rocksdb/db/dbformat_test.cc
Islam AbdelRahman 7c14abf2c7 Improve BytewiseComparatorImpl::FindShortestSeparator
Summary:
The current implementation find the first different byte and try to increment it, if it cannot it return the original key
we can improve this by keep going after the first different byte to find the first non 0xFF byte and increment it

After trying this patch on some logdevice sst files I see decrease in there index block size by 8.5%

Test Plan: existing tests and updated test

Reviewers: yhchiang, andrewkr, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D56241
2016-04-25 23:02:14 -07:00

201 lines
6.9 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#include "db/dbformat.h"
#include "util/logging.h"
#include "util/testharness.h"
namespace rocksdb {
static std::string IKey(const std::string& user_key,
uint64_t seq,
ValueType vt) {
std::string encoded;
AppendInternalKey(&encoded, ParsedInternalKey(user_key, seq, vt));
return encoded;
}
static std::string Shorten(const std::string& s, const std::string& l) {
std::string result = s;
InternalKeyComparator(BytewiseComparator()).FindShortestSeparator(&result, l);
return result;
}
static std::string ShortSuccessor(const std::string& s) {
std::string result = s;
InternalKeyComparator(BytewiseComparator()).FindShortSuccessor(&result);
return result;
}
static void TestKey(const std::string& key,
uint64_t seq,
ValueType vt) {
std::string encoded = IKey(key, seq, vt);
Slice in(encoded);
ParsedInternalKey decoded("", 0, kTypeValue);
ASSERT_TRUE(ParseInternalKey(in, &decoded));
ASSERT_EQ(key, decoded.user_key.ToString());
ASSERT_EQ(seq, decoded.sequence);
ASSERT_EQ(vt, decoded.type);
ASSERT_TRUE(!ParseInternalKey(Slice("bar"), &decoded));
}
class FormatTest : public testing::Test {};
TEST_F(FormatTest, InternalKey_EncodeDecode) {
const char* keys[] = { "", "k", "hello", "longggggggggggggggggggggg" };
const uint64_t seq[] = {
1, 2, 3,
(1ull << 8) - 1, 1ull << 8, (1ull << 8) + 1,
(1ull << 16) - 1, 1ull << 16, (1ull << 16) + 1,
(1ull << 32) - 1, 1ull << 32, (1ull << 32) + 1
};
for (unsigned int k = 0; k < sizeof(keys) / sizeof(keys[0]); k++) {
for (unsigned int s = 0; s < sizeof(seq) / sizeof(seq[0]); s++) {
TestKey(keys[k], seq[s], kTypeValue);
TestKey("hello", 1, kTypeDeletion);
}
}
}
TEST_F(FormatTest, InternalKeyShortSeparator) {
// When user keys are same
ASSERT_EQ(IKey("foo", 100, kTypeValue),
Shorten(IKey("foo", 100, kTypeValue),
IKey("foo", 99, kTypeValue)));
ASSERT_EQ(IKey("foo", 100, kTypeValue),
Shorten(IKey("foo", 100, kTypeValue),
IKey("foo", 101, kTypeValue)));
ASSERT_EQ(IKey("foo", 100, kTypeValue),
Shorten(IKey("foo", 100, kTypeValue),
IKey("foo", 100, kTypeValue)));
ASSERT_EQ(IKey("foo", 100, kTypeValue),
Shorten(IKey("foo", 100, kTypeValue),
IKey("foo", 100, kTypeDeletion)));
// When user keys are misordered
ASSERT_EQ(IKey("foo", 100, kTypeValue),
Shorten(IKey("foo", 100, kTypeValue),
IKey("bar", 99, kTypeValue)));
// When user keys are different, but correctly ordered
ASSERT_EQ(IKey("g", kMaxSequenceNumber, kValueTypeForSeek),
Shorten(IKey("foo", 100, kTypeValue),
IKey("hello", 200, kTypeValue)));
ASSERT_EQ(IKey("ABC2", kMaxSequenceNumber, kValueTypeForSeek),
Shorten(IKey("ABC1AAAAA", 100, kTypeValue),
IKey("ABC2ABB", 200, kTypeValue)));
ASSERT_EQ(IKey("AAA2", kMaxSequenceNumber, kValueTypeForSeek),
Shorten(IKey("AAA1AAA", 100, kTypeValue),
IKey("AAA2AA", 200, kTypeValue)));
ASSERT_EQ(
IKey("AAA2", kMaxSequenceNumber, kValueTypeForSeek),
Shorten(IKey("AAA1AAA", 100, kTypeValue), IKey("AAA4", 200, kTypeValue)));
ASSERT_EQ(
IKey("AAA1B", kMaxSequenceNumber, kValueTypeForSeek),
Shorten(IKey("AAA1AAA", 100, kTypeValue), IKey("AAA2", 200, kTypeValue)));
ASSERT_EQ(IKey("AAA2", kMaxSequenceNumber, kValueTypeForSeek),
Shorten(IKey("AAA1AAA", 100, kTypeValue),
IKey("AAA2A", 200, kTypeValue)));
ASSERT_EQ(
IKey("AAA1", 100, kTypeValue),
Shorten(IKey("AAA1", 100, kTypeValue), IKey("AAA2", 200, kTypeValue)));
// When start user key is prefix of limit user key
ASSERT_EQ(IKey("foo", 100, kTypeValue),
Shorten(IKey("foo", 100, kTypeValue),
IKey("foobar", 200, kTypeValue)));
// When limit user key is prefix of start user key
ASSERT_EQ(IKey("foobar", 100, kTypeValue),
Shorten(IKey("foobar", 100, kTypeValue),
IKey("foo", 200, kTypeValue)));
}
TEST_F(FormatTest, InternalKeyShortestSuccessor) {
ASSERT_EQ(IKey("g", kMaxSequenceNumber, kValueTypeForSeek),
ShortSuccessor(IKey("foo", 100, kTypeValue)));
ASSERT_EQ(IKey("\xff\xff", 100, kTypeValue),
ShortSuccessor(IKey("\xff\xff", 100, kTypeValue)));
}
TEST_F(FormatTest, IterKeyOperation) {
IterKey k;
const char p[] = "abcdefghijklmnopqrstuvwxyz";
const char q[] = "0123456789";
ASSERT_EQ(std::string(k.GetKey().data(), k.GetKey().size()),
std::string(""));
k.TrimAppend(0, p, 3);
ASSERT_EQ(std::string(k.GetKey().data(), k.GetKey().size()),
std::string("abc"));
k.TrimAppend(1, p, 3);
ASSERT_EQ(std::string(k.GetKey().data(), k.GetKey().size()),
std::string("aabc"));
k.TrimAppend(0, p, 26);
ASSERT_EQ(std::string(k.GetKey().data(), k.GetKey().size()),
std::string("abcdefghijklmnopqrstuvwxyz"));
k.TrimAppend(26, q, 10);
ASSERT_EQ(std::string(k.GetKey().data(), k.GetKey().size()),
std::string("abcdefghijklmnopqrstuvwxyz0123456789"));
k.TrimAppend(36, q, 1);
ASSERT_EQ(std::string(k.GetKey().data(), k.GetKey().size()),
std::string("abcdefghijklmnopqrstuvwxyz01234567890"));
k.TrimAppend(26, q, 1);
ASSERT_EQ(std::string(k.GetKey().data(), k.GetKey().size()),
std::string("abcdefghijklmnopqrstuvwxyz0"));
// Size going up, memory allocation is triggered
k.TrimAppend(27, p, 26);
ASSERT_EQ(std::string(k.GetKey().data(), k.GetKey().size()),
std::string("abcdefghijklmnopqrstuvwxyz0"
"abcdefghijklmnopqrstuvwxyz"));
}
TEST_F(FormatTest, UpdateInternalKey) {
std::string user_key("abcdefghijklmnopqrstuvwxyz");
uint64_t new_seq = 0x123456;
ValueType new_val_type = kTypeDeletion;
std::string ikey;
AppendInternalKey(&ikey, ParsedInternalKey(user_key, 100U, kTypeValue));
size_t ikey_size = ikey.size();
UpdateInternalKey(&ikey, new_seq, new_val_type);
ASSERT_EQ(ikey_size, ikey.size());
Slice in(ikey);
ParsedInternalKey decoded;
ASSERT_TRUE(ParseInternalKey(in, &decoded));
ASSERT_EQ(user_key, decoded.user_key.ToString());
ASSERT_EQ(new_seq, decoded.sequence);
ASSERT_EQ(new_val_type, decoded.type);
}
} // namespace rocksdb
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}