Tools/TestWebKitAPI/Tests/WebCore/DFACombiner.cpp

/*
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#include "config.h"

#include "DFAHelpers.h"
#include <WebCore/DFACombiner.h>
#include <wtf/MainThread.h>

using namespace WebCore;
using namespace ContentExtensions;

namespace TestWebKitAPI {

class DFACombinerTest : public testing::Test {
public:
    virtual void SetUp()
    {
        WTF::initializeMainThread();
    }
};

Vector<DFA> combine(Vector<DFA> dfas, unsigned minimumSize)
{
    DFACombiner combiner;
    for (DFA& dfa : dfas)
        combiner.addDFA(WTFMove(dfa));

    Vector<DFA> output;
    combiner.combineDFAs(minimumSize, [&output](DFA&& dfa) {
        output.append(dfa);
    });
    return output;
}

TEST_F(DFACombinerTest, Basic)
{
    Vector<DFA> dfas = { buildDFAFromPatterns({ "foo"}), buildDFAFromPatterns({ "bar"}) };
    Vector<DFA> combinedDFAs = combine(dfas, 10000);
    EXPECT_EQ(static_cast<size_t>(1), combinedDFAs.size());

    DFA reference = buildDFAFromPatterns({ "foo", "bar"});
    reference.minimize();
    EXPECT_EQ(countLiveNodes(reference), countLiveNodes(combinedDFAs.first()));
}


TEST_F(DFACombinerTest, IdenticalDFAs)
{
    Vector<DFA> dfas = { buildDFAFromPatterns({ "foo"}), buildDFAFromPatterns({ "foo"}) };
    Vector<DFA> combinedDFAs = combine(dfas, 10000);
    EXPECT_EQ(static_cast<size_t>(1), combinedDFAs.size());

    // The result should have the exact same size as the minimized input.
    DFA reference = buildDFAFromPatterns({ "foo"});
    reference.minimize();
    EXPECT_EQ(countLiveNodes(reference), countLiveNodes(combinedDFAs.first()));
}

TEST_F(DFACombinerTest, NoInput)
{
    DFACombiner combiner;
    unsigned counter = 0;
    combiner.combineDFAs(100000, [&counter](DFA&& dfa) {
        ++counter;
    });
    EXPECT_EQ(static_cast<unsigned>(0), counter);
}

TEST_F(DFACombinerTest, SingleInput)
{
    Vector<DFA> dfas = { buildDFAFromPatterns({ "WebKit"}) };
    Vector<DFA> combinedDFAs = combine(dfas, 10000);
    EXPECT_EQ(static_cast<size_t>(1), combinedDFAs.size());

    DFA reference = buildDFAFromPatterns({ "WebKit"});
    reference.minimize();
    EXPECT_EQ(countLiveNodes(reference), countLiveNodes(combinedDFAs.first()));
}

TEST_F(DFACombinerTest, InputTooLargeForMinimumSize)
{
    Vector<DFA> dfas = { buildDFAFromPatterns({ "foo"}), buildDFAFromPatterns({ "bar"}) };
    Vector<DFA> combinedDFAs = combine(dfas, 2);
    EXPECT_EQ(static_cast<size_t>(2), combinedDFAs.size());
    EXPECT_EQ(static_cast<size_t>(4), countLiveNodes(combinedDFAs[0]));
    EXPECT_EQ(static_cast<size_t>(4), countLiveNodes(combinedDFAs[1]));
}

TEST_F(DFACombinerTest, CombinedInputReachesMinimumSize)
{
    Vector<DFA> dfas = { buildDFAFromPatterns({ "foo"}), buildDFAFromPatterns({ "bar"}), buildDFAFromPatterns({ "WebKit"}) };
    Vector<DFA> combinedDFAs = combine(dfas, 5);
    EXPECT_EQ(static_cast<size_t>(2), combinedDFAs.size());
    EXPECT_EQ(static_cast<size_t>(7), countLiveNodes(combinedDFAs[0]));
    EXPECT_EQ(static_cast<size_t>(6), countLiveNodes(combinedDFAs[1]));
}

} // namespace TestWebKitAPI