diff options
Diffstat (limited to 'sql/opt_range.cc')
| -rw-r--r-- | sql/opt_range.cc | 59 |
1 files changed, 32 insertions, 27 deletions
diff --git a/sql/opt_range.cc b/sql/opt_range.cc index 13c2f6333b1..b6f81ab07eb 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -2463,9 +2463,9 @@ int QUICK_SELECT::get_next() if (range->flag & NO_MIN_RANGE) // Read first record { - int error; - if ((error=file->index_first(record))) - DBUG_RETURN(error); // Empty table + int local_error; + if ((local_error=file->index_first(record))) + DBUG_RETURN(local_error); // Empty table if (cmp_next(range) == 0) DBUG_RETURN(0); range=0; // No matching records; go to next range @@ -2499,13 +2499,13 @@ int QUICK_SELECT::get_next() /* compare if found key is over max-value */ /* Returns 0 if key <= range->max_key */ -int QUICK_SELECT::cmp_next(QUICK_RANGE *range) +int QUICK_SELECT::cmp_next(QUICK_RANGE *range_arg) { - if (range->flag & NO_MAX_RANGE) - return (0); /* key can't be to large */ + if (range_arg->flag & NO_MAX_RANGE) + return 0; /* key can't be to large */ KEY_PART *key_part=key_parts; - for (char *key=range->max_key, *end=key+range->max_length; + for (char *key=range_arg->max_key, *end=key+range_arg->max_length; key < end; key+= key_part++->part_length) { @@ -2526,7 +2526,7 @@ int QUICK_SELECT::cmp_next(QUICK_RANGE *range) if (cmp > 0) return 1; } - return (range->flag & NEAR_MAX) ? 1 : 0; // Exact match + return (range_arg->flag & NEAR_MAX) ? 1 : 0; // Exact match } @@ -2610,9 +2610,9 @@ int QUICK_SELECT_DESC::get_next() if (range->flag & NO_MAX_RANGE) // Read last record { - int error; - if ((error=file->index_last(record))) - DBUG_RETURN(error); // Empty table + int local_error; + if ((local_error=file->index_last(record))) + DBUG_RETURN(local_error); // Empty table if (cmp_prev(range) == 0) DBUG_RETURN(0); range=0; // No matching records; go to next range @@ -2666,16 +2666,18 @@ int QUICK_SELECT_DESC::get_next() } } + /* - * Returns 0 if found key is inside range (found key >= range->min_key). - */ -int QUICK_SELECT_DESC::cmp_prev(QUICK_RANGE *range) + Returns 0 if found key is inside range (found key >= range->min_key). +*/ + +int QUICK_SELECT_DESC::cmp_prev(QUICK_RANGE *range_arg) { - if (range->flag & NO_MIN_RANGE) - return (0); /* key can't be to small */ + if (range_arg->flag & NO_MIN_RANGE) + return 0; /* key can't be to small */ KEY_PART *key_part = key_parts; - for (char *key = range->min_key, *end = key + range->min_length; + for (char *key = range_arg->min_key, *end = key + range_arg->min_length; key < end; key += key_part++->part_length) { @@ -2699,42 +2701,45 @@ int QUICK_SELECT_DESC::cmp_prev(QUICK_RANGE *range) if (cmp < 0) return 1; } - return (range->flag & NEAR_MIN) ? 1 : 0; // Exact match + return (range_arg->flag & NEAR_MIN) ? 1 : 0; // Exact match } + /* * True if this range will require using HA_READ_AFTER_KEY See comment in get_next() about this */ -bool QUICK_SELECT_DESC::range_reads_after_key(QUICK_RANGE *range) +bool QUICK_SELECT_DESC::range_reads_after_key(QUICK_RANGE *range_arg) { - return ((range->flag & (NO_MAX_RANGE | NEAR_MAX)) || - !(range->flag & EQ_RANGE) || - head->key_info[index].key_length != range->max_length) ? 1 : 0; + return ((range_arg->flag & (NO_MAX_RANGE | NEAR_MAX)) || + !(range_arg->flag & EQ_RANGE) || + head->key_info[index].key_length != range_arg->max_length) ? 1 : 0; } + /* True if we are reading over a key that may have a NULL value */ -bool QUICK_SELECT_DESC::test_if_null_range(QUICK_RANGE *range, +bool QUICK_SELECT_DESC::test_if_null_range(QUICK_RANGE *range_arg, uint used_key_parts) { uint offset,end; KEY_PART *key_part = key_parts, *key_part_end= key_part+used_key_parts; - for (offset= 0, end = min(range->min_length, range->max_length) ; + for (offset= 0, end = min(range_arg->min_length, range_arg->max_length) ; offset < end && key_part != key_part_end ; offset += key_part++->part_length) { uint null_length=test(key_part->null_bit); - if (!memcmp((char*) range->min_key+offset, (char*) range->max_key+offset, + if (!memcmp((char*) range_arg->min_key+offset, + (char*) range_arg->max_key+offset, key_part->part_length + null_length)) { offset+=null_length; continue; } - if (null_length && range->min_key[offset]) + if (null_length && range_arg->min_key[offset]) return 1; // min_key is null and max_key isn't // Range doesn't cover NULL. This is ok if there is no more null parts break; @@ -2747,7 +2752,7 @@ bool QUICK_SELECT_DESC::test_if_null_range(QUICK_RANGE *range, */ if (key_part != key_part_end && key_part->null_bit) { - if (offset >= range->min_length || range->min_key[offset]) + if (offset >= range_arg->min_length || range_arg->min_key[offset]) return 1; // Could be null key_part++; } |