rocksdb/file/random_access_file_reader_test.cc
anand76 ab13d43e1d Pass a timeout to FileSystem for random reads (#6751)
Summary:
Calculate ```IOOptions::timeout``` using ```ReadOptions::deadline``` and pass it to ```FileSystem::Read/FileSystem::MultiRead```. This allows us to impose a tighter bound on the time taken by Get/MultiGet on FileSystem/Envs that support IO timeouts. Even on those that don't support, check in ```RandomAccessFileReader::Read``` and ```MultiRead``` and return ```Status::TimedOut()``` if the deadline is exceeded.

For now, TableReader creation, which might do file opens and reads, are not covered. It will be implemented in another PR.

Tests:
Update existing unit tests to verify the correct timeout value is being passed
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6751

Reviewed By: riversand963

Differential Revision: D21285631

Pulled By: anand1976

fbshipit-source-id: d89af843e5a91ece866e87aa29438b52a65a8567
2020-04-30 14:50:39 -07:00

276 lines
7.7 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "port/port.h"
#include "port/stack_trace.h"
#include "rocksdb/file_system.h"
#include "file/random_access_file_reader.h"
#include "test_util/testharness.h"
#include "test_util/testutil.h"
namespace ROCKSDB_NAMESPACE {
class RandomAccessFileReaderTest : public testing::Test {
public:
void SetUp() override {
test::ResetTmpDirForDirectIO();
env_ = Env::Default();
fs_ = FileSystem::Default();
test_dir_ = test::PerThreadDBPath("random_access_file_reader_test");
ASSERT_OK(fs_->CreateDir(test_dir_, IOOptions(), nullptr));
alignment_ = GetAlignment();
}
void TearDown() override {
EXPECT_OK(test::DestroyDir(env_, test_dir_));
}
bool IsDirectIOSupported() {
Write(".direct", "");
FileOptions opt;
opt.use_direct_reads = true;
std::unique_ptr<FSRandomAccessFile> f;
auto s = fs_->NewRandomAccessFile(Path(".direct"), opt, &f, nullptr);
return s.ok();
}
void Write(const std::string& fname, const std::string& content) {
std::unique_ptr<FSWritableFile> f;
ASSERT_OK(fs_->NewWritableFile(Path(fname), FileOptions(), &f, nullptr));
ASSERT_OK(f->Append(content, IOOptions(), nullptr));
ASSERT_OK(f->Close(IOOptions(), nullptr));
}
void Read(const std::string& fname, const FileOptions& opts,
std::unique_ptr<RandomAccessFileReader>* reader) {
std::string fpath = Path(fname);
std::unique_ptr<FSRandomAccessFile> f;
ASSERT_OK(fs_->NewRandomAccessFile(fpath, opts, &f, nullptr));
(*reader).reset(new RandomAccessFileReader(std::move(f), fpath, env_));
}
void AssertResult(const std::string& content,
const std::vector<FSReadRequest>& reqs) {
for (const auto& r : reqs) {
ASSERT_OK(r.status);
ASSERT_EQ(r.len, r.result.size());
ASSERT_EQ(content.substr(r.offset, r.len), r.result.ToString());
}
}
size_t alignment() const { return alignment_; }
private:
Env* env_;
std::shared_ptr<FileSystem> fs_;
std::string test_dir_;
size_t alignment_;
std::string Path(const std::string& fname) {
return test_dir_ + "/" + fname;
}
size_t GetAlignment() {
std::string f = "get_alignment";
Write(f, "");
std::unique_ptr<RandomAccessFileReader> r;
Read(f, FileOptions(), &r);
size_t alignment = r->file()->GetRequiredBufferAlignment();
EXPECT_OK(fs_->DeleteFile(Path(f), IOOptions(), nullptr));
return alignment;
}
};
TEST_F(RandomAccessFileReaderTest, ReadDirectIO) {
if (!IsDirectIOSupported()) {
printf("Direct IO is not supported, skip this test\n");
return;
}
std::string fname = "read-direct-io";
Random rand(0);
std::string content;
test::RandomString(&rand, static_cast<int>(alignment()), &content);
Write(fname, content);
FileOptions opts;
opts.use_direct_reads = true;
std::unique_ptr<RandomAccessFileReader> r;
Read(fname, opts, &r);
ASSERT_TRUE(r->use_direct_io());
size_t offset = alignment() / 2;
size_t len = alignment() / 3;
Slice result;
AlignedBuf buf;
for (bool for_compaction : {true, false}) {
ASSERT_OK(r->Read(IOOptions(), offset, len, &result, nullptr, &buf,
for_compaction));
ASSERT_EQ(result.ToString(), content.substr(offset, len));
}
}
TEST_F(RandomAccessFileReaderTest, MultiReadDirectIO) {
if (!IsDirectIOSupported()) {
printf("Direct IO is not supported, skip this test\n");
return;
}
// Creates a file with 3 pages.
std::string fname = "multi-read-direct-io";
Random rand(0);
std::string content;
test::RandomString(&rand, 3 * static_cast<int>(alignment()), &content);
Write(fname, content);
FileOptions opts;
opts.use_direct_reads = true;
std::unique_ptr<RandomAccessFileReader> r;
Read(fname, opts, &r);
ASSERT_TRUE(r->use_direct_io());
{
// Reads 2 blocks in the 1st page.
// The results should be SharedSlices of the same underlying buffer.
//
// Illustration (each x is a 1/4 page)
// First page: xxxx
// 1st block: x
// 2nd block: xx
FSReadRequest r0;
r0.offset = 0;
r0.len = alignment() / 4;
r0.scratch = nullptr;
FSReadRequest r1;
r1.offset = alignment() / 2;
r1.len = alignment() / 2;
r1.scratch = nullptr;
std::vector<FSReadRequest> reqs;
reqs.push_back(std::move(r0));
reqs.push_back(std::move(r1));
AlignedBuf aligned_buf;
ASSERT_OK(
r->MultiRead(IOOptions(), reqs.data(), reqs.size(), &aligned_buf));
AssertResult(content, reqs);
}
{
// Reads 3 blocks:
// 1st block in the 1st page;
// 2nd block from the middle of the 1st page to the middle of the 2nd page;
// 3rd block in the 2nd page.
// The results should be SharedSlices of the same underlying buffer.
//
// Illustration (each x is a 1/4 page)
// 2 pages: xxxxxxxx
// 1st block: x
// 2nd block: xxxx
// 3rd block: x
FSReadRequest r0;
r0.offset = 0;
r0.len = alignment() / 4;
r0.scratch = nullptr;
FSReadRequest r1;
r1.offset = alignment() / 2;
r1.len = alignment();
r1.scratch = nullptr;
FSReadRequest r2;
r2.offset = 2 * alignment() - alignment() / 4;
r2.len = alignment() / 4;
r2.scratch = nullptr;
std::vector<FSReadRequest> reqs;
reqs.push_back(std::move(r0));
reqs.push_back(std::move(r1));
reqs.push_back(std::move(r2));
AlignedBuf aligned_buf;
ASSERT_OK(
r->MultiRead(IOOptions(), reqs.data(), reqs.size(), &aligned_buf));
AssertResult(content, reqs);
}
{
// Reads 3 blocks:
// 1st block in the middle of the 1st page;
// 2nd block in the middle of the 2nd page;
// 3rd block in the middle of the 3rd page.
// The results should be SharedSlices of the same underlying buffer.
//
// Illustration (each x is a 1/4 page)
// 3 pages: xxxxxxxxxxxx
// 1st block: xx
// 2nd block: xx
// 3rd block: xx
FSReadRequest r0;
r0.offset = alignment() / 4;
r0.len = alignment() / 2;
r0.scratch = nullptr;
FSReadRequest r1;
r1.offset = alignment() + alignment() / 4;
r1.len = alignment() / 2;
r1.scratch = nullptr;
FSReadRequest r2;
r2.offset = 2 * alignment() + alignment() / 4;
r2.len = alignment() / 2;
r2.scratch = nullptr;
std::vector<FSReadRequest> reqs;
reqs.push_back(std::move(r0));
reqs.push_back(std::move(r1));
reqs.push_back(std::move(r2));
AlignedBuf aligned_buf;
ASSERT_OK(
r->MultiRead(IOOptions(), reqs.data(), reqs.size(), &aligned_buf));
AssertResult(content, reqs);
}
{
// Reads 2 blocks:
// 1st block in the middle of the 1st page;
// 2nd block in the middle of the 3rd page.
// The results are two different buffers.
//
// Illustration (each x is a 1/4 page)
// 3 pages: xxxxxxxxxxxx
// 1st block: xx
// 2nd block: xx
FSReadRequest r0;
r0.offset = alignment() / 4;
r0.len = alignment() / 2;
r0.scratch = nullptr;
FSReadRequest r1;
r1.offset = 2 * alignment() + alignment() / 4;
r1.len = alignment() / 2;
r1.scratch = nullptr;
std::vector<FSReadRequest> reqs;
reqs.push_back(std::move(r0));
reqs.push_back(std::move(r1));
AlignedBuf aligned_buf;
ASSERT_OK(
r->MultiRead(IOOptions(), reqs.data(), reqs.size(), &aligned_buf));
AssertResult(content, reqs);
}
}
} // namespace ROCKSDB_NAMESPACE
int main(int argc, char** argv) {
ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}