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// Copyright (c) 2012 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 "table/filter_block.h"
#include "leveldb/filter_policy.h"
#include "util/coding.h"
#include "util/hash.h"
#include "util/logging.h"
#include "util/testharness.h"
#include "util/testutil.h"
namespace leveldb {
// For testing: emit an array with one hash value per key
class TestHashFilter : public FilterPolicy {
public:
virtual const char* Name() const { return "TestHashFilter"; }
virtual void CreateFilter(const Slice* keys, int n, std::string* dst) const {
for (int i = 0; i < n; i++) {
uint32_t h = Hash(keys[i].data(), keys[i].size(), 1);
PutFixed32(dst, h);
}
}
virtual bool KeyMayMatch(const Slice& key, const Slice& filter) const {
uint32_t h = Hash(key.data(), key.size(), 1);
for (size_t i = 0; i + 4 <= filter.size(); i += 4) {
if (h == DecodeFixed32(filter.data() + i)) {
return true;
}
}
return false;
}
};
class FilterBlockTest {
public:
TestHashFilter policy_;
};
TEST(FilterBlockTest, EmptyBuilder) {
FilterBlockBuilder builder(&policy_);
Slice block = builder.Finish();
ASSERT_EQ("\\x00\\x00\\x00\\x00\\x0b", EscapeString(block));
FilterBlockReader reader(&policy_, block);
ASSERT_TRUE(reader.KeyMayMatch(0, "foo"));
ASSERT_TRUE(reader.KeyMayMatch(100000, "foo"));
}
TEST(FilterBlockTest, SingleChunk) {
FilterBlockBuilder builder(&policy_);
builder.StartBlock(100);
builder.AddKey("foo");
builder.AddKey("bar");
builder.AddKey("box");
builder.StartBlock(200);
builder.AddKey("box");
builder.StartBlock(300);
builder.AddKey("hello");
Slice block = builder.Finish();
FilterBlockReader reader(&policy_, block);
ASSERT_TRUE(reader.KeyMayMatch(100, "foo"));
ASSERT_TRUE(reader.KeyMayMatch(100, "bar"));
ASSERT_TRUE(reader.KeyMayMatch(100, "box"));
ASSERT_TRUE(reader.KeyMayMatch(100, "hello"));
ASSERT_TRUE(reader.KeyMayMatch(100, "foo"));
ASSERT_TRUE(!reader.KeyMayMatch(100, "missing"));
ASSERT_TRUE(!reader.KeyMayMatch(100, "other"));
}
TEST(FilterBlockTest, MultiChunk) {
FilterBlockBuilder builder(&policy_);
// First filter
builder.StartBlock(0);
builder.AddKey("foo");
builder.StartBlock(2000);
builder.AddKey("bar");
// Second filter
builder.StartBlock(3100);
builder.AddKey("box");
// Third filter is empty
// Last filter
builder.StartBlock(9000);
builder.AddKey("box");
builder.AddKey("hello");
Slice block = builder.Finish();
FilterBlockReader reader(&policy_, block);
// Check first filter
ASSERT_TRUE(reader.KeyMayMatch(0, "foo"));
ASSERT_TRUE(reader.KeyMayMatch(2000, "bar"));
ASSERT_TRUE(!reader.KeyMayMatch(0, "box"));
ASSERT_TRUE(!reader.KeyMayMatch(0, "hello"));
// Check second filter
ASSERT_TRUE(reader.KeyMayMatch(3100, "box"));
ASSERT_TRUE(!reader.KeyMayMatch(3100, "foo"));
ASSERT_TRUE(!reader.KeyMayMatch(3100, "bar"));
ASSERT_TRUE(!reader.KeyMayMatch(3100, "hello"));
// Check third filter (empty)
ASSERT_TRUE(!reader.KeyMayMatch(4100, "foo"));
ASSERT_TRUE(!reader.KeyMayMatch(4100, "bar"));
ASSERT_TRUE(!reader.KeyMayMatch(4100, "box"));
ASSERT_TRUE(!reader.KeyMayMatch(4100, "hello"));
// Check last filter
ASSERT_TRUE(reader.KeyMayMatch(9000, "box"));
ASSERT_TRUE(reader.KeyMayMatch(9000, "hello"));
ASSERT_TRUE(!reader.KeyMayMatch(9000, "foo"));
ASSERT_TRUE(!reader.KeyMayMatch(9000, "bar"));
}
} // namespace leveldb
int main(int argc, char** argv) { return leveldb::test::RunAllTests(); }
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