bitcore-node-zcash/deps/boost/log/attributes/attribute_value_set.hpp

481 lines
17 KiB
C++

/*
* Copyright Andrey Semashev 2007 - 2013.
* Distributed under the Boost Software License, Version 1.0.
* (See accompanying file LICENSE_1_0.txt or copy at
* http://www.boost.org/LICENSE_1_0.txt)
*/
/*!
* \file attribute_value_set.hpp
* \author Andrey Semashev
* \date 21.04.2007
*
* This header file contains definition of attribute value set. The set is constructed from
* three attribute sets (global, thread-specific and source-specific) and contains attribute
* values.
*/
#ifndef BOOST_LOG_ATTRIBUTE_VALUE_SET_HPP_INCLUDED_
#define BOOST_LOG_ATTRIBUTE_VALUE_SET_HPP_INCLUDED_
#include <cstddef>
#include <utility>
#include <iterator>
#include <boost/move/core.hpp>
#include <boost/log/detail/config.hpp>
#include <boost/log/attributes/attribute_name.hpp>
#include <boost/log/attributes/attribute.hpp>
#include <boost/log/attributes/attribute_value.hpp>
#include <boost/log/attributes/attribute_set.hpp>
#include <boost/log/expressions/keyword_fwd.hpp>
#include <boost/log/detail/header.hpp>
#ifdef BOOST_HAS_PRAGMA_ONCE
#pragma once
#endif
namespace boost {
BOOST_LOG_OPEN_NAMESPACE
/*!
* \brief A set of attribute values
*
* The set of attribute values is an associative container with attribute name as a key and
* a pointer to attribute value object as a mapped type. This is a collection of elements with unique
* keys, that is, there can be only one attribute value with a given name in the set. With respect to
* read-only capabilities, the set interface is close to \c std::unordered_map.
*
* The set is designed to be only capable of adding elements to it. Once added, the attribute value
* cannot be removed from the set.
*
* An instance of attribute value set can be constructed from three attribute sets. The constructor attempts to
* accommodate values of all attributes from the sets. The situation when a same-named attribute is found
* in more than one attribute set is possible. This problem is solved on construction of the value set: the three
* attribute sets have different priorities when it comes to solving conflicts.
*
* From the library perspective the three source attribute sets are global, thread-specific and source-specific
* attributes, with the latter having the highest priority. This feature allows to override attributes of wider scopes
* with the more specific ones.
*
* For sake of performance, the attribute values are not immediately acquired from attribute sets at construction.
* Instead, on-demand acquisition is performed either on iterator dereferencing or on call to the \c freeze method.
* Once acquired, the attribute value stays within the set until its destruction. This nuance does not affect
* other set properties, such as size or lookup ability. The logging core automatically freezes the set
* at the right point, so users should not be bothered unless they manually create attribute value sets.
*
* \note The attribute sets that were used for the value set construction must not be modified or destroyed
* until the value set is frozen. Otherwise the behavior is undefined.
*/
class attribute_value_set
{
BOOST_COPYABLE_AND_MOVABLE_ALT(attribute_value_set)
public:
//! Key type
typedef attribute_name key_type;
//! Mapped attribute type
typedef attribute_value mapped_type;
//! Value type
typedef std::pair< const key_type, mapped_type > value_type;
//! Reference type
typedef value_type& reference;
//! Const reference type
typedef value_type const& const_reference;
//! Pointer type
typedef value_type* pointer;
//! Const pointer type
typedef value_type const* const_pointer;
//! Size type
typedef std::size_t size_type;
//! Pointer difference type
typedef std::ptrdiff_t difference_type;
#ifndef BOOST_LOG_DOXYGEN_PASS
private:
struct implementation;
friend struct implementation;
//! A base class for the container nodes
struct node_base
{
node_base* m_pPrev;
node_base* m_pNext;
node_base();
BOOST_DELETED_FUNCTION(node_base(node_base const&))
BOOST_DELETED_FUNCTION(node_base& operator= (node_base const&))
};
//! Container elements
struct node;
friend struct node;
struct node :
public node_base
{
value_type m_Value;
bool m_DynamicallyAllocated;
node(key_type const& key, mapped_type& data, bool dynamic);
};
public:
class const_iterator;
friend class const_iterator;
class const_iterator
{
public:
// Standard typedefs
typedef attribute_value_set::difference_type difference_type;
typedef attribute_value_set::value_type value_type;
typedef attribute_value_set::const_reference reference;
typedef attribute_value_set::const_pointer pointer;
typedef std::bidirectional_iterator_tag iterator_category;
public:
// Constructors
BOOST_CONSTEXPR const_iterator() : m_pNode(NULL), m_pContainer(NULL) {}
explicit const_iterator(node_base* n, attribute_value_set* cont) BOOST_NOEXCEPT :
m_pNode(n),
m_pContainer(cont)
{
}
// Comparison
bool operator== (const_iterator const& that) const BOOST_NOEXCEPT
{
return (m_pNode == that.m_pNode);
}
bool operator!= (const_iterator const& that) const BOOST_NOEXCEPT
{
return (m_pNode != that.m_pNode);
}
// Modification
const_iterator& operator++ ()
{
m_pContainer->freeze();
m_pNode = m_pNode->m_pNext;
return *this;
}
const_iterator& operator-- ()
{
m_pContainer->freeze();
m_pNode = m_pNode->m_pPrev;
return *this;
}
const_iterator operator++ (int)
{
const_iterator tmp(*this);
m_pContainer->freeze();
m_pNode = m_pNode->m_pNext;
return tmp;
}
const_iterator operator-- (int)
{
const_iterator tmp(*this);
m_pContainer->freeze();
m_pNode = m_pNode->m_pPrev;
return tmp;
}
// Dereferencing
pointer operator-> () const BOOST_NOEXCEPT { return &(static_cast< node* >(m_pNode)->m_Value); }
reference operator* () const BOOST_NOEXCEPT { return static_cast< node* >(m_pNode)->m_Value; }
private:
node_base* m_pNode;
attribute_value_set* m_pContainer;
};
#else
/*!
* Constant iterator type with bidirectional capabilities.
*/
typedef implementation_defined const_iterator;
#endif // BOOST_LOG_DOXYGEN_PASS
private:
//! Pointer to the container implementation
implementation* m_pImpl;
public:
/*!
* Default constructor
*
* The constructor creates an empty set which can be filled later by subsequent
* calls of \c insert method. Optionally, the amount of storage reserved for elements
* to be inserted may be passed to the constructor.
* The constructed set is frozen.
*
* \param reserve_count Number of elements to reserve space for.
*/
BOOST_LOG_API explicit attribute_value_set(size_type reserve_count = 8);
/*!
* Move constructor
*/
attribute_value_set(BOOST_RV_REF(attribute_value_set) that) BOOST_NOEXCEPT : m_pImpl(that.m_pImpl)
{
that.m_pImpl = NULL;
}
/*!
* The constructor adopts three attribute sets into the value set.
* The \a source_attrs attributes have the greatest preference when a same-named
* attribute is found in several sets, \a global_attrs has the least.
* The constructed set is not frozen.
*
* \param source_attrs A set of source-specific attributes.
* \param thread_attrs A set of thread-specific attributes.
* \param global_attrs A set of global attributes.
* \param reserve_count Amount of elements to reserve space for, in addition to the elements in the three attribute sets provided.
*/
BOOST_LOG_API attribute_value_set(
attribute_set const& source_attrs,
attribute_set const& thread_attrs,
attribute_set const& global_attrs,
size_type reserve_count = 8);
/*!
* The constructor adopts three attribute sets into the value set.
* The \a source_attrs attributes have the greatest preference when a same-named
* attribute is found in several sets, \a global_attrs has the least.
* The constructed set is not frozen.
*
* \pre The \a source_attrs set is frozen.
*
* \param source_attrs A set of source-specific attributes.
* \param thread_attrs A set of thread-specific attributes.
* \param global_attrs A set of global attributes.
* \param reserve_count Amount of elements to reserve space for, in addition to the elements in the three attribute sets provided.
*/
BOOST_LOG_API attribute_value_set(
attribute_value_set const& source_attrs,
attribute_set const& thread_attrs,
attribute_set const& global_attrs,
size_type reserve_count = 8);
/*!
* The constructor adopts three attribute sets into the value set.
* The \a source_attrs attributes have the greatest preference when a same-named
* attribute is found in several sets, \a global_attrs has the least.
* The constructed set is not frozen.
*
* \pre The \a source_attrs set is frozen.
*
* \param source_attrs A set of source-specific attributes.
* \param thread_attrs A set of thread-specific attributes.
* \param global_attrs A set of global attributes.
* \param reserve_count Amount of elements to reserve space for, in addition to the elements in the three attribute sets provided.
*/
attribute_value_set(
BOOST_RV_REF(attribute_value_set) source_attrs,
attribute_set const& thread_attrs,
attribute_set const& global_attrs,
size_type reserve_count = 8) : m_pImpl(NULL)
{
construct(static_cast< attribute_value_set& >(source_attrs), thread_attrs, global_attrs, reserve_count);
}
/*!
* Copy constructor.
*
* \pre The original set is frozen.
* \post The constructed set is frozen, <tt>std::equal(begin(), end(), that.begin()) == true</tt>
*/
BOOST_LOG_API attribute_value_set(attribute_value_set const& that);
/*!
* Destructor. Releases all referenced attribute values.
*/
BOOST_LOG_API ~attribute_value_set() BOOST_NOEXCEPT;
/*!
* Assignment operator
*/
attribute_value_set& operator= (attribute_value_set that) BOOST_NOEXCEPT
{
this->swap(that);
return *this;
}
/*!
* Swaps two sets
*
* \b Throws: Nothing.
*/
void swap(attribute_value_set& that) BOOST_NOEXCEPT
{
register implementation* const p = m_pImpl;
m_pImpl = that.m_pImpl;
that.m_pImpl = p;
}
/*!
* \return Iterator to the first element of the set.
*/
BOOST_LOG_API const_iterator begin() const;
/*!
* \return Iterator to the after-the-last element of the set.
*/
BOOST_LOG_API const_iterator end() const;
/*!
* \return Number of elements in the set.
*/
BOOST_LOG_API size_type size() const;
/*!
* \return true if there are no elements in the container, false otherwise.
*/
bool empty() const { return (this->size() == 0); }
/*!
* The method finds the attribute value by name.
*
* \param key Attribute name.
* \return Iterator to the found element or \c end() if the attribute with such name is not found.
*/
BOOST_LOG_API const_iterator find(key_type key) const;
/*!
* Alternative lookup syntax.
*
* \param key Attribute name.
* \return A pointer to the attribute value if it is found with \a key, default-constructed mapped value otherwise.
*/
mapped_type operator[] (key_type key) const
{
const_iterator it = this->find(key);
if (it != this->end())
return it->second;
else
return mapped_type();
}
/*!
* Alternative lookup syntax.
*
* \param keyword Attribute keyword.
* \return A \c value_ref with extracted attribute value if it is found, empty \c value_ref otherwise.
*/
template< typename DescriptorT, template< typename > class ActorT >
typename result_of::extract< typename expressions::attribute_keyword< DescriptorT, ActorT >::value_type, DescriptorT >::type
operator[] (expressions::attribute_keyword< DescriptorT, ActorT > const& keyword) const
{
typedef typename expressions::attribute_keyword< DescriptorT, ActorT >::value_type attr_value_type;
typedef typename result_of::extract< attr_value_type, DescriptorT >::type result_type;
const_iterator it = this->find(keyword.get_name());
if (it != this->end())
return it->second.extract< attr_value_type, DescriptorT >();
else
return result_type();
}
/*!
* The method counts the number of the attribute value occurrences in the set. Since there can be only one
* attribute value with a particular key, the method always return 0 or 1.
*
* \param key Attribute name.
* \return The number of times the attribute value is found in the container.
*/
size_type count(key_type key) const { return size_type(this->find(key) != this->end()); }
/*!
* The method acquires values of all adopted attributes.
*
* \post The set is frozen.
*/
BOOST_LOG_API void freeze();
/*!
* Inserts an element into the set. The complexity of the operation is amortized constant.
*
* \pre The set is frozen.
*
* \param key The attribute name.
* \param mapped The attribute value.
*
* \returns An iterator to the inserted element and \c true if insertion succeeded. Otherwise,
* if the set already contains a same-named attribute value, iterator to the
* existing element and \c false.
*/
BOOST_LOG_API std::pair< const_iterator, bool > insert(key_type key, mapped_type const& mapped);
/*!
* Inserts an element into the set. The complexity of the operation is amortized constant.
*
* \pre The set is frozen.
*
* \param value The attribute name and value.
*
* \returns An iterator to the inserted element and \c true if insertion succeeded. Otherwise,
* if the set already contains a same-named attribute value, iterator to the
* existing element and \c false.
*/
std::pair< const_iterator, bool > insert(const_reference value) { return this->insert(value.first, value.second); }
/*!
* Mass insertion method. The complexity of the operation is linear to the number of elements inserted.
*
* \pre The set is frozen.
*
* \param begin A forward iterator that points to the first element to be inserted.
* \param end A forward iterator that points to the after-the-last element to be inserted.
*/
template< typename FwdIteratorT >
void insert(FwdIteratorT begin, FwdIteratorT end)
{
for (; begin != end; ++begin)
this->insert(*begin);
}
/*!
* Mass insertion method with ability to acquire iterators to the inserted elements.
* The complexity of the operation is linear to the number of elements inserted times the complexity
* of filling the \a out iterator.
*
* \pre The set is frozen.
*
* \param begin A forward iterator that points to the first element to be inserted.
* \param end A forward iterator that points to the after-the-last element to be inserted.
* \param out An output iterator that receives results of insertion of the elements.
*/
template< typename FwdIteratorT, typename OutputIteratorT >
void insert(FwdIteratorT begin, FwdIteratorT end, OutputIteratorT out)
{
for (; begin != end; ++begin, ++out)
*out = this->insert(*begin);
}
#ifndef BOOST_LOG_DOXYGEN_PASS
private:
//! Constructs the object by moving from \a source_attrs. This function is mostly needed to maintain ABI stable between C++03 and C++11.
BOOST_LOG_API void construct(
attribute_value_set& source_attrs,
attribute_set const& thread_attrs,
attribute_set const& global_attrs,
size_type reserve_count);
#endif // BOOST_LOG_DOXYGEN_PASS
};
/*!
* Free swap overload
*/
inline void swap(attribute_value_set& left, attribute_value_set& right) BOOST_NOEXCEPT
{
left.swap(right);
}
BOOST_LOG_CLOSE_NAMESPACE // namespace log
} // namespace boost
#include <boost/log/detail/footer.hpp>
#endif // BOOST_LOG_ATTRIBUTE_VALUE_SET_HPP_INCLUDED_