Commit ba8be739 authored by unknown's avatar unknown
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Fix for bug#20648 We introduce a new field method for knowing "real size", and... 

Fix for bug#20648 We introduce a new field method for knowing "real size", and we now in archive null unused bits of a row to null before writing. 


sql/field.cc:
  data_length for field needs to be calculated directly.
sql/field.h:
  The new method data_length() returns the "real" length of the field.
sql/ha_archive.cc:
  Before a write_row() archive nulls space beyond the size of the row in varchars to make sure that compression only sees NULL.
parent 6071b686

sql/field.cc

+5 −0
Original line number Diff line number Diff line
@@ -6412,6 +6412,11 @@ void Field_varstring::sql_type(String &res) const 
}





uint Field_varstring::data_length(const char *from)

{

  return length_bytes == 1 ? (uint) (uchar) *ptr : uint2korr(ptr);

}



/*

  Functions to create a packed row.

  Here the number of length bytes are depending on the given max_length

sql/field.h

+6 −0
Original line number Diff line number Diff line
@@ -144,6 +144,11 @@ class Field 
    table, which is located on disk).

  */

  virtual uint32 pack_length_in_rec() const { return pack_length(); }



  /*

    data_length() return the "real size" of the data in memory.

  */

  virtual uint32 data_length(const char *from) { return pack_length(); }

  virtual uint32 sort_length() const { return pack_length(); }

  virtual void reset(void) { bzero(ptr,pack_length()); }

  virtual void reset_fields() {}
@@ -1102,6 +1107,7 @@ class Field_varstring :public Field_longstr { 
  int key_cmp(const byte *str, uint length);

  uint packed_col_length(const char *to, uint length);

  uint max_packed_col_length(uint max_length);

  uint data_length(const char *from);

  uint size_of() const { return sizeof(*this); }

  enum_field_types real_type() const { return MYSQL_TYPE_VARCHAR; }

  bool has_charset(void) const

sql/ha_archive.cc

+22 −0
Original line number Diff line number Diff line
@@ -710,6 +710,28 @@ int ha_archive::write_row(byte *buf) 
    if (init_archive_writer())

      DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE);



  /*

    Varchar structures are constant in size but are not cleaned up request

    to request. The following sets all unused space to null to improve

    compression.

  */

  for (Field **field=table->field ; *field ; field++)

  {

    DBUG_PRINT("archive",("Pack is %d\n", (*field)->pack_length()));

    DBUG_PRINT("archive",("MyPack is %d\n", (*field)->data_length((char*) buf + (*field)->offset())));

    if ((*field)->real_type() == MYSQL_TYPE_VARCHAR) 

    {

      uint actual_length= (*field)->data_length((char*) buf + (*field)->offset());

      uint offset= (*field)->offset() + actual_length + 

        (actual_length > 255 ? 2 : 1);

      DBUG_PRINT("archive",("Offset is %d -> %d\n", actual_length, offset));

      /*

      if ((*field)->pack_length() + (*field)->offset() != offset)

        bzero(buf + offset, (size_t)((*field)->pack_length() + (actual_length > 255 ? 2 : 1) - (*field)->data_length));

    */

    }

  }



  share->rows_recorded++;

  rc= real_write_row(buf, share->archive_write);

  pthread_mutex_unlock(&share->mutex);