+/******** End of sqlite3rtree.h *********/
+/******** Begin file sqlite3session.h *********/
+
+#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
+
+
+/*
+** CAPI3REF: Session Object Handle
+*/
+typedef struct sqlite3_session sqlite3_session;
+
+/*
+** CAPI3REF: Changeset Iterator Handle
+*/
+typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
+
+/*
+** CAPI3REF: Create A New Session Object
+**
+** 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.
+*/
+SQLITE_API 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
+**
+** 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.
+*/
+SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
+
+
+/*
+** CAPI3REF: Enable Or Disable A Session Object
+**
+** 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.
+*/
+SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
+
+/*
+** CAPI3REF: Set Or Clear the Indirect Change Flag
+**
+** 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.
+*/
+SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
+
+/*
+** CAPI3REF: Attach A Table To A Session Object
+**
+** 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.
+*/
+SQLITE_API int sqlite3session_attach(
+ sqlite3_session *pSession, /* Session object */
+ const char *zTab /* Table name */
+);
+
+/*
+** CAPI3REF: Set a table filter on a Session Object.
+**
+** 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 is not tracked. Note that once a table is
+** attached, xFilter will not be called again.
+*/
+SQLITE_API 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
+**
+** 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.
+*/
+SQLITE_API int sqlite3session_changeset(
+ sqlite3_session *pSession, /* Session object */
+ int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
+ void **ppChangeset /* OUT: Buffer containing changeset */
+);
+
+/*
+** CAPI3REF: Load The Difference Between Tables Into A 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 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().
+*/
+SQLITE_API int sqlite3session_diff(
+ sqlite3_session *pSession,
+ const char *zFromDb,
+ const char *zTbl,
+ char **pzErrMsg
+);
+
+
+/*
+** CAPI3REF: Generate A Patchset From A Session Object
+**
+** 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).
+*/
+SQLITE_API 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.
+*/
+SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
+
+/*
+** CAPI3REF: Create An Iterator To Traverse A Changeset
+**
+** 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.
+*/
+SQLITE_API 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 */
+);
+
+
+/*
+** CAPI3REF: Advance A Changeset Iterator
+**
+** This function may only be used with iterators created by 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.
+*/
+SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
+
+/*
+** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
+**
+** 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].
+**
+** If argument pzTab is not NULL, then *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 pnCol is not NULL, then *pnCol is
+** set to the number of columns in the table affected by the change. If
+** pbIncorrect 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. Finally, if pOp is not NULL, then *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.
+**
+** 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.
+*/
+SQLITE_API 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
+**
+** 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.
+*/
+SQLITE_API 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
+**
+** 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.
+*/
+SQLITE_API 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
+**
+** 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.
+*/
+SQLITE_API 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
+**
+** 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.
+*/
+SQLITE_API 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
+**
+** 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.
+*/
+SQLITE_API int sqlite3changeset_fk_conflicts(
+ sqlite3_changeset_iter *pIter, /* Changeset iterator */
+ int *pnOut /* OUT: Number of FK violations */
+);
+
+
+/*
+** CAPI3REF: Finalize A Changeset Iterator
+**
+** 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):
+**
+** sqlite3changeset_start();
+** while( SQLITE_ROW==sqlite3changeset_next() ){
+** // Do something with change.
+** }
+** rc = sqlite3changeset_finalize();
+** if( rc!=SQLITE_OK ){
+** // An error has occurred
+** }
+*/
+SQLITE_API 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.
+*/
+SQLITE_API 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:
+**
+** 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;
+** }
+**
+** Refer to the sqlite3_changegroup documentation below for details.
+*/
+SQLITE_API 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: Changegroup Handle
+*/
+typedef struct sqlite3_changegroup sqlite3_changegroup;
+
+/*
+** CAPI3REF: Create A New Changegroup Object
+**
+** 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().
+*/
+SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
+
+/*
+** CAPI3REF: Add A Changeset To A 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. 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
+** final contents of the changegroup is undefined.
+**
+** If no error occurs, SQLITE_OK is returned.
+*/
+SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
+
+/*
+** CAPI3REF: Obtain A Composite Changeset From A 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().
+*/
+SQLITE_API 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
+*/
+SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
+
+/*
+** CAPI3REF: Apply A Changeset To A Database
+**
+** Apply a changeset to a database. This function attempts 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 this function 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 to this function 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 this function 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, this 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, this 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 applications conflict
+** resolution strategy.
+**
+** All changes made by this function 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.
+*/
+SQLITE_API 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 */
+);
+
+/*
+** 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: 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_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.
+*/
+SQLITE_API 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 */
+);
+SQLITE_API 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
+);
+SQLITE_API 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
+);
+SQLITE_API int sqlite3changeset_start_strm(
+ sqlite3_changeset_iter **pp,
+ int (*xInput)(void *pIn, void *pData, int *pnData),
+ void *pIn
+);
+SQLITE_API int sqlite3session_changeset_strm(
+ sqlite3_session *pSession,
+ int (*xOutput)(void *pOut, const void *pData, int nData),
+ void *pOut
+);
+SQLITE_API int sqlite3session_patchset_strm(
+ sqlite3_session *pSession,
+ int (*xOutput)(void *pOut, const void *pData, int nData),
+ void *pOut
+);
+SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
+ int (*xInput)(void *pIn, void *pData, int *pnData),
+ void *pIn
+);
+SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
+ int (*xOutput)(void *pOut, const void *pData, int nData),
+ void *pOut
+);
+
+
+/*
+** Make sure we can call this stuff from C++.
+*/
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
+
+/******** End of sqlite3session.h *********/
+/******** Begin file fts5.h *********/
+/*
+** 2014 May 31
+**
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
+**
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** Interfaces to extend FTS5. Using the interfaces defined in this file,
+** FTS5 may be extended with:
+**
+** * custom tokenizers, and
+** * custom auxiliary functions.
+*/
+
+
+#ifndef _FTS5_H
+#define _FTS5_H
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*************************************************************************
+** CUSTOM AUXILIARY FUNCTIONS
+**
+** Virtual table implementations may overload SQL functions by implementing
+** the sqlite3_module.xFindFunction() method.
+*/
+
+typedef struct Fts5ExtensionApi Fts5ExtensionApi;
+typedef struct Fts5Context Fts5Context;
+typedef struct Fts5PhraseIter Fts5PhraseIter;
+
+typedef void (*fts5_extension_function)(
+ const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
+ Fts5Context *pFts, /* First arg to pass to pApi functions */
+ sqlite3_context *pCtx, /* Context for returning result/error */
+ int nVal, /* Number of values in apVal[] array */
+ sqlite3_value **apVal /* Array of trailing arguments */
+);
+
+struct Fts5PhraseIter {
+ const unsigned char *a;
+ const unsigned char *b;
+};
+
+/*
+** EXTENSION API FUNCTIONS
+**
+** xUserData(pFts):
+** Return a copy of the context pointer the extension function was
+** registered with.
+**
+** xColumnTotalSize(pFts, iCol, pnToken):
+** If parameter iCol is less than zero, set output variable *pnToken
+** to the total number of tokens in the FTS5 table. Or, if iCol is
+** non-negative but less than the number of columns in the table, return
+** the total number of tokens in column iCol, considering all rows in
+** the FTS5 table.
+**
+** If parameter iCol is greater than or equal to the number of columns
+** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
+** an OOM condition or IO error), an appropriate SQLite error code is
+** returned.
+**
+** xColumnCount(pFts):
+** Return the number of columns in the table.
+**
+** xColumnSize(pFts, iCol, pnToken):
+** If parameter iCol is less than zero, set output variable *pnToken
+** to the total number of tokens in the current row. Or, if iCol is
+** non-negative but less than the number of columns in the table, set
+** *pnToken to the number of tokens in column iCol of the current row.
+**
+** If parameter iCol is greater than or equal to the number of columns
+** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
+** an OOM condition or IO error), an appropriate SQLite error code is
+** returned.
+**
+** This function may be quite inefficient if used with an FTS5 table
+** created with the "columnsize=0" option.
+**
+** xColumnText:
+** This function attempts to retrieve the text of column iCol of the
+** current document. If successful, (*pz) is set to point to a buffer
+** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
+** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
+** if an error occurs, an SQLite error code is returned and the final values
+** of (*pz) and (*pn) are undefined.
+**
+** xPhraseCount:
+** Returns the number of phrases in the current query expression.
+**
+** xPhraseSize:
+** Returns the number of tokens in phrase iPhrase of the query. Phrases
+** are numbered starting from zero.
+**
+** xInstCount:
+** Set *pnInst to the total number of occurrences of all phrases within
+** the query within the current row. Return SQLITE_OK if successful, or
+** an error code (i.e. SQLITE_NOMEM) if an error occurs.
+**
+** This API can be quite slow if used with an FTS5 table created with the
+** "detail=none" or "detail=column" option. If the FTS5 table is created
+** with either "detail=none" or "detail=column" and "content=" option
+** (i.e. if it is a contentless table), then this API always returns 0.
+**
+** xInst:
+** Query for the details of phrase match iIdx within the current row.
+** Phrase matches are numbered starting from zero, so the iIdx argument
+** should be greater than or equal to zero and smaller than the value
+** output by xInstCount().
+**
+** Usually, output parameter *piPhrase is set to the phrase number, *piCol
+** to the column in which it occurs and *piOff the token offset of the
+** first token of the phrase. The exception is if the table was created
+** with the offsets=0 option specified. In this case *piOff is always
+** set to -1.
+**
+** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM)
+** if an error occurs.
+**
+** This API can be quite slow if used with an FTS5 table created with the
+** "detail=none" or "detail=column" option.
+**
+** xRowid:
+** Returns the rowid of the current row.
+**
+** xTokenize:
+** Tokenize text using the tokenizer belonging to the FTS5 table.
+**
+** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
+** This API function is used to query the FTS table for phrase iPhrase
+** of the current query. Specifically, a query equivalent to:
+**
+** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
+**
+** with $p set to a phrase equivalent to the phrase iPhrase of the
+** current query is executed. Any column filter that applies to
+** phrase iPhrase of the current query is included in $p. For each
+** row visited, the callback function passed as the fourth argument
+** is invoked. The context and API objects passed to the callback
+** function may be used to access the properties of each matched row.
+** Invoking Api.xUserData() returns a copy of the pointer passed as
+** the third argument to pUserData.
+**
+** If the callback function returns any value other than SQLITE_OK, the
+** query is abandoned and the xQueryPhrase function returns immediately.
+** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
+** Otherwise, the error code is propagated upwards.
+**
+** If the query runs to completion without incident, SQLITE_OK is returned.
+** Or, if some error occurs before the query completes or is aborted by
+** the callback, an SQLite error code is returned.
+**
+**
+** xSetAuxdata(pFts5, pAux, xDelete)
+**
+** Save the pointer passed as the second argument as the extension functions
+** "auxiliary data". The pointer may then be retrieved by the current or any
+** future invocation of the same fts5 extension function made as part of
+** of the same MATCH query using the xGetAuxdata() API.
+**
+** Each extension function is allocated a single auxiliary data slot for
+** each FTS query (MATCH expression). If the extension function is invoked
+** more than once for a single FTS query, then all invocations share a
+** single auxiliary data context.
+**
+** If there is already an auxiliary data pointer when this function is
+** invoked, then it is replaced by the new pointer. If an xDelete callback
+** was specified along with the original pointer, it is invoked at this
+** point.
+**
+** The xDelete callback, if one is specified, is also invoked on the
+** auxiliary data pointer after the FTS5 query has finished.
+**
+** If an error (e.g. an OOM condition) occurs within this function, an
+** the auxiliary data is set to NULL and an error code returned. If the
+** xDelete parameter was not NULL, it is invoked on the auxiliary data
+** pointer before returning.
+**
+**
+** xGetAuxdata(pFts5, bClear)
+**
+** Returns the current auxiliary data pointer for the fts5 extension
+** function. See the xSetAuxdata() method for details.
+**
+** If the bClear argument is non-zero, then the auxiliary data is cleared
+** (set to NULL) before this function returns. In this case the xDelete,
+** if any, is not invoked.
+**
+**
+** xRowCount(pFts5, pnRow)
+**
+** This function is used to retrieve the total number of rows in the table.
+** In other words, the same value that would be returned by:
+**
+** SELECT count(*) FROM ftstable;
+**
+** xPhraseFirst()
+** This function is used, along with type Fts5PhraseIter and the xPhraseNext
+** method, to iterate through all instances of a single query phrase within
+** the current row. This is the same information as is accessible via the
+** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
+** to use, this API may be faster under some circumstances. To iterate
+** through instances of phrase iPhrase, use the following code:
+**
+** Fts5PhraseIter iter;
+** int iCol, iOff;
+** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
+** iCol>=0;
+** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
+** ){
+** // An instance of phrase iPhrase at offset iOff of column iCol
+** }
+**
+** The Fts5PhraseIter structure is defined above. Applications should not
+** modify this structure directly - it should only be used as shown above
+** with the xPhraseFirst() and xPhraseNext() API methods (and by
+** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
+**
+** This API can be quite slow if used with an FTS5 table created with the
+** "detail=none" or "detail=column" option. If the FTS5 table is created
+** with either "detail=none" or "detail=column" and "content=" option
+** (i.e. if it is a contentless table), then this API always iterates
+** through an empty set (all calls to xPhraseFirst() set iCol to -1).
+**
+** xPhraseNext()
+** See xPhraseFirst above.
+**
+** xPhraseFirstColumn()
+** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
+** and xPhraseNext() APIs described above. The difference is that instead
+** of iterating through all instances of a phrase in the current row, these
+** APIs are used to iterate through the set of columns in the current row
+** that contain one or more instances of a specified phrase. For example:
+**
+** Fts5PhraseIter iter;
+** int iCol;
+** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
+** iCol>=0;
+** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
+** ){
+** // Column iCol contains at least one instance of phrase iPhrase
+** }
+**
+** This API can be quite slow if used with an FTS5 table created with the
+** "detail=none" option. If the FTS5 table is created with either
+** "detail=none" "content=" option (i.e. if it is a contentless table),
+** then this API always iterates through an empty set (all calls to
+** xPhraseFirstColumn() set iCol to -1).
+**
+** The information accessed using this API and its companion
+** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
+** (or xInst/xInstCount). The chief advantage of this API is that it is
+** significantly more efficient than those alternatives when used with
+** "detail=column" tables.
+**
+** xPhraseNextColumn()
+** See xPhraseFirstColumn above.
+*/
+struct Fts5ExtensionApi {
+ int iVersion; /* Currently always set to 3 */
+
+ void *(*xUserData)(Fts5Context*);
+
+ int (*xColumnCount)(Fts5Context*);
+ int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
+ int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
+
+ int (*xTokenize)(Fts5Context*,
+ const char *pText, int nText, /* Text to tokenize */
+ void *pCtx, /* Context passed to xToken() */
+ int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
+ );
+
+ int (*xPhraseCount)(Fts5Context*);
+ int (*xPhraseSize)(Fts5Context*, int iPhrase);
+
+ int (*xInstCount)(Fts5Context*, int *pnInst);
+ int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
+
+ sqlite3_int64 (*xRowid)(Fts5Context*);
+ int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
+ int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
+
+ int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
+ int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
+ );
+ int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
+ void *(*xGetAuxdata)(Fts5Context*, int bClear);
+
+ int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
+ void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
+
+ int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
+ void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
+};
+
+/*
+** CUSTOM AUXILIARY FUNCTIONS
+*************************************************************************/
+
+/*************************************************************************
+** CUSTOM TOKENIZERS
+**
+** Applications may also register custom tokenizer types. A tokenizer
+** is registered by providing fts5 with a populated instance of the
+** following structure. All structure methods must be defined, setting
+** any member of the fts5_tokenizer struct to NULL leads to undefined
+** behaviour. The structure methods are expected to function as follows:
+**
+** xCreate:
+** This function is used to allocate and initialize a tokenizer instance.
+** A tokenizer instance is required to actually tokenize text.
+**
+** The first argument passed to this function is a copy of the (void*)
+** pointer provided by the application when the fts5_tokenizer object
+** was registered with FTS5 (the third argument to xCreateTokenizer()).
+** The second and third arguments are an array of nul-terminated strings
+** containing the tokenizer arguments, if any, specified following the
+** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
+** to create the FTS5 table.
+**
+** The final argument is an output variable. If successful, (*ppOut)
+** should be set to point to the new tokenizer handle and SQLITE_OK
+** returned. If an error occurs, some value other than SQLITE_OK should
+** be returned. In this case, fts5 assumes that the final value of *ppOut
+** is undefined.
+**
+** xDelete:
+** This function is invoked to delete a tokenizer handle previously
+** allocated using xCreate(). Fts5 guarantees that this function will
+** be invoked exactly once for each successful call to xCreate().
+**
+** xTokenize:
+** This function is expected to tokenize the nText byte string indicated
+** by argument pText. pText may or may not be nul-terminated. The first
+** argument passed to this function is a pointer to an Fts5Tokenizer object
+** returned by an earlier call to xCreate().
+**
+** The second argument indicates the reason that FTS5 is requesting
+** tokenization of the supplied text. This is always one of the following
+** four values:
+**
+** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
+** or removed from the FTS table. The tokenizer is being invoked to
+** determine the set of tokens to add to (or delete from) the
+** FTS index.
+**
+** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
+** against the FTS index. The tokenizer is being called to tokenize
+** a bareword or quoted string specified as part of the query.
+**
+** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
+** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
+** followed by a "*" character, indicating that the last token
+** returned by the tokenizer will be treated as a token prefix.
+**
+** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
+** satisfy an fts5_api.xTokenize() request made by an auxiliary
+** function. Or an fts5_api.xColumnSize() request made by the same
+** on a columnsize=0 database.
+** </ul>
+**
+** For each token in the input string, the supplied callback xToken() must
+** be invoked. The first argument to it should be a copy of the pointer
+** passed as the second argument to xTokenize(). The third and fourth
+** arguments are a pointer to a buffer containing the token text, and the
+** size of the token in bytes. The 4th and 5th arguments are the byte offsets
+** of the first byte of and first byte immediately following the text from
+** which the token is derived within the input.
+**
+** The second argument passed to the xToken() callback ("tflags") should
+** normally be set to 0. The exception is if the tokenizer supports
+** synonyms. In this case see the discussion below for details.
+**
+** FTS5 assumes the xToken() callback is invoked for each token in the
+** order that they occur within the input text.
+**
+** If an xToken() callback returns any value other than SQLITE_OK, then
+** the tokenization should be abandoned and the xTokenize() method should
+** immediately return a copy of the xToken() return value. Or, if the
+** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
+** if an error occurs with the xTokenize() implementation itself, it
+** may abandon the tokenization and return any error code other than
+** SQLITE_OK or SQLITE_DONE.
+**
+** SYNONYM SUPPORT
+**
+** Custom tokenizers may also support synonyms. Consider a case in which a
+** user wishes to query for a phrase such as "first place". Using the
+** built-in tokenizers, the FTS5 query 'first + place' will match instances
+** of "first place" within the document set, but not alternative forms
+** such as "1st place". In some applications, it would be better to match
+** all instances of "first place" or "1st place" regardless of which form
+** the user specified in the MATCH query text.
+**
+** There are several ways to approach this in FTS5:
+**
+** <ol><li> By mapping all synonyms to a single token. In this case, the
+** In the above example, this means that the tokenizer returns the
+** same token for inputs "first" and "1st". Say that token is in
+** fact "first", so that when the user inserts the document "I won
+** 1st place" entries are added to the index for tokens "i", "won",
+** "first" and "place". If the user then queries for '1st + place',
+** the tokenizer substitutes "first" for "1st" and the query works
+** as expected.
+**
+** <li> By adding multiple synonyms for a single term to the FTS index.
+** In this case, when tokenizing query text, the tokenizer may
+** provide multiple synonyms for a single term within the document.
+** FTS5 then queries the index for each synonym individually. For
+** example, faced with the query:
+**
+** <codeblock>
+** ... MATCH 'first place'</codeblock>
+**
+** the tokenizer offers both "1st" and "first" as synonyms for the
+** first token in the MATCH query and FTS5 effectively runs a query
+** similar to:
+**
+** <codeblock>
+** ... MATCH '(first OR 1st) place'</codeblock>
+**
+** except that, for the purposes of auxiliary functions, the query
+** still appears to contain just two phrases - "(first OR 1st)"
+** being treated as a single phrase.
+**
+** <li> By adding multiple synonyms for a single term to the FTS index.
+** Using this method, when tokenizing document text, the tokenizer
+** provides multiple synonyms for each token. So that when a
+** document such as "I won first place" is tokenized, entries are
+** added to the FTS index for "i", "won", "first", "1st" and
+** "place".
+**
+** This way, even if the tokenizer does not provide synonyms
+** when tokenizing query text (it should not - to do would be
+** inefficient), it doesn't matter if the user queries for
+** 'first + place' or '1st + place', as there are entires in the
+** FTS index corresponding to both forms of the first token.
+** </ol>
+**
+** Whether it is parsing document or query text, any call to xToken that
+** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
+** is considered to supply a synonym for the previous token. For example,
+** when parsing the document "I won first place", a tokenizer that supports
+** synonyms would call xToken() 5 times, as follows:
+**
+** <codeblock>
+** xToken(pCtx, 0, "i", 1, 0, 1);
+** xToken(pCtx, 0, "won", 3, 2, 5);
+** xToken(pCtx, 0, "first", 5, 6, 11);
+** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
+** xToken(pCtx, 0, "place", 5, 12, 17);
+**</codeblock>
+**
+** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
+** xToken() is called. Multiple synonyms may be specified for a single token
+** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
+** There is no limit to the number of synonyms that may be provided for a
+** single token.
+**
+** In many cases, method (1) above is the best approach. It does not add
+** extra data to the FTS index or require FTS5 to query for multiple terms,
+** so it is efficient in terms of disk space and query speed. However, it
+** does not support prefix queries very well. If, as suggested above, the
+** token "first" is subsituted for "1st" by the tokenizer, then the query:
+**
+** <codeblock>
+** ... MATCH '1s*'</codeblock>
+**
+** will not match documents that contain the token "1st" (as the tokenizer
+** will probably not map "1s" to any prefix of "first").
+**
+** For full prefix support, method (3) may be preferred. In this case,
+** because the index contains entries for both "first" and "1st", prefix
+** queries such as 'fi*' or '1s*' will match correctly. However, because
+** extra entries are added to the FTS index, this method uses more space
+** within the database.
+**
+** Method (2) offers a midpoint between (1) and (3). Using this method,
+** a query such as '1s*' will match documents that contain the literal
+** token "1st", but not "first" (assuming the tokenizer is not able to
+** provide synonyms for prefixes). However, a non-prefix query like '1st'
+** will match against "1st" and "first". This method does not require
+** extra disk space, as no extra entries are added to the FTS index.
+** On the other hand, it may require more CPU cycles to run MATCH queries,
+** as separate queries of the FTS index are required for each synonym.
+**
+** When using methods (2) or (3), it is important that the tokenizer only
+** provide synonyms when tokenizing document text (method (2)) or query
+** text (method (3)), not both. Doing so will not cause any errors, but is
+** inefficient.
+*/
+typedef struct Fts5Tokenizer Fts5Tokenizer;
+typedef struct fts5_tokenizer fts5_tokenizer;
+struct fts5_tokenizer {
+ int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
+ void (*xDelete)(Fts5Tokenizer*);
+ int (*xTokenize)(Fts5Tokenizer*,
+ void *pCtx,
+ int flags, /* Mask of FTS5_TOKENIZE_* flags */
+ const char *pText, int nText,
+ int (*xToken)(
+ void *pCtx, /* Copy of 2nd argument to xTokenize() */
+ int tflags, /* Mask of FTS5_TOKEN_* flags */
+ const char *pToken, /* Pointer to buffer containing token */
+ int nToken, /* Size of token in bytes */
+ int iStart, /* Byte offset of token within input text */
+ int iEnd /* Byte offset of end of token within input text */
+ )
+ );
+};
+
+/* Flags that may be passed as the third argument to xTokenize() */
+#define FTS5_TOKENIZE_QUERY 0x0001
+#define FTS5_TOKENIZE_PREFIX 0x0002
+#define FTS5_TOKENIZE_DOCUMENT 0x0004
+#define FTS5_TOKENIZE_AUX 0x0008
+
+/* Flags that may be passed by the tokenizer implementation back to FTS5
+** as the third argument to the supplied xToken callback. */
+#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
+
+/*
+** END OF CUSTOM TOKENIZERS
+*************************************************************************/
+
+/*************************************************************************
+** FTS5 EXTENSION REGISTRATION API
+*/
+typedef struct fts5_api fts5_api;
+struct fts5_api {
+ int iVersion; /* Currently always set to 2 */
+
+ /* Create a new tokenizer */
+ int (*xCreateTokenizer)(
+ fts5_api *pApi,
+ const char *zName,
+ void *pContext,
+ fts5_tokenizer *pTokenizer,
+ void (*xDestroy)(void*)
+ );
+
+ /* Find an existing tokenizer */
+ int (*xFindTokenizer)(
+ fts5_api *pApi,
+ const char *zName,
+ void **ppContext,
+ fts5_tokenizer *pTokenizer
+ );
+
+ /* Create a new auxiliary function */
+ int (*xCreateFunction)(
+ fts5_api *pApi,
+ const char *zName,
+ void *pContext,
+ fts5_extension_function xFunction,
+ void (*xDestroy)(void*)
+ );
+};
+
+/*
+** END OF REGISTRATION API
+*************************************************************************/
+
+#ifdef __cplusplus
+} /* end of the 'extern "C"' block */
+#endif
+
+#endif /* _FTS5_H */
+
+/******** End of fts5.h *********/