Repo created

libs/search/cbv.cpp

@@ -0,0 +1,126 @@
+#include "search/cbv.hpp"
+
+#include <limits>
+#include <vector>
+
+using namespace std;
+
+namespace search
+{
+namespace
+{
+uint64_t constexpr kModulo = 18446744073709551557LLU;
+}  // namespace
+
+// static
+CBV const & CBV::GetFull()
+{
+  static CBV const fullCBV(true /*full*/);
+  return fullCBV;
+}
+
+CBV::CBV(unique_ptr<coding::CompressedBitVector> p) : m_p(std::move(p)) {}
+
+CBV::CBV(CBV && cbv) : m_p(std::move(cbv.m_p)), m_isFull(cbv.m_isFull)
+{
+  cbv.m_isFull = false;
+}
+
+CBV::CBV(bool full) : m_isFull(full) {}
+
+CBV & CBV::operator=(unique_ptr<coding::CompressedBitVector> p)
+{
+  m_p = std::move(p);
+  m_isFull = false;
+
+  return *this;
+}
+
+CBV & CBV::operator=(CBV && rhs)
+{
+  if (this == &rhs)
+    return *this;
+
+  m_p = std::move(rhs.m_p);
+  m_isFull = rhs.m_isFull;
+
+  rhs.m_isFull = false;
+
+  return *this;
+}
+
+void CBV::SetFull()
+{
+  m_p.Reset();
+  m_isFull = true;
+}
+
+void CBV::Reset()
+{
+  m_p.Reset();
+  m_isFull = false;
+}
+
+bool CBV::HasBit(uint64_t id) const
+{
+  if (IsFull())
+    return true;
+  if (IsEmpty())
+    return false;
+  return m_p->GetBit(id);
+}
+
+uint64_t CBV::PopCount() const
+{
+  ASSERT(!IsFull(), ());
+  if (IsEmpty())
+    return 0;
+  return m_p->PopCount();
+}
+
+CBV CBV::Union(CBV const & rhs) const
+{
+  if (IsFull() || rhs.IsEmpty())
+    return *this;
+  if (IsEmpty() || rhs.IsFull())
+    return rhs;
+  return CBV(coding::CompressedBitVector::Union(*m_p, *rhs.m_p));
+}
+
+CBV CBV::Intersect(CBV const & rhs) const
+{
+  if (IsFull() || rhs.IsEmpty())
+    return rhs;
+  if (IsEmpty() || rhs.IsFull())
+    return *this;
+  return CBV(coding::CompressedBitVector::Intersect(*m_p, *rhs.m_p));
+}
+
+CBV CBV::Take(uint64_t n) const
+{
+  if (IsEmpty())
+    return *this;
+  if (IsFull())
+  {
+    vector<uint64_t> groups(static_cast<size_t>((n + 63) / 64), numeric_limits<uint64_t>::max());
+    uint64_t const r = n % 64;
+    if (r != 0)
+    {
+      ASSERT(!groups.empty(), ());
+      groups.back() = (static_cast<uint64_t>(1) << r) - 1;
+    }
+    return CBV(coding::DenseCBV::BuildFromBitGroups(std::move(groups)));
+  }
+
+  return CBV(m_p->LeaveFirstSetNBits(n));
+}
+
+uint64_t CBV::Hash() const
+{
+  if (IsEmpty())
+    return 0;
+  if (IsFull())
+    return kModulo;
+  return coding::CompressedBitVectorHasher::Hash(*m_p) % kModulo;
+}
+}  // namespace search