Commit dc83777a authored by Howard Chu's avatar Howard Chu
Browse files

Minor tweaks, update relfunc behavior

parent 25529a4c
......@@ -662,6 +662,7 @@ typedef struct MDB_dbx {
MDB_cmp_func *md_cmp; /**< function for comparing keys */
MDB_cmp_func *md_dcmp; /**< function for comparing data items */
MDB_rel_func *md_rel; /**< user relocate function */
void *md_relctx; /**< user-provided context for md_rel */
MDB_dbi md_parent; /**< parent DB of a sub-DB */
unsigned int md_dirty; /**< TRUE if DB was written in this txn */
} MDB_dbx;
......@@ -923,15 +924,6 @@ mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
return txn->mt_dbxs[dbi].md_cmp(a, b);
}
/** Compare two data items according to a particular database.
* This returns a comparison as if the two items were data items of
* a sorted duplicates #MDB_DUPSORT database.
* @param[in] txn A transaction handle returned by #mdb_txn_begin()
* @param[in] dbi A database handle returned by #mdb_open()
* @param[in] a The first item to compare
* @param[in] b The second item to compare
* @return < 0 if a < b, 0 if a == b, > 0 if a > b
*/
int
mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
{
......@@ -4731,4 +4723,13 @@ int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
return MDB_SUCCESS;
}
int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
{
if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
return EINVAL;
txn->mt_dbxs[dbi].md_relctx = ctx;
return MDB_SUCCESS;
}
/** @} */
......@@ -125,13 +125,18 @@ typedef struct MDB_val {
typedef int (MDB_cmp_func)(const MDB_val *a, const MDB_val *b);
/** A callback function used to relocate a position-dependent data item
* in a fixed-address database. The \b newptr gives the item's current address in
* the memory map, and \b oldptr gives its previous address. This callback is
* expected to walk through the fields of the record in newptr and modify any
* in a fixed-address database. The \b newptr gives the item's desired address in
* the memory map, and \b oldptr gives its previous address. The item's actual
* data resides at the address in \b item. This callback is expected to walk
* through the fields of the record in \b item and modify any
* values based at the \b oldptr address to be relative to the \b newptr address.
* @param[in,out] item The item that is to be relocated.
* @param[in] oldptr The previous address.
* @param[in] newptr The new address to relocate to.
* @param[in] relctx An application-provided context, set by #mdb_set_relctx().
* @todo This feature is currently unimplemented.
*/
typedef void (MDB_rel_func)(void *newptr, void *oldptr, size_t size);
typedef void (MDB_rel_func)(MDB_val *item, void *oldptr, void *newptr, void *relctx);
/** @defgroup mdb_env Environment Flags
* @{
......@@ -178,7 +183,10 @@ typedef void (MDB_rel_func)(void *newptr, void *oldptr, size_t size);
#define MDB_CURRENT 0x40
/* @} */
/** Cursor operations */
/** Cursor Get operations
* This is the set of all operations for retrieving data
* using a cursor.
*/
typedef enum MDB_cursor_op {
MDB_FIRST, /**< Position at first key/data item */
MDB_FIRST_DUP, /**< Position at first data item of current key.
......@@ -596,8 +604,8 @@ void mdb_close(MDB_txn *txn, MDB_dbi dbi);
* with #mdb_open(), the keys are compared lexically, with shorter keys collating
* before longer keys.
* @warning This function must be called before any data access functions are used,
* otherwise data corruption may occur. The same function must be used by every
* process accessing the database, every time the database is used.
* otherwise data corruption may occur. The same comparison function must be used by every
* program accessing the database, every time the database is used.
* @param[in] txn A transaction handle returned by #mdb_txn_begin()
* @param[in] dbi A database handle returned by #mdb_open()
* @param[in] cmp A #MDB_cmp_func function
......@@ -618,8 +626,8 @@ int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp);
* with #mdb_open(), the data items are compared lexically, with shorter items collating
* before longer items.
* @warning This function must be called before any data access functions are used,
* otherwise data corruption may occur. The same function must be used by every
* process accessing the database, every time the database is used.
* otherwise data corruption may occur. The same comparison function must be used by every
* program accessing the database, every time the database is used.
* @param[in] txn A transaction handle returned by #mdb_txn_begin()
* @param[in] dbi A database handle returned by #mdb_open()
* @param[in] cmp A #MDB_cmp_func function
......@@ -650,6 +658,21 @@ int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp);
*/
int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel);
/** Set a context pointer for a #MDB_FIXEDMAP database's relocation function.
* See #mdb_set_relfunc and #MDB_rel_func for more details.
* @param[in] txn A transaction handle returned by #mdb_txn_begin()
* @param[in] dbi A database handle returned by #mdb_open()
* @param[in] ctx An arbitrary pointer for whatever the application needs.
* It will be passed to the callback function set by #mdb_set_relfunc
* as its \b relctx parameter whenever the callback is invoked.
* @return A non-zero error value on failure and 0 on success. Some possible
* errors are:
* <ul>
* <li>EINVAL - an invalid parameter was specified.
* </ul>
*/
int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx);
/** Get items from a database.
* This function retrieves key/data pairs from the database. The address
* and length of the data associated with the specified \b key are returned
......@@ -852,5 +875,15 @@ int mdb_cursor_count(MDB_cursor *cursor, size_t *countp);
*/
int mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b);
/** Compare two data items according to a particular database.
* This returns a comparison as if the two items were data items of
* a sorted duplicates #MDB_DUPSORT database.
* @param[in] txn A transaction handle returned by #mdb_txn_begin()
* @param[in] dbi A database handle returned by #mdb_open()
* @param[in] a The first item to compare
* @param[in] b The second item to compare
* @return < 0 if a < b, 0 if a == b, > 0 if a > b
*/
int mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b);
/** @} */
#endif /* _MDB_H_ */
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