/**
* @return Numeric meta data information for the channel or <code>null</code>
* @throws Exception on error
*/
private Display determineDisplay() throws Exception {
// Try numeric meta data
final PreparedStatement statement =
reader
.getRDB()
.getConnection()
.prepareStatement(reader.getSQL().numeric_meta_sel_by_channel);
try {
statement.setInt(1, channel_id);
final ResultSet result = statement.executeQuery();
if (result.next()) {
final NumberFormat format = NumberFormats.format(result.getInt(7)); // prec
return ValueFactory.newDisplay(
result.getDouble(1), // lowerDisplayLimit
result.getDouble(5), // lowerAlarmLimit
result.getDouble(3), // lowerWarningLimit
result.getString(8), // units
format, // numberFormat
result.getDouble(4), // upperWarningLimit
result.getDouble(6), // upperAlarmLimit
result.getDouble(2), // upperDisplayLimit
result.getDouble(1), // lowerCtrlLimit
result.getDouble(2)); // upperCtrlLimit
}
} finally {
statement.close();
}
// No numeric display meta data
return null;
}
/**
* See if there are array elements.
*
* @param dbl0 Value of the first (maybe only) array element
* @param result ResultSet for the sample table with blob
* @return Array with given element and maybe more.
* @throws Exception on error, including 'cancel'
*/
private double[] readBlobArrayElements(final double dbl0, final ResultSet result)
throws Exception {
final String datatype;
if (reader.isOracle()) datatype = result.getString(7);
else datatype = result.getString(8);
// ' ' or NULL indicate: Scalar, not an array
if (datatype == null || " ".equals(datatype) || result.wasNull()) return new double[] {dbl0};
// Decode BLOB
final byte[] bytes = result.getBytes(reader.isOracle() ? 8 : 9);
final ByteArrayInputStream stream = new ByteArrayInputStream(bytes);
final DataInputStream data = new DataInputStream(stream);
if ("d".equals(datatype)) { // Read Double typed array elements
final int nelm = data.readInt();
final double[] array = new double[nelm];
for (int i = 0; i < nelm; i++) array[i] = data.readDouble();
data.close();
return array;
}
// TODO Decode 'l' Long and 'i' Integer?
else {
throw new Exception("Sample BLOBs of type '" + datatype + "' are not decoded");
}
}
/**
* @return Numeric meta data information for the channel or <code>null</code>
* @throws Exception on error
*/
private List<String> determineLabels() throws Exception {
// Try enumerated meta data
List<String> labels = null;
final PreparedStatement statement =
reader
.getRDB()
.getConnection()
.prepareStatement(reader.getSQL().enum_sel_num_val_by_channel);
try {
statement.setInt(1, channel_id);
final ResultSet result = statement.executeQuery();
if (result.next()) {
labels = new ArrayList<String>();
do {
final int id = result.getInt(1);
final String val = result.getString(2);
// Expect vals for ids 0, 1, 2, ...
if (id != labels.size())
throw new Exception(
"Enum IDs for channel with ID " + channel_id + " not in sequential order");
labels.add(val);
} while (result.next());
}
} finally {
statement.close();
}
// Anything found?
if (labels == null || labels.size() <= 0) return null; // Nothing found
return labels;
}
/**
* Extract value from SQL result
*
* @param result ResultSet that must contain contain time, severity, ..., value
* @param handle_array Try to read array elements, or only a scalar value?
* @return IValue Decoded IValue
* @throws Exception on error, including cancellation
*/
protected VType decodeSampleTableValue(final ResultSet result, final boolean handle_array)
throws Exception {
// Get time stamp
final java.sql.Timestamp stamp = result.getTimestamp(1);
// Oracle has nanoseconds in TIMESTAMP, other RDBs in separate column
if (!reader.isOracle()) stamp.setNanos(result.getInt(7));
final Timestamp time = TimestampHelper.fromSQLTimestamp(stamp);
// Get severity/status
final String status = reader.getStatus(result.getInt(3));
final AlarmSeverity severity = filterSeverity(reader.getSeverity(result.getInt(2)), status);
// Determine the value type
// Try double
final double dbl0 = result.getDouble(5);
if (!result.wasNull()) {
// Is it an error to have enumeration strings for double samples?
// In here, we handle it by returning enumeration samples,
// because the meta data would be wrong for double values.
if (labels != null) return new ArchiveVEnum(time, severity, status, labels, (int) dbl0);
// Double data.
if (handle_array) { // Get array elements - if any.
final double data[] =
reader.useArrayBlob()
? readBlobArrayElements(dbl0, result)
: readArrayElements(time, dbl0, severity);
if (data.length == 1) return new ArchiveVNumber(time, severity, status, display, data[0]);
else return new ArchiveVNumberArray(time, severity, status, display, data);
} else return new ArchiveVNumber(time, severity, status, display, dbl0);
}
// Try integer
final int num = result.getInt(4);
if (!result.wasNull()) { // Enumerated integer?
if (labels != null) return new ArchiveVEnum(time, severity, status, labels, num);
return new ArchiveVNumber(time, severity, status, display, num);
}
// Default to string
final String txt = result.getString(6);
return new ArchiveVString(time, severity, status, txt);
}
/**
* Given the time and first element of the sample, see if there are more array elements.
*
* @param stamp Time stamp of the sample
* @param dbl0 Value of the first (maybe only) array element
* @param severity Severity of the sample
* @return Array with given element and maybe more.
* @throws Exception on error, including 'cancel'
*/
private double[] readArrayElements(
final Timestamp stamp, final double dbl0, final AlarmSeverity severity) throws Exception {
// For performance reasons, only look for array data until we hit a scalar sample.
if (is_an_array == false) return new double[] {dbl0};
// See if there are more array elements
if (sel_array_samples == null) { // Lazy initialization
sel_array_samples =
reader.getRDB().getConnection().prepareStatement(reader.getSQL().sample_sel_array_vals);
}
sel_array_samples.setInt(1, channel_id);
sel_array_samples.setTimestamp(2, TimestampHelper.toSQLTimestamp(stamp));
// MySQL keeps nanoseconds in designated column, not TIMESTAMP
if (!reader.isOracle()) sel_array_samples.setInt(3, stamp.getNanoSec());
// Assemble array of unknown size in ArrayList ....
final ArrayList<Double> vals = new ArrayList<Double>();
reader.addForCancellation(sel_array_samples);
try {
final ResultSet res = sel_array_samples.executeQuery();
vals.add(new Double(dbl0));
while (res.next()) vals.add(res.getDouble(1));
res.close();
} finally {
reader.removeFromCancellation(sel_array_samples);
}
// Convert to plain double array
final int N = vals.size();
final double ret[] = new double[N];
for (int i = 0; i < N; i++) ret[i] = vals.get(i).doubleValue();
// Check if it's in fact just a scalar, and a valid one
if (N == 1 && severity != AlarmSeverity.UNDEFINED) { // Found a perfect non-array sample:
// Assume that the data is scalar, skip the array check from now on
is_an_array = false;
}
return ret;
}
/**
* Initialize
*
* @param reader RDBArchiveReader
* @param channel_id ID of channel
* @param start Start time
* @param end End time
* @throws Exception on error
*/
public RawSampleIterator(
final RDBArchiveReader reader,
final int channel_id,
final Timestamp start,
final Timestamp end)
throws Exception {
super(reader, channel_id);
try {
determineInitialSample(start, end);
} catch (Exception ex) {
if (!RDBArchiveReader.isCancellation(ex)) throw ex;
// Else: Not a real error; return empty iterator
value = null;
}
}
/**
* @param reader RDBArchiveReader
* @param channel_id ID of channel
* @throws Exception on error
*/
AbstractRDBValueIterator(final RDBArchiveReader reader, final int channel_id) throws Exception {
this.reader = reader;
this.channel_id = channel_id;
try {
this.display = determineDisplay();
this.labels = determineLabels();
} catch (final Exception ex) {
// Set iterator to empty
close();
if (!RDBArchiveReader.isCancellation(ex)) throw ex;
// Else: Not a real error, return empty iterator
}
if (labels == null && display == null)
display =
ValueFactory.newDisplay(
0.0, 0.0, 0.0, "", NumberFormats.format(0), 0.0, 0.0, 10.0, 0.0, 10.0);
}
/** {@inheritDoc} */
@Override
@SuppressWarnings("nls")
public VType next() throws Exception {
// This should not happen...
if (result_set == null)
throw new Exception("RawSampleIterator.next(" + channel_id + ") called after end");
// Remember value to return...
final VType result = value;
// ... and prepare next value
try {
if (result_set.next()) value = decodeSampleTableValue(result_set, true);
else close();
} catch (Exception ex) {
close();
if (!RDBArchiveReader.isCancellation(ex)) throw ex;
// Else: Not a real error; return empty iterator
}
return result;
}
