text: //===--- MultiMapCacheTest.cpp --------------------------------------------===//
  //
  // This source file is part of the Swift.org open source project
  //
  // Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
  // Licensed under Apache License v2.0 with Runtime Library Exception
  //
  // See https://swift.org/LICENSE.txt for license information
  // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
  //
  //===----------------------------------------------------------------------===//
  
  #include "swift/Basic/MultiMapCache.h"
  #include "swift/Basic/Range.h"
  #include "gtest/gtest.h"
  #include <random>
  
  using namespace swift;
  
  TEST(MultiMapCache, powersTest) {
    std::function<bool(unsigned, std::vector<unsigned> &)> cacheCompute =
        [&](unsigned key, std::vector<unsigned> &outArray) {
          outArray.push_back(key);
          outArray.push_back(key * key);
          outArray.push_back(key * key * key);
          return true;
        };
    MultiMapCache<unsigned, unsigned> cache(cacheCompute);
  
    EXPECT_TRUE(cache.empty());
    EXPECT_EQ(cache.size(), 0u);
    for (unsigned index : range(1, 256)) {
      auto array = *cache.get(index);
      for (unsigned power : array) {
        EXPECT_EQ(power % index, 0u);
      }
    }
    EXPECT_FALSE(cache.empty());
    EXPECT_EQ(cache.size(), 255u);
    for (unsigned index : range(1, 256)) {
      auto array = *cache.get(index);
      for (unsigned power : array) {
        EXPECT_EQ(power % index, 0u);
      }
    }
    EXPECT_FALSE(cache.empty());
    EXPECT_EQ(cache.size(), 255u);
  
    cache.clear();
    EXPECT_TRUE(cache.empty());
    EXPECT_EQ(cache.size(), 0u);
  }
  
  TEST(MultiMapCache, smallTest) {
    std::function<bool(unsigned, SmallVectorImpl<unsigned> &)> cacheCompute =
        [&](unsigned key, SmallVectorImpl<unsigned> &outArray) {
          outArray.push_back(key);
          outArray.push_back(key * key);
          outArray.push_back(key * key * key);
          return true;
        };
    SmallMultiMapCache<unsigned, unsigned> cache(cacheCompute);
  
    EXPECT_TRUE(cache.empty());
    EXPECT_EQ(cache.size(), 0u);
    for (unsigned index : range(1, 256)) {
      auto array = *cache.get(index);
      for (unsigned power : array) {
        EXPECT_EQ(power % index, 0u);
      }
    }
    EXPECT_FALSE(cache.empty());
    EXPECT_EQ(cache.size(), 255u);
    for (unsigned index : range(1, 256)) {
      auto array = *cache.get(index);
      for (unsigned power : array) {
        EXPECT_EQ(power % index, 0u);
      }
    }
    EXPECT_FALSE(cache.empty());
    EXPECT_EQ(cache.size(), 255u);
  
    cache.clear();
    EXPECT_TRUE(cache.empty());
    EXPECT_EQ(cache.size(), 0u);
  }
  