test/utf16align.test

# 2006 February 16
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# 
# This file contains code to verify that the SQLITE_UTF16_ALIGNED
# flag passed into the sqlite3_create_collation() function insures
# that all strings passed to that function are aligned on an even
# byte boundary.
#
# $Id: utf16align.test,v 1.2 2008/11/07 03:29:34 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Skip this entire test if we do not support UTF16
#
ifcapable !utf16 {
  finish_test
  return
}

# Create a database with a UTF16 encoding.  Put in lots of string
# data of varying lengths.
#
do_test utf16align-1.0 {
  set unaligned_string_counter 0
  add_alignment_test_collations [sqlite3_connection_pointer db]
  execsql {
    PRAGMA encoding=UTF16;
    CREATE TABLE t1(
      id INTEGER PRIMARY KEY,
      spacer TEXT,
      a TEXT COLLATE utf16_aligned,
      b TEXT COLLATE utf16_unaligned
    );
    INSERT INTO t1(a) VALUES("abc");
    INSERT INTO t1(a) VALUES("defghi");
    INSERT INTO t1(a) VALUES("jklmnopqrstuv");
    INSERT INTO t1(a) VALUES("wxyz0123456789-");
    UPDATE t1 SET b=a||'-'||a;
    INSERT INTO t1(a,b) SELECT a||b, b||a FROM t1;
    INSERT INTO t1(a,b) SELECT a||b, b||a FROM t1;
    INSERT INTO t1(a,b) SELECT a||b, b||a FROM t1;
    INSERT INTO t1(a,b) VALUES('one','two');
    INSERT INTO t1(a,b) SELECT a, b FROM t1;
    UPDATE t1 SET spacer = CASE WHEN rowid&1 THEN 'x' ELSE 'xx' END;
    SELECT count(*) FROM t1;
  }
} 66
do_test utf16align-1.1 {
  set unaligned_string_counter
} 0

# Creating an index that uses the unaligned collation.  We should see
# some unaligned strings passed to the collating function.
#
do_test utf16align-1.2 {
  execsql {
    CREATE INDEX t1i1 ON t1(spacer, b);
  }
  # puts $unaligned_string_counter
  expr {$unaligned_string_counter>0}
} 1

# Create another index that uses the aligned collation.  This time
# there should be no unaligned accesses
#
do_test utf16align-1.3 {
  set unaligned_string_counter 0
  execsql {
    CREATE INDEX t1i2 ON t1(spacer, a);
  }
  expr {$unaligned_string_counter>0}
} 0
integrity_check utf16align-1.4

# ticket #3482
#
db close
sqlite3 db :memory:
do_test utf16align-2.1 {
  db eval {
    PRAGMA encoding=UTF16be;
    SELECT hex(ltrim(x'6efcda'));
  }
} {6EFC}

finish_test