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Commit e85df7fe authored by Vladislav Vaintroub's avatar Vladislav Vaintroub
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MDEV-19702 Refactor Bitmap<N> to be based on ulonglong, not on uint32 

Removed Field_map, since it was used only in a single function.

Fixed is_indexed_agg_distinct(), since it relied on initialization of
Bitmap in constructor.

Fixes MDEV-25888 in 10.4
parent 0b9a59bb
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Showing with 175 additions and 231 deletions
sql/sql_bitmap.h
View file @ e85df7fe
......@@ -27,10 +27,36 @@
#include <my_bitmap.h>
#include <my_bit.h>
/* An iterator to quickly walk over bits in unlonglong bitmap. */
class Table_map_iterator
{
ulonglong bmp;
uint no;
public:
Table_map_iterator(ulonglong t) : bmp(t), no(0) {}
int next_bit()
{
static const char last_bit[16] = { 32, 0, 1, 0,
2, 0, 1, 0,
3, 0, 1, 0,
2, 0, 1, 0 };
uint bit;
while ((bit= last_bit[bmp & 0xF]) == 32)
{
no += 4;
bmp= bmp >> 4;
if (!bmp)
return BITMAP_END;
}
bmp &= ~(1LL << bit);
return no + bit;
}
int operator++(int) { return next_bit(); }
enum { BITMAP_END= 64 };
};
template <uint width> class Bitmap
{
/*
Workaround GCC optimizer bug (generating SSE instuctions on unaligned data)
*/
......@@ -43,12 +69,38 @@ template <uint width> class Bitmap
#pragma GCC target ("no-sse")
#endif
uint32 buffer[(width + 31) / 32];
public:
Bitmap()
private:
static const int BITS_PER_ELEMENT= sizeof(ulonglong) * 8;
static const int ARRAY_ELEMENTS= (width + BITS_PER_ELEMENT - 1) / BITS_PER_ELEMENT;
static const ulonglong ALL_BITS_SET= ULLONG_MAX;
ulonglong buffer[ARRAY_ELEMENTS];
uint bit_index(uint n) const
{
DBUG_ASSERT(n < width);
return ARRAY_ELEMENTS == 1 ? 0 : n / BITS_PER_ELEMENT;
}
ulonglong bit_mask(uint n) const
{
clear_all();
DBUG_ASSERT(n < width);
return ARRAY_ELEMENTS == 1 ? 1ULL << n : 1ULL << (n % BITS_PER_ELEMENT);
}
ulonglong last_element_mask(int n) const
{
DBUG_ASSERT(n % BITS_PER_ELEMENT != 0);
return bit_mask(n) - 1;
}
public:
/*
The default constructor does nothing.
The caller is supposed to either zero the memory
or to call set_all()/clear_all()/set_prefix()
to initialize bitmap.
*/
Bitmap() { }
explicit Bitmap(uint prefix)
{
set_prefix(prefix);
......@@ -57,50 +109,76 @@ template <uint width> class Bitmap
{
set_prefix(prefix);
}
uint length() const
{
return width;
}
void set_bit(uint n)
{
DBUG_ASSERT(n < width);
((uchar*)buffer)[n / 8] |= (1 << (n & 7));
buffer[bit_index(n)] |= bit_mask(n);
}
void clear_bit(uint n)
{
DBUG_ASSERT(n < width);
((uchar*)buffer)[n / 8] &= ~(1 << (n & 7));
buffer[bit_index(n)] &= ~bit_mask(n);
}
bool is_set(uint n) const
{
return buffer[bit_index(n)] & bit_mask(n);
}
void set_prefix(uint prefix_size)
{
set_if_smaller(prefix_size, width);
uint prefix_bytes, prefix_bits, d;
uchar* m = (uchar*)buffer;
if ((prefix_bytes = prefix_size / 8))
memset(m, 0xff, prefix_bytes);
m += prefix_bytes;
if ((prefix_bits = prefix_size & 7))
{
*(m++) = (1 << prefix_bits) - 1;
// As the prefix bits are set, lets count this byte too as a prefix byte.
prefix_bytes++;
}
if ((d = (width + 7) / 8 - prefix_bytes))
memset(m, 0, d);
size_t idx= prefix_size / BITS_PER_ELEMENT;
for (size_t i= 0; i < idx; i++)
buffer[i]= ALL_BITS_SET;
if (prefix_size % BITS_PER_ELEMENT)
buffer[idx++]= last_element_mask(prefix_size);
for (size_t i= idx; i < ARRAY_ELEMENTS; i++)
buffer[i]= 0;
}
bool is_prefix(uint prefix_size) const
{
DBUG_ASSERT(prefix_size <= width);
size_t idx= prefix_size / BITS_PER_ELEMENT;
for (size_t i= 0; i < idx; i++)
if (buffer[i] != ALL_BITS_SET)
return false;
if (prefix_size % BITS_PER_ELEMENT)
if (buffer[idx++] != last_element_mask(prefix_size))
return false;
for (size_t i= idx; i < ARRAY_ELEMENTS; i++)
if (buffer[i] != 0)
return false;
return true;
}
void set_all()
{
set_prefix(width);
if (width % BITS_PER_ELEMENT)
set_prefix(width);
else if (ARRAY_ELEMENTS > 1)
memset(buffer, 0xff, sizeof(buffer));
else
buffer[0] = ALL_BITS_SET;
}
void clear_all()
{
memset(buffer, 0x00, sizeof(buffer));
if (ARRAY_ELEMENTS > 1)
memset(buffer, 0, sizeof(buffer));
else
buffer[0]= 0;
}
void intersect(Bitmap & map2)
void intersect(const Bitmap& map2)
{
for (uint i = 0; i < array_elements(buffer); i++)
for (size_t i= 0; i < ARRAY_ELEMENTS; i++)
buffer[i] &= map2.buffer[i];
}
......@@ -112,27 +190,13 @@ template <uint width> class Bitmap
*/
void intersect_and_pad(ulonglong map2buff, bool pad_with_ones)
{
compile_time_assert(sizeof(ulonglong) == 8);
uint32 tmp[2];
int8store(tmp, map2buff);
buffer[0] &= map2buff;
buffer[0] &= tmp[0];
if (array_elements(buffer) > 1)
buffer[1] &= tmp[1];
if (array_elements(buffer) <= 2)
return;
if (pad_with_ones)
{
memset((char*)buffer + 8, 0xff , sizeof(buffer) - 8);
if (width != sizeof(buffer) * 8)
{
((uchar*)buffer)[sizeof(buffer)-1] = last_byte_mask(width);
}
}
else
memset((char*)buffer + 8, 0 , sizeof(buffer) - 8);
for (size_t i= 1; i < ARRAY_ELEMENTS; i++)
buffer[i]= pad_with_ones ? ALL_BITS_SET : 0;
if (ARRAY_ELEMENTS > 1 && (width % BITS_PER_ELEMENT) && pad_with_ones)
buffer[ARRAY_ELEMENTS - 1]= last_element_mask(width);
}
public:
......@@ -140,141 +204,110 @@ template <uint width> class Bitmap
{
intersect_and_pad(map2buff, 0);
}
/* Use highest bit for all bits above sizeof(ulonglong)*8. */
/* Use highest bit for all bits above first element. */
void intersect_extended(ulonglong map2buff)
{
intersect_and_pad(map2buff, (map2buff & (1ULL << 63)));
}
void subtract(Bitmap & map2)
void subtract(const Bitmap& map2)
{
for (size_t i = 0; i < array_elements(buffer); i++)
for (size_t i= 0; i < ARRAY_ELEMENTS; i++)
buffer[i] &= ~(map2.buffer[i]);
}
void merge(Bitmap & map2)
void merge(const Bitmap& map2)
{
for (size_t i = 0; i < array_elements(buffer); i++)
for (size_t i= 0; i < ARRAY_ELEMENTS; i++)
buffer[i] |= map2.buffer[i];
}
bool is_set(uint n) const
{
DBUG_ASSERT(n < width);
return ((uchar*)buffer)[n / 8] & (1 << (n & 7));
}
bool is_prefix(uint prefix_size) const
{
uint prefix_mask = last_byte_mask(prefix_size);
uchar* m = (uchar*)buffer;
uchar* end_prefix = m + (prefix_size - 1) / 8;
uchar* end;
DBUG_ASSERT(prefix_size <= width);
/* Empty prefix is always true */
if (!prefix_size)
return true;
while (m < end_prefix)
if (*m++ != 0xff)
return false;
end = ((uchar*)buffer) + (width + 7) / 8 - 1;
if (m == end)
return ((*m & last_byte_mask(width)) == prefix_mask);
if (*m != prefix_mask)
return false;
while (++m < end)
if (*m != 0)
return false;
return ((*m & last_byte_mask(width)) == 0);
}
bool is_clear_all() const
{
for (size_t i= 0; i < array_elements(buffer); i++)
for (size_t i= 0; i < ARRAY_ELEMENTS; i++)
if (buffer[i])
return false;
return true;
}
bool is_set_all() const
{
if (width == sizeof(buffer) * 8)
{
for (size_t i = 0; i < array_elements(buffer); i++)
if (buffer[i] != 0xFFFFFFFFU)
return false;
return true;
}
else
return is_prefix(width);
}
bool is_subset(const Bitmap & map2) const
bool is_subset(const Bitmap& map2) const
{
for (size_t i= 0; i < array_elements(buffer); i++)
for (size_t i= 0; i < ARRAY_ELEMENTS; i++)
if (buffer[i] & ~(map2.buffer[i]))
return false;
return true;
}
bool is_overlapping(const Bitmap & map2) const
bool is_overlapping(const Bitmap& map2) const
{
for (size_t i = 0; i < array_elements(buffer); i++)
for (size_t i= 0; i < ARRAY_ELEMENTS; i++)
if (buffer[i] & map2.buffer[i])
return true;
return false;
}
bool operator==(const Bitmap & map2) const
bool operator==(const Bitmap& map2) const
{
return memcmp(buffer, map2.buffer, sizeof(buffer)) == 0;
if (ARRAY_ELEMENTS > 1)
return !memcmp(buffer,map2.buffer,sizeof(buffer));
return buffer[0] == map2.buffer[0];
}
bool operator!=(const Bitmap & map2) const
bool operator!=(const Bitmap& map2) const
{
return !(*this == map2);
}
/*
Print hexadecimal representation of bitmap.
Truncate trailing zeros.
*/
char *print(char *buf) const
{
char *s=buf;
const uchar *e=(uchar *)buffer, *b=e+sizeof(buffer)-1;
while (!*b && b>e)
b--;
if ((*s=_dig_vec_upper[*b >> 4]) != '0')
s++;
*s++=_dig_vec_upper[*b & 15];
while (--b>=e)
size_t last; /*index of the last non-zero element, or 0. */
for (last= ARRAY_ELEMENTS - 1; last && !buffer[last]; last--){}
const int HEX_DIGITS_PER_ELEMENT= BITS_PER_ELEMENT / 4;
for (size_t i= 0; i < last; i++)
{
*s++=_dig_vec_upper[*b >> 4];
*s++=_dig_vec_upper[*b & 15];
ulonglong num = buffer[i];
uint shift = BITS_PER_ELEMENT - 4;
size_t pos= i * HEX_DIGITS_PER_ELEMENT;
for (size_t j= 0; j < HEX_DIGITS_PER_ELEMENT; j++)
{
buf[pos + j]= _dig_vec_upper[(num >> shift) & 0xf];
shift += 4;
}
}
*s=0;
longlong2str(buffer[last], buf, 16);
return buf;
}
ulonglong to_ulonglong() const
{
DBUG_ASSERT(sizeof(buffer) >= 4);
uchar *b=(uchar *)buffer;
if (sizeof(buffer) >= 8)
return uint8korr(b);
return (ulonglong) uint4korr(b);
return buffer[0];
}
uint bits_set()
{
uint res = 0;
for (size_t i = 0; i < array_elements(buffer); i++)
res += my_count_bits_uint32(buffer[i]);
uint res= 0;
for (size_t i= 0; i < ARRAY_ELEMENTS; i++)
res += my_count_bits(buffer[i]);
return res;
}
class Iterator
{
Bitmap &map;
uint no;
const Bitmap& map;
uint offset;
Table_map_iterator tmi;
public:
Iterator(Bitmap<width> &map2): map(map2), no(0) {}
int operator++(int) {
if (no == width) return BITMAP_END;
while (!map.is_set(no))
Iterator(const Bitmap<width>& map2) : map(map2), offset(0), tmi(map2.buffer[0]) {}
int operator++(int)
{
for (;;)
{
if ((++no) == width) return BITMAP_END;
int nextbit= tmi++;
if (nextbit != Table_map_iterator::BITMAP_END)
return offset + nextbit;
if (offset + BITS_PER_ELEMENT >= map.length())
return BITMAP_END;
offset += BITS_PER_ELEMENT;
tmi= Table_map_iterator(map.buffer[offset / BITS_PER_ELEMENT]);
}
return no++;
}
enum { BITMAP_END = width };
};
......@@ -283,98 +316,8 @@ template <uint width> class Bitmap
#pragma GCC pop_options
#undef NEED_GCC_NO_SSE_WORKAROUND
#endif
};
/* An iterator to quickly walk over bits in ulonglong bitmap. */
class Table_map_iterator
{
ulonglong bmp;
uint no;
public:
Table_map_iterator(ulonglong t) : bmp(t), no(0) {}
uint next_bit()
{
static const uchar last_bit[16]= {32, 0, 1, 0,
2, 0, 1, 0,
3, 0, 1, 0,
2, 0, 1, 0};
uint bit;
while ((bit= last_bit[bmp & 0xF]) == 32)
{
no += 4;
bmp= bmp >> 4;
if (!bmp)
return BITMAP_END;
}
bmp &= ~(1ULL << bit);
return no + bit;
}
uint operator++(int) { return next_bit(); }
enum { BITMAP_END= 64 };
};
template <> class Bitmap<64>
{
ulonglong map;
public:
Bitmap<64>() { }
explicit Bitmap<64>(uint prefix_to_set) { set_prefix(prefix_to_set); }
void init(uint prefix_to_set) { set_prefix(prefix_to_set); }
uint length() const { return 64; }
void set_bit(uint n) { map|= ((ulonglong)1) << n; }
void clear_bit(uint n) { map&= ~(((ulonglong)1) << n); }
void set_prefix(uint n)
{
if (n >= length())
set_all();
else
map= (((ulonglong)1) << n)-1;
}
void set_all() { map=~(ulonglong)0; }
void clear_all() { map=(ulonglong)0; }
void intersect(Bitmap<64>& map2) { map&= map2.map; }
void intersect(ulonglong map2) { map&= map2; }
void intersect_extended(ulonglong map2) { map&= map2; }
void subtract(Bitmap<64>& map2) { map&= ~map2.map; }
void merge(Bitmap<64>& map2) { map|= map2.map; }
bool is_set(uint n) const { return MY_TEST(map & (((ulonglong) 1) << n)); }
bool is_prefix(uint n) const { return map == (((ulonglong)1) << n)-1; }
bool is_clear_all() const { return map == (ulonglong)0; }
bool is_set_all() const { return map == ~(ulonglong)0; }
bool is_subset(const Bitmap<64>& map2) const { return !(map & ~map2.map); }
bool is_overlapping(const Bitmap<64>& map2) const { return (map & map2.map)!= 0; }
bool operator==(const Bitmap<64>& map2) const { return map == map2.map; }
char *print(char *buf) const {
longlong2str(longlong(map), buf, 16);
return buf;
}
ulonglong to_ulonglong() const { return map; }
class Iterator : public Table_map_iterator
{
public:
Iterator(Bitmap<64> &map2) : Table_map_iterator(map2.map) {}
};
uint bits_set()
{
//TODO: use my_count_bits()
uint res= 0, i= 0;
for (; i < 64 ; i++)
{
if (map & ((ulonglong)1<<i))
res++;
}
return res;
}
};
#if MAX_INDEXES <= 64
typedef Bitmap<64> key_map; /* Used for finding keys */
#elif MAX_INDEXES > 128
#error "MAX_INDEXES values greater than 128 is not supported."
#else
typedef Bitmap<((MAX_INDEXES+7)/8*8)> key_map; /* Used for finding keys */
#endif
typedef Bitmap<MAX_INDEXES> key_map; /* Used for finding keys */
#endif /* SQL_BITMAP_INCLUDED */
sql/sql_select.cc
View file @ e85df7fe
......@@ -7046,7 +7046,6 @@ void optimize_keyuse(JOIN *join, DYNAMIC_ARRAY *keyuse_array)
}
}
/**
Check for the presence of AGGFN(DISTINCT a) queries that may be subject
to loose index scan.
......@@ -7084,7 +7083,6 @@ is_indexed_agg_distinct(JOIN *join, List<Item_field> *out_args)
{
Item_sum **sum_item_ptr;
bool result= false;
Field_map first_aggdistinct_fields;
if (join->table_count != 1 || /* reference more than 1 table */
join->select_distinct || /* or a DISTINCT */
......@@ -7094,10 +7092,11 @@ is_indexed_agg_distinct(JOIN *join, List<Item_field> *out_args)
if (join->make_sum_func_list(join->all_fields, join->fields_list, true))
return false;
Bitmap<MAX_FIELDS> first_aggdistinct_fields;
bool first_aggdistinct_fields_initialized= false;
for (sum_item_ptr= join->sum_funcs; *sum_item_ptr; sum_item_ptr++)
{
Item_sum *sum_item= *sum_item_ptr;
Field_map cur_aggdistinct_fields;
Item *expr;
/* aggregate is not AGGFN(DISTINCT) or more than 1 argument to it */
switch (sum_item->sum_func())
......@@ -7120,6 +7119,8 @@ is_indexed_agg_distinct(JOIN *join, List<Item_field> *out_args)
We don't worry about duplicates as these will be sorted out later in
get_best_group_min_max
*/
Bitmap<MAX_FIELDS> cur_aggdistinct_fields;
cur_aggdistinct_fields.clear_all();
for (uint i= 0; i < sum_item->get_arg_count(); i++)
{
expr= sum_item->get_arg(i);
......@@ -7138,8 +7139,11 @@ is_indexed_agg_distinct(JOIN *join, List<Item_field> *out_args)
If there are multiple aggregate functions, make sure that they all
refer to exactly the same set of columns.
*/
if (first_aggdistinct_fields.is_clear_all())
first_aggdistinct_fields.merge(cur_aggdistinct_fields);
if (!first_aggdistinct_fields_initialized)
{
first_aggdistinct_fields= cur_aggdistinct_fields;
first_aggdistinct_fields_initialized=true;
}
else if (first_aggdistinct_fields != cur_aggdistinct_fields)
return false;
}
......
sql/table.h
View file @ e85df7fe
......@@ -1193,9 +1193,6 @@ struct st_cond_statistic;
#define CHECK_ROW_FOR_NULLS_TO_REJECT (1 << 0)
#define REJECT_ROW_DUE_TO_NULL_FIELDS (1 << 1)
/* Bitmap of table's fields */
typedef Bitmap<MAX_FIELDS> Field_map;
class SplM_opt_info;
struct vers_select_conds_t;
......
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