diff options
Diffstat (limited to 'sql/key.cc')
| -rw-r--r-- | sql/key.cc | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/sql/key.cc b/sql/key.cc index f2cebfe6d82..b65851cf7c1 100644 --- a/sql/key.cc +++ b/sql/key.cc @@ -1,5 +1,5 @@ /* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved. - Copyright (c) 2018, 2020, MariaDB + Copyright (c) 2018, 2021, MariaDB 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 @@ -495,6 +495,7 @@ int key_cmp(KEY_PART_INFO *key_part, const uchar *key, uint key_length) { int cmp; store_length= key_part->store_length; + int sort_order = (key_part->key_part_flag & HA_REVERSE_SORT) ? -1 : 1; if (key_part->null_bit) { /* This key part allows null values; NULL is lower than everything */ @@ -503,19 +504,19 @@ int key_cmp(KEY_PART_INFO *key_part, const uchar *key, uint key_length) { /* the range is expecting a null value */ if (!field_is_null) - return 1; // Found key is > range + return sort_order; // Found key is > range /* null -- exact match, go to next key part */ continue; } else if (field_is_null) - return -1; // NULL is less than any value + return -sort_order; // NULL is less than any value key++; // Skip null byte store_length--; } if ((cmp=key_part->field->key_cmp(key, key_part->length)) < 0) - return -1; + return -sort_order; if (cmp > 0) - return 1; + return sort_order; } return 0; // Keys are equal } @@ -573,6 +574,9 @@ int key_rec_cmp(void *key_p, uchar *first_rec, uchar *second_rec) /* loop over every key part */ do { + const int GREATER= key_part->key_part_flag & HA_REVERSE_SORT ? -1 : +1; + const int LESS= -GREATER; + field= key_part->field; if (key_part->null_bit) @@ -593,12 +597,12 @@ int key_rec_cmp(void *key_p, uchar *first_rec, uchar *second_rec) ; /* Fall through, no NULL fields */ else { - DBUG_RETURN(+1); + DBUG_RETURN(GREATER); } } else if (!sec_is_null) { - DBUG_RETURN(-1); + DBUG_RETURN(LESS); } else goto next_loop; /* Both were NULL */ @@ -612,7 +616,7 @@ int key_rec_cmp(void *key_p, uchar *first_rec, uchar *second_rec) */ if ((result= field->cmp_prefix(field->ptr+first_diff, field->ptr+sec_diff, key_part->length))) - DBUG_RETURN(result); + DBUG_RETURN(result * GREATER); next_loop: key_part++; key_part_num++; |