GRIFFIN: str = char implementation

core/src/main/java/io/questdb/griffin/engine/functions/eq/EqStrCharFunctionFactory.java

+/*******************************************************************************
+ *    ___                  _   ____  ____
+ *   / _ \ _   _  ___  ___| |_|  _ \| __ )
+ *  | | | | | | |/ _ \/ __| __| | | |  _ \
+ *  | |_| | |_| |  __/\__ \ |_| |_| | |_) |
+ *   \__\_\\__,_|\___||___/\__|____/|____/
+ *
+ * Copyright (C) 2014-2019 Appsicle
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ ******************************************************************************/
+
+package io.questdb.griffin.engine.functions.eq;
+
+import io.questdb.cairo.CairoConfiguration;
+import io.questdb.cairo.sql.Function;
+import io.questdb.cairo.sql.Record;
+import io.questdb.griffin.FunctionFactory;
+import io.questdb.griffin.engine.functions.BinaryFunction;
+import io.questdb.griffin.engine.functions.BooleanFunction;
+import io.questdb.griffin.engine.functions.UnaryFunction;
+import io.questdb.std.ObjList;
+
+public class EqStrCharFunctionFactory implements FunctionFactory {
+    @Override
+    public String getSignature() {
+        return "=(SA)";
+    }
+
+    @Override
+    public Function newInstance(ObjList<Function> args, int position, CairoConfiguration configuration) {
+        // there are optimisation opportunities
+        // 1. when one of args is constant null comparison can boil down to checking
+        //    length of non-constant (must be -1)
+        // 2. when one of arguments is constant, save method call and use a field
+
+        Function a = args.getQuick(0);
+        Function b = args.getQuick(1);
+
+        if (a.isConstant() && !b.isConstant()) {
+            return createHalfConstantFunc(position, a, b);
+        }
+
+        if (!a.isConstant() && b.isConstant()) {
+            return createHalfConstantFunc(position, b, a);
+        }
+
+        return new Func(position, a, b);
+    }
+
+    private Function createHalfConstantFunc(int position, Function constFunc, Function varFunc) {
+        return new ConstCheckFunc(position, varFunc, constFunc.getChar(null));
+    }
+
+    private static class ConstCheckFunc extends BooleanFunction implements UnaryFunction {
+        private final Function arg;
+        private final char constant;
+
+        public ConstCheckFunc(int position, Function arg, char constant) {
+            super(position);
+            this.arg = arg;
+            this.constant = constant;
+        }
+
+        @Override
+        public Function getArg() {
+            return arg;
+        }
+
+        @Override
+        public boolean getBool(Record rec) {
+            CharSequence value = arg.getStr(rec);
+            if (value == null) {
+                return false;
+            }
+
+            final int len = value.length();
+            if (len == 0) {
+                return false;
+            }
+            return value.charAt(0) == constant;
+        }
+    }
+
+    private static class Func extends BooleanFunction implements BinaryFunction {
+
+        private final Function left;
+        private final Function right;
+
+        public Func(int position, Function left, Function right) {
+            super(position);
+            this.left = left;
+            this.right = right;
+        }
+
+        @Override
+        public Function getLeft() {
+            return left;
+        }
+
+        @Override
+        public Function getRight() {
+            return right;
+        }
+
+        @Override
+        public boolean getBool(Record rec) {
+            // important to compare A and B strings in case
+            // these are columns of the same record
+            // records have re-usable character sequences
+            final CharSequence a = left.getStr(rec);
+            final char b = right.getChar(rec);
+
+            if (a == null) {
+                return false;
+            }
+
+            int len = a.length();
+            if (len == 0) {
+                return false;
+            }
+
+            return a.charAt(0) == b;
+        }
+    }
+}

core/src/main/java/io/questdb/griffin/engine/functions/eq/EqSymStrFunctionFactory.java

+/*******************************************************************************
+ *    ___                  _   ____  ____
+ *   / _ \ _   _  ___  ___| |_|  _ \| __ )
+ *  | | | | | | |/ _ \/ __| __| | | |  _ \
+ *  | |_| | |_| |  __/\__ \ |_| |_| | |_) |
+ *   \__\_\\__,_|\___||___/\__|____/|____/
+ *
+ * Copyright (C) 2014-2019 Appsicle
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ ******************************************************************************/
+
+package io.questdb.griffin.engine.functions.eq;
+
+import io.questdb.cairo.CairoConfiguration;
+import io.questdb.cairo.sql.Function;
+import io.questdb.cairo.sql.Record;
+import io.questdb.griffin.FunctionFactory;
+import io.questdb.griffin.engine.functions.BinaryFunction;
+import io.questdb.griffin.engine.functions.BooleanFunction;
+import io.questdb.griffin.engine.functions.UnaryFunction;
+import io.questdb.std.Chars;
+import io.questdb.std.ObjList;
+
+public class EqSymStrFunctionFactory implements FunctionFactory {
+    @Override
+    public String getSignature() {
+        return "=(KS)";
+    }
+
+    @Override
+    public Function newInstance(ObjList<Function> args, int position, CairoConfiguration configuration) {
+        // there are optimisation opportunities
+        // 1. when one of args is constant null comparison can boil down to checking
+        //    length of non-constant (must be -1)
+        // 2. when one of arguments is constant, save method call and use a field
+
+        Function a = args.getQuick(0);
+        Function b = args.getQuick(1);
+
+        if (a.isConstant() && !b.isConstant()) {
+            return createHalfConstantFunc(position, a, b);
+        }
+
+        if (!a.isConstant() && b.isConstant()) {
+            return createHalfConstantFunc(position, b, a);
+        }
+
+        return new Func(position, a, b);
+    }
+
+    private Function createHalfConstantFunc(int position, Function constFunc, Function varFunc) {
+        CharSequence constValue = constFunc.getStr(null);
+
+        if (constValue == null) {
+            return new NullCheckFunc(position, varFunc);
+        }
+
+        return new ConstCheckFunc(position, varFunc, constValue);
+    }
+
+    private static class NullCheckFunc extends BooleanFunction implements UnaryFunction {
+        private final Function arg;
+
+        public NullCheckFunc(int position, Function arg) {
+            super(position);
+            this.arg = arg;
+        }
+
+        @Override
+        public Function getArg() {
+            return arg;
+        }
+
+        @Override
+        public boolean getBool(Record rec) {
+            return arg.getSymbol(rec) == null;
+        }
+    }
+
+    private static class ConstCheckFunc extends BooleanFunction implements UnaryFunction {
+        private final Function arg;
+        private final CharSequence constant;
+
+        public ConstCheckFunc(int position, Function arg, CharSequence constant) {
+            super(position);
+            this.arg = arg;
+            this.constant = constant;
+        }
+
+        @Override
+        public Function getArg() {
+            return arg;
+        }
+
+        @Override
+        public boolean getBool(Record rec) {
+            return Chars.equalsNc(constant, arg.getSymbol(rec));
+        }
+    }
+
+    private static class Func extends BooleanFunction implements BinaryFunction {
+
+        private final Function left;
+        private final Function right;
+
+        public Func(int position, Function left, Function right) {
+            super(position);
+            this.left = left;
+            this.right = right;
+        }
+
+        @Override
+        public Function getLeft() {
+            return left;
+        }
+
+        @Override
+        public Function getRight() {
+            return right;
+        }
+
+        @Override
+        public boolean getBool(Record rec) {
+            // important to compare A and B strings in case
+            // these are columns of the same record
+            // records have re-usable character sequences
+            final CharSequence a = left.getSymbol(rec);
+            final CharSequence b = right.getStr(rec);
+
+            if (a == null) {
+                return b == null;
+            }
+
+            return b != null && Chars.equals(a, b);
+        }
+    }
+}

core/src/main/resources/META-INF/services/io.questdb.griffin.FunctionFactory

@@ -21,6 +21,7 @@
 #
 ################################################################################
 
+
 ################################################################################
 #    ___                  _   ____  ____
 #   / _ \ _   _  ___  ___| |_|  _ \| __ )
@@ -55,6 +56,7 @@ io.questdb.griffin.engine.functions.eq.EqLongFunctionFactory
 io.questdb.griffin.engine.functions.eq.EqDoubleFunctionFactory
 io.questdb.griffin.engine.functions.eq.EqLong256StrFunctionFactory
 io.questdb.griffin.engine.functions.eq.EqLong256FunctionFactory
+io.questdb.griffin.engine.functions.eq.EqStrCharFunctionFactory
 
 # '<>'
 io.questdb.griffin.engine.functions.eq.NotEqStrFunctionFactory