L4/Examples/main.cpp

#include <iostream>
#include <string>
#include <utility>
#include <vector>
#include "LocalMemory/HashTableService.h"

using namespace L4;

void SimpleExample() {
  EpochManagerConfig epochConfig{1000, std::chrono::milliseconds(100), 1};
  LocalMemory::HashTableService service{epochConfig};

  auto hashTableIndex = service.AddHashTable(
      HashTableConfig("Table1", HashTableConfig::Setting{1000000}));

  std::vector<std::pair<std::string, std::string>> keyValuePairs = {
      {"key1", "value1"}, {"key2", "value2"}, {"key3", "value3"},
      {"key4", "value4"}, {"key5", "value5"},
  };

  // Write data.
  {
    auto context = service.GetContext();
    auto& hashTable = context[hashTableIndex];

    for (const auto& keyValuePair : keyValuePairs) {
      const auto& keyStr = keyValuePair.first;
      const auto& valStr = keyValuePair.second;

      IWritableHashTable::Key key;
      key.m_data = reinterpret_cast<const std::uint8_t*>(keyStr.c_str());
      key.m_size = keyStr.size();

      IWritableHashTable::Value val;
      val.m_data = reinterpret_cast<const std::uint8_t*>(valStr.c_str());
      val.m_size = valStr.size();

      hashTable.Add(key, val);
    }
  }

  // Read data.
  {
    auto context = service.GetContext();

    // Once a context is retrieved, the operations such as
    // operator[] on the context and Get() are lock-free.
    auto& hashTable = context[hashTableIndex];

    for (const auto& keyValuePair : keyValuePairs) {
      const auto& keyStr = keyValuePair.first;

      IWritableHashTable::Key key;
      key.m_data = reinterpret_cast<const std::uint8_t*>(keyStr.c_str());
      key.m_size = keyStr.size();

      IWritableHashTable::Value val;
      hashTable.Get(key, val);

      std::cout << std::string(reinterpret_cast<const char*>(val.m_data),
                               val.m_size)
                << std::endl;
    }
  }
}

void CacheHashTableExample() {
  LocalMemory::HashTableService service;

  HashTableConfig::Cache cacheConfig{
      1024 * 1024,               // 1MB cache
      std::chrono::seconds(60),  // Record will exipre in 60 seconds
      true                       // Remove any expired records during eviction.
  };

  auto hashTableIndex = service.AddHashTable(HashTableConfig(
      "Table1", HashTableConfig::Setting{1000000}, cacheConfig));

  (void)hashTableIndex;
  // Use hash table similar to SimpleExample().
}

int main() {
  SimpleExample();

  CacheHashTableExample();

  return 0;
}