source: trunk/nv/stl/string_table.hh @ 431

// Copyright (C) 2014-2015 ChaosForge Ltd
// http://chaosforge.org/
//
// This file is part of Nova libraries. 
// For conditions of distribution and use, see copying.txt file in root folder.

/**
 * @file string_table.hh
 * @author Kornel Kisielewicz
 */

#ifndef NV_STL_STRING_TABLE_HH
#define NV_STL_STRING_TABLE_HH

#include <nv/common.hh>
#include <nv/stl/vector.hh>
#include <nv/stl/string.hh>
#include <nv/stl/unordered_map.hh>
#include <nv/stl/stream.hh>

namespace nv
{

        class string_table : noncopyable
        {
        public:
                typedef string_view value_type;
                typedef shash64 key_type;
                typedef uint64 hash_type;
                typedef uint32 size_type;
                typedef uint16 length_type;
                typedef unordered_map< hash_type, size_type > indexer_type;
                typedef vector< char > storage_type;
                typedef indexer_type::const_iterator const_iterator;

                string_table() {}
                string_table( stream& in );
                void insert( string_table* in );
                key_type insert( const value_type& str )
                {
                        hash_type hash_value = str.get_hash< uint64 >();
                        insert( hash_value, str );
                        return key_type( hash_value );
                }

                bool exists( key_type i ) const 
                {
                        return m_map.find( i.value() ) != m_map.end();
                }

                value_type at( key_type i ) const
                {
                        const auto& it = m_map.find( i.value() );
                        NV_ASSERT_ALWAYS( it != m_map.end(), "Key not found in string_table!" );
                        return extract_raw( it->second );
                }

                value_type operator[]( key_type i ) const
                {
                        const auto& it = m_map.find( i.value() );
                        return it != m_map.end() ? extract_raw( it->second ) : value_type();
                }

                uint32 size() const { return m_map.size(); }
                bool empty() const { return m_map.empty(); }
                uint32 dump_size() const;
                void dump( stream& out ) const;
        protected:
                void insert( hash_type h, const value_type& str )
                {
                        NV_ASSERT_ALWAYS( str.size() < 0xFFF0, "String table can only hold strings up to 64k!" );
                        auto it = m_map.find( h );
                        if ( it != m_map.end() )
                        {
                                // TODO : perform comparison check if in debug mode!
                                return;
                        }
                        insert_raw( h, str.data(), static_cast<length_type>( str.size() ) );
                }


                size_type insert_raw( hash_type h, const char* str, length_type s );

                value_type extract_raw( size_type index ) const
                {
                        uint16 length = *reinterpret_cast<const uint16*>( m_data.data() + index );
                        return value_type( m_data.data() + index + 2, length );
                }

                indexer_type m_map;
                storage_type m_data;
        };

}

#endif // NV_STL_STRING_TABLE_HH