Examples with Function.identity java.util.function.Function.identity used on opensource projects

Example 1 with Function.identity

use of java.util.function.Function.identity in project presto by prestodb.

the class HiveMetadata method getTableStatistics.

@Override
public TableStatistics getTableStatistics(ConnectorSession session, ConnectorTableHandle tableHandle, Optional<ConnectorTableLayoutHandle> tableLayoutHandle, List<ColumnHandle> columnHandles, Constraint<ColumnHandle> constraint) {
    if (!isStatisticsEnabled(session)) {
        return TableStatistics.empty();
    }
    if (!tableLayoutHandle.isPresent() || !((HiveTableLayoutHandle) tableLayoutHandle.get()).isPushdownFilterEnabled()) {
        Map<String, ColumnHandle> columns = columnHandles.stream().map(HiveColumnHandle.class::cast).filter(not(HiveColumnHandle::isHidden)).collect(toImmutableMap(HiveColumnHandle::getName, Function.identity()));
        Map<String, Type> columnTypes = columns.entrySet().stream().collect(toImmutableMap(Map.Entry::getKey, entry -> getColumnMetadata(session, tableHandle, entry.getValue()).getType()));
        List<HivePartition> partitions = partitionManager.getPartitions(metastore, tableHandle, constraint, session).getPartitions();
        return hiveStatisticsProvider.getTableStatistics(session, ((HiveTableHandle) tableHandle).getSchemaTableName(), columns, columnTypes, partitions);
    }
    verify(!constraint.predicate().isPresent());
    HiveTableLayoutHandle hiveLayoutHandle = (HiveTableLayoutHandle) tableLayoutHandle.get();
    Set<String> columnNames = columnHandles.stream().map(HiveColumnHandle.class::cast).map(HiveColumnHandle::getName).collect(toImmutableSet());
    Set<ColumnHandle> allColumnHandles = ImmutableSet.<ColumnHandle>builder().addAll(columnHandles).addAll(hiveLayoutHandle.getPredicateColumns().values().stream().filter(column -> !columnNames.contains(column.getName())).collect(toImmutableList())).build();
    Map<String, ColumnHandle> allColumns = Maps.uniqueIndex(allColumnHandles, column -> ((HiveColumnHandle) column).getName());
    Map<String, Type> allColumnTypes = allColumns.entrySet().stream().collect(toImmutableMap(Map.Entry::getKey, entry -> getColumnMetadata(session, tableHandle, entry.getValue()).getType()));
    Constraint<ColumnHandle> combinedConstraint = new Constraint<>(constraint.getSummary().intersect(hiveLayoutHandle.getDomainPredicate().transform(subfield -> isEntireColumn(subfield) ? subfield.getRootName() : null).transform(allColumns::get)));
    SubfieldExtractor subfieldExtractor = new SubfieldExtractor(functionResolution, rowExpressionService.getExpressionOptimizer(), session);
    RowExpression domainPredicate = rowExpressionService.getDomainTranslator().toPredicate(hiveLayoutHandle.getDomainPredicate().transform(subfield -> subfieldExtractor.toRowExpression(subfield, allColumnTypes.get(subfield.getRootName()))));
    RowExpression combinedPredicate = binaryExpression(SpecialFormExpression.Form.AND, ImmutableList.of(hiveLayoutHandle.getRemainingPredicate(), domainPredicate));
    List<HivePartition> partitions = partitionManager.getPartitions(metastore, tableHandle, combinedConstraint, session).getPartitions();
    TableStatistics tableStatistics = hiveStatisticsProvider.getTableStatistics(session, ((HiveTableHandle) tableHandle).getSchemaTableName(), allColumns, allColumnTypes, partitions);
    return filterStatsCalculatorService.filterStats(tableStatistics, combinedPredicate, session, ImmutableBiMap.copyOf(allColumns).inverse(), allColumnTypes);
}