diff options
Diffstat (limited to '')
| -rw-r--r-- | ext/session/sqlite3session.h | 1721 |
1 files changed, 1721 insertions, 0 deletions
diff --git a/ext/session/sqlite3session.h b/ext/session/sqlite3session.h new file mode 100644 index 0000000..10d0133 --- /dev/null +++ b/ext/session/sqlite3session.h @@ -0,0 +1,1721 @@ + +#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); + +/* +** CAPIREF: Conigure 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 value for the second parameter is +** [SQLITE_SESSION_OBJCONFIG_SIZE]. +** +** Arguments for sqlite3session_object_config() +** +** The following values may passed as the the 4th 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. +*/ +int sqlite3session_object_config(sqlite3_session*, int op, void *pArg); + +/* +*/ +#define SQLITE_SESSION_OBJCONFIG_SIZE 1 + +/* +** 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: 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 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. 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: 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. +*/ +#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 +#define SQLITE_CHANGESETAPPLY_INVERT 0x0002 + +/* +** 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) */ |