Add NumericTrie.

include/numeric_range_trie_test.h

@@ -0,0 +1,60 @@
+#pragma once
+
+#include <map>
+#include "sorted_array.h"
+
+constexpr char MAX_LEVEL = 4;
+constexpr short EXPANSE = 256;
+
+class NumericTrieNode {
+    NumericTrieNode** children = nullptr;
+    sorted_array seq_ids;
+
+    void insert(const int32_t& value, const uint32_t& seq_id, char& level);
+
+    void search_lesser_helper(const int32_t& value, char& level, std::vector<NumericTrieNode*>& matches);
+public:
+
+    ~NumericTrieNode() {
+        if (children != nullptr) {
+            for (auto i = 0; i < EXPANSE; i++) {
+                delete children[i];
+            }
+        }
+
+        delete [] children;
+    }
+
+    void insert(const int32_t& value, const uint32_t& seq_id);
+
+    void search_range(const int32_t& low,const int32_t& high,
+                      uint32_t*& ids, uint32_t& ids_length);
+
+    void search_lesser(const int32_t& value, uint32_t*& ids, uint32_t& ids_length);
+
+    void search_greater(const int32_t& value, uint32_t*& ids, uint32_t& ids_length);
+};
+
+class NumericTrie {
+    NumericTrieNode* negative_trie = nullptr;
+    NumericTrieNode* positive_trie = nullptr;
+
+public:
+
+    ~NumericTrie() {
+        delete negative_trie;
+        delete positive_trie;
+    }
+
+    void insert(const int32_t& value, const uint32_t& seq_id);
+
+    void search_range(const int32_t& low, const bool& low_inclusive,
+                      const int32_t& high, const bool& high_inclusive,
+                      uint32_t*& ids, uint32_t& ids_length);
+
+    void search_lesser(const int32_t& value, const bool& inclusive,
+                       uint32_t*& ids, uint32_t& ids_length);
+
+    void search_greater(const int32_t& value, const bool& inclusive,
+                        uint32_t*& ids, uint32_t& ids_length);
+};

src/numeric_range_trie.cpp

@@ -0,0 +1,122 @@
+#include "numeric_range_trie_test.h"
+#include "array_utils.h"
+
+void NumericTrie::insert(const int32_t& value, const uint32_t& seq_id) {
+    if (value < 0) {
+        if (negative_trie == nullptr) {
+            negative_trie = new NumericTrieNode();
+        }
+
+        negative_trie->insert(std::abs(value), seq_id);
+    } else {
+        if (positive_trie == nullptr) {
+            positive_trie = new NumericTrieNode();
+        }
+
+        positive_trie->insert(value, seq_id);
+    }
+}
+
+void NumericTrie::search_range(const int32_t& low, const bool& low_inclusive,
+                               const int32_t& high, const bool& high_inclusive,
+                               uint32_t*& ids, uint32_t& ids_length) {
+    if (low < 0 && high >= 0) {
+        // Have to combine the results of >low from negative_trie and <high from positive_trie
+
+        uint32_t* negative_ids = nullptr;
+        uint32_t negative_ids_length = 0;
+        if (!(low == -1 && !low_inclusive)) {
+            auto abs_low = std::abs(low);
+            // Since we store absolute values, search_lesser would yield result for >low from negative_trie.
+            negative_trie->search_lesser(low_inclusive ? abs_low : abs_low - 1, negative_ids, negative_ids_length);
+        }
+
+        uint32_t* positive_ids = nullptr;
+        uint32_t positive_ids_length = 0;
+        if (!(high == 0 && !high_inclusive)) {
+            positive_trie->search_lesser(high_inclusive ? high : high - 1, positive_ids, positive_ids_length);
+        }
+
+        ids_length = ArrayUtils::or_scalar(negative_ids, negative_ids_length, positive_ids, positive_ids_length, &ids);
+
+        delete [] negative_ids;
+        delete [] positive_ids;
+        return;
+    }
+}
+
+void NumericTrieNode::insert(const int32_t& value, const uint32_t& seq_id) {
+    char level = 0;
+    return insert(value, seq_id, level);
+}
+
+inline int get_index(const int32_t& value, char& level) {
+    return (value >> (8 * (MAX_LEVEL - level))) & 0xFF;
+}
+
+void NumericTrieNode::insert(const int32_t& value, const uint32_t& seq_id, char& level) {
+    if (level > MAX_LEVEL) {
+        return;
+    }
+
+    if (!seq_ids.contains(seq_id)) {
+        seq_ids.append(seq_id);
+    }
+
+    if (++level <= MAX_LEVEL) {
+        if (children == nullptr) {
+            children = new NumericTrieNode* [EXPANSE]{nullptr};
+        }
+
+        auto index = get_index(value, level);
+        if (children[index] == nullptr) {
+            children[index] = new NumericTrieNode();
+        }
+
+        return children[index]->insert(value, seq_id, level);
+    }
+}
+
+void NumericTrieNode::search_lesser(const int32_t& value, uint32_t*& ids, uint32_t& ids_length) {
+    char level = 0;
+    std::vector<NumericTrieNode*> matches;
+    search_lesser_helper(value, level, matches);
+
+    for (auto const& match: matches) {
+        uint32_t* out = nullptr;
+        auto const& m_seq_ids = match->seq_ids.uncompress();
+        ids_length = ArrayUtils::or_scalar(m_seq_ids, match->seq_ids.getLength(), ids, ids_length, &out);
+
+        delete [] m_seq_ids;
+        delete [] ids;
+        ids = out;
+    }
+}
+
+void NumericTrieNode::search_lesser_helper(const int32_t& value, char& level, std::vector<NumericTrieNode*>& matches) {
+    if (level > MAX_LEVEL) {
+        return;
+    } else if (level == MAX_LEVEL) {
+        matches.push_back(this);
+        return;
+    }
+
+    if (children == nullptr) {
+        return;
+    }
+
+    auto index = get_index(value, ++level);
+    if (children[index] == nullptr) {
+        return;
+    }
+
+    children[index]->search_lesser_helper(value, level, matches);
+
+    while (--index >= 0) {
+        if (children[index] != nullptr) {
+            matches.push_back(children[index]);
+        }
+    }
+
+    --level;
+}

test/numeric_range_trie_test.cpp

@@ -0,0 +1,41 @@
+#include <gtest/gtest.h>
+#include "numeric_range_trie_test.h"
+
+class NumericRangeTrieTest : public ::testing::Test {
+protected:
+
+    virtual void SetUp() {}
+
+    virtual void TearDown() {}
+};
+
+TEST_F(NumericRangeTrieTest, Insert) {
+    auto trie = new NumericTrie();
+    std::vector<std::pair<int32_t, uint32_t>> pairs = {
+            {-8192, 8},
+            {-16384, 32},
+            {-24576, 35},
+            {-32768, 43},
+            {8192, 49},
+            {16384, 56},
+            {24576, 58},
+            {32768, 91}
+    };
+
+    for (auto const pair: pairs) {
+        trie->insert(pair.first, pair.second);
+    }
+
+    uint32_t* ids = nullptr;
+    uint32_t ids_length = 0;
+
+    trie->search_range(-32768, true, 32768, true, ids, ids_length);
+
+    ASSERT_EQ(pairs.size(), ids_length);
+    for (uint32_t i = 0; i < pairs.size(); i++) {
+        ASSERT_EQ(pairs[i].second, ids[i]);
+    }
+
+    delete [] ids;
+    delete trie;
+}