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.model.api.YangStmtMapping;
  13 import org.opendaylight.yangtools.yang.model.api.meta.DeclaredStatement;
  14 import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
  15 import org.opendaylight.yangtools.yang.model.api.stmt.OrderedByEffectiveStatement;
  16 import org.opendaylight.yangtools.yang.model.api.stmt.OrderedByStatement;
  17 import org.opendaylight.yangtools.yang.parser.rfc7950.stmt.BaseStringStatementSupport;
  18 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext;
  19 import org.opendaylight.yangtools.yang.parser.spi.meta.SubstatementValidator;
  20
  21 public final class OrderedByStatementSupport
  22         extends BaseStringStatementSupport<OrderedByStatement, OrderedByEffectiveStatement> {
  23     private static final SubstatementValidator SUBSTATEMENT_VALIDATOR =
  24             SubstatementValidator.builder(YangStmtMapping.ORDERED_BY).build();
  25     private static final OrderedByStatementSupport INSTANCE = new OrderedByStatementSupport();
  26
  27     /*
  28      * Ordered-by has low argument cardinality, hence we can reuse them in case declaration does not have any
  29      * substatements (which is the usual case).
  30      */
  31     private static final @NonNull EmptyOrderedByStatement EMPTY_SYSTEM_DECL = new EmptyOrderedByStatement("system");
  32     private static final @NonNull EmptyOrderedByStatement EMPTY_USER_DECL = new EmptyOrderedByStatement("user");
  33     private static final @NonNull EmptyOrderedByEffectiveStatement EMPTY_SYSTEM_EFF =
  34             new EmptyOrderedByEffectiveStatement(EMPTY_SYSTEM_DECL);
  35     private static final @NonNull EmptyOrderedByEffectiveStatement EMPTY_USER_EFF =
  36             new EmptyOrderedByEffectiveStatement(EMPTY_USER_DECL);
  37
  38     private OrderedByStatementSupport() {
  39         super(YangStmtMapping.ORDERED_BY);
  40     }
  41
  42     public static OrderedByStatementSupport getInstance() {
  43         return INSTANCE;
  44     }
  45
  46     @Override
  47     public String parseArgumentValue(final StmtContext<?, ?, ?> ctx, final String value) {
  48         return value;
  49     }
  50
  51     @Override
  52     public String internArgument(final String rawArgument) {
  53         if ("user".equals(rawArgument)) {
  54             return "user";
  55         } else if ("system".equals(rawArgument)) {
  56             return "system";
  57         } else {
  58             return rawArgument;
  59         }
  60     }
  61
  62     @Override
  63     protected SubstatementValidator getSubstatementValidator() {
  64         return SUBSTATEMENT_VALIDATOR;
  65     }
  66
  67     @Override
  68     protected OrderedByStatement createDeclared(final StmtContext<String, OrderedByStatement, ?> ctx,
  69             final ImmutableList<? extends DeclaredStatement<?>> substatements) {
  70         return new RegularOrderedByStatement(ctx.coerceStatementArgument(), substatements);
  71     }
  72
  73     @Override
  74     protected OrderedByStatement createEmptyDeclared(final StmtContext<String, OrderedByStatement, ?> ctx) {
  75         final String argument = ctx.coerceStatementArgument();
  76         switch (argument) {
  77             case "system":
  78                 return EMPTY_SYSTEM_DECL;
  79             case "user":
  80                 return EMPTY_USER_DECL;
  81             default:
  82                 throw new IllegalStateException("Unhandled argument " + argument);
  83         }
  84     }
  85
  86     @Override
  87     protected OrderedByEffectiveStatement createEffective(
  88             final StmtContext<String, OrderedByStatement, OrderedByEffectiveStatement> ctx,
  89             final OrderedByStatement declared,
  90             final ImmutableList<? extends EffectiveStatement<?, ?>> substatements) {
  91         return new RegularOrderedByEffectiveStatement(declared, substatements);
  92     }
  93
  94     @Override
  95     protected OrderedByEffectiveStatement createEmptyEffective(
  96             final StmtContext<String, OrderedByStatement, OrderedByEffectiveStatement> ctx,
  97             final OrderedByStatement declared) {
  98         // Aggressively reuse effective instances which are backed by the corresponding empty declared instance, as this
  99         // is the case unless there is a weird extension in use.
 100         if (EMPTY_USER_DECL.equals(declared)) {
 101             // Most likely to be seen (as system is the default)
 102             return EMPTY_USER_EFF;
 103         } else if (EMPTY_SYSTEM_DECL.equals(declared)) {
 104             return EMPTY_SYSTEM_EFF;
 105         } else {
 106             return new EmptyOrderedByEffectiveStatement(declared);
 107         }
 108     }
 109 }