Add more serialization implementation.

This commit is contained in:
Matthias Vallentin 2013-06-04 15:30:27 -07:00
parent a5572dd66f
commit 751cf61293
6 changed files with 129 additions and 42 deletions

View file

@ -46,12 +46,23 @@ CounterVector::size_type CounterVector::Size() const
return bits_->Blocks() / width_;
}
bool CounterVector::Serialize(SerialInfo* info) const
{
return SerialObj::Serialize(info);
}
CounterVector* CounterVector::Unserialize(UnserialInfo* info)
{
return reinterpret_cast<CounterVector*>(
SerialObj::Unserialize(info, SER_COUNTERVECTOR));
}
IMPLEMENT_SERIAL(CounterVector, SER_COUNTERVECTOR)
bool CounterVector::DoSerialize(SerialInfo* info) const
{
DO_SERIALIZE(SER_COUNTERVECTOR, SerialObj);
if ( ! SERIALIZE(&bits_) )
if ( ! SERIALIZE(bits_) )
return false;
return SERIALIZE(static_cast<uint64>(width_));
}
@ -60,9 +71,9 @@ bool CounterVector::DoUnserialize(UnserialInfo* info)
{
DO_UNSERIALIZE(SerialObj);
return false;
// TODO: Ask Robin how to unserialize non-pointer members.
//if ( ! UNSERIALIZE(&bits_) )
// return false;
bits_ = BitVector::Unserialize(info);
if ( ! bits_ )
return false;
uint64 width;
if ( ! UNSERIALIZE(&width) )
return false;
@ -90,6 +101,18 @@ HashPolicy::HashVector DoubleHashing::Hash(const void* x, size_t n) const
return h;
}
BloomFilter::BloomFilter(size_t k)
: hash_(new hash_policy(k))
{
}
BloomFilter::~BloomFilter()
{
if ( hash_ )
delete hash_;
}
bool BloomFilter::Serialize(SerialInfo* info) const
{
return SerialObj::Serialize(info);
@ -101,24 +124,21 @@ BloomFilter* BloomFilter::Unserialize(UnserialInfo* info)
SerialObj::Unserialize(info, SER_BLOOMFILTER));
}
// FIXME: should abstract base classes also have IMPLEMENT_SERIAL?
//IMPLEMENT_SERIAL(BloomFilter, SER_BLOOMFILTER)
bool BloomFilter::DoSerialize(SerialInfo* info) const
{
DO_SERIALIZE(SER_BLOOMFILTER, SerialObj);
// TODO: Make the hash policy serializable.
//if ( ! SERIALIZE(hash_) )
// return false;
return SERIALIZE(static_cast<uint64>(elements_));
if ( ! SERIALIZE(static_cast<uint16>(hash_->K())) )
return false;
return SERIALIZE(static_cast<uint16>(elements_));
}
bool BloomFilter::DoUnserialize(UnserialInfo* info)
{
DO_UNSERIALIZE(SerialObj);
// TODO: Make the hash policy serializable.
//if ( ! hash_ = HashPolicy::Unserialize(info) )
// return false;
uint16 k;
if ( ! UNSERIALIZE(&k) )
return false;
hash_ = new hash_policy(static_cast<size_t>(k));
uint64 elements;
if ( UNSERIALIZE(&elements) )
return false;
@ -126,7 +146,7 @@ bool BloomFilter::DoUnserialize(UnserialInfo* info)
return true;
}
size_t BasicBloomFilter::Cells(double fp, size_t capacity)
size_t BasicBloomFilter::M(double fp, size_t capacity)
{
double ln2 = std::log(2);
return std::ceil(-(capacity * std::log(fp) / ln2 / ln2));
@ -138,9 +158,16 @@ size_t BasicBloomFilter::K(size_t cells, size_t capacity)
return round<size_t>(frac * std::log(2));
}
BasicBloomFilter::BasicBloomFilter(size_t cells, HashPolicy* hash)
: BloomFilter(hash), bits_(cells)
BasicBloomFilter::BasicBloomFilter(double fp, size_t capacity)
: BloomFilter(K(M(fp, capacity), capacity))
{
bits_ = new BitVector(M(fp, capacity));
}
BasicBloomFilter::BasicBloomFilter(size_t cells, size_t capacity)
: BloomFilter(K(cells, capacity))
{
bits_ = new BitVector(cells);
}
IMPLEMENT_SERIAL(BasicBloomFilter, SER_BASICBLOOMFILTER)
@ -148,38 +175,50 @@ IMPLEMENT_SERIAL(BasicBloomFilter, SER_BASICBLOOMFILTER)
bool BasicBloomFilter::DoSerialize(SerialInfo* info) const
{
DO_SERIALIZE(SER_BASICBLOOMFILTER, BloomFilter);
// TODO: Make the hash policy serializable.
//if ( ! SERIALIZE(&bits_) )
// return false;
return true;
return SERIALIZE(bits_);
}
bool BasicBloomFilter::DoUnserialize(UnserialInfo* info)
{
DO_UNSERIALIZE(BloomFilter);
// TODO: Non-pointer member deserialization?
return true;
bits_ = BitVector::Unserialize(info);
return bits_ == NULL;
}
void BasicBloomFilter::AddImpl(const HashPolicy::HashVector& h)
{
for ( size_t i = 0; i < h.size(); ++i )
bits_.set(h[i] % h.size());
bits_->Set(h[i] % h.size());
}
size_t BasicBloomFilter::CountImpl(const HashPolicy::HashVector& h) const
{
for ( size_t i = 0; i < h.size(); ++i )
if ( ! bits_[h[i] % h.size()] )
if ( ! (*bits_)[h[i] % h.size()] )
return 0;
return 1;
}
IMPLEMENT_SERIAL(CountingBloomFilter, SER_COUNTINGBLOOMFILTER)
bool CountingBloomFilter::DoSerialize(SerialInfo* info) const
{
DO_SERIALIZE(SER_BASICBLOOMFILTER, BloomFilter);
return SERIALIZE(cells_);
}
bool CountingBloomFilter::DoUnserialize(UnserialInfo* info)
{
DO_UNSERIALIZE(BloomFilter);
cells_ = CounterVector::Unserialize(info);
return cells_ == NULL;
}
void CountingBloomFilter::AddImpl(const HashPolicy::HashVector& h)
{
for ( size_t i = 0; i < h.size(); ++i )
cells_.Increment(h[i] % h.size(), 1);
cells_->Increment(h[i] % h.size(), 1);
}
size_t CountingBloomFilter::CountImpl(const HashPolicy::HashVector& h) const
@ -188,7 +227,7 @@ size_t CountingBloomFilter::CountImpl(const HashPolicy::HashVector& h) const
std::numeric_limits<CounterVector::size_type>::max();
for ( size_t i = 0; i < h.size(); ++i )
{
CounterVector::size_type cnt = cells_.Count(h[i] % h.size());
CounterVector::size_type cnt = cells_->Count(h[i] % h.size());
if ( cnt < min )
min = cnt;
}

View file

@ -151,9 +151,13 @@ private:
/**
* The abstract base class for Bloom filters.
*/
class BloomFilter : SerialObj {
class BloomFilter : public SerialObj {
public:
virtual ~BloomFilter() { delete hash_; }
// At this point we won't let the user choose the hash policy, but we might
// open up the interface in the future.
typedef DoubleHashing hash_policy;
virtual ~BloomFilter();
/**
* Adds an element of type T to the Bloom filter.
@ -193,10 +197,10 @@ public:
static BloomFilter* Unserialize(UnserialInfo* info);
protected:
DECLARE_SERIAL(BloomFilter);
DECLARE_ABSTRACT_SERIAL(BloomFilter);
BloomFilter() { };
BloomFilter(HashPolicy* hash) : hash_(hash) { }
BloomFilter(size_t k);
virtual void AddImpl(const HashPolicy::HashVector& hashes) = 0;
virtual size_t CountImpl(const HashPolicy::HashVector& hashes) const = 0;
@ -211,10 +215,42 @@ private:
*/
class BasicBloomFilter : public BloomFilter {
public:
static size_t Cells(double fp, size_t capacity);
/**
* Computes the number of cells based a given false-positive rate and
* capacity. In the literature, this parameter often has the name *M*.
*
* @param fp The false-positive rate.
*
* @param capacity The number of exepected elements.
*
* Returns: The number cells needed to support a false-positive rate of *fp*
* with at most *capacity* elements.
*/
static size_t M(double fp, size_t capacity);
/**
* Computes the optimal number of hash functions based on the number cells
* and expected number of elements.
*
* @param cells The number of cells (*m*).
*
* @param capacity The maximum number of elements.
*
* Returns: the optimal number of hash functions for a false-positive rate of
* *fp* for at most *capacity* elements.
*/
static size_t K(size_t cells, size_t capacity);
BasicBloomFilter(size_t cells, HashPolicy* hash);
/**
* Constructs a basic Bloom filter with a given false-positive rate and
* capacity.
*/
BasicBloomFilter(double fp, size_t capacity);
/**
* Constructs a basic Bloom filter with a given number of cells and capacity.
*/
BasicBloomFilter(size_t cells, size_t capacity);
protected:
DECLARE_SERIAL(BasicBloomFilter);
@ -225,7 +261,7 @@ protected:
virtual size_t CountImpl(const HashPolicy::HashVector& h) const;
private:
BitVector bits_;
BitVector* bits_;
};
/**
@ -233,18 +269,18 @@ private:
*/
class CountingBloomFilter : public BloomFilter {
public:
CountingBloomFilter(unsigned width, HashPolicy* hash);
CountingBloomFilter(unsigned width);
protected:
DECLARE_SERIAL(CountingBloomFilter);
CountingBloomFilter();
CountingBloomFilter() { }
virtual void AddImpl(const HashPolicy::HashVector& h);
virtual size_t CountImpl(const HashPolicy::HashVector& h) const;
private:
CounterVector cells_;
CounterVector* cells_;
};
#endif

View file

@ -249,6 +249,7 @@ extern OpaqueType* md5_type;
extern OpaqueType* sha1_type;
extern OpaqueType* sha256_type;
extern OpaqueType* entropy_type;
extern OpaqueType* bloomfilter_type;
// Initializes globals that don't pertain to network/event analysis.
extern void init_general_global_var();

View file

@ -518,23 +518,31 @@ bool EntropyVal::DoUnserialize(UnserialInfo* info)
return true;
}
BloomFilterVal::BloomFilterVal() : OpaqueVal(bloomfilter_type)
{
}
BloomFilterVal::BloomFilterVal(OpaqueType* t) : OpaqueVal(t)
{
}
BloomFilterVal::~BloomFilterVal()
{
if ( bloom_filter_ )
delete bloom_filter_;
}
IMPLEMENT_SERIAL(BloomFilterVal, SER_BLOOMFILTER_VAL);
bool BloomFilterVal::DoSerialize(SerialInfo* info) const
{
DO_SERIALIZE(SER_BLOOMFILTER_VAL, OpaqueVal);
// TODO: implement.
return true;
return SERIALIZE(bloom_filter_);
}
bool BloomFilterVal::DoUnserialize(UnserialInfo* info)
{
DO_UNSERIALIZE(OpaqueVal);
// TODO: implement.
return true;
bloom_filter_ = BloomFilter::Unserialize(info);
return bloom_filter_ == NULL;
}

View file

@ -112,6 +112,7 @@ private:
class BloomFilterVal : public OpaqueVal {
public:
BloomFilterVal();
~BloomFilterVal();
protected:
friend class Val;

View file

@ -53,6 +53,7 @@ SERIAL_IS(BITVECTOR, 0x1500)
SERIAL_IS(COUNTERVECTOR, 0xa000)
SERIAL_IS(BLOOMFILTER, 0xa100)
SERIAL_IS(BASICBLOOMFILTER, 0xa200)
SERIAL_IS(COUNTINGBLOOMFILTER, 0xa300)
// These are the externally visible types.
const SerialType SER_NONE = 0;
@ -211,5 +212,6 @@ SERIAL_CONST2(BITVECTOR)
SERIAL_CONST2(COUNTERVECTOR)
SERIAL_CONST2(BLOOMFILTER)
SERIAL_CONST2(BASICBLOOMFILTER)
SERIAL_CONST2(COUNTINGBLOOMFILTER)
#endif