add bench

include/xcdat.hpp

@@ -70,9 +70,8 @@ template <class Trie>
 
 [[maybe_unused]] std::vector<std::string> load_strings(std::string_view filepath) {
     std::ifstream ifs(filepath);
-    if (!ifs) {
-        return {};
-    }
+    XCDAT_THROW_IF(!ifs.good(), "Cannot open the input file");
+
     std::vector<std::string> strs;
     for (std::string str; std::getline(ifs, str);) {
         strs.push_back(str);

include/xcdat/bc_vector_7.hpp

@@ -141,6 +141,14 @@ class bc_vector_7 {
         return m_ints_l1.size() / 2;
     }
 
+    inline std::uint64_t num_free_units() const {
+        return m_num_frees;
+    }
+
+    inline std::uint64_t num_nodes() const {
+        return num_units() - num_free_units();
+    }
+
     inline std::uint64_t num_leaves() const {
         return m_leaves.num_ones();
     }

include/xcdat/bc_vector_8.hpp

@@ -109,6 +109,14 @@ class bc_vector_8 {
         return m_bytes[0].size() / 2;
     }
 
+    inline std::uint64_t num_free_units() const {
+        return m_num_frees;
+    }
+
+    inline std::uint64_t num_nodes() const {
+        return num_units() - num_free_units();
+    }
+
     inline std::uint64_t num_leaves() const {
         return m_leaves.num_ones();
     }

include/xcdat/trie.hpp

@@ -72,6 +72,21 @@ class trie {
         return m_table.max_length();
     }
 
+    //! Get the number of trie nodes.
+    inline std::uint64_t num_nodes() const {
+        return m_bcvec.num_nodes();
+    }
+
+    //! Get the number of DA units.
+    inline std::uint64_t num_units() const {
+        return m_bcvec.num_units();
+    }
+
+    //! Get the number of unused DA units.
+    inline std::uint64_t num_free_units() const {
+        return m_bcvec.num_free_units();
+    }
+
     //! Lookup the ID of the keyword.
     inline std::optional<std::uint64_t> lookup(std::string_view key) const {
         std::uint64_t kpos = 0, npos = 0;
@@ -98,12 +113,18 @@ class trie {
 
     //! Decode the keyword associated with the ID.
     inline std::string decode(std::uint64_t id) const {
-        if (num_keys() <= id) {
-            return {};
-        }
-
         std::string decoded;
         decoded.reserve(max_length());
+        decode(id, decoded);
+        return decoded;
+    }
+
+    //! Decode the keyword associated with the ID.
+    inline void decode(std::uint64_t id, std::string& decoded) const {
+        decoded.clear();
+        if (num_keys() <= id) {
+            return;
+        }
 
         std::uint64_t npos = id_to_npos(id);
         std::uint64_t tpos = m_bcvec.is_leaf(npos) ? m_bcvec.link(npos) : UINT64_MAX;
@@ -118,7 +139,6 @@ class trie {
         if (tpos != 0 && tpos != UINT64_MAX) {
             m_tvec.decode(tpos, [&](char c) { decoded.push_back(c); });
         }
-        return decoded;
     }
 
     //! An iterator class for common prefix search.

tools/CMakeLists.txt

@@ -5,6 +5,7 @@ set(XCDAT_FILES
     "xcdat_prefix_search"
     "xcdat_predictive_search"
     "xcdat_enumerate"
+    "xcdat_benchmark"
 )
 
 foreach(XCDAT_FILE ${XCDAT_FILES})

tools/xcdat_benchmark.cpp

@@ -0,0 +1,144 @@
+#include <chrono>
+#include <random>
+
+#include <xcdat.hpp>
+
+#include "cmd_line_parser/parser.hpp"
+#include "tinyformat/tinyformat.h"
+
+static constexpr int num_trials = 10;
+
+cmd_line_parser::parser make_parser(int argc, char** argv) {
+    cmd_line_parser::parser p(argc, argv);
+    p.add("input_keys", "Input filepath of data keys");
+    p.add("num_samples", "Number of sample keys for benchmark (default=1000)", "-n", false);
+    p.add("random_seed", "Random seed for sampling (default=13)", "-s", false);
+    return p;
+}
+
+auto sample_keys(const std::vector<std::string>& keys, std::uint64_t num_samples, std::uint64_t random_seed) {
+    std::vector<std::string_view> sampled_keys(num_samples);
+    std::vector<std::uint64_t> sampled_ids(num_samples);
+
+    std::mt19937_64 engine(random_seed);
+    std::uniform_int_distribution<std::uint64_t> dist(0, keys.size() - 1);
+
+    for (std::uint64_t i = 0; i < num_samples; i++) {
+        sampled_ids[i] = dist(engine);
+        sampled_keys[i] = std::string_view(keys[sampled_ids[i]]);
+    }
+
+    return std::make_tuple(std::move(sampled_keys), std::move(sampled_ids));
+}
+
+template <class Trie>
+Trie benchmark_build(const std::vector<std::string>& keys) {
+    const auto start_tp = std::chrono::high_resolution_clock::now();
+    Trie trie(keys);
+    const auto stop_tp = std::chrono::high_resolution_clock::now();
+
+    const auto dur_ms = std::chrono::duration_cast<std::chrono::milliseconds>(stop_tp - start_tp);
+    const double time_in_sec = dur_ms.count() / 1000.0;
+    const double memory_in_bytes = xcdat::memory_in_bytes(trie);
+
+    tfm::printfln("Number of trie nodes: %d", trie.num_nodes());
+    tfm::printfln("Number of DA units: %d", trie.num_units());
+    tfm::printfln("Number of free DA units: %d", trie.num_free_units());
+    tfm::printfln("Memory usage in bytes: %d", memory_in_bytes);
+    tfm::printfln("Memory usage in MiB: %g", memory_in_bytes / (1024.0 * 1024.0));
+    tfm::printfln("Construction time in seconds: %g", time_in_sec);
+
+    return trie;
+}
+
+template <class Trie>
+void benchmark_lookup(const Trie& trie, const std::vector<std::string_view>& queries) {
+    // Warmup
+    volatile std::uint64_t tmp = 0;
+    for (const auto& query : queries) {
+        tmp += trie.lookup(query).value();
+    }
+
+    // Measure
+    const auto start_tp = std::chrono::high_resolution_clock::now();
+    for (int r = 0; r < num_trials; r++) {
+        for (const auto& query : queries) {
+            tmp += trie.lookup(query).value();
+        }
+    }
+    const auto stop_tp = std::chrono::high_resolution_clock::now();
+
+    const auto dur_us = std::chrono::duration_cast<std::chrono::microseconds>(stop_tp - start_tp);
+    const auto elapsed_us = static_cast<double>(dur_us.count());
+
+    tfm::printfln("Lookup time in microsec/query: %g", elapsed_us / (num_trials * queries.size()));
+}
+
+template <class Trie>
+void benchmark_decode(const Trie& trie, const std::vector<std::uint64_t>& queries) {
+    // Warmup
+    std::string tmp;
+    for (const std::uint64_t query : queries) {
+        trie.decode(query, tmp);
+    }
+
+    // Measure
+    const auto start_tp = std::chrono::high_resolution_clock::now();
+    for (int r = 0; r < num_trials; r++) {
+        for (const std::uint64_t query : queries) {
+            trie.decode(query, tmp);
+        }
+    }
+    const auto stop_tp = std::chrono::high_resolution_clock::now();
+
+    const auto dur_us = std::chrono::duration_cast<std::chrono::microseconds>(stop_tp - start_tp);
+    const auto elapsed_us = static_cast<double>(dur_us.count());
+
+    tfm::printfln("Decode time in microsec/query: %g", elapsed_us / (num_trials * queries.size()));
+}
+
+template <class Trie>
+void benchmark(std::vector<std::string> keys, const std::vector<std::string_view>& q_keys,
+               const std::vector<std::uint64_t>& q_ids) {
+    const auto trie = benchmark_build<Trie>(keys);
+
+    benchmark_lookup(trie, q_keys);
+    benchmark_decode(trie, q_ids);
+}
+
+int main(int argc, char** argv) {
+#ifndef NDEBUG
+    tfm::warnfln("The code is running in debug mode.");
+#endif
+    std::ios::sync_with_stdio(false);
+
+    auto p = make_parser(argc, argv);
+    if (!p.parse()) {
+        return 1;
+    }
+
+    const auto input_keys = p.get<std::string>("input_keys");
+    const auto num_samples = p.get<std::uint64_t>("num_samples", 1000);
+    const auto random_seed = p.get<std::uint64_t>("random_seed", 13);
+
+    auto keys = xcdat::load_strings(input_keys);
+    if (keys.empty()) {
+        tfm::errorfln("Error: The input dataset is empty.");
+        return 1;
+    }
+
+    // To unique
+    std::sort(keys.begin(), keys.end());
+    keys.erase(std::unique(keys.begin(), keys.end()), keys.end());
+
+    tfm::printfln("Number of keys: %d", keys.size());
+    auto [q_keys, q_ids] = sample_keys(keys, num_samples, random_seed);
+
+    tfm::printfln("** xcdat::trie_7_type **");
+    benchmark<xcdat::trie_7_type>(keys, q_keys, q_ids);
+
+    tfm::printfln("** xcdat::trie_8_type **");
+    benchmark<xcdat::trie_8_type>(keys, q_keys, q_ids);
+
+    return 0;
+}