EQL: implement stringContains function

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/expression/function/EqlFunctionRegistry.java

@@ -11,6 +11,7 @@
 import org.elasticsearch.xpack.eql.expression.function.scalar.string.Length;
 import org.elasticsearch.xpack.eql.expression.function.scalar.string.StartsWith;
 import org.elasticsearch.xpack.eql.expression.function.scalar.string.Substring;
+import org.elasticsearch.xpack.eql.expression.function.scalar.string.StringContains;
 import org.elasticsearch.xpack.eql.expression.function.scalar.string.Wildcard;
 import org.elasticsearch.xpack.ql.expression.function.FunctionDefinition;
 import org.elasticsearch.xpack.ql.expression.function.FunctionRegistry;
@@ -32,6 +33,7 @@ private static FunctionDefinition[][] functions() {
                 def(EndsWith.class, EndsWith::new, "endswith"),
                 def(Length.class, Length::new, "length"),
                 def(StartsWith.class, StartsWith::new, "startswith"),
+                def(StringContains.class, StringContains::new, "stringcontains"),
                 def(Substring.class, Substring::new, "substring"),
                 def(Wildcard.class, Wildcard::new, "wildcard"),
             }

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/expression/function/scalar/string/StringContains.java

@@ -0,0 +1,116 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+package org.elasticsearch.xpack.eql.expression.function.scalar.string;
+
+import org.elasticsearch.xpack.ql.expression.Expression;
+import org.elasticsearch.xpack.ql.expression.Expressions;
+import org.elasticsearch.xpack.ql.expression.FieldAttribute;
+import org.elasticsearch.xpack.ql.expression.function.scalar.ScalarFunction;
+import org.elasticsearch.xpack.ql.expression.gen.pipeline.Pipe;
+import org.elasticsearch.xpack.ql.expression.gen.script.ScriptTemplate;
+import org.elasticsearch.xpack.ql.expression.gen.script.Scripts;
+import org.elasticsearch.xpack.ql.tree.NodeInfo;
+import org.elasticsearch.xpack.ql.tree.Source;
+import org.elasticsearch.xpack.ql.type.DataType;
+import org.elasticsearch.xpack.ql.type.DataTypes;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+
+import static java.lang.String.format;
+import static org.elasticsearch.xpack.eql.expression.function.scalar.string.StringContainsFunctionProcessor.doProcess;
+import static org.elasticsearch.xpack.ql.expression.TypeResolutions.isStringAndExact;
+import static org.elasticsearch.xpack.ql.expression.gen.script.ParamsBuilder.paramsBuilder;
+
+/**
+ * EQL specific stringContains function.
+ * stringContains(a, b)
+ * Returns true if b is a substring of a
+ */
+public class StringContains extends ScalarFunction {
+
+    private final Expression string, substring;
+
+    public StringContains(Source source, Expression string, Expression substring) {
+        super(source, Arrays.asList(string, substring));
+        this.string = string;
+        this.substring = substring;
+    }
+
+    @Override
+    protected TypeResolution resolveType() {
+        if (!childrenResolved()) {
+            return new TypeResolution("Unresolved children");
+        }
+
+        TypeResolution resolution = isStringAndExact(string, sourceText(), Expressions.ParamOrdinal.FIRST);
+        if (resolution.unresolved()) {
+            return resolution;
+        }
+
+        return isStringAndExact(substring, sourceText(), Expressions.ParamOrdinal.SECOND);
+    }
+
+    @Override
+    protected Pipe makePipe() {
+        return new StringContainsFunctionPipe(source(), this,
+                Expressions.pipe(string), Expressions.pipe(substring));
+    }
+
+    @Override
+    public boolean foldable() {
+        return string.foldable() && substring.foldable();
+    }
+
+    @Override
+    public Object fold() {
+        return doProcess(string.fold(), substring.fold());
+    }
+
+    @Override
+    protected NodeInfo<? extends Expression> info() {
+        return NodeInfo.create(this, StringContains::new, string, substring);
+    }
+
+    @Override
+    public ScriptTemplate asScript() {
+        return asScriptFrom(asScript(string), asScript(substring));
+    }
+
+    protected ScriptTemplate asScriptFrom(ScriptTemplate stringScript, ScriptTemplate substringScript) {
+        return new ScriptTemplate(format(Locale.ROOT, formatTemplate("{eql}.%s(%s,%s)"),
+                "stringContains",
+                stringScript.template(),
+                substringScript.template()),
+                paramsBuilder()
+                        .script(stringScript.params())
+                        .script(substringScript.params())
+                        .build(), dataType());
+    }
+
+    @Override
+    public ScriptTemplate scriptWithField(FieldAttribute field) {
+        return new ScriptTemplate(processScript(Scripts.DOC_VALUE),
+                paramsBuilder().variable(field.exactAttribute().name()).build(),
+                dataType());
+    }
+
+    @Override
+    public DataType dataType() {
+        return DataTypes.BOOLEAN;
+    }
+
+    @Override
+    public Expression replaceChildren(List<Expression> newChildren) {
+        if (newChildren.size() != 2) {
+            throw new IllegalArgumentException("expected [2] children but received [" + newChildren.size() + "]");
+        }
+
+        return new StringContains(source(), newChildren.get(0), newChildren.get(1));
+    }
+}

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/expression/function/scalar/string/StringContainsFunctionPipe.java

@@ -0,0 +1,106 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+package org.elasticsearch.xpack.eql.expression.function.scalar.string;
+
+import org.elasticsearch.xpack.ql.execution.search.QlSourceBuilder;
+import org.elasticsearch.xpack.ql.expression.Expression;
+import org.elasticsearch.xpack.ql.expression.gen.pipeline.Pipe;
+import org.elasticsearch.xpack.ql.tree.NodeInfo;
+import org.elasticsearch.xpack.ql.tree.Source;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+
+public class StringContainsFunctionPipe extends Pipe {
+
+    private final Pipe string, substring;
+
+    public StringContainsFunctionPipe(Source source, Expression expression, Pipe string, Pipe substring) {
+        super(source, expression, Arrays.asList(string, substring));
+        this.string = string;
+        this.substring = substring;
+    }
+
+    @Override
+    public final Pipe replaceChildren(List<Pipe> newChildren) {
+        if (newChildren.size() != 2) {
+            throw new IllegalArgumentException("expected [2] children but received [" + newChildren.size() + "]");
+        }
+        return replaceChildren(newChildren.get(0), newChildren.get(1));
+    }
+
+    @Override
+    public final Pipe resolveAttributes(AttributeResolver resolver) {
+        Pipe newString = string.resolveAttributes(resolver);
+        Pipe newSubstring = substring.resolveAttributes(resolver);
+        if (newString == string && newSubstring == substring) {
+            return this;
+        }
+        return replaceChildren(newString, newSubstring);
+    }
+
+    @Override
+    public boolean supportedByAggsOnlyQuery() {
+        return string.supportedByAggsOnlyQuery() && substring.supportedByAggsOnlyQuery();
+    }
+
+    @Override
+    public boolean resolved() {
+        return string.resolved() && substring.resolved();
+    }
+
+    protected Pipe replaceChildren(Pipe string, Pipe substring) {
+        return new StringContainsFunctionPipe(source(), expression(), string, substring);
+    }
+
+    @Override
+    public final void collectFields(QlSourceBuilder sourceBuilder) {
+        string.collectFields(sourceBuilder);
+        substring.collectFields(sourceBuilder);
+    }
+
+    @Override
+    protected NodeInfo<StringContainsFunctionPipe> info() {
+        return NodeInfo.create(this, StringContainsFunctionPipe::new, expression(), string, substring);
+    }
+
+    @Override
+    public StringContainsFunctionProcessor asProcessor() {
+        return new StringContainsFunctionProcessor(string.asProcessor(), substring.asProcessor());
+    }
+
+    public Pipe string() {
+        return string;
+    }
+
+    public Pipe substring() {
+        return substring;
+    }
+
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(source(), string(), substring());
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+
+        StringContainsFunctionPipe other = (StringContainsFunctionPipe) obj;
+        return Objects.equals(source(), other.source())
+                && Objects.equals(string(), other.string())
+                && Objects.equals(substring(), other.substring());
+    }
+}

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/expression/function/scalar/string/StringContainsFunctionProcessor.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+package org.elasticsearch.xpack.eql.expression.function.scalar.string;
+
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.xpack.eql.EqlIllegalArgumentException;
+import org.elasticsearch.xpack.ql.expression.gen.processor.Processor;
+
+import java.io.IOException;
+import java.util.Objects;
+
+public class StringContainsFunctionProcessor implements Processor {
+
+    public static final String NAME = "sstc";
+
+    private final Processor string, substring;
+
+    public StringContainsFunctionProcessor(Processor string, Processor substring) {
+        this.string = string;
+        this.substring = substring;
+    }
+
+    public StringContainsFunctionProcessor(StreamInput in) throws IOException {
+        string = in.readNamedWriteable(Processor.class);
+        substring = in.readNamedWriteable(Processor.class);
+    }
+
+    @Override
+    public final void writeTo(StreamOutput out) throws IOException {
+        out.writeNamedWriteable(string);
+        out.writeNamedWriteable(substring);
+    }
+
+    @Override
+    public Object process(Object input) {
+        return doProcess(string.process(input), substring.process(input));
+    }
+
+    public static Object doProcess(Object string, Object substring) {
+        if (string == null) {
+            return null;
+        }
+
+        throwIfNotString(string);
+        throwIfNotString(substring);
+
+        String strString = string.toString();
+        String strSubstring = substring.toString();
+        return StringUtils.stringContains(strString, strSubstring);
+    }
+
+    private static void throwIfNotString(Object obj) {
+        if (!(obj instanceof String || obj instanceof Character)) {
+            throw new EqlIllegalArgumentException("A string/char is required; received [{}]", obj);
+        }
+    }
+
+    protected Processor string() {
+        return string;
+    }
+
+    public Processor substring() {
+        return substring;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+
+        StringContainsFunctionProcessor other = (StringContainsFunctionProcessor) obj;
+        return Objects.equals(string(), other.string())
+                && Objects.equals(substring(), other.substring());
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(string(), substring());
+    }
+
+
+    @Override
+    public String getWriteableName() {
+        return NAME;
+    }
+}

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/expression/function/scalar/string/StringUtils.java

@@ -60,6 +60,23 @@ static String between(String string, String left, String right, boolean greedy,
         return string.substring(start, idx);
     }
 
+    /**
+     * Checks if {@code string} contains {@code substring} string.
+     *
+     * @param string    string to search through.
+     * @param substring string to search for.
+     * @return {@code true} if {@code string} string contains {@code substring} string.
+     */
+    static boolean stringContains(String string, String substring) {
+        if (hasLength(string) == false || hasLength(substring) == false) {
+            return false;
+        }
+
+        string = string.toLowerCase(Locale.ROOT);
+        substring = substring.toLowerCase(Locale.ROOT);
+        return string.contains(substring);
+    }
+
     /**
      * Returns a substring using the Python slice semantics, meaning
      * start and end can be negative
@@ -70,7 +87,7 @@ static String substringSlice(String string, int start, int end) {
         }
 
         int length = string.length();
-        
+
         // handle first negative values
         if (start < 0) {
             start += length;

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/expression/function/scalar/string/Substring.java

@@ -127,4 +127,4 @@ public Expression replaceChildren(List<Expression> newChildren) {
 
         return new Substring(source(), newChildren.get(0), newChildren.get(1), newChildren.get(2));
     }
-}
+}

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/expression/function/scalar/whitelist/InternalEqlScriptUtils.java

@@ -11,6 +11,7 @@
 import org.elasticsearch.xpack.eql.expression.function.scalar.string.LengthFunctionProcessor;
 import org.elasticsearch.xpack.eql.expression.function.scalar.string.StartsWithFunctionProcessor;
 import org.elasticsearch.xpack.eql.expression.function.scalar.string.SubstringFunctionProcessor;
+import org.elasticsearch.xpack.eql.expression.function.scalar.string.StringContainsFunctionProcessor;
 import org.elasticsearch.xpack.ql.expression.function.scalar.whitelist.InternalQlScriptUtils;
 
 /*
@@ -38,6 +39,10 @@ public static Boolean startsWith(String s, String pattern) {
         return (Boolean) StartsWithFunctionProcessor.doProcess(s, pattern);
     }
 
+    public static Boolean stringContains(String string, String substring) {
+        return (Boolean) StringContainsFunctionProcessor.doProcess(string, substring);
+    }
+
     public static String substring(String s, Number start, Number end) {
         return (String) SubstringFunctionProcessor.doProcess(s, start, end);
     }