Examples with ExpressionWalker org.apache.hadoop.hive.ql.lib.ExpressionWalker used on opensource projects

Example 1 with ExpressionWalker

use of org.apache.hadoop.hive.ql.lib.ExpressionWalker in project hive by apache.

the class TypeCheckProcFactory method genExprNode.

protected static Map<ASTNode, ExprNodeDesc> genExprNode(ASTNode expr, TypeCheckCtx tcCtx, TypeCheckProcFactory tf) throws SemanticException {
    // Create the walker, the rules dispatcher and the context.
    // create a walker which walks the tree in a DFS manner while maintaining
    // the operator stack. The dispatcher
    // generates the plan from the operator tree
    Map<Rule, NodeProcessor> opRules = new LinkedHashMap<Rule, NodeProcessor>();
    opRules.put(new RuleRegExp("R1", HiveParser.TOK_NULL + "%"), tf.getNullExprProcessor());
    opRules.put(new RuleRegExp("R2", HiveParser.Number + "%|" + HiveParser.IntegralLiteral + "%|" + HiveParser.NumberLiteral + "%"), tf.getNumExprProcessor());
    opRules.put(new RuleRegExp("R3", HiveParser.Identifier + "%|" + HiveParser.StringLiteral + "%|" + HiveParser.TOK_CHARSETLITERAL + "%|" + HiveParser.TOK_STRINGLITERALSEQUENCE + "%|" + "%|" + HiveParser.KW_IF + "%|" + HiveParser.KW_CASE + "%|" + HiveParser.KW_WHEN + "%|" + HiveParser.KW_IN + "%|" + HiveParser.KW_ARRAY + "%|" + HiveParser.KW_MAP + "%|" + HiveParser.KW_STRUCT + "%|" + HiveParser.KW_EXISTS + "%|" + HiveParser.TOK_SUBQUERY_OP_NOTIN + "%"), tf.getStrExprProcessor());
    opRules.put(new RuleRegExp("R4", HiveParser.KW_TRUE + "%|" + HiveParser.KW_FALSE + "%"), tf.getBoolExprProcessor());
    opRules.put(new RuleRegExp("R5", HiveParser.TOK_DATELITERAL + "%|" + HiveParser.TOK_TIMESTAMPLITERAL + "%|" + HiveParser.TOK_TIMESTAMPLOCALTZLITERAL + "%"), tf.getDateTimeExprProcessor());
    opRules.put(new RuleRegExp("R6", HiveParser.TOK_INTERVAL_YEAR_MONTH_LITERAL + "%|" + HiveParser.TOK_INTERVAL_DAY_TIME_LITERAL + "%|" + HiveParser.TOK_INTERVAL_YEAR_LITERAL + "%|" + HiveParser.TOK_INTERVAL_MONTH_LITERAL + "%|" + HiveParser.TOK_INTERVAL_DAY_LITERAL + "%|" + HiveParser.TOK_INTERVAL_HOUR_LITERAL + "%|" + HiveParser.TOK_INTERVAL_MINUTE_LITERAL + "%|" + HiveParser.TOK_INTERVAL_SECOND_LITERAL + "%"), tf.getIntervalExprProcessor());
    opRules.put(new RuleRegExp("R7", HiveParser.TOK_TABLE_OR_COL + "%"), tf.getColumnExprProcessor());
    opRules.put(new RuleRegExp("R8", HiveParser.TOK_SUBQUERY_EXPR + "%"), tf.getSubQueryExprProcessor());
    // The dispatcher fires the processor corresponding to the closest matching
    // rule and passes the context along
    Dispatcher disp = new DefaultRuleDispatcher(tf.getDefaultExprProcessor(), opRules, tcCtx);
    GraphWalker ogw = new ExpressionWalker(disp);
    // Create a list of top nodes
    ArrayList<Node> topNodes = Lists.<Node>newArrayList(expr);
    HashMap<Node, Object> nodeOutputs = new LinkedHashMap<Node, Object>();
    ogw.startWalking(topNodes, nodeOutputs);
    return convert(nodeOutputs);
}

Example 2 with ExpressionWalker

use of org.apache.hadoop.hive.ql.lib.ExpressionWalker in project hive by apache.

the class PcrExprProcFactory method walkExprTree.

/**
 * Remove partition conditions when necessary from the the expression tree.
 *
 * @param tabAlias
 *          the table alias
 * @param parts
 *          the list of all pruned partitions for the table
 * @param vcs
 *          virtual columns referenced
 * @param pred
 *          expression tree of the target filter operator
 * @return the node information of the root expression
 * @throws SemanticException
 */
public static NodeInfoWrapper walkExprTree(String tabAlias, ArrayList<Partition> parts, List<VirtualColumn> vcs, ExprNodeDesc pred) throws SemanticException {
    // Create the walker, the rules dispatcher and the context.
    PcrExprProcCtx pprCtx = new PcrExprProcCtx(tabAlias, parts, vcs);
    Map<SemanticRule, SemanticNodeProcessor> exprRules = new LinkedHashMap<SemanticRule, SemanticNodeProcessor>();
    exprRules.put(new RuleRegExp("R1", ExprNodeColumnDesc.class.getName() + "%"), getColumnProcessor());
    exprRules.put(new RuleRegExp("R2", ExprNodeFieldDesc.class.getName() + "%"), getFieldProcessor());
    exprRules.put(new RuleRegExp("R5", ExprNodeGenericFuncDesc.class.getName() + "%"), getGenericFuncProcessor());
    // The dispatcher fires the processor corresponding to the closest matching
    // rule and passes the context along
    SemanticDispatcher disp = new DefaultRuleDispatcher(getDefaultExprProcessor(), exprRules, pprCtx);
    SemanticGraphWalker egw = new ExpressionWalker(disp);
    List<Node> startNodes = new ArrayList<Node>();
    startNodes.add(pred);
    HashMap<Node, Object> outputMap = new HashMap<Node, Object>();
    egw.startWalking(startNodes, outputMap);
    // Return the wrapper of the root node
    return (NodeInfoWrapper) outputMap.get(pred);
}

Example 3 with ExpressionWalker

use of org.apache.hadoop.hive.ql.lib.ExpressionWalker in project hive by apache.

the class ExprWalkerProcFactory method extractPushdownPreds.

/**
 * Extracts pushdown predicates from the given list of predicate expression.
 *
 * @param opContext
 *          operator context used for resolving column references
 * @param op
 *          operator of the predicates being processed
 * @param preds
 * @return The expression walker information
 * @throws SemanticException
 */
public static ExprWalkerInfo extractPushdownPreds(OpWalkerInfo opContext, Operator<? extends OperatorDesc> op, List<ExprNodeDesc> preds) throws SemanticException {
    // Create the walker, the rules dispatcher and the context.
    ExprWalkerInfo exprContext = new ExprWalkerInfo(op);
    // create a walker which walks the tree in a DFS manner while maintaining
    // the operator stack. The dispatcher
    // generates the plan from the operator tree
    Map<SemanticRule, SemanticNodeProcessor> exprRules = new LinkedHashMap<SemanticRule, SemanticNodeProcessor>();
    exprRules.put(new TypeRule(ExprNodeColumnDesc.class), getColumnProcessor());
    exprRules.put(new TypeRule(ExprNodeFieldDesc.class), getFieldProcessor());
    exprRules.put(new TypeRule(ExprNodeGenericFuncDesc.class), getGenericFuncProcessor());
    // The dispatcher fires the processor corresponding to the closest matching
    // rule and passes the context along
    SemanticDispatcher disp = new DefaultRuleDispatcher(getDefaultExprProcessor(), exprRules, exprContext);
    SemanticGraphWalker egw = new ExpressionWalker(disp);
    List<Node> startNodes = new ArrayList<Node>();
    List<ExprNodeDesc> clonedPreds = new ArrayList<ExprNodeDesc>();
    for (ExprNodeDesc node : preds) {
        ExprNodeDesc clone = node.clone();
        clonedPreds.add(clone);
        exprContext.getNewToOldExprMap().put(clone, node);
    }
    startNodes.addAll(clonedPreds);
    egw.startWalking(startNodes, null);
    HiveConf conf = opContext.getParseContext().getConf();
    // check the root expression for final candidates
    for (ExprNodeDesc pred : clonedPreds) {
        extractFinalCandidates(pred, exprContext, conf);
    }
    return exprContext;
}