use Exporter;
use Data::Dumper;
+use Digest::SHA1 qw( sha1_hex );
use SQL::Translator::Utils qw(debug normalize_name);
use base qw(Exporter);
if (!$source->compare_relationship_keys($unique_constraints{$uniq}, \@primary)) {
$table->add_constraint(
type => 'unique',
- name => "$uniq",
+ name => _create_unique_symbol($uniq),
fields => $unique_constraints{$uniq}
);
my $index = $table->add_index(
- # TODO: Pick a better than that wont conflict
- name => $unique_constraints{$uniq}->[0],
+ name => _create_unique_symbol(join('_', @{$unique_constraints{$uniq}})),
fields => $unique_constraints{$uniq},
type => 'NORMAL',
);
if (scalar(@keys)) {
$table->add_constraint(
type => 'foreign_key',
- name => $table->name . "_fk_$keys[0]",
+ name => _create_unique_symbol($table->name
+ . '_fk_'
+ . join('_', @keys)),
fields => \@keys,
reference_fields => \@refkeys,
reference_table => $rel_table,
);
my $index = $table->add_index(
- name => join('_', @keys),
+ name => _create_unique_symbol(join('_', @keys)),
fields => \@keys,
type => 'NORMAL',
);
return 1;
}
-1;
+# TODO - is there a reasonable way to pass configuration?
+# Default of 64 comes from mysql's limit.
+our $MAX_SYMBOL_LENGTH ||= 64;
+our $COLLISION_TAG_LENGTH ||= 8;
+
+# -------------------------------------------------------------------
+# $resolved_name = _create_unique_symbol($desired_name)
+#
+# If desired_name is really long, it will be truncated in a way that
+# has a high probability of leaving it unique.
+# -------------------------------------------------------------------
+sub _create_unique_symbol {
+ my $desired_name = shift;
+ return $desired_name if length $desired_name <= $MAX_SYMBOL_LENGTH;
+ my $truncated_name = substr $desired_name, 0, $MAX_SYMBOL_LENGTH - $COLLISION_TAG_LENGTH - 1;
+
+ # Hex isn't the most space-efficient, but it skirts around allowed
+ # charset issues
+ my $digest = sha1_hex($desired_name);
+ my $collision_tag = substr $digest, 0, $COLLISION_TAG_LENGTH;
+
+ return $truncated_name
+ . '_'
+ . $collision_tag;
+}
+
+1;