1 files changed, 123 insertions, 0 deletions
diff --git a/predicate-search/src/main/java/com/yahoo/search/predicate/index/PredicateIntervalStore.java b/predicate-search/src/main/java/com/yahoo/search/predicate/index/PredicateIntervalStore.java
new file mode 100644
index 00000000000..2e6598ff252
--- /dev/null
+++ b/predicate-search/src/main/java/com/yahoo/search/predicate/index/PredicateIntervalStore.java
@@ -0,0 +1,123 @@
+// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.search.predicate.index;
+
+import com.google.common.primitives.Ints;
+import com.yahoo.search.predicate.serialization.SerializationHelper;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * @author bjorncs
+ */
+public class PredicateIntervalStore {
+
+    private final int[][] intervalsList;
+
+    public PredicateIntervalStore(int[][] intervalsList) {
+        this.intervalsList = intervalsList;
+    }
+
+    public int[] get(int intervalRef) {
+        assert intervalRef < intervalsList.length;
+        return intervalsList[intervalRef];
+    }
+
+    public void writeToOutputStream(DataOutputStream out) throws IOException {
+        out.writeInt(intervalsList.length);
+        for (int[] intervals : intervalsList) {
+            SerializationHelper.writeIntArray(intervals, out);
+        }
+    }
+
+    public static PredicateIntervalStore fromInputStream(DataInputStream in) throws IOException {
+        int length = in.readInt();
+        int[][] intervalsList = new int[length][];
+        for (int i = 0; i < length; i++) {
+            intervalsList[i] = SerializationHelper.readIntArray(in);
+        }
+        return new PredicateIntervalStore(intervalsList);
+    }
+
+    public static class Builder {
+        private final List<int[]> intervalsListBuilder = new ArrayList<>();
+        private final Map<Entry, Integer> intervalsListIndexes = new HashMap<>();
+        private final Map<Integer, Integer> entriesForSize = new HashMap<>();
+        private int cacheHits = 0;
+        private int totalInserts = 0;
+
+        public int insert(List<Integer> intervals) {
+            int size = intervals.size();
+            if (size == 0) {
+                throw new IllegalArgumentException("Cannot insert interval list of size 0");
+            }
+            int[] array = Ints.toArray(intervals);
+            Entry entry = new Entry(array);
+            ++totalInserts;
+            if (intervalsListIndexes.containsKey(entry)) {
+                ++cacheHits;
+                return intervalsListIndexes.get(entry);
+            } else {
+                int index = intervalsListBuilder.size();
+                intervalsListBuilder.add(array);
+                intervalsListIndexes.put(entry, index);
+                entriesForSize.merge(size, 1, Integer::sum);
+                return index;
+            }
+        }
+
+        public PredicateIntervalStore build() {
+            int nIntervals = intervalsListBuilder.size();
+            int[][] intervalsList = new int[nIntervals][];
+            for (int i = 0; i < nIntervals; i++) {
+                intervalsList[i] = intervalsListBuilder.get(i);
+            }
+            return new PredicateIntervalStore(intervalsList);
+        }
+
+        public int getCacheHits() {
+            return cacheHits;
+        }
+
+        public int getTotalInserts() {
+            return totalInserts;
+        }
+
+        public Map<Integer, Integer> getEntriesForSize() {
+            return entriesForSize;
+        }
+
+        public int getNumberOfIntervals() {
+            return intervalsListBuilder.size();
+        }
+
+        private static class Entry {
+            public final int[] intervals;
+            public final int hashCode;
+
+            public Entry(int[] intervals) {
+                this.intervals = intervals;
+                this.hashCode = Arrays.hashCode(intervals);
+            }
+
+            @Override
+            public boolean equals(Object o) {
+                if (this == o) return true;
+                if (o == null || getClass() != o.getClass()) return false;
+                Entry entry = (Entry) o;
+                return Arrays.equals(intervals, entry.intervals);
+            }
+
+            @Override
+            public int hashCode() {
+                return hashCode;
+            }
+        }
+    }
+}