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mariadb/sql/field_conv.cc
Sergey Petrunya f240aa4cbf field_conv.cc: added comments 
opt_range.cc: modified print_key() so that it doesn't do memory re-allocs when
printing multipart keys over varchar columns. When it did, key printout in 
debug trace was interrupted with my_malloc/free printouts.
2011-08-17 12:32:15 +04:00

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/* Copyright (C) 2000-2003 MySQL AB
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/**
@file
@brief
Functions to copy data to or from fields
This could be done with a single short function but opencoding this
gives much more speed.
*/
#include "mysql_priv.h"
#include <m_ctype.h>
static void do_field_eq(Copy_field *copy)
{
memcpy(copy->to_ptr,copy->from_ptr,copy->from_length);
}
static void do_field_1(Copy_field *copy)
{
copy->to_ptr[0]=copy->from_ptr[0];
}
static void do_field_2(Copy_field *copy)
{
copy->to_ptr[0]=copy->from_ptr[0];
copy->to_ptr[1]=copy->from_ptr[1];
}
static void do_field_3(Copy_field *copy)
{
copy->to_ptr[0]=copy->from_ptr[0];
copy->to_ptr[1]=copy->from_ptr[1];
copy->to_ptr[2]=copy->from_ptr[2];
}
static void do_field_4(Copy_field *copy)
{
copy->to_ptr[0]=copy->from_ptr[0];
copy->to_ptr[1]=copy->from_ptr[1];
copy->to_ptr[2]=copy->from_ptr[2];
copy->to_ptr[3]=copy->from_ptr[3];
}
static void do_field_6(Copy_field *copy)
{ // For blob field
copy->to_ptr[0]=copy->from_ptr[0];
copy->to_ptr[1]=copy->from_ptr[1];
copy->to_ptr[2]=copy->from_ptr[2];
copy->to_ptr[3]=copy->from_ptr[3];
copy->to_ptr[4]=copy->from_ptr[4];
copy->to_ptr[5]=copy->from_ptr[5];
}
static void do_field_8(Copy_field *copy)
{
copy->to_ptr[0]=copy->from_ptr[0];
copy->to_ptr[1]=copy->from_ptr[1];
copy->to_ptr[2]=copy->from_ptr[2];
copy->to_ptr[3]=copy->from_ptr[3];
copy->to_ptr[4]=copy->from_ptr[4];
copy->to_ptr[5]=copy->from_ptr[5];
copy->to_ptr[6]=copy->from_ptr[6];
copy->to_ptr[7]=copy->from_ptr[7];
}
static void do_field_to_null_str(Copy_field *copy)
{
if (*copy->from_null_ptr & copy->from_bit)
{
bzero(copy->to_ptr,copy->from_length);
copy->to_null_ptr[0]=1; // Always bit 1
}
else
{
copy->to_null_ptr[0]=0;
memcpy(copy->to_ptr,copy->from_ptr,copy->from_length);
}
}
static void do_outer_field_to_null_str(Copy_field *copy)
{
if (*copy->null_row ||
(copy->from_null_ptr && (*copy->from_null_ptr & copy->from_bit)))
{
bzero(copy->to_ptr,copy->from_length);
copy->to_null_ptr[0]=1; // Always bit 1
}
else
{
copy->to_null_ptr[0]=0;
memcpy(copy->to_ptr,copy->from_ptr,copy->from_length);
}
}
int
set_field_to_null(Field *field)
{
if (field->real_maybe_null())
{
field->set_null();
field->reset();
return 0;
}
field->reset();
switch (field->table->in_use->count_cuted_fields) {
case CHECK_FIELD_WARN:
field->set_warning(MYSQL_ERROR::WARN_LEVEL_WARN, WARN_DATA_TRUNCATED, 1);
/* fall through */
case CHECK_FIELD_IGNORE:
return 0;
case CHECK_FIELD_ERROR_FOR_NULL:
if (!field->table->in_use->no_errors)
my_error(ER_BAD_NULL_ERROR, MYF(0), field->field_name);
return -1;
}
DBUG_ASSERT(0); // impossible
return -1;
}
/**
Set field to NULL or TIMESTAMP or to next auto_increment number.
@param field Field to update
@param no_conversions Set to 1 if we should return 1 if field can't
take null values.
If set to 0 we will do store the 'default value'
if the field is a special field. If not we will
give an error.
@retval
0 Field could take 0 or an automatic conversion was used
@retval
-1 Field could not take NULL and no conversion was used.
If no_conversion was not set, an error message is printed
*/
int
set_field_to_null_with_conversions(Field *field, bool no_conversions)
{
if (field->real_maybe_null())
{
field->set_null();
field->reset();
return 0;
}
if (no_conversions)
return -1;
/*
Check if this is a special type, which will get a special walue
when set to NULL (TIMESTAMP fields which allow setting to NULL
are handled by first check).
*/
if (field->type() == MYSQL_TYPE_TIMESTAMP)
{
((Field_timestamp*) field)->set_time();
return 0; // Ok to set time to NULL
}
field->reset();
if (field == field->table->next_number_field)
{
field->table->auto_increment_field_not_null= FALSE;
return 0; // field is set in fill_record()
}
switch (field->table->in_use->count_cuted_fields) {
case CHECK_FIELD_WARN:
field->set_warning(MYSQL_ERROR::WARN_LEVEL_WARN, ER_BAD_NULL_ERROR, 1);
/* fall through */
case CHECK_FIELD_IGNORE:
return 0;
case CHECK_FIELD_ERROR_FOR_NULL:
if (!field->table->in_use->no_errors)
my_error(ER_BAD_NULL_ERROR, MYF(0), field->field_name);
return -1;
}
DBUG_ASSERT(0); // impossible
return -1;
}
static void do_skip(Copy_field *copy __attribute__((unused)))
{
}
/*
Copy: (NULLable field) -> (NULLable field)
note: if the record we're copying from is NULL-complemetned (i.e.
from_field->table->null_row==1), it will also have all NULLable columns to be
set to NULLs, so we dont need to check table->null_row here.
*/
static void do_copy_null(Copy_field *copy)
{
if (*copy->from_null_ptr & copy->from_bit)
{
*copy->to_null_ptr|=copy->to_bit;
copy->to_field->reset();
}
else
{
*copy->to_null_ptr&= ~copy->to_bit;
(copy->do_copy2)(copy);
}
}
/*
Copy: (not-NULL field in table that can be NULL-complemented) -> (NULLable
field)
*/
static void do_outer_field_null(Copy_field *copy)
{
if (*copy->null_row ||
(copy->from_null_ptr && (*copy->from_null_ptr & copy->from_bit)))
{
*copy->to_null_ptr|=copy->to_bit;
copy->to_field->reset();
}
else
{
*copy->to_null_ptr&= ~copy->to_bit;
(copy->do_copy2)(copy);
}
}
/* Copy: (NULL-able field) -> (not NULL-able field) */
static void do_copy_not_null(Copy_field *copy)
{
if (*copy->from_null_ptr & copy->from_bit)
{
copy->to_field->set_warning(MYSQL_ERROR::WARN_LEVEL_WARN,
WARN_DATA_TRUNCATED, 1);
copy->to_field->reset();
}
else
(copy->do_copy2)(copy);
}
/* Copy: (non-NULLable field) -> (NULLable field) */
static void do_copy_maybe_null(Copy_field *copy)
{
*copy->to_null_ptr&= ~copy->to_bit;
(copy->do_copy2)(copy);
}
/* timestamp and next_number has special handling in case of NULL values */
static void do_copy_timestamp(Copy_field *copy)
{
if (*copy->from_null_ptr & copy->from_bit)
{
/* Same as in set_field_to_null_with_conversions() */
((Field_timestamp*) copy->to_field)->set_time();
}
else
(copy->do_copy2)(copy);
}
static void do_copy_next_number(Copy_field *copy)
{
if (*copy->from_null_ptr & copy->from_bit)
{
/* Same as in set_field_to_null_with_conversions() */
copy->to_field->table->auto_increment_field_not_null= FALSE;
copy->to_field->reset();
}
else
(copy->do_copy2)(copy);
}
static void do_copy_blob(Copy_field *copy)
{
ulong length=((Field_blob*) copy->from_field)->get_length();
((Field_blob*) copy->to_field)->store_length(length);
memcpy_fixed(copy->to_ptr,copy->from_ptr,sizeof(char*));
}
static void do_conv_blob(Copy_field *copy)
{
copy->from_field->val_str(&copy->tmp);
((Field_blob *) copy->to_field)->store(copy->tmp.ptr(),
copy->tmp.length(),
copy->tmp.charset());
}
/** Save blob in copy->tmp for GROUP BY. */
static void do_save_blob(Copy_field *copy)
{
char buff[MAX_FIELD_WIDTH];
String res(buff,sizeof(buff),copy->tmp.charset());
copy->from_field->val_str(&res);
copy->tmp.copy(res);
((Field_blob *) copy->to_field)->store(copy->tmp.ptr(),
copy->tmp.length(),
copy->tmp.charset());
}
static void do_field_string(Copy_field *copy)
{
char buff[MAX_FIELD_WIDTH];
copy->tmp.set_quick(buff,sizeof(buff),copy->tmp.charset());
copy->from_field->val_str(&copy->tmp);
copy->to_field->store(copy->tmp.c_ptr_quick(),copy->tmp.length(),
copy->tmp.charset());
}
static void do_field_enum(Copy_field *copy)
{
if (copy->from_field->val_int() == 0)
((Field_enum *) copy->to_field)->store_type((ulonglong) 0);
else
do_field_string(copy);
}
static void do_field_varbinary_pre50(Copy_field *copy)
{
char buff[MAX_FIELD_WIDTH];
copy->tmp.set_quick(buff,sizeof(buff),copy->tmp.charset());
copy->from_field->val_str(&copy->tmp);
/* Use the same function as in 4.1 to trim trailing spaces */
uint length= my_lengthsp_8bit(&my_charset_bin, copy->tmp.c_ptr_quick(),
copy->from_field->field_length);
copy->to_field->store(copy->tmp.c_ptr_quick(), length,
copy->tmp.charset());
}
static void do_field_int(Copy_field *copy)
{
longlong value= copy->from_field->val_int();
copy->to_field->store(value,
test(copy->from_field->flags & UNSIGNED_FLAG));
}
static void do_field_real(Copy_field *copy)
{
double value=copy->from_field->val_real();
copy->to_field->store(value);
}
static void do_field_decimal(Copy_field *copy)
{
my_decimal value;
copy->to_field->store_decimal(copy->from_field->val_decimal(&value));
}
static void do_field_temporal(Copy_field *copy)
{
MYSQL_TIME ltime;
copy->from_field->get_date(&ltime, TIME_FUZZY_DATE);
copy->to_field->store_time_dec(&ltime, copy->from_field->decimals());
}
/**
string copy for single byte characters set when to string is shorter than
from string.
*/
static void do_cut_string(Copy_field *copy)
{
CHARSET_INFO *cs= copy->from_field->charset();
memcpy(copy->to_ptr,copy->from_ptr,copy->to_length);
/* Check if we loosed any important characters */
if (cs->cset->scan(cs,
(char*) copy->from_ptr + copy->to_length,
(char*) copy->from_ptr + copy->from_length,
MY_SEQ_SPACES) < copy->from_length - copy->to_length)
{
copy->to_field->set_warning(MYSQL_ERROR::WARN_LEVEL_WARN,
WARN_DATA_TRUNCATED, 1);
}
}
/**
string copy for multi byte characters set when to string is shorter than
from string.
*/
static void do_cut_string_complex(Copy_field *copy)
{ // Shorter string field
int well_formed_error;
CHARSET_INFO *cs= copy->from_field->charset();
const uchar *from_end= copy->from_ptr + copy->from_length;
uint copy_length= cs->cset->well_formed_len(cs,
(char*) copy->from_ptr,
(char*) from_end,
copy->to_length / cs->mbmaxlen,
&well_formed_error);
if (copy->to_length < copy_length)
copy_length= copy->to_length;
memcpy(copy->to_ptr, copy->from_ptr, copy_length);
/* Check if we lost any important characters */
if (well_formed_error ||
cs->cset->scan(cs, (char*) copy->from_ptr + copy_length,
(char*) from_end,
MY_SEQ_SPACES) < (copy->from_length - copy_length))
{
copy->to_field->set_warning(MYSQL_ERROR::WARN_LEVEL_WARN,
WARN_DATA_TRUNCATED, 1);
}
if (copy_length < copy->to_length)
cs->cset->fill(cs, (char*) copy->to_ptr + copy_length,
copy->to_length - copy_length, ' ');
}
static void do_expand_binary(Copy_field *copy)
{
CHARSET_INFO *cs= copy->from_field->charset();
memcpy(copy->to_ptr,copy->from_ptr,copy->from_length);
cs->cset->fill(cs, (char*) copy->to_ptr+copy->from_length,
copy->to_length-copy->from_length, '\0');
}
static void do_expand_string(Copy_field *copy)
{
CHARSET_INFO *cs= copy->from_field->charset();
memcpy(copy->to_ptr,copy->from_ptr,copy->from_length);
cs->cset->fill(cs, (char*) copy->to_ptr+copy->from_length,
copy->to_length-copy->from_length, ' ');
}
static void do_varstring1(Copy_field *copy)
{
uint length= (uint) *(uchar*) copy->from_ptr;
if (length > copy->to_length- 1)
{
length=copy->to_length - 1;
if (copy->from_field->table->in_use->count_cuted_fields &&
copy->to_field)
copy->to_field->set_warning(MYSQL_ERROR::WARN_LEVEL_WARN,
WARN_DATA_TRUNCATED, 1);
}
*(uchar*) copy->to_ptr= (uchar) length;
memcpy(copy->to_ptr+1, copy->from_ptr + 1, length);
}
static void do_varstring1_mb(Copy_field *copy)
{
int well_formed_error;
CHARSET_INFO *cs= copy->from_field->charset();
uint from_length= (uint) *(uchar*) copy->from_ptr;
const uchar *from_ptr= copy->from_ptr + 1;
uint to_char_length= (copy->to_length - 1) / cs->mbmaxlen;
uint length= cs->cset->well_formed_len(cs, (char*) from_ptr,
(char*) from_ptr + from_length,
to_char_length, &well_formed_error);
if (length < from_length)
{
if (current_thd->count_cuted_fields)
copy->to_field->set_warning(MYSQL_ERROR::WARN_LEVEL_WARN,
WARN_DATA_TRUNCATED, 1);
}
*copy->to_ptr= (uchar) length;
memcpy(copy->to_ptr + 1, from_ptr, length);
}
static void do_varstring2(Copy_field *copy)
{
uint length=uint2korr(copy->from_ptr);
if (length > copy->to_length- HA_KEY_BLOB_LENGTH)
{
length=copy->to_length-HA_KEY_BLOB_LENGTH;
if (copy->from_field->table->in_use->count_cuted_fields &&
copy->to_field)
copy->to_field->set_warning(MYSQL_ERROR::WARN_LEVEL_WARN,
WARN_DATA_TRUNCATED, 1);
}
int2store(copy->to_ptr,length);
memcpy(copy->to_ptr+HA_KEY_BLOB_LENGTH, copy->from_ptr + HA_KEY_BLOB_LENGTH,
length);
}
static void do_varstring2_mb(Copy_field *copy)
{
int well_formed_error;
CHARSET_INFO *cs= copy->from_field->charset();
uint char_length= (copy->to_length - HA_KEY_BLOB_LENGTH) / cs->mbmaxlen;
uint from_length= uint2korr(copy->from_ptr);
const uchar *from_beg= copy->from_ptr + HA_KEY_BLOB_LENGTH;
uint length= cs->cset->well_formed_len(cs, (char*) from_beg,
(char*) from_beg + from_length,
char_length, &well_formed_error);
if (length < from_length)
{
if (current_thd->count_cuted_fields)
copy->to_field->set_warning(MYSQL_ERROR::WARN_LEVEL_WARN,
WARN_DATA_TRUNCATED, 1);
}
int2store(copy->to_ptr, length);
memcpy(copy->to_ptr+HA_KEY_BLOB_LENGTH, from_beg, length);
}
/***************************************************************************
** The different functions that fills in a Copy_field class
***************************************************************************/
/**
copy of field to maybe null string.
If field is null then the all bytes are set to 0.
if field is not null then the first byte is set to 1 and the rest of the
string is the field value.
The 'to' buffer should have a size of field->pack_length()+1
*/
void Copy_field::set(uchar *to,Field *from)
{
from_ptr=from->ptr;
to_ptr=to;
from_length=from->pack_length();
if (from->maybe_null())
{
from_null_ptr=from->null_ptr;
from_bit= from->null_bit;
to_ptr[0]= 1; // Null as default value
to_null_ptr= (uchar*) to_ptr++;
to_bit= 1;
if (from->table->maybe_null)
{
null_row= &from->table->null_row;
do_copy= do_outer_field_to_null_str;
}
else
do_copy= do_field_to_null_str;
}
else
{
to_null_ptr= 0; // For easy debugging
do_copy= do_field_eq;
}
}
/*
To do:
If 'save' is set to true and the 'from' is a blob field, do_copy is set to
do_save_blob rather than do_conv_blob. The only differences between them
appears to be:
- do_save_blob allocates and uses an intermediate buffer before calling
Field_blob::store. Is this in order to trigger the call to
well_formed_copy_nchars, by changing the pointer copy->tmp.ptr()?
That call will take place anyway in all known cases.
- The above causes a truncation to MAX_FIELD_WIDTH. Is this the intended
effect? Truncation is handled by well_formed_copy_nchars anyway.
*/
void Copy_field::set(Field *to,Field *from,bool save)
{
if (to->type() == MYSQL_TYPE_NULL)
{
to_null_ptr=0; // For easy debugging
to_ptr=0;
do_copy=do_skip;
return;
}
from_field=from;
to_field=to;
from_ptr=from->ptr;
from_length=from->pack_length();
to_ptr= to->ptr;
to_length=to_field->pack_length();
// set up null handling
from_null_ptr=to_null_ptr=0;
if (from->maybe_null())
{
from_null_ptr= from->null_ptr;
from_bit= from->null_bit;
if (to_field->real_maybe_null())
{
to_null_ptr= to->null_ptr;
to_bit= to->null_bit;
if (from_null_ptr)
do_copy= do_copy_null;
else
{
null_row= &from->table->null_row;
do_copy= do_outer_field_null;
}
}
else
{
if (to_field->type() == MYSQL_TYPE_TIMESTAMP)
do_copy= do_copy_timestamp; // Automatic timestamp
else if (to_field == to_field->table->next_number_field)
do_copy= do_copy_next_number;
else
do_copy= do_copy_not_null;
}
}
else if (to_field->real_maybe_null())
{
to_null_ptr= to->null_ptr;
to_bit= to->null_bit;
do_copy= do_copy_maybe_null;
}
else
do_copy=0;
if ((to->flags & BLOB_FLAG) && save)
do_copy2= do_save_blob;
else
do_copy2= get_copy_func(to,from);
if (!do_copy) // Not null
do_copy=do_copy2;
}
Copy_field::Copy_func *
Copy_field::get_copy_func(Field *to,Field *from)
{
if (to->flags & BLOB_FLAG)
{
if (!(from->flags & BLOB_FLAG) || from->charset() != to->charset())
return do_conv_blob;
if (from_length != to_length)
{
// Correct pointer to point at char pointer
to_ptr+= to_length - to->table->s->blob_ptr_size;
from_ptr+= from_length- from->table->s->blob_ptr_size;
return do_copy_blob;
}
}
else
{
if (to->real_type() == MYSQL_TYPE_BIT ||
from->real_type() == MYSQL_TYPE_BIT)
return do_field_int;
if (to->result_type() == DECIMAL_RESULT)
return do_field_decimal;
if (from->cmp_type() == TIME_RESULT)
{
/* If types are not 100 % identical then convert trough get_date() */
if (!to->eq_def(from) ||
((to->table->in_use->variables.sql_mode &
(MODE_NO_ZERO_IN_DATE | MODE_NO_ZERO_DATE)) &&
mysql_type_to_time_type(to->type()) != MYSQL_TIMESTAMP_TIME))
return do_field_temporal;
/* Do binary copy */
}
// Check if identical fields
if (from->result_type() == STRING_RESULT)
{
/*
Detect copy from pre 5.0 varbinary to varbinary as of 5.0 and
use special copy function that removes trailing spaces and thus
repairs data.
*/
if (from->type() == MYSQL_TYPE_VAR_STRING && !from->has_charset() &&
to->type() == MYSQL_TYPE_VARCHAR && !to->has_charset())
return do_field_varbinary_pre50;
if (to->real_type() != from->real_type())
{
if (from->real_type() == MYSQL_TYPE_ENUM ||
from->real_type() == MYSQL_TYPE_SET)
if (to->result_type() != STRING_RESULT)
return do_field_int; // Convert SET to number
return do_field_string;
}
if (to->real_type() == MYSQL_TYPE_ENUM ||
to->real_type() == MYSQL_TYPE_SET)
{
if (!to->eq_def(from))
{
if (from->real_type() == MYSQL_TYPE_ENUM &&
to->real_type() == MYSQL_TYPE_ENUM)
return do_field_enum;
return do_field_string;
}
}
else if (to->charset() != from->charset())
return do_field_string;
else if (to->real_type() == MYSQL_TYPE_VARCHAR)
{
if (((Field_varstring*) to)->length_bytes !=
((Field_varstring*) from)->length_bytes)
return do_field_string;
if (to_length != from_length)
return (((Field_varstring*) to)->length_bytes == 1 ?
(from->charset()->mbmaxlen == 1 ? do_varstring1 :
do_varstring1_mb) :
(from->charset()->mbmaxlen == 1 ? do_varstring2 :
do_varstring2_mb));
else
return (((Field_varstring*) from)->length_bytes == 1 ?
do_varstring1 : do_varstring2);
}
else if (to_length < from_length)
return (from->charset()->mbmaxlen == 1 ?
do_cut_string : do_cut_string_complex);
else if (to_length > from_length)
{
if (to->charset() == &my_charset_bin)
return do_expand_binary;
return do_expand_string;
}
}
else if (to->real_type() != from->real_type() ||
to_length != from_length)
{
if (to->real_type() == MYSQL_TYPE_DECIMAL ||
to->result_type() == STRING_RESULT)
return do_field_string;
if (to->result_type() == INT_RESULT)
return do_field_int;
return do_field_real;
}
else
{
if (!to->eq_def(from))
{
if (to->real_type() == MYSQL_TYPE_DECIMAL)
return do_field_string;
if (to->result_type() == INT_RESULT)
return do_field_int;
else
return do_field_real;
}
}
}
/* Identical field types */
switch (to_length) {
case 1: return do_field_1;
case 2: return do_field_2;
case 3: return do_field_3;
case 4: return do_field_4;
case 6: return do_field_6;
case 8: return do_field_8;
}
return do_field_eq;
}
/** Simple quick field convert that is called on insert. */
int field_conv(Field *to,Field *from)
{
if (to->real_type() == from->real_type() &&
!(to->type() == MYSQL_TYPE_BLOB && to->table->copy_blobs))
{
if (to->pack_length() == from->pack_length() &&
!(to->flags & UNSIGNED_FLAG && !(from->flags & UNSIGNED_FLAG)) &&
to->decimals() == from->decimals() &&
to->real_type() != MYSQL_TYPE_ENUM &&
to->real_type() != MYSQL_TYPE_SET &&
to->real_type() != MYSQL_TYPE_BIT &&
(to->real_type() != MYSQL_TYPE_NEWDECIMAL ||
to->field_length == from->field_length) &&
from->charset() == to->charset() &&
(!(to->table->in_use->variables.sql_mode &
(MODE_NO_ZERO_IN_DATE | MODE_NO_ZERO_DATE | MODE_INVALID_DATES)) ||
(to->type() != MYSQL_TYPE_DATE &&
to->type() != MYSQL_TYPE_DATETIME)) &&
(from->real_type() != MYSQL_TYPE_VARCHAR ||
((Field_varstring*)from)->length_bytes ==
((Field_varstring*)to)->length_bytes))
{ // Identical fields
/*
This may happen if one does 'UPDATE ... SET x=x'
The test is here mostly for valgrind, but can also be relevant
if memcpy() is implemented with prefetch-write
*/
if (to->ptr != from->ptr)
memcpy(to->ptr,from->ptr,to->pack_length());
return 0;
}
}
if (to->type() == MYSQL_TYPE_BLOB)
{ // Be sure the value is stored
Field_blob *blob=(Field_blob*) to;
from->val_str(&blob->value);
/*
Copy value if copy_blobs is set, or source is not a string and
we have a pointer to its internal string conversion buffer.
*/
if (to->table->copy_blobs ||
(!blob->value.is_alloced() &&
from->real_type() != MYSQL_TYPE_STRING &&
from->real_type() != MYSQL_TYPE_VARCHAR))
blob->value.copy();
return blob->store(blob->value.ptr(),blob->value.length(),from->charset());
}
if (from->real_type() == MYSQL_TYPE_ENUM &&
to->real_type() == MYSQL_TYPE_ENUM &&
from->val_int() == 0)
{
((Field_enum *)(to))->store_type(0);
return 0;
}
if (from->result_type() == REAL_RESULT)
return to->store(from->val_real());
if (from->result_type() == DECIMAL_RESULT)
{
my_decimal buff;
return to->store_decimal(from->val_decimal(&buff));
}
if (from->cmp_type() == TIME_RESULT)
{
MYSQL_TIME ltime;
if (from->get_date(&ltime, TIME_FUZZY_DATE))
return to->reset();
else
return to->store_time_dec(&ltime, from->decimals());
}
if ((from->result_type() == STRING_RESULT &&
(to->result_type() == STRING_RESULT ||
(from->real_type() != MYSQL_TYPE_ENUM &&
from->real_type() != MYSQL_TYPE_SET))) ||
to->type() == MYSQL_TYPE_DECIMAL)
{
char buff[MAX_FIELD_WIDTH];
String result(buff,sizeof(buff),from->charset());
from->val_str(&result);
/*
We use c_ptr_quick() here to make it easier if to is a float/double
as the conversion routines will do a copy of the result doesn't
end with \0. Can be replaced with .ptr() when we have our own
string->double conversion.
*/
return to->store(result.c_ptr_quick(),result.length(),from->charset());
}
return to->store(from->val_int(), test(from->flags & UNSIGNED_FLAG));
}
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