mdbx-test: initial/incomplete/draft test for get-cached feature.

test/CMakeLists.txt

@@ -292,6 +292,7 @@ else()
         add_extra_test(dbi)
         add_extra_test(open)
         add_extra_test(txn)
+        add_extra_test(get_cached)
       endif()
       add_extra_test(hex_base64_base58)
     endif()

test/extra/get_cached.c++

@@ -0,0 +1,140 @@
+#include "mdbx.h++"
+
+#include <chrono>
+#include <deque>
+#include <iostream>
+#include <vector>
+#if defined(__cpp_lib_latch) && __cpp_lib_latch >= 201907L
+#include <latch>
+#include <thread>
+#endif
+
+#if defined(ENABLE_MEMCHECK) || defined(MDBX_CI)
+#if MDBX_DEBUG || !defined(NDEBUG)
+#define RELIEF_FACTOR 16
+#else
+#define RELIEF_FACTOR 8
+#endif
+#elif MDBX_DEBUG || !defined(NDEBUG) || defined(__APPLE__) || defined(_WIN32)
+#define RELIEF_FACTOR 4
+#elif UINTPTR_MAX > 0xffffFFFFul || ULONG_MAX > 0xffffFFFFul
+#define RELIEF_FACTOR 2
+#else
+#define RELIEF_FACTOR 1
+#endif
+
+// static const auto NN = 1000u / RELIEF_FACTOR;
+
+#if defined(__cpp_lib_latch) && __cpp_lib_latch >= 201907L
+static const auto N = std::min(17u, std::thread::hardware_concurrency());
+#else
+static const auto N = 3u;
+#endif
+
+static void logger_nofmt(MDBX_log_level_t loglevel, const char *function, int line, const char *msg,
+                         unsigned length) noexcept {
+  (void)length;
+  (void)loglevel;
+  fflush(nullptr);
+  std::cout << function << ":" << line << " " << msg;
+  std::cout.flush();
+}
+
+static char log_buffer[1024];
+
+//--------------------------------------------------------------------------------------------
+
+typedef MDBX_cache_result_t (*get_cached_t)(const MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *key, MDBX_val *data,
+                                            MDBX_cache_entry *entry);
+
+static bool check_state(const MDBX_cache_result_t &r, const MDBX_error_t wanna_errcode,
+                        const MDBX_cache_status_t wanna_status, unsigned line) {
+  if (r.errcode == wanna_errcode && r.status == wanna_status)
+    return true;
+  std::cerr << "unecpected (at " << line
+            << "): "
+               "err "
+            << r.errcode << " (wanna " << wanna_errcode
+            << "), "
+               "status "
+            << r.status << " (wanna " << wanna_status << ")" << std::endl;
+  return false;
+}
+
+bool case0(mdbx::env env) {
+  get_cached_t get_cached = mdbx_cache_get_SingleThreaded;
+  auto txn = env.start_write();
+  auto table = txn.create_map("case0", mdbx::key_mode::usual, mdbx::value_mode::single);
+
+  MDBX_val data;
+  MDBX_cache_entry entry;
+  MDBX_cache_result_t r;
+
+  bool ok = true;
+  mdbx_cache_init(&entry);
+  r = get_cached(txn, table, mdbx::slice("key"), &data, &entry);
+  ok = check_state(r, MDBX_NOTFOUND, MDBX_CACHE_DIRTY, __LINE__) && ok;
+
+  txn.commit_embark_read();
+  r = get_cached(txn, table, mdbx::slice("key"), &data, &entry);
+  ok = check_state(r, MDBX_NOTFOUND, MDBX_CACHE_REFRESHED, __LINE__) && ok;
+
+  {
+    auto params = mdbx::env::operate_parameters(42);
+    params.options.no_sticky_threads = true;
+    mdbx::env_managed env2(env.get_path(), params);
+    auto txn2 = env2.start_write();
+    txn2.drop_map("case0");
+    txn2.commit();
+  }
+  txn.renew_reading();
+  r = get_cached(txn, table, mdbx::slice("key"), &data, &entry);
+  ok = check_state(r, MDBX_NOTFOUND, MDBX_CACHE_CONFIRMED, __LINE__) && ok;
+
+  txn.abort();
+  txn = env.start_write();
+  table = txn.create_map("case0", mdbx::key_mode::usual, mdbx::value_mode::single);
+  r = get_cached(txn, table, mdbx::slice("key"), &data, &entry);
+  ok = check_state(r, MDBX_NOTFOUND, MDBX_CACHE_DIRTY, __LINE__) && ok;
+
+  txn.commit_embark_read();
+  r = get_cached(txn, table, mdbx::slice("key"), &data, &entry);
+  ok = check_state(r, MDBX_NOTFOUND, MDBX_CACHE_CONFIRMED, __LINE__) && ok;
+
+  return ok;
+}
+
+//--------------------------------------------------------------------------------------------
+
+int doit() {
+  mdbx::path db_filename = "test-get-cached";
+  mdbx::env::remove(db_filename);
+
+  mdbx::env_managed env(db_filename, mdbx::env_managed::create_parameters(),
+                        mdbx::env::operate_parameters(N + 2, 0, mdbx::env::nested_transactions));
+
+  bool ok = case0(env);
+  // ok = case1(env) && ok;
+  // ok = case2(env) && ok;
+
+  if (ok) {
+    std::cout << "OK\n";
+    return EXIT_SUCCESS;
+  } else {
+    std::cout << "FAIL!\n";
+    return EXIT_FAILURE;
+  }
+}
+
+int main(int argc, char *argv[]) {
+  (void)argc;
+  (void)argv;
+  mdbx_setup_debug_nofmt(MDBX_LOG_NOTICE, MDBX_DBG_ASSERT | MDBX_DBG_LEGACY_MULTIOPEN, logger_nofmt, log_buffer,
+                         sizeof(log_buffer));
+  try {
+    return doit();
+  } catch (const std::exception &ex) {
+    std::cerr << "Exception: " << ex.what() << "\n";
+    return EXIT_FAILURE;
+  }
+}