Java tutorial
/* * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.facebook.presto.atop; import com.facebook.presto.spi.ConnectorSession; import com.facebook.presto.spi.block.BlockBuilder; import com.facebook.presto.spi.type.Type; import com.facebook.presto.spi.type.TypeSignature; import com.google.common.collect.ImmutableList; import io.airlift.slice.Slices; import java.util.Arrays; import java.util.List; import java.util.Map; import java.util.function.Function; import java.util.stream.Collectors; import static com.facebook.presto.atop.AtopTable.AtopColumn.END_TIME; import static com.facebook.presto.atop.AtopTable.AtopColumn.HOST_IP; import static com.facebook.presto.atop.AtopTable.AtopColumn.START_TIME; import static com.facebook.presto.atop.AtopTable.AtopColumnParser.bigintParser; import static com.facebook.presto.atop.AtopTable.AtopColumnParser.varcharParser; import static com.facebook.presto.spi.type.DateTimeEncoding.packDateTimeWithZone; import static com.facebook.presto.spi.type.StandardTypes.BIGINT; import static com.facebook.presto.spi.type.StandardTypes.DOUBLE; import static com.facebook.presto.spi.type.StandardTypes.INTERVAL_DAY_TO_SECOND; import static com.facebook.presto.spi.type.StandardTypes.TIMESTAMP_WITH_TIME_ZONE; import static com.facebook.presto.spi.type.StandardTypes.VARCHAR; import static com.facebook.presto.spi.type.TypeSignature.parseTypeSignature; import static java.util.Objects.requireNonNull; public enum AtopTable { DISKS("disks", "DSK", baseColumnsAnd(new AtopColumn("device_name", VARCHAR, varcharParser(6)), new AtopColumn("utilization_percent", DOUBLE, (fields, type, builder, session) -> { long durationMillis = Long.valueOf(fields.get(5)) * 1000; long ioMillis = Long.valueOf(fields.get(7)); double utilization = Math.round(100.0 * ioMillis / (double) durationMillis); if (utilization > 100) { utilization = 100; } type.writeDouble(builder, utilization); }), new AtopColumn("io_time", INTERVAL_DAY_TO_SECOND, (fields, type, builder, session) -> { long millis = Long.valueOf(fields.get(7)); type.writeLong(builder, millis); }), new AtopColumn("read_requests", BIGINT, bigintParser(8)), new AtopColumn("sectors_read", BIGINT, bigintParser(9)), new AtopColumn("write_requests", BIGINT, bigintParser(10)), new AtopColumn("sectors_written", BIGINT, bigintParser(11)))), REBOOTS("reboots", "DSK", ImmutableList.of(HOST_IP, new AtopColumn("power_on_time", TIMESTAMP_WITH_TIME_ZONE, (fields, type, builder, session) -> { long millisUtc = Long.valueOf(fields.get(2)) * 1000; long durationMillis = Long.valueOf(fields.get(5)) * 1000; long value = packDateTimeWithZone(millisUtc - durationMillis, session.getTimeZoneKey()); type.writeLong(builder, value); }))); private final String name; private final String atopLabel; private final List<AtopColumn> columns; private final Map<String, AtopColumn> columnIndex; AtopTable(String name, String atopLabel, List<AtopColumn> columns) { this.atopLabel = atopLabel; this.name = requireNonNull(name, "name is null"); this.columns = ImmutableList.copyOf(requireNonNull(columns, "columns is null")); columnIndex = this.columns.stream().collect(Collectors.toMap(AtopColumn::getName, Function.identity())); } private static List<AtopColumn> baseColumnsAnd(AtopColumn... additionalColumns) { ImmutableList.Builder<AtopColumn> columns = ImmutableList.builder(); columns.add(HOST_IP); // 0th field is the label (i.e. table name) // 1st field is the name of the host, but isn't fully qualified columns.add(START_TIME); // 2nd field is the end timestamp as unix time columns.add(END_TIME); // 3rd field is the date, but we already have the epoch // 4th field is the time, but we already have the epoch // 5th field is the duration, and will be combined with 2 to compute start_time columns.addAll(Arrays.asList(additionalColumns)); return columns.build(); } public String getName() { return name; } public String getAtopLabel() { return atopLabel; } public AtopColumn getColumn(String name) { return columnIndex.get(name); } public List<AtopColumn> getColumns() { return columns; } public static class AtopColumn { public static final AtopColumn HOST_IP = new AtopColumn("host_ip", VARCHAR, (fields, type, builder, session) -> { throw new UnsupportedOperationException(); }); public static final AtopColumn START_TIME = new AtopColumn("start_time", TIMESTAMP_WITH_TIME_ZONE, ((fields, type, builder, session) -> { long millisUtc = Long.valueOf(fields.get(2)) * 1000; long durationMillis = Long.valueOf(fields.get(5)) * 1000; long value = packDateTimeWithZone(millisUtc - durationMillis, session.getTimeZoneKey()); type.writeLong(builder, value); })); public static final AtopColumn END_TIME = new AtopColumn("end_time", TIMESTAMP_WITH_TIME_ZONE, ((fields, type, builder, session) -> { long millisUtc = Long.valueOf(fields.get(2)) * 1000; type.writeLong(builder, packDateTimeWithZone(millisUtc, session.getTimeZoneKey())); })); private final String name; private final TypeSignature type; private final AtopColumnParser parser; private AtopColumn(String name, String type, AtopColumnParser parser) { this.name = requireNonNull(name, "name is null"); this.type = parseTypeSignature(type); this.parser = requireNonNull(parser, "parser is null"); } public String getName() { return name; } public TypeSignature getType() { return type; } public AtopColumnParser getParser() { return parser; } } public interface AtopColumnParser { void parse(List<String> fields, Type type, BlockBuilder builder, ConnectorSession session); static AtopColumnParser varcharParser(int index) { return ((fields, type, builder, session) -> type.writeSlice(builder, Slices.utf8Slice(fields.get(index)))); } static AtopColumnParser bigintParser(int index) { return ((fields, type, builder, session) -> type.writeLong(builder, Long.valueOf(fields.get(index)))); } } }