1 files changed, 104 insertions, 0 deletions
diff --git a/sql/sql_type_string.cc b/sql/sql_type_string.cc
new file mode 100644
index 00000000..df46ef74
--- /dev/null
+++ b/sql/sql_type_string.cc
@@ -0,0 +1,104 @@
+/*
+   Copyright (c) 2019, 2020 MariaDB
+
+   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., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA */
+
+#include "mariadb.h"
+
+#include "sql_class.h"
+#include "sql_type_string.h"
+
+
+uchar *
+StringPack::pack(uchar *to, const uchar *from, uint max_length) const
+{
+  size_t length=      MY_MIN(m_octet_length, max_length);
+  size_t local_char_length= char_length();
+  DBUG_PRINT("debug", ("length: %zu ", length));
+
+  if (length > local_char_length)
+    local_char_length= charset()->charpos(from, from + length,
+                                          local_char_length);
+  set_if_smaller(length, local_char_length);
+ 
+  /*
+     TODO: change charset interface to add a new function that does 
+           the following or add a flag to lengthsp to do it itself 
+           (this is for not packing padding adding bytes in BINARY 
+           fields).
+  */
+  if (mbmaxlen() == 1)
+  {
+    while (length && from[length-1] == charset()->pad_char)
+      length --;
+  }
+  else
+    length= charset()->lengthsp((const char*) from, length);
+
+  // Length always stored little-endian
+  *to++= (uchar) length;
+  if (m_octet_length > 255)
+    *to++= (uchar) (length >> 8);
+
+  // Store the actual bytes of the string
+  memcpy(to, from, length);
+  return to+length;
+}
+
+
+const uchar *
+StringPack::unpack(uchar *to, const uchar *from, const uchar *from_end,
+                   uint param_data) const
+{
+  uint from_length, length;
+
+  /*
+    Compute the declared length of the field on the master. This is
+    used to decide if one or two bytes should be read as length.
+   */
+  if (param_data)
+    from_length= (((param_data >> 4) & 0x300) ^ 0x300) + (param_data & 0x00ff);
+  else
+    from_length= m_octet_length;
+
+  DBUG_PRINT("debug",
+             ("param_data: 0x%x, field_length: %u, from_length: %u",
+              param_data, m_octet_length, from_length));
+  /*
+    Compute the actual length of the data by reading one or two bits
+    (depending on the declared field length on the master).
+   */
+  if (from_length > 255)
+  {
+    if (from + 2 > from_end)
+      return 0;
+    length= uint2korr(from);
+    from+= 2;
+  }
+  else
+  {
+    if (from + 1 > from_end)
+      return 0;
+    length= (uint) *from++;
+  }
+  if (from + length > from_end || length > m_octet_length)
+    return 0;
+
+  memcpy(to, from, length);
+  // Pad the string with the pad character of the fields charset
+  charset()->fill((char*) to + length,
+                  m_octet_length - length,
+                  charset()->pad_char);
+  return from+length;
+}