public String appendLockHint(LockMode mode, String tableName) {
if (mode.greaterThan(LockMode.READ)) {
return tableName + " holdlock";
} else {
return tableName;
}
}
public String applyLocksToSql(String sql, Map aliasedLockModes, Map keyColumnNames) {
Iterator itr = aliasedLockModes.entrySet().iterator();
StringBuffer buffer = new StringBuffer(sql);
int correction = 0;
while (itr.hasNext()) {
final Map.Entry entry = (Map.Entry) itr.next();
final LockMode lockMode = (LockMode) entry.getValue();
if (lockMode.greaterThan(LockMode.READ)) {
final String alias = (String) entry.getKey();
int start = -1, end = -1;
if (sql.endsWith(" " + alias)) {
start = (sql.length() - alias.length()) + correction;
end = start + alias.length();
} else {
int position = sql.indexOf(" " + alias + " ");
if (position <= -1) {
position = sql.indexOf(" " + alias + ",");
}
if (position > -1) {
start = position + correction + 1;
end = start + alias.length();
}
}
if (start > -1) {
final String lockHint = appendLockHint(lockMode, alias);
buffer.replace(start, end, lockHint);
correction += (lockHint.length() - alias.length());
}
}
}
return buffer.toString();
}
public LockingStrategy getLockingStrategy(Lockable lockable, LockMode lockMode) {
// InterSystems Cache' does not current support "SELECT ... FOR UPDATE" syntax...
// Set your transaction mode to READ_COMMITTED before using
if (lockMode == LockMode.PESSIMISTIC_FORCE_INCREMENT) {
return new PessimisticForceIncrementLockingStrategy(lockable, lockMode);
} else if (lockMode == LockMode.PESSIMISTIC_WRITE) {
return new PessimisticWriteUpdateLockingStrategy(lockable, lockMode);
} else if (lockMode == LockMode.PESSIMISTIC_READ) {
return new PessimisticReadUpdateLockingStrategy(lockable, lockMode);
} else if (lockMode == LockMode.OPTIMISTIC) {
return new OptimisticLockingStrategy(lockable, lockMode);
} else if (lockMode == LockMode.OPTIMISTIC_FORCE_INCREMENT) {
return new OptimisticForceIncrementLockingStrategy(lockable, lockMode);
} else if (lockMode.greaterThan(LockMode.READ)) {
return new UpdateLockingStrategy(lockable, lockMode);
} else {
return new SelectLockingStrategy(lockable, lockMode);
}
}
@Override
public String applyLocksToSql(String sql, LockOptions aliasedLockOptions, Map keyColumnNames) {
// TODO: merge additional lockoptions support in Dialect.applyLocksToSql
final Iterator itr = aliasedLockOptions.getAliasLockIterator();
final StringBuilder buffer = new StringBuilder(sql);
int correction = 0;
while (itr.hasNext()) {
final Map.Entry entry = (Map.Entry) itr.next();
final LockMode lockMode = (LockMode) entry.getValue();
if (lockMode.greaterThan(LockMode.READ)) {
final String alias = (String) entry.getKey();
int start = -1;
int end = -1;
if (sql.endsWith(" " + alias)) {
start = (sql.length() - alias.length()) + correction;
end = start + alias.length();
} else {
int position = sql.indexOf(" " + alias + " ");
if (position <= -1) {
position = sql.indexOf(" " + alias + ",");
}
if (position > -1) {
start = position + correction + 1;
end = start + alias.length();
}
}
if (start > -1) {
final String lockHint = appendLockHint(lockMode, alias);
buffer.replace(start, end, lockHint);
correction += (lockHint.length() - alias.length());
}
}
}
return buffer.toString();
}
