yang/yang-parser-rfc7950/src/main/java/org/opendaylight/yangtools/yang/parser/rfc7950/stmt/ordered_by/OrderedByStatementSupport.java

   1 /*
   2  * Copyright (c) 2017 Pantheon Technologies, s.r.o. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.yangtools.yang.parser.rfc7950.stmt.ordered_by;
   9
  10 import com.google.common.collect.ImmutableList;
  11 import org.eclipse.jdt.annotation.NonNull;
  12 import org.opendaylight.yangtools.yang.common.Ordering;
  13 import org.opendaylight.yangtools.yang.model.api.YangStmtMapping;
  14 import org.opendaylight.yangtools.yang.model.api.meta.DeclaredStatement;
  15 import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
  16 import org.opendaylight.yangtools.yang.model.api.stmt.OrderedByEffectiveStatement;
  17 import org.opendaylight.yangtools.yang.model.api.stmt.OrderedByStatement;
  18 import org.opendaylight.yangtools.yang.parser.rfc7950.stmt.BaseStatementSupport;
  19 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext;
  20 import org.opendaylight.yangtools.yang.parser.spi.meta.SubstatementValidator;
  21 import org.opendaylight.yangtools.yang.parser.spi.source.SourceException;
  22
  23 public final class OrderedByStatementSupport
  24         extends BaseStatementSupport<Ordering, OrderedByStatement, OrderedByEffectiveStatement> {
  25     private static final SubstatementValidator SUBSTATEMENT_VALIDATOR =
  26             SubstatementValidator.builder(YangStmtMapping.ORDERED_BY).build();
  27     private static final OrderedByStatementSupport INSTANCE = new OrderedByStatementSupport();
  28
  29     /*
  30      * Ordered-by has low argument cardinality, hence we can reuse them in case declaration does not have any
  31      * substatements (which is the usual case).
  32      */
  33     private static final @NonNull EmptyOrderedByStatement EMPTY_SYSTEM_DECL =
  34             new EmptyOrderedByStatement(Ordering.SYSTEM);
  35     private static final @NonNull EmptyOrderedByStatement EMPTY_USER_DECL =
  36             new EmptyOrderedByStatement(Ordering.USER);
  37     private static final @NonNull EmptyOrderedByEffectiveStatement EMPTY_SYSTEM_EFF =
  38             new EmptyOrderedByEffectiveStatement(EMPTY_SYSTEM_DECL);
  39     private static final @NonNull EmptyOrderedByEffectiveStatement EMPTY_USER_EFF =
  40             new EmptyOrderedByEffectiveStatement(EMPTY_USER_DECL);
  41
  42     private OrderedByStatementSupport() {
  43         super(YangStmtMapping.ORDERED_BY, CopyPolicy.CONTEXT_INDEPENDENT);
  44     }
  45
  46     public static OrderedByStatementSupport getInstance() {
  47         return INSTANCE;
  48     }
  49
  50     @Override
  51     public Ordering parseArgumentValue(final StmtContext<?, ?, ?> ctx, final String value) {
  52         try {
  53             return Ordering.forArgument(value);
  54         } catch (IllegalArgumentException e) {
  55             throw new SourceException(ctx.getStatementSourceReference(), e, "Invalid ordered-by argument '%s'", value);
  56         }
  57     }
  58
  59     @Override
  60     public String internArgument(final String rawArgument) {
  61         if ("user".equals(rawArgument)) {
  62             return "user";
  63         } else if ("system".equals(rawArgument)) {
  64             return "system";
  65         } else {
  66             return rawArgument;
  67         }
  68     }
  69
  70     @Override
  71     protected SubstatementValidator getSubstatementValidator() {
  72         return SUBSTATEMENT_VALIDATOR;
  73     }
  74
  75     @Override
  76     protected OrderedByStatement createDeclared(final StmtContext<Ordering, OrderedByStatement, ?> ctx,
  77             final ImmutableList<? extends DeclaredStatement<?>> substatements) {
  78         return new RegularOrderedByStatement(ctx.coerceStatementArgument(), substatements);
  79     }
  80
  81     @Override
  82     protected OrderedByStatement createEmptyDeclared(final StmtContext<Ordering, OrderedByStatement, ?> ctx) {
  83         final Ordering argument = ctx.coerceStatementArgument();
  84         switch (argument) {
  85             case SYSTEM:
  86                 return EMPTY_SYSTEM_DECL;
  87             case USER:
  88                 return EMPTY_USER_DECL;
  89             default:
  90                 throw new IllegalStateException("Unhandled argument " + argument);
  91         }
  92     }
  93
  94     @Override
  95     protected OrderedByEffectiveStatement createEffective(
  96             final StmtContext<Ordering, OrderedByStatement, OrderedByEffectiveStatement> ctx,
  97             final OrderedByStatement declared,
  98             final ImmutableList<? extends EffectiveStatement<?, ?>> substatements) {
  99         return new RegularOrderedByEffectiveStatement(declared, substatements);
 100     }
 101
 102     @Override
 103     protected OrderedByEffectiveStatement createEmptyEffective(
 104             final StmtContext<Ordering, OrderedByStatement, OrderedByEffectiveStatement> ctx,
 105             final OrderedByStatement declared) {
 106         // Aggressively reuse effective instances which are backed by the corresponding empty declared instance, as this
 107         // is the case unless there is a weird extension in use.
 108         if (EMPTY_USER_DECL.equals(declared)) {
 109             // Most likely to be seen (as system is the default)
 110             return EMPTY_USER_EFF;
 111         } else if (EMPTY_SYSTEM_DECL.equals(declared)) {
 112             return EMPTY_SYSTEM_EFF;
 113         } else {
 114             return new EmptyOrderedByEffectiveStatement(declared);
 115         }
 116     }
 117 }