ringfilecache.cc

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/*
                          Aleph_w
 
  Data structures & Algorithms
  version 2.0.0b
  https://github.com/lrleon/Aleph-w
 
  This file is part of Aleph-w library
 
  Copyright (c) 2002-2026 Leandro Rabindranath Leon
 
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
 
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
 
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/
 
 
#include <gtest/gtest.h>
 
#include <ringfilecache.H>
 
#include <atomic>
#include <chrono>
#include <cstring>
#include <filesystem>
#include <random>
#include <string>
#include <vector>
 
using namespace Aleph;
using namespace std;
namespace fs = std::filesystem;
 
namespace {
 
struct TempPaths
{
  fs::path pars;
  fs::path cache;
};
 
TempPaths make_temp_paths()
{
  static std::atomic<unsigned long long> counter{0};
  const auto now = std::chrono::steady_clock::now().time_since_epoch().count();
  const auto id = std::to_string(now) + "_" + std::to_string(counter++);
 
  const fs::path dir = fs::temp_directory_path() / "aleph_ringcache_tests";
  fs::create_directories(dir);
  return {dir / (id + ".pars"), dir / (id + ".cache")};
}
 
struct TempFiles
{
  TempPaths paths;
  explicit TempFiles(TempPaths p) : paths(std::move(p)) {}
  ~TempFiles()
  {
    std::error_code ec;
    fs::remove(paths.pars, ec);
    fs::remove(paths.cache, ec);
  }
};
 
template <typename T>
std::vector<T> to_vector(const Array<T> &arr)
{
  std::vector<T> out;
  for (size_t i = 0; i < arr.size(); ++i)
    out.push_back(arr[i]);
  return out;
}
 
TEST(RingFileCache, basic_put_read_get_and_overflow)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 4);
  ASSERT_TRUE(RingFileCache<int>::test(tmp.paths.pars.string()));
 
  RingFileCache<int> cache(tmp.paths.pars.string());
  EXPECT_TRUE(cache.is_initialized());
  EXPECT_EQ(cache.capacity(), 4u);
  EXPECT_EQ(cache.size(), 0u);
  EXPECT_TRUE(cache.read_all().is_empty());
 
  EXPECT_TRUE(cache.put(1));
  EXPECT_TRUE(cache.put(2));
  EXPECT_TRUE(cache.put(3));
  EXPECT_TRUE(cache.put(4));
  EXPECT_FALSE(cache.put(5)); // full
  EXPECT_EQ(cache.size(), 4u);
 
  int buf[4] = {0, 0, 0, 0};
  EXPECT_TRUE(cache.read(buf, 4));
  EXPECT_EQ(std::vector<int>(buf, buf + 4), std::vector<int>({1, 2, 3, 4}));
  EXPECT_EQ(cache.read_first(), 1);
  EXPECT_EQ(cache.read_last(), 4);
  EXPECT_EQ(cache.oldest(), 1);
  EXPECT_EQ(cache.oldest(2), 3);
 
  EXPECT_TRUE(cache.get(2));
  EXPECT_EQ(cache.size(), 2u);
  EXPECT_EQ(cache.read_first(), 3);
  EXPECT_EQ(cache.read_last(), 4);
  EXPECT_TRUE(cache.get(2));
  EXPECT_TRUE(cache.is_empty());
 
  EXPECT_THROW(cache.read_first(), std::underflow_error);
  EXPECT_THROW(cache.read_last(), std::underflow_error);
  EXPECT_FALSE(cache.get(1));          // cannot extract if empty
  EXPECT_FALSE(cache.read(buf, 1));    // cannot read if empty
}
 
TEST(RingFileCache, read_from_position_pointer_and_iterator)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 5);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  for (int v : {10, 20, 30, 40})
    ASSERT_TRUE(cache.put(v));
 
  auto sub = cache.read_from(1, 2);
  EXPECT_EQ(to_vector(sub), std::vector<int>({20, 30}));
 
  RingFileCache<int>::Pointer ptr(cache); // at head (10)
  ptr += 2;                               // points to 30
  auto sub_ptr = cache.read_from(ptr, 3); // should stop at available items
  EXPECT_EQ(to_vector(sub_ptr), std::vector<int>({30, 40}));
 
  std::vector<int> iterated;
  for (auto it = cache.get_it(); it.has_curr(); it.next_ne())
    iterated.push_back(it.get_curr_ne());
  EXPECT_EQ(iterated, std::vector<int>({10, 20, 30, 40}));
}
 
TEST(RingFileCache, persistence_and_flush)
{
  TempPaths paths = make_temp_paths();
  TempFiles tmp(paths);
  {
    RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 6);
    RingFileCache<int> cache(tmp.paths.pars.string());
    for (int v : {1, 2, 3})
      ASSERT_TRUE(cache.put(v));
    cache.flush();
  }
 
  RingFileCache<int> reopened(tmp.paths.pars.string());
  EXPECT_EQ(reopened.size(), 3u);
  EXPECT_EQ(reopened.read_first(), 1);
  EXPECT_EQ(reopened.read_last(), 3);
  auto all = reopened.read_all();
  EXPECT_EQ(to_vector(all), std::vector<int>({1, 2, 3}));
  reopened.get(2);
  EXPECT_EQ(reopened.size(), 1u);
  EXPECT_EQ(reopened.read_first(), 3);
}
 
TEST(RingFileCache, resize_and_append)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 2);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  cache.put(7);
  cache.put(8);
  EXPECT_EQ(cache.capacity(), 2u);
  cache.resize(5);
  EXPECT_EQ(cache.capacity(), 5u);
  EXPECT_TRUE(cache.put(9));
  EXPECT_TRUE(cache.put(10));
  EXPECT_TRUE(cache.put(11));
 
  auto all = cache.read_all();
  EXPECT_EQ(to_vector(all), std::vector<int>({7, 8, 9, 10, 11}));
}
 
TEST(RingFileCache, read_all_empty_is_safe)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 3);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  auto all = cache.read_all();
  EXPECT_TRUE(all.is_empty());
}
 
TEST(RingFileCache, pointer_offsets_and_wraparound_iteration)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 3);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  cache.put(1);
  cache.put(2);
  cache.put(3);
 
  RingFileCache<int>::Pointer ptr(cache); // at head
  EXPECT_EQ(ptr.get_pos_respect_to_head(), 0u);
 
  auto first_two = cache.read_from(ptr, 2);
  EXPECT_EQ(to_vector(first_two), std::vector<int>({1, 2}));
 
  ptr += 1;
  EXPECT_EQ(ptr.get_pos_respect_to_head(), 1u);
 
  ptr += 5; // wraps around dimension 3
  EXPECT_EQ(ptr.get_pos_respect_to_head(), 0u);
 
  cache.get(2); // remove 1 and 2
  cache.put(4);
  cache.put(5);
 
  RingFileCache<int>::Pointer head_ptr(cache);
  auto wrapped = cache.read_from(head_ptr, 3);
  EXPECT_EQ(to_vector(wrapped), std::vector<int>({3, 4, 5}));
 
  std::vector<int> iterated;
  for (auto it = cache.get_it(); it.has_curr(); it.next_ne())
    iterated.push_back(it.get_curr_ne());
  EXPECT_EQ(iterated, std::vector<int>({3, 4, 5}));
}
 
TEST(RingFileCache, init_and_close_are_idempotent_and_persistent)
{
  TempPaths paths = make_temp_paths();
  TempFiles tmp(paths);
 
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 4);
  RingFileCache<int> cache;
  cache.init(tmp.paths.pars.string());
  ASSERT_TRUE(cache.is_initialized());
  cache.put(42);
  cache.close();
  cache.close(); // should be a no-op
 
  RingFileCache<int> reopened(tmp.paths.pars.string());
  EXPECT_EQ(reopened.size(), 1u);
  EXPECT_EQ(reopened.read_first(), 42);
}
 
TEST(RingFileCache, is_full_method)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 3);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  EXPECT_FALSE(cache.is_full());
  EXPECT_TRUE(cache.is_empty());
 
  cache.put(1);
  EXPECT_FALSE(cache.is_full());
  EXPECT_FALSE(cache.is_empty());
 
  cache.put(2);
  cache.put(3);
  EXPECT_TRUE(cache.is_full());
  EXPECT_FALSE(cache.is_empty());
 
  cache.get(1);
  EXPECT_FALSE(cache.is_full());
}
 
TEST(RingFileCache, wraparound_stress_test)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 4);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  // Fill, empty, refill multiple cycles to stress wraparound
  for (int cycle = 0; cycle < 5; ++cycle)
    {
      // Fill completely
      for (int i = 0; i < 4; ++i)
        ASSERT_TRUE(cache.put(cycle * 10 + i));
      EXPECT_TRUE(cache.is_full());
 
      // Verify contents
      for (int i = 0; i < 4; ++i)
        EXPECT_EQ(cache.oldest(i), cycle * 10 + i);
 
      // Empty completely
      EXPECT_TRUE(cache.get(4));
      EXPECT_TRUE(cache.is_empty());
    }
 
  // Partial fill/empty cycles
  for (int cycle = 0; cycle < 10; ++cycle)
    {
      cache.put(cycle);
      cache.put(cycle + 100);
      EXPECT_EQ(cache.size(), 2u);
      EXPECT_EQ(cache.read_first(), cycle);
      EXPECT_EQ(cache.read_last(), cycle + 100);
      cache.get(2);
    }
}
 
TEST(RingFileCache, resize_with_wrapped_data)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 4);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  // Create wraparound: fill, remove some, add more
  cache.put(1);
  cache.put(2);
  cache.put(3);
  cache.put(4);
  cache.get(2);  // remove 1, 2 -> head moves forward
  cache.put(5);
  cache.put(6);  // now data wraps: [5, 6, 3, 4] with head at index 2
 
  EXPECT_EQ(cache.size(), 4u);
  auto before = cache.read_all();
  EXPECT_EQ(to_vector(before), std::vector<int>({3, 4, 5, 6}));
 
  // Resize while wrapped
  cache.resize(8);
  EXPECT_EQ(cache.capacity(), 8u);
  EXPECT_EQ(cache.size(), 4u);
 
  // Data should still be correct after resize
  auto after = cache.read_all();
  EXPECT_EQ(to_vector(after), std::vector<int>({3, 4, 5, 6}));
 
  // Can add more now
  EXPECT_TRUE(cache.put(7));
  EXPECT_TRUE(cache.put(8));
  EXPECT_TRUE(cache.put(9));
  EXPECT_TRUE(cache.put(10));
  EXPECT_EQ(cache.size(), 8u);
  EXPECT_TRUE(cache.is_full());
}
 
TEST(RingFileCache, resize_same_size_and_empty)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 4);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  // Resize empty cache
  cache.resize(6);
  EXPECT_EQ(cache.capacity(), 6u);
  EXPECT_EQ(cache.size(), 0u);
 
  // Resize to same size should be no-op (but allowed)
  cache.put(1);
  cache.resize(6);
  EXPECT_EQ(cache.capacity(), 6u);
  EXPECT_EQ(cache.size(), 1u);
  EXPECT_EQ(cache.read_first(), 1);
}
 
TEST(RingFileCache, iterator_exhaustion_throws)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 3);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  cache.put(1);
  cache.put(2);
 
  auto it = cache.get_it();
  EXPECT_TRUE(it.has_curr());
  EXPECT_EQ(it.get_curr(), 1);
  it.next();
  EXPECT_EQ(it.get_curr(), 2);
  it.next();
  EXPECT_FALSE(it.has_curr());
 
  // get_curr() should throw when exhausted
  EXPECT_THROW(it.get_curr(), std::overflow_error);
  // next() should throw when exhausted
  EXPECT_THROW(it.next(), std::overflow_error);
}
 
TEST(RingFileCache, oldest_bounds_check)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 5);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  cache.put(10);
  cache.put(20);
  cache.put(30);
 
  EXPECT_EQ(cache.oldest(0), 10);
  EXPECT_EQ(cache.oldest(1), 20);
  EXPECT_EQ(cache.oldest(2), 30);
 
  // Out of bounds should throw
  EXPECT_THROW(cache.oldest(3), std::overflow_error);
  EXPECT_THROW(cache.oldest(100), std::overflow_error);
}
 
TEST(RingFileCache, double_init_throws)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 4);
 
  RingFileCache<int> cache;
  cache.init(tmp.paths.pars.string());
  EXPECT_TRUE(cache.is_initialized());
 
  // Second init should throw
  EXPECT_THROW(cache.init(tmp.paths.pars.string()), std::domain_error);
}
 
TEST(RingFileCache, pointer_negative_arithmetic)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 5);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  for (int i = 0; i < 5; ++i)
    cache.put(i * 10);
 
  RingFileCache<int>::Pointer ptr(cache, 2);  // points to entry with value 20
  EXPECT_EQ(cache.read(ptr), 20);
 
  ptr -= 1;
  EXPECT_EQ(cache.read(ptr), 10);
 
  ptr -= 1;
  EXPECT_EQ(cache.read(ptr), 0);
 
  // Wraparound backward
  ptr -= 1;
  EXPECT_EQ(cache.read(ptr), 40);  // wraps to last entry
 
  ptr -= 2;
  EXPECT_EQ(cache.read(ptr), 20);
 
  // Large negative offset
  ptr -= 7;  // 7 % 5 = 2 steps back from 20 -> 0
  EXPECT_EQ(cache.read(ptr), 0);
}
 
TEST(RingFileCache, pointer_with_negative_delta_via_plus_operator)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 4);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  for (int i = 0; i < 4; ++i)
    cache.put(i);
 
  RingFileCache<int>::Pointer ptr(cache, 2);  // at value 2
  EXPECT_EQ(cache.read(ptr), 2);
 
  auto ptr2 = ptr + (-1);  // should go back 1
  EXPECT_EQ(cache.read(ptr2), 1);
 
  ptr2 = ptr + (-3);  // should wrap to value 3
  EXPECT_EQ(cache.read(ptr2), 3);
}
 
// Test with a non-int trivially copyable type
struct TestRecord
{
  int id;
  double value;
  char tag[8];
 
  bool operator==(const TestRecord &other) const
  {
    return id == other.id && value == other.value &&
           std::strncmp(tag, other.tag, 8) == 0;
  }
};
 
TEST(RingFileCache, non_int_trivially_copyable_type)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<TestRecord>::create(tmp.paths.pars.string(),
                                     tmp.paths.cache.string(), 3);
  RingFileCache<TestRecord> cache(tmp.paths.pars.string());
 
  TestRecord r1{1, 3.14, "alpha"};
  TestRecord r2{2, 2.71, "beta"};
  TestRecord r3{3, 1.41, "gamma"};
 
  EXPECT_TRUE(cache.put(r1));
  EXPECT_TRUE(cache.put(r2));
  EXPECT_TRUE(cache.put(r3));
  EXPECT_TRUE(cache.is_full());
 
  EXPECT_EQ(cache.read_first(), r1);
  EXPECT_EQ(cache.read_last(), r3);
  EXPECT_EQ(cache.oldest(1), r2);
 
  cache.get(1);
  EXPECT_EQ(cache.read_first(), r2);
}
 
TEST(RingFileCache, empty_cache_operations)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 5);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  EXPECT_TRUE(cache.is_empty());
  EXPECT_FALSE(cache.is_full());
  EXPECT_EQ(cache.size(), 0u);
  EXPECT_EQ(cache.avail(), 5u);
 
  // These should return false, not throw
  EXPECT_FALSE(cache.get(1));
  int buf[1];
  EXPECT_FALSE(cache.read(buf, 1));
 
  // read_all on empty returns empty array
  auto all = cache.read_all();
  EXPECT_TRUE(all.is_empty());
 
  // Iterator on empty cache
  auto it = cache.get_it();
  EXPECT_FALSE(it.has_curr());
}
 
TEST(RingFileCache, read_from_beyond_available)
{
  TempFiles tmp(make_temp_paths());
  RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 10);
  RingFileCache<int> cache(tmp.paths.pars.string());
 
  cache.put(1);
  cache.put(2);
  cache.put(3);
 
  // read_from with pos beyond size should return partial or empty
  auto result = cache.read_from(5, 3);  // pos=5 but only 3 items exist
  EXPECT_TRUE(result.is_empty());
 
  // read_from with large m should stop at available items
  auto result2 = cache.read_from(1, 100);  // start at 1, request 100, only 2 available
  EXPECT_EQ(to_vector(result2), std::vector<int>({2, 3}));
}
 
TEST(RingFileCache, persistence_after_wraparound)
{
  TempPaths paths = make_temp_paths();
  TempFiles tmp(paths);
 
  {
    RingFileCache<int>::create(tmp.paths.pars.string(), tmp.paths.cache.string(), 4);
    RingFileCache<int> cache(tmp.paths.pars.string());
 
    // Create wraparound state
    cache.put(1);
    cache.put(2);
    cache.put(3);
    cache.put(4);
    cache.get(2);  // remove 1, 2
    cache.put(5);
    cache.put(6);
    // State: [5, 6, 3, 4] with head at 2
 
    cache.flush();
  }
 
  // Reopen and verify wraparound state persisted correctly
  RingFileCache<int> reopened(tmp.paths.pars.string());
  EXPECT_EQ(reopened.size(), 4u);
  auto all = reopened.read_all();
  EXPECT_EQ(to_vector(all), std::vector<int>({3, 4, 5, 6}));
}
 
} // namespace