1 /***************************************************************************** 2 3 Copyright (c) 2006, 2009, Oracle and/or its affiliates. All Rights Reserved. 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License, version 2.0, 7 as published by the Free Software Foundation. 8 9 This program is also distributed with certain software (including 10 but not limited to OpenSSL) that is licensed under separate terms, 11 as designated in a particular file or component or in included license 12 documentation. The authors of MySQL hereby grant you an additional 13 permission to link the program and your derivative works with the 14 separately licensed software that they have included with MySQL. 15 16 This program is distributed in the hope that it will be useful, 17 but WITHOUT ANY WARRANTY; without even the implied warranty of 18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 GNU General Public License, version 2.0, for more details. 20 21 You should have received a copy of the GNU General Public License along with 22 this program; if not, write to the Free Software Foundation, Inc., 23 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA 24 25 *****************************************************************************/ 26 27 /**************************************************//** 28 @file include/row0ext.h 29 Caching of externally stored column prefixes 30 31 Created September 2006 Marko Makela 32 *******************************************************/ 33 34 #ifndef row0ext_h 35 #define row0ext_h 36 37 #include "univ.i" 38 #include "row0types.h" 39 #include "data0types.h" 40 #include "mem0mem.h" 41 #include "dict0types.h" 42 43 /********************************************************************//** 44 Creates a cache of column prefixes of externally stored columns. 45 @return own: column prefix cache */ 46 UNIV_INTERN 47 row_ext_t* 48 row_ext_create( 49 /*===========*/ 50 ulint n_ext, /*!< in: number of externally stored columns */ 51 const ulint* ext, /*!< in: col_no's of externally stored columns 52 in the InnoDB table object, as reported by 53 dict_col_get_no(); NOT relative to the records 54 in the clustered index */ 55 ulint flags, /*!< in: table->flags */ 56 const dtuple_t* tuple, /*!< in: data tuple containing the field 57 references of the externally stored 58 columns; must be indexed by col_no; 59 the clustered index record must be 60 covered by a lock or a page latch 61 to prevent deletion (rollback or purge). */ 62 mem_heap_t* heap); /*!< in: heap where created */ 63 64 /********************************************************************//** 65 Looks up a column prefix of an externally stored column. 66 @return column prefix, or NULL if the column is not stored externally, 67 or pointer to field_ref_zero if the BLOB pointer is unset */ 68 UNIV_INLINE 69 const byte* 70 row_ext_lookup_ith( 71 /*===============*/ 72 const row_ext_t* ext, /*!< in/out: column prefix cache */ 73 ulint i, /*!< in: index of ext->ext[] */ 74 ulint* len); /*!< out: length of prefix, in bytes, 75 at most the length determined by 76 DICT_MAX_FIELD_LEN_BY_FORMAT() */ 77 /********************************************************************//** 78 Looks up a column prefix of an externally stored column. 79 @return column prefix, or NULL if the column is not stored externally, 80 or pointer to field_ref_zero if the BLOB pointer is unset */ 81 UNIV_INLINE 82 const byte* 83 row_ext_lookup( 84 /*===========*/ 85 const row_ext_t* ext, /*!< in: column prefix cache */ 86 ulint col, /*!< in: column number in the InnoDB 87 table object, as reported by 88 dict_col_get_no(); NOT relative to the 89 records in the clustered index */ 90 ulint* len); /*!< out: length of prefix, in bytes, 91 at most the length determined by 92 DICT_MAX_FIELD_LEN_BY_FORMAT() */ 93 94 /** Prefixes of externally stored columns */ 95 struct row_ext_t{ 96 ulint n_ext; /*!< number of externally stored columns */ 97 const ulint* ext; /*!< col_no's of externally stored columns */ 98 byte* buf; /*!< backing store of the column prefix cache */ 99 ulint max_len;/*!< maximum prefix length, it could be 100 REC_ANTELOPE_MAX_INDEX_COL_LEN or 101 REC_VERSION_56_MAX_INDEX_COL_LEN depending 102 on row format */ 103 ulint len[1]; /*!< prefix lengths; 0 if not cached */ 104 }; 105 106 #ifndef UNIV_NONINL 107 #include "row0ext.ic" 108 #endif 109 110 #endif 111