From 81709a8bbb274fab561c15c73f1ef40c49a79f98 Mon Sep 17 00:00:00 2001
From: canepat <16927169+canepat@users.noreply.github.com>
Date: Sun, 13 Nov 2022 13:48:48 +0100
Subject: [PATCH] Move non-constexpr array initialization Add RecSplit methods
 to add key one by one Remove ctor/dtor template parameters made invalid in
 C++20 Add unit test

---
 sux/function/RecSplit.hpp  | 20 ++++++++++++++++++--
 sux/util/Vector.hpp        |  8 ++++----
 test/function/recsplit.hpp | 30 ++++++++++++++++++++++++++++++
 3 files changed, 52 insertions(+), 6 deletions(-)

diff --git a/sux/function/RecSplit.hpp b/sux/function/RecSplit.hpp
index 733ba7f..5152a66 100644
--- a/sux/function/RecSplit.hpp
+++ b/sux/function/RecSplit.hpp
@@ -307,17 +307,32 @@ template <size_t LEAF_SIZE, util::AllocType AT = util::AllocType::MALLOC> class
 	// For each bucket size, the Golomb-Rice parameter (upper 8 bits) and the number of bits to
 	// skip in the fixed part of the tree (lower 24 bits).
 	static constexpr array<uint32_t, MAX_BUCKET_SIZE> memo = fill_golomb_rice<LEAF_SIZE>();
-	static constexpr array<uint8_t, MAX_LEAF_SIZE> bij_midstop = fill_bij_midstop();
 
 	size_t bucket_size;
 	size_t nbuckets;
 	size_t keys_count;
 	RiceBitVector<AT> descriptors;
 	DoubleEF<AT> ef;
+    std::vector<hash128_t> key_hashes;
 
   public:
 	RecSplit() {}
 
+    RecSplit(const size_t _keys_count, const size_t _bucket_size) {
+        this->bucket_size = _bucket_size;
+        this->keys_count = _keys_count;
+        key_hashes.reserve(this->keys_count);
+    }
+
+    void add_key(const string& key) {
+        key_hashes.push_back(first_hash(key.c_str(), key.size()));
+    }
+
+    void build() {
+        hash_gen(key_hashes.data());
+        key_hashes.clear();
+    }
+
 	/** Builds a RecSplit instance using a given list of keys and bucket size.
 	 *
 	 * **Warning**: duplicate keys will cause this method to never return.
@@ -448,7 +463,8 @@ template <size_t LEAF_SIZE, util::AllocType AT = util::AllocType::MALLOC> class
 	}
 
 	void recSplit(vector<uint64_t> &bucket, vector<uint64_t> &temp, size_t start, size_t end, typename RiceBitVector<AT>::Builder &builder, vector<uint32_t> &unary, const int level) {
-		const auto m = end - start;
+        static const array<uint8_t, MAX_LEAF_SIZE> bij_midstop = fill_bij_midstop();
+        const auto m = end - start;
 		assert(m > 1);
 		uint64_t x = start_seed[level];
 
diff --git a/sux/util/Vector.hpp b/sux/util/Vector.hpp
index 0459041..d9f29c9 100644
--- a/sux/util/Vector.hpp
+++ b/sux/util/Vector.hpp
@@ -92,13 +92,13 @@ template <typename T, AllocType AT = MALLOC> class Vector : public Expandable {
 	T *data = nullptr;
 
   public:
-	Vector<T, AT>() = default;
+	Vector() = default;
 
-	explicit Vector<T, AT>(size_t length) { size(length); }
+	explicit Vector(size_t length) { size(length); }
 
-	explicit Vector<T, AT>(const T *data, size_t length) : Vector(length) { memcpy(this->data, data, length); }
+	explicit Vector(const T *data, size_t length) : Vector(length) { memcpy(this->data, data, length); }
 
-	~Vector<T, AT>() {
+	~Vector() {
 		if (data) {
 			if (AT == MALLOC) {
 				free(data);
diff --git a/test/function/recsplit.hpp b/test/function/recsplit.hpp
index 8605786..5485f90 100644
--- a/test/function/recsplit.hpp
+++ b/test/function/recsplit.hpp
@@ -135,3 +135,33 @@ TEST(recsplit_test, small_text_dump_and_load) {
 	recsplit_unit_test(rs_load, keys);
 	remove(filename);
 }
+
+TEST(recsplit_test, small_text_dump_and_load_one_by_one) {
+	vector<string> keys;
+	keys.push_back("a");
+	keys.push_back("b");
+	keys.push_back("c");
+	keys.push_back("d");
+
+	const char *filename = "test/test_dump";
+
+	RecSplit<8> rs_dump(keys.size(), 2);
+	for (size_t i = 0; i < keys.size(); i++) rs_dump.add_key(keys[i]);
+	rs_dump.build();
+
+	fstream fs;
+	fs.exceptions(fstream::failbit | fstream::badbit);
+	fs.open(filename, fstream::out | fstream::binary | fstream::trunc);
+	fs << rs_dump;
+	fs.close();
+
+	RecSplit<8> rs_load;
+	fs.open(filename, std::fstream::in | std::fstream::binary);
+	fs >> rs_load;
+	fs.close();
+
+	for (size_t i = 0; i < rs_dump.size(); i++) ASSERT_EQ(rs_dump(keys[i]), rs_load(keys[i]));
+
+	recsplit_unit_test(rs_load, keys);
+	remove(filename);
+}