org.marid.db.dao

Interface DaqReader<T extends Serializable>

Type Parameters:

T - Data record type.

All Superinterfaces:

AutoCloseable, DaqMXBean

All Known Subinterfaces:

DaqWriter<T>, NumericReader, NumericWriter

public interface DaqReader<T extends Serializable>
extends DaqMXBean, AutoCloseable

Generic DAQ DAO.

Author:

Dmitry Ovchinnikov.

Method Summary

Modifier and Type	Method and Description
DataRecord<T>	fetchRecord(long tag, long instant) Get a tag record by tag and timestamp.
List<DataRecord<T>>	fetchRecords(long[] tags, long from, long to) Fetches all the records within the given time range.
Map<Long,String>	hash(long from, long to, boolean includeData, String algorithm) Hashes record range.
long	tagCount(long from, long to) Get tag count within the given time range.
long[]	tags(long from, long to) Get all tags within the given time range.

Methods inherited from interface org.marid.db.dao.DaqMXBean

getRecordCount

Methods inherited from interface java.lang.AutoCloseable

close

Method Detail

tags

long[] tags(long from,
            long to)

Get all tags within the given time range.

Parameters:

from - Lower bound (inclusive).

to - Upper bound (exclusive).

Returns:

Tag set.

tagCount

long tagCount(long from,
              long to)

Get tag count within the given time range.

Parameters:

from - Lower bound (inclusive).

to - Upper bound (exclusive).

Returns:

Tag count.

fetchRecord

DataRecord<T> fetchRecord(long tag,
                          long instant)

Get a tag record by tag and timestamp.

Parameters:

tag - Record tag.

instant - Timestamp.

Returns:

Data record.

fetchRecords

List<DataRecord<T>> fetchRecords(long[] tags,
                                 long from,
                                 long to)

Fetches all the records within the given time range.

Parameters:

tags - Tags to be fetched.

from - Lower bound (inclusive).

to - Upper bound (exclusive).

Returns:

Fetched records.

hash

Map<Long,String> hash(long from,
                      long to,
                      boolean includeData,
                      String algorithm)

Hashes record range.

Parameters:

from - Lower bound (inclusive).

to - Upper bound (exclusive).

includeData - Whether include data or not.

algorithm - Digest algorithm (e.g. SHA-1 or MD5).

Returns:

Hashes.