thin-provisioning-tools/unit-tests/rolling_hash_t.cc

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2015-09-03 17:32:29 +05:30
#include "gmock/gmock.h"
#include "base/rolling_hash.h"
using namespace base;
using namespace boost;
using namespace std;
using namespace testing;
//----------------------------------------------------------------
namespace {
class RollingHashTests : public Test {
public:
RollingHashTests()
: window_size_(4096),
rhash_(window_size_) {
}
typedef vector<uint8_t> bytes;
bytes random_bytes(unsigned count) {
bytes v(count, 0);
for (unsigned i = 0; i < count; i++)
v[i] = random_byte();
return v;
}
uint8_t random_byte() const {
return random() % 256;
}
void apply_bytes(bytes const &bs) {
for (unsigned i = 0; i < bs.size(); i++)
rhash_.step(bs[i]);
}
unsigned window_size_;
rolling_hash rhash_;
};
class ContentBasedHashTests : public Test {
public:
ContentBasedHashTests()
: window_size_(8192),
h_(window_size_) {
}
typedef vector<uint8_t> bytes;
bytes random_bytes(unsigned count) {
bytes v(count, 0);
for (unsigned i = 0; i < count; i++)
v[i] = random_byte();
return v;
}
uint8_t random_byte() const {
return random() % 256;
}
unsigned window_size_;
content_based_hash h_;
};
}
//----------------------------------------------------------------
TEST_F(RollingHashTests, ctr)
{
}
//--------------------------------
TEST_F(RollingHashTests, hash_changes)
{
bytes bs = random_bytes(window_size_ * 100);
uint32_t prev = rhash_.get_hash();
for (unsigned i = 0; i < bs.size(); i++) {
rhash_.step(bs[i]);
ASSERT_NE(rhash_.get_hash(), prev);
prev = rhash_.get_hash();
}
}
TEST_F(RollingHashTests, hash_repeats)
{
bytes bs = random_bytes(window_size_);
apply_bytes(bs);
uint32_t h1 = rhash_.get_hash();
apply_bytes(bs);
ASSERT_EQ(rhash_.get_hash(), h1);
}
TEST_F(RollingHashTests, reset_is_deterministic)
{
uint8_t bytes[] = "lksdfuwerh,sdg";
for (unsigned i = 0; i < sizeof(bytes) - 1; i++)
rhash_.step(bytes[i]);
uint32_t h1 = rhash_.get_hash();
rhash_.reset();
for (unsigned i = 0; i < sizeof(bytes) - 1; i++)
rhash_.step(bytes[i]);
uint32_t h2 = rhash_.get_hash();
ASSERT_EQ(h1, h2);
}
//----------------------------------------------------------------
TEST_F(ContentBasedHashTests, ctr)
{
}
TEST_F(ContentBasedHashTests, chunk_limits_respected)
{
unsigned min = 100000, max = 0;
bytes bs = random_bytes(1024 * 1024 * 100);
vector<unsigned> counts(window_size_, 0);
for (unsigned i = 0; i < bs.size(); i++) {
optional<unsigned> b = h_.step(bs[i]);
if (b) {
counts[*b]++;
if (*b < min)
min = *b;
if (*b > max)
max = *b;
}
}
#if 1
for (unsigned i = 0; i < counts.size(); i++)
cerr << i << ": " << counts[i] << "\n";
cerr << "min: " << min << ", max: " << max << "\n";
#endif
}
//----------------------------------------------------------------