[GitHub] [ignite-3] korlov42 commented on a diff in pull request #898: IGNITE-17192 Binary Tuple Implementation

[GitBox <gi...@apache.org>]

korlov42 commented on code in PR #898:
URL: https://github.com/apache/ignite-3/pull/898#discussion_r906032963


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modules/schema/src/main/java/org/apache/ignite/internal/schema/BinaryTupleSchema.java:
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@@ -0,0 +1,247 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.ignite.internal.schema;
+
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.LocalTime;
+import java.util.Arrays;
+import java.util.UUID;
+import org.apache.ignite.lang.IgniteInternalException;
+
+/**
+ * Description of a binary tuple.
+ */
+public class BinaryTupleSchema {
+    /** Size of a tuple header, in bytes. */
+    public static int HEADER_SIZE = 1;
+
+    /** Mask for size of entries in variable-length offset table. */
+    public static final int VARSIZE_MASK = 0x011;
+
+    /** Flag that indicates null map presence. */
+    public static final int NULLMAP_FLAG = 0b100;
+
+    /** Default value for UUID elements. */
+    public static final UUID DEFAULT_UUID = new UUID(0, 0);
+
+    /** Default value for Date elements (Jan 1st 1 BC). */
+    public static final LocalDate DEFAULT_DATE = LocalDate.of(0, 1, 1);
+
+    /** Default value for Time elements (00:00:00). */
+    public static final LocalTime DEFAULT_TIME = LocalTime.of(0, 0);
+
+    /** Default value for DateTime elements (Jan 1st 1 BC, 00:00:00). */
+    public static final LocalDateTime DEFAULT_DATE_TIME = LocalDateTime.of(0, 1, 1, 0, 0);
+
+    /** Default value for Timestamp elements. */
+    public static final Instant DEFAULT_TIMESTAMP = Instant.EPOCH;
+
+    /**
+     * Tuple element description used for tuple parsing and building.
+     *
+     * For binary tuples encoding of values is determined by its basic type and the value itself. Parameters
+     * like precision and scale defined for columns in schema are not taken into account. The only exception
+     * is the Decimal type where the scale parameter is required for decoding.
+     *
+     * To keep things simple we have the scale parameter everywhere but really use it only for Decimals.
+     */
+    public static final class Element {
+        final NativeTypeSpec typeSpec;
+
+        final int decimalScale;
+
+        final boolean nullable;
+
+        public Element(NativeType type, boolean nullable) {
+            typeSpec = type.spec();
+
+            if (typeSpec == NativeTypeSpec.DECIMAL) {
+                DecimalNativeType decimalType = (DecimalNativeType) type;
+                decimalScale = decimalType.scale();
+            } else {
+                decimalScale = 0;
+            }
+
+            this.nullable = nullable;
+        }
+    }
+
+    /** Descriptors of all tuple elements. */
+    private final Element[] elements;
+
+    /** Indicates if the schema contains one or more nullable elements. */
+    private final boolean hasNullables;
+
+    /**
+     * Constructor.
+     *
+     * @param elements Tuple element descriptors.
+     */
+    private BinaryTupleSchema(Element[] elements) {
+        this.elements = elements;
+        this.hasNullables = Arrays.stream(elements).anyMatch(element -> element.nullable);
+    }
+
+    /**
+     * Create a tuple schema based on a range of row columns.
+     *
+     * @param descriptor Row schema.
+     * @param colBegin First columns in the range.
+     * @param colEnd Last column in the range (exclusive).
+     * @return Tuple schema.
+     */
+    private static BinaryTupleSchema createSchema(SchemaDescriptor descriptor, int colBegin, int colEnd) {
+        int numCols = colEnd - colBegin;
+
+        Element[] elements = new Element[numCols];
+
+        for (int i = 0; i < numCols; i++) {
+            Column column = descriptor.column(i);
+            elements[i] = new Element(column.type(), column.nullable());
+        }
+
+        return new BinaryTupleSchema(elements);
+    }
+
+    /**
+     * Create a tuple schema with specified elements.
+     *
+     * @param elements Tuple elements.
+     * @return Tuple schema.
+     */
+    public static BinaryTupleSchema create(Element[] elements) {
+        return new BinaryTupleSchema(elements.clone());
+    }
+
+    /**
+     * Create a schema for binary tuples with all columns of a row.
+     *
+     * @param descriptor Row schema.
+     * @return Tuple schema.
+     */
+    public static BinaryTupleSchema createRowSchema(SchemaDescriptor descriptor) {
+        return createSchema(descriptor, 0, descriptor.length());
+    }
+
+    /**
+     * Create a schema for binary tuples with key-only columns of a row.
+     *
+     * @param descriptor Row schema.
+     * @return Tuple schema.
+     */
+    public static BinaryTupleSchema createKeySchema(SchemaDescriptor descriptor) {
+        return createSchema(descriptor, 0, descriptor.keyColumns().length());
+    }
+
+    /**
+     * Create a schema for binary tuples with value-only columns of a row.
+     *
+     * @param descriptor Row schema.
+     * @return Tuple schema.
+     */
+    public static BinaryTupleSchema createValueSchema(SchemaDescriptor descriptor) {
+        return createSchema(descriptor, descriptor.keyColumns().length(), descriptor.length());
+    }
+
+    /**
+     * Create a schema for binary tuples with selected row columns.
+     *
+     * @param descriptor Row schema.
+     * @param indexes List of columns.
+     * @return Tuple schema.
+     */
+    public static BinaryTupleSchema createValueSchema(SchemaDescriptor descriptor, int[] indexes) {
+        Element[] elements = new Element[indexes.length];
+
+        for (int i : indexes) {

Review Comment:
   perhaps, it would be better replace `int[]` with BitSet. WDYT?



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