChangeset,
** </pre>
**
** Is replaced by:
**
** <pre>
** int (*xOutput)(void *pOut, const void *pData, int nData),
** void *pOut
** </pre>
**
** The xOutput callback is invoked zero or more times to return data to
** the application. The first parameter passed to each call is a copy of the
** pOut pointer supplied by the application. The second parameter, pData,
** points to a buffer nData bytes in size containing the chunk of output
** data being returned. If the xOutput callback successfully processes the
** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
** it should return some other SQLite error code. In this case processing
** is immediately abandoned and the streaming API function returns a copy
** of the xOutput error code to the application.
**
** The sessions module never invokes an xOutput callback with the third
** parameter set to a value less than or equal to zero. Other than this,
** no guarantees are made as to the size of the chunks of data returned.
*/
int sqlite3changeset_apply_strm(
sqlite3 *db, /* Apply change to "main" db of this handle */
int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
void *pIn, /* First arg for xInput */
int(*xFilter)(
void *pCtx, /* Copy of sixth arg to _apply() */
const char *zTab /* Table name */
),
int(*xConflict)(
void *pCtx, /* Copy of sixth arg to _apply() */
int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
sqlite3_changeset_iter *p /* Handle describing change and conflict */
),
void *pCtx /* First argument passed to xConflict */
);
int sqlite3changeset_apply_v2_strm(
sqlite3 *db, /* Apply change to "main" db of this handle */
int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
void *pIn, /* First arg for xInput */
int(*xFilter)(
void *pCtx, /* Copy of sixth arg to _apply() */
const char *zTab /* Table name */
),
int(*xConflict)(
void *pCtx, /* Copy of sixth arg to _apply() */
int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
sqlite3_changeset_iter *p /* Handle describing change and conflict */
),
void *pCtx, /* First argument passed to xConflict */
void **ppRebase, int *pnRebase,
int flags
);
int sqlite3changeset_concat_strm(
int (*xInputA)(void *pIn, void *pData, int *pnData),
void *pInA,
int (*xInputB)(void *pIn, void *pData, int *pnData),
void *pInB,
int (*xOutput)(void *pOut, const void *pData, int nData),
void *pOut
);
int sqlite3changeset_invert_strm(
int (*xInput)(void *pIn, void *pData, int *pnData),
void *pIn,
int (*xOutput)(void *pOut, const void *pData, int nData),
void *pOut
);
int sqlite3changeset_start_strm(
sqlite3_changeset_iter **pp,
int (*xInput)(void *pIn, void *pData, int *pnData),
void *pIn
);
int sqlite3changeset_start_v2_strm(
sqlite3_changeset_iter **pp,
int (*xInput)(void *pIn, void *pData, int *pnData),
void *pIn,
int flags
);
int sqlite3session_changeset_strm(
sqlite3_session *pSession,
int (*xOutput)(void *pOut, const void *pData, int nData),
void *pOut
);
int sqlite3session_patchset_strm(
sqlite3_session *pSession,
int (*xOutput)(void *pOut, const void *pData, int nData),
void *pOut
);
int sqlite3changegroup_add_strm(sqlite3_changegroup*,
int (*xInput)(void *pIn, void *pData, int *pnData),
void *pIn
);
int sqlite3changegroup_output_strm(sqlite3_changegroup*,
int (*xOutput)(void *pOut, const void *pData, int nData),
void *pOut
);
int sqlite3rebaser_rebase_strm(
sqlite3_rebaser *pRebaser,
int (*xInput)(void *pIn, void *pData, int *pnData),
void *pIn,
int (*xOutput)(void *pOut, const void *pData, int nData),
void *pOut
);
/*
** CAPI3REF: Configure global parameters
**
** The sqlite3session_config() interface is used to make global configuration
** changes to the sessions module in order to tune it to the specific needs
** of the application.
**
** The sqlite3session_config() interface is not threadsafe. If it is invoked
** while any other thread is inside any other sessions method then the
** results are undefined. Furthermore, if it is invoked after any sessions
** related objects have been created, the results are also undefined.
**
** The first argument to the sqlite3session_config() function must be one
** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
** interpretation of the (void*) value passed as the second parameter and
** the effect of calling this function depends on the value of the first
** parameter.
**
** <dl>
** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
** By default, the sessions module streaming interfaces attempt to input
** and output data in approximately 1 KiB chunks. This operand may be used
** to set and query the value of this configuration setting. The pointer
** passed as the second argument must point to a value of type (int).
** If this value is greater than 0, it is used as the new streaming data
** chunk size for both input and output. Before returning, the (int) value
** pointed to by pArg is set to the final value of the streaming interface
** chunk size.
** </dl>
**
** This function returns SQLITE_OK if successful, or an SQLite error code
** otherwise.
*/
int sqlite3session_config(int op, void *pArg);
/*
** CAPI3REF: Values for sqlite3session_config().
*/
#define SQLITE_SESSION_CONFIG_STRMSIZE 1
/*
** Make sure we can call this stuff from C++.
*/
#ifdef __cplusplus
}
#endif
#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
|