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Diffstat (limited to '')
-rw-r--r-- | storage/innobase/include/row0ext.ic | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/storage/innobase/include/row0ext.ic b/storage/innobase/include/row0ext.ic new file mode 100644 index 00000000..913b51b3 --- /dev/null +++ b/storage/innobase/include/row0ext.ic @@ -0,0 +1,87 @@ +/***************************************************************************** + +Copyright (c) 2006, 2009, Oracle and/or its affiliates. All Rights Reserved. + +This program is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free Software +Foundation; version 2 of the License. + +This program is distributed in the hope that it will be useful, but WITHOUT +ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS +FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. + +You should have received a copy of the GNU General Public License along with +this program; if not, write to the Free Software Foundation, Inc., +51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA + +*****************************************************************************/ + +/**************************************************//** +@file include/row0ext.ic +Caching of externally stored column prefixes + +Created September 2006 Marko Makela +*******************************************************/ + +#include "rem0types.h" +#include "btr0types.h" + +/********************************************************************//** +Looks up a column prefix of an externally stored column. +@return column prefix, or NULL if the column is not stored externally, +or pointer to field_ref_zero if the BLOB pointer is unset */ +UNIV_INLINE +const byte* +row_ext_lookup_ith( +/*===============*/ + const row_ext_t* ext, /*!< in/out: column prefix cache */ + ulint i, /*!< in: index of ext->ext[] */ + ulint* len) /*!< out: length of prefix, in bytes, + at most ext->max_len */ +{ + ut_ad(ext); + ut_ad(len); + ut_ad(i < ext->n_ext); + + *len = ext->len[i]; + + ut_ad(*len <= ext->max_len); + ut_ad(ext->max_len > 0); + + if (*len == 0) { + /* The BLOB could not be fetched to the cache. */ + return(field_ref_zero); + } else { + return(ext->buf + i * ext->max_len); + } +} + +/********************************************************************//** +Looks up a column prefix of an externally stored column. +@return column prefix, or NULL if the column is not stored externally, +or pointer to field_ref_zero if the BLOB pointer is unset */ +UNIV_INLINE +const byte* +row_ext_lookup( +/*===========*/ + const row_ext_t* ext, /*!< in: column prefix cache */ + ulint col, /*!< in: column number in the InnoDB + table object, as reported by + dict_col_get_no(); NOT relative to the + records in the clustered index */ + ulint* len) /*!< out: length of prefix, in bytes, + at most ext->max_len */ +{ + ulint i; + + ut_ad(ext); + ut_ad(len); + + for (i = 0; i < ext->n_ext; i++) { + if (col == ext->ext[i]) { + return(row_ext_lookup_ith(ext, i, len)); + } + } + + return(NULL); +} |