Add MultiTermItem and MultiRangeItem, draft

3 files changed, 397 insertions, 1 deletions

diff --git a/container-search/abi-spec.json b/container-search/abi-spec.json
index 17b95162709..108ccdc02c2 100644
--- a/container-search/abi-spec.json
+++ b/container-search/abi-spec.json
@@ -899,6 +899,43 @@
     ],
     "fields" : [ ]
   },
+  "com.yahoo.prelude.query.MultiRangeItem$Limit": {
+    "superClass": "java.lang.Enum",
+    "interfaces": [],
+    "attributes": [
+      "public",
+      "final",
+      "enum"
+    ],
+    "methods": [
+      "public static com.yahoo.prelude.query.MultiRangeItem$Limit[] values()",
+      "public static com.yahoo.prelude.query.MultiRangeItem$Limit valueOf(java.lang.String)"
+    ],
+    "fields": [
+      "public static final enum com.yahoo.prelude.query.MultiRangeItem$Limit INCLUSIVE",
+      "public static final enum com.yahoo.prelude.query.MultiRangeItem$Limit EXCLUSIVE"
+    ]
+  },
+  "com.yahoo.prelude.query.MultiRangeItem": {
+    "superClass": "com.yahoo.prelude.query.MultiTermItem",
+    "interfaces": [],
+    "attributes": [
+      "public"
+    ],
+    "methods": [
+      "public static com.yahoo.prelude.query.MultiRangeItem overRanges(java.lang.String, com.yahoo.prelude.query.MultiRangeItem$Limit, java.lang.String, com.yahoo.prelude.query.MultiRangeItem$Limit)",
+      "public static com.yahoo.prelude.query.MultiRangeItem overPoints(java.lang.String, com.yahoo.prelude.query.MultiRangeItem$Limit, com.yahoo.prelude.query.MultiRangeItem$Limit)",
+      "public com.yahoo.prelude.query.MultiRangeItem add(java.lang.Number, java.lang.Number)",
+      "public void setIndexName(java.lang.String)",
+      "protected void appendBodyString(java.lang.StringBuilder)",
+      "public void disclose(com.yahoo.prelude.query.textualrepresentation.Discloser)",
+      "public com.yahoo.prelude.query.Item clone()",
+      "public boolean equals(java.lang.Object)",
+      "public int hashCode()",
+      "public bridge synthetic java.lang.Object clone()"
+    ],
+    "fields": []
+  },
   "com.yahoo.prelude.query.NearItem" : {
     "superClass" : "com.yahoo.prelude.query.CompositeItem",
     "interfaces" : [ ],
@@ -8670,4 +8707,4 @@
     ],
     "fields" : [ ]
   }
-}
\ No newline at end of file
+}
diff --git a/container-search/src/main/java/com/yahoo/prelude/query/MultiRangeItem.java b/container-search/src/main/java/com/yahoo/prelude/query/MultiRangeItem.java
new file mode 100644
index 00000000000..fb77f010df2
--- /dev/null
+++ b/container-search/src/main/java/com/yahoo/prelude/query/MultiRangeItem.java
@@ -0,0 +1,278 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.prelude.query;
+
+import com.yahoo.prelude.query.textualrepresentation.Discloser;
+
+import java.nio.ByteBuffer;
+import java.util.AbstractMap;
+import java.util.AbstractSet;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.SortedMap;
+import java.util.TreeMap;
+
+import static java.util.Comparator.comparingDouble;
+import static java.util.Objects.requireNonNull;
+
+/**
+ * A term which contains a set of numerical ranges; a match with any of these indicates a match.
+ * <p>
+ * This is a stricter version of an {@link OrItem} containing multiple {@link RangeItem}s, where all
+ * ranges must be specified against the same field, or pair of fields, and where all the left boundaries,
+ * and all the right boundaries, share whether they are {@link Limit#INCLUSIVE} or {@link Limit#EXCLUSIVE}.
+ * Furthermore, all overlapping ranges are joined, such that the set of ranges this represents is
+ * guaranteed to be non-overlapping, and thus, sorted order of start and end boundaries is the same,
+ * which allows efficient filtering of document points or ranges by whether they are included in any of
+ * the ranges contained in this term. Note that touching ranges, like [3, 5) and [5, 7), will be joined
+ * unless this item is declared to have exclusive boundaries at both ends, or if one of the items is contained
+ * within the other, e.g., (3, 5) and (5, 5) (see below for explanation of weirdness).
+ * <p>
+ * In the absence of a range type in the schema definition, all ranges (and points) contained in documents
+ * are taken to be inclusive at both ends. However, intersection of range starts from documents and range
+ * ends from the query is inclusive, i.e., matching on equality, iff. both boundaries are inclusive, and
+ * likewise for intersection between range starts from query and range ends from documents. It is therefore
+ * possible to achieve any matching by choosing inclusiveness for the query ranges properly.
+ * For the case where document ranges are to be treated as exclusive, and the query has single points, this
+ * becomes weird, since the ranges [1, 1), (1, 1] and (1, 1) are all logically empty, but this still works :)
+ *
+ * Unless ranges are added in ascending start order, the implementation lazily sorts and merges ranges,
+ * when a representation of the item is required. This is typically when the query is serialized and sent
+ * to the backend, or when trace information is written, or {@link #toString()} is called on the item.
+ * Adding ranges in ascending order is much faster than not; ascending order here has the rather lax
+ * requirement that each added interval is not completely before the current last interval.
+ *
+ * @author jonmv
+ */
+public class MultiRangeItem extends MultiTermItem {
+
+    public enum Limit {
+        /** Points match the boundaries of ranges which are inclusive. */
+        INCLUSIVE,
+        /** Points do not match the boundaries of ranges which are exclusive. */
+        EXCLUSIVE;
+    }
+
+    static class Range {
+
+        final Number start;
+        final Number end;
+
+        Range(Number start, Number end) {
+            this.start = start;
+            this.end = end;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) return true;
+            if (o == null || getClass() != o.getClass()) return false;
+            Range range = (Range) o;
+            return start.equals(range.start) && end.equals(range.end);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(start, end);
+        }
+
+    }
+
+    private static final Comparator<Number> comparator = comparingDouble(Number::doubleValue);
+
+    private final String startIndex;
+    private final String endIndex;
+    private final boolean startInclusive;
+    private final boolean endInclusive;
+    private List<Range> ranges = new ArrayList<>();
+    private boolean sorted = true;
+
+
+    /** A multi range item with ranges to intersect with ranges given by the pair of index names. */
+    private MultiRangeItem(String startIndex, Limit startInclusive,
+                           String endIndex, Limit endInclusive) {
+        if (startIndex.isBlank()) throw new IllegalArgumentException("start index name must be non-blank");
+        if (endIndex.isBlank()) throw new IllegalArgumentException("end index name must be non-blank");
+        this.startIndex = startIndex;
+        this.endIndex = endIndex;
+        this.startInclusive = startInclusive == requireNonNull(Limit.INCLUSIVE);
+        this.endInclusive = endInclusive == requireNonNull(Limit.INCLUSIVE);
+    }
+
+    /** A multi range item with the given ranges to intersect with the ranges defined by the two given index names. */
+    public static MultiRangeItem overRanges(String startIndex, Limit startInclusive, String endIndex, Limit endInclusive) {
+        return new MultiRangeItem(startIndex, startInclusive, endIndex, endInclusive);
+    }
+
+    /** A multi range item with ranges to contain the points defined by the single given index name. */
+    public static MultiRangeItem overPoints(String index, Limit startInclusive, Limit endInclusive) {
+        return overRanges(index, startInclusive, index, endInclusive);
+    }
+
+    /** Adds the given range to this item. More efficient when each added range is not completely before the current last one. */
+    public MultiRangeItem add(Number start, Number end) {
+        if (comparator.compare(start, end) > 0)
+            throw new IllegalArgumentException("ranges must satisfy start <= end, but got " + start + " > " + end);
+
+        Range range = new Range(start, end);
+        // If the list of ranges is still sorted, we try to keep it sorted.
+        if (sorted && ! ranges.isEmpty()) {
+            // If the new range is not completely before the current last range, we can prune, and keep a sorted list.
+            Range last = ranges.get(ranges.size() - 1);
+            sorted = overlap(range.end, last.start);
+            if (sorted) {
+                // Pop all ranges that overlap with the new range ...
+                Range popped = range;
+                for (int i = ranges.size(); i-- > 0; )
+                    if (overlap(ranges.get(i).end, range.start))
+                        popped = ranges.remove(i);
+                    else
+                        break;
+                // ... then add a new range, possibly with start and end from the popped and last ranges.
+                ranges.add(popped == range ? range : new Range(min(popped.start, range.start), max(last.end, range.end)));
+                return this;
+            }
+        }
+        ranges.add(range);
+        return this;
+    }
+
+    private boolean overlap(Number endOfFirst, Number startOfSecond) {
+        int comparison = comparator.compare(endOfFirst, startOfSecond);
+        return comparison > 0 || comparison == 0 && startInclusive | endInclusive;
+    }
+
+    private Number min(Number a, Number b) {
+        return comparator.compare(a, b) <= 0 ? a : b;
+    }
+
+    private Number max(Number a, Number b) {
+        return comparator.compare(a, b) >= 0 ? a : b;
+    }
+
+    private List<Range> sortedRanges() {
+        if (sorted)
+            return ranges;
+
+        ranges.sort(comparingDouble(range -> range.start.doubleValue()));
+
+        List<Range> pruned = new ArrayList<>();
+        Range start = ranges.get(0), end = start;
+        for (int i = 1; i < ranges.size(); i++) {
+            Range range = ranges.get(i);
+            if (overlap(end.end, range.start)) {
+                end = comparator.compare(end.end, range.end) < 0 ? range : end;
+            }
+            else {
+                pruned.add(start == end ? start : new Range(start.start, end.end));
+                start = end = range;
+            }
+        }
+        pruned.add(start == end ? start : new Range(start.start, end.end));
+
+        sorted = true;
+        return ranges = pruned;
+    }
+
+    @Override
+    public void setIndexName(String index) { } // This makes no sense :<
+
+    @Override
+    OperatorType operatorType() {
+        return OperatorType.OR;
+    }
+
+    @Override
+    TermType termType() {
+        return TermType.RANGES;
+    }
+
+    @Override
+    int terms() {
+        return sortedRanges().size();
+    }
+
+    @Override
+    void encodeBlueprint(ByteBuffer buffer) {
+        boolean sameIndex = startIndex.equals(endIndex);
+        byte metadata = 0;
+        if (sameIndex)      metadata |= 0b00000001;
+        if (startInclusive) metadata |= 0b00000010;
+        if (endInclusive)   metadata |= 0b00000100;
+        buffer.put(metadata);
+        putString(startIndex, buffer);
+        if ( ! sameIndex) putString(endIndex, buffer);
+    }
+
+    @Override
+    void encodeTerms(ByteBuffer buffer) {
+        for (Range range : sortedRanges()) {
+            buffer.putDouble(range.start.doubleValue());
+            buffer.putDouble(range.end.doubleValue());
+        }
+    }
+
+    @Override
+    protected void appendBodyString(StringBuilder buffer) {
+        asCompositeItem().appendBodyString(buffer);
+    }
+
+    @Override
+    public void disclose(Discloser discloser) {
+        asCompositeItem().disclose(discloser);
+    }
+
+    @Override
+    public Item clone() {
+        MultiRangeItem clone = (MultiRangeItem) super.clone();
+        clone.ranges = new ArrayList<>(ranges);
+        return clone;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        if ( ! super.equals(o)) return false;
+        MultiRangeItem that = (MultiRangeItem) o;
+        return    startInclusive == that.startInclusive
+               && endInclusive == that.endInclusive
+               && startIndex.equals(that.startIndex)
+               && endIndex.equals(that.endIndex)
+               && sortedRanges().equals(that.sortedRanges());
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), startIndex, endIndex, startInclusive, endInclusive, sortedRanges());
+    }
+
+    Item asCompositeItem() {
+        OrItem root = new OrItem();
+        if (startIndex.equals(endIndex)) {
+            for (Range range : sortedRanges()) {
+                root.addItem(new IntItem(new com.yahoo.prelude.query.Limit(range.start, startInclusive),
+                                         new com.yahoo.prelude.query.Limit(range.end, endInclusive),
+                                         startIndex));
+            }
+        }
+        else {
+            for (Range range : sortedRanges()) {
+                AndItem pair = new AndItem();
+                pair.addItem(new IntItem(new com.yahoo.prelude.query.Limit(range.start, startInclusive),
+                                         com.yahoo.prelude.query.Limit.POSITIVE_INFINITY,
+                                         startIndex));
+                pair.addItem(new IntItem(com.yahoo.prelude.query.Limit.NEGATIVE_INFINITY,
+                                         new com.yahoo.prelude.query.Limit(range.end, endInclusive),
+                                         endIndex));
+                root.addItem(pair);
+            }
+        }
+        return root;
+    }
+
+}
\ No newline at end of file
diff --git a/container-search/src/main/java/com/yahoo/prelude/query/MultiTermItem.java b/container-search/src/main/java/com/yahoo/prelude/query/MultiTermItem.java
new file mode 100644
index 00000000000..94c2efab68f
--- /dev/null
+++ b/container-search/src/main/java/com/yahoo/prelude/query/MultiTermItem.java
@@ -0,0 +1,81 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.prelude.query;
+
+import com.yahoo.prelude.query.textualrepresentation.Discloser;
+
+import java.nio.ByteBuffer;
+
+/**
+ * A term which wraps a set of similar simple terms, all joined with {@code AND} or {@code OR}.
+ *
+ * This class exists to encompass similarities in the serialization of such multi-term constructs.
+ *
+ * @author jonmv
+ */
+abstract class MultiTermItem extends SimpleTaggableItem {
+
+    enum OperatorType {
+
+        AND(0),
+        OR(1);
+
+        private final byte code;
+
+        OperatorType(int code) { this.code = (byte) code; }
+
+    }
+
+    enum TermType {
+
+        RANGES(0);
+
+        private final byte code;
+
+        TermType(int code) { this.code = (byte) code; }
+
+    }
+
+    /** The operator used to join all wrapped terms. */
+    abstract OperatorType operatorType();
+
+    /** The term type of the wrapped terms. */
+    abstract TermType termType();
+
+    /** The number of wrapped terms. */
+    abstract int terms();
+
+    /** Encode term type and common properties to the buffer. */
+    abstract void encodeBlueprint(ByteBuffer buffer);
+
+    /** Encode all wrapped terms to the buffer. */
+    abstract void encodeTerms(ByteBuffer buffer);
+
+    @Override
+    public final ItemType getItemType() {
+        return ItemType.MULTI_TERM;
+    }
+
+    @Override
+    public final String getName() {
+        return getItemType().name();
+    }
+
+    @Override
+    public final int encode(ByteBuffer buffer) {
+        super.encodeThis(buffer);
+        byte metadata = 0;
+        metadata |= (operatorType().code << 5) & 0b11100000;
+        metadata |= (    termType().code     ) & 0b00011111;
+        buffer.put(metadata);
+        buffer.putInt(terms());
+        encodeBlueprint(buffer);
+        encodeTerms(buffer);
+        return 1;
+    }
+
+    @Override
+    public final int getTermCount() {
+        return 1;
+    }
+
+}