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BUG#22583 (RBR between MyISAM and non-MyISAM tables containing BIT field

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does not work): Changing packed row format to only include null bits
for those columns that are present in the row as well as writing BIT
columns in a storage engine-independent format.

The change in row format is incompatible with the previous format and a
slave will not be able to read the new events.
This commit is contained in:
mats@romeo.(none)
2007-02-12 16:46:42 +01:00
parent 0b4e65e12b
commit e61a1841a5
38 changed files with 549 additions and 267 deletions
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113
sql/sql_class.cc
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@ -2527,30 +2527,113 @@ my_size_t THD::max_row_length_blob(TABLE *table, const byte *data) const
}
my_size_t THD::pack_row(TABLE *table, MY_BITMAP const* cols, byte *row_data,
const byte *record) const
/*
Pack a record of data for a table into a format suitable for
transfer via the binary log.
SYNOPSIS
THD::pack_row()
table Table describing the format of the record
cols Bitmap with a set bit for each column that should be
stored in the row
row_data Pointer to memory where row will be written
record Pointer to record that should be packed. It is assumed
that the pointer refers to either record[0] or
record[1], but no such check is made since the code does
not rely on that.
DESCRIPTION
The format for a row in transfer with N fields is the following:
ceil(N/8) null bytes:
One null bit for every column *regardless of whether it can be
null or not*. This simplifies the decoding. Observe that the
number of null bits is equal to the number of set bits in the
'cols' bitmap. The number of null bytes is the smallest number
of bytes necessary to store the null bits.
Padding bits are 1.
N packets:
Each field is stored in packed format.
RETURN VALUE
The number of bytes written at 'row_data'.
*/
my_size_t
THD::pack_row(TABLE *table, MY_BITMAP const* cols,
byte *const row_data, const byte *record) const
{
Field **p_field= table->field, *field;
int n_null_bytes= table->s->null_bytes;
byte *ptr;
uint i;
int const null_byte_count= (bitmap_bits_set(cols) + 7) / 8;
byte *pack_ptr = row_data + null_byte_count;
byte *null_ptr = row_data;
my_ptrdiff_t const rec_offset= record - table->record[0];
my_ptrdiff_t const def_offset= table->s->default_values - table->record[0];
memcpy(row_data, record, n_null_bytes);
ptr= row_data+n_null_bytes;
for (i= 0 ; (field= *p_field) ; i++, p_field++)
/*
We write the null bits and the packed records using one pass
through all the fields. The null bytes are written little-endian,
i.e., the first fields are in the first byte.
*/
unsigned int null_bits= (1U << 8) - 1;
// Mask to mask out the correct but among the null bits
unsigned int null_mask= 1U;
for ( ; (field= *p_field) ; p_field++)
{
if (bitmap_is_set(cols,i))
DBUG_PRINT("debug", ("null_mask=%d; null_ptr=%p; row_data=%p; null_byte_count=%d",
null_mask, null_ptr, row_data, null_byte_count));
if (bitmap_is_set(cols, p_field - table->field))
{
my_ptrdiff_t const offset=
field->is_null(rec_offset) ? def_offset : rec_offset;
field->move_field_offset(offset);
ptr= (byte*)field->pack((char *) ptr, field->ptr);
field->move_field_offset(-offset);
my_ptrdiff_t offset;
if (field->is_null(rec_offset))
{
offset= def_offset;
null_bits |= null_mask;
}
else
{
offset= rec_offset;
null_bits &= ~null_mask;
/*
We only store the data of the field if it is non-null
*/
field->move_field_offset(offset);
pack_ptr= (byte*)field->pack((char *) pack_ptr, field->ptr);
field->move_field_offset(-offset);
}
null_mask <<= 1;
if ((null_mask & 0xFF) == 0)
{
DBUG_ASSERT(null_ptr < row_data + null_byte_count);
null_mask = 1U;
*null_ptr++ = null_bits;
null_bits= (1U << 8) - 1;
}
}
}
return (static_cast<my_size_t>(ptr - row_data));
/*
Write the last (partial) byte, if there is one
*/
if ((null_mask & 0xFF) > 1)
{
DBUG_ASSERT(null_ptr < row_data + null_byte_count);
*null_ptr++ = null_bits;
}
/*
The null pointer should now point to the first byte of the
packed data. If it doesn't, something is very wrong.
*/
DBUG_ASSERT(null_ptr == row_data + null_byte_count);
return static_cast<my_size_t>(pack_ptr - row_data);
}