sapling/eden/fs/store/test/BlobCacheTest.cpp
Xavier Deguillard a29d465ee8 fs: fix license header
Summary:
With Facebook having been renamed Meta Platforms, we need to change the license
headers.

Reviewed By: fanzeyi

Differential Revision: D33407812

fbshipit-source-id: b11bfbbf13a48873f0cea75f212cc7b07a68fb2e
2022-01-04 15:00:07 -08:00

121 lines
4.0 KiB
C++

/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This software may be used and distributed according to the terms of the
* GNU General Public License version 2.
*/
#include "eden/fs/store/BlobCache.h"
#include <folly/portability/GTest.h>
#include "eden/fs/model/Blob.h"
using namespace folly::literals;
using namespace facebook::eden;
namespace {
const auto hash3 =
ObjectId::fromHex("0000000000000000000000000000000000000000");
const auto hash4 =
ObjectId::fromHex("0000000000000000000000000000000000000001");
const auto hash5 =
ObjectId::fromHex("0000000000000000000000000000000000000002");
const auto hash6 =
ObjectId::fromHex("0000000000000000000000000000000000000003");
const auto hash9 =
ObjectId::fromHex("0000000000000000000000000000000000000004");
// Each blob's name corresponds to its length in bytes.
const auto blob3 = std::make_shared<Blob>(hash3, "333"_sp);
const auto blob4 = std::make_shared<Blob>(hash4, "4444"_sp);
const auto blob5 = std::make_shared<Blob>(hash5, "55555"_sp);
const auto blob6 = std::make_shared<Blob>(hash6, "666666"_sp);
const auto blob9 = std::make_shared<Blob>(hash9, "999999999"_sp);
} // namespace
TEST(BlobCache, evicts_oldest_on_insertion) {
auto cache = BlobCache::create(10, 0);
cache->insert(blob3);
cache->insert(blob4); // blob4 is considered more recent than blob3
EXPECT_EQ(7, cache->getStats().totalSizeInBytes);
cache->insert(blob5); // evicts blob3
EXPECT_EQ(9, cache->getStats().totalSizeInBytes);
EXPECT_EQ(nullptr, cache->get(hash3).object)
<< "Inserting blob5 should evict oldest (blob3)";
EXPECT_EQ(blob4, cache->get(hash4).object) << "But blob4 still fits";
cache->insert(blob3); // evicts blob5
EXPECT_EQ(7, cache->getStats().totalSizeInBytes);
EXPECT_EQ(nullptr, cache->get(hash5).object)
<< "Inserting blob3 again evicts blob5 because blob4 was accessed";
EXPECT_EQ(blob4, cache->get(hash4).object);
}
TEST(BlobCache, inserting_large_blob_evicts_multiple_small_blobs) {
auto cache = BlobCache::create(10, 0);
cache->insert(blob3);
cache->insert(blob4);
cache->insert(blob9);
EXPECT_FALSE(cache->get(hash3).object);
EXPECT_FALSE(cache->get(hash4).object);
EXPECT_EQ(blob9, cache->get(hash9).object);
}
TEST(BlobCache, preserves_minimum_number_of_entries) {
auto cache = BlobCache::create(1, 3);
cache->insert(blob3);
cache->insert(blob4);
cache->insert(blob5);
cache->insert(blob6);
EXPECT_EQ(15, cache->getStats().totalSizeInBytes);
EXPECT_FALSE(cache->get(hash3).object);
EXPECT_TRUE(cache->get(hash4).object);
EXPECT_TRUE(cache->get(hash5).object);
EXPECT_TRUE(cache->get(hash6).object);
}
TEST(BlobCache, can_forget_cached_entries) {
auto cache = BlobCache::create(100, 0);
auto handle3 = cache->insert(
std::make_shared<Blob>(hash3, "blob3"_sp),
BlobCache::Interest::WantHandle);
auto handle4 = cache->insert(
std::make_shared<Blob>(hash4, "blob4"_sp),
BlobCache::Interest::WantHandle);
// The use of WantHandle causes these reset() calls to evict from the cache.
handle3.reset();
handle4.reset();
EXPECT_FALSE(cache->get(hash3).object);
EXPECT_FALSE(cache->get(hash4).object);
}
TEST(BlobCache, does_not_forget_blob_until_last_handle_is_forgotten) {
auto cache = BlobCache::create(100, 0);
auto blob = std::make_shared<Blob>(hash6, "newblob"_sp);
auto weak = std::weak_ptr<const Blob>{blob};
cache->insert(blob, BlobCache::Interest::UnlikelyNeededAgain);
auto handle0 = cache->insert(blob, BlobCache::Interest::WantHandle);
auto result1 = cache->get(hash6, BlobCache::Interest::WantHandle);
auto result2 = cache->get(hash6, BlobCache::Interest::WantHandle);
EXPECT_TRUE(result1.object);
EXPECT_TRUE(result2.object);
EXPECT_EQ(result1.object, result2.object);
blob.reset();
result1.object.reset();
result2.object.reset();
EXPECT_TRUE(weak.lock());
handle0.reset();
EXPECT_TRUE(weak.lock());
result1.interestHandle.reset();
EXPECT_TRUE(weak.lock());
result2.interestHandle.reset();
EXPECT_FALSE(weak.lock());
}