NSearch.h

#ifndef AFX_NSEARCH_H__8336E133_90C5_4059_8605_6066BD37D042__INCLUDED_
#define AFX_NSEARCH_H__8336E133_90C5_4059_8605_6066BD37D042__INCLUDED_
#include "Search.h"

//=========================================================================
//@{ @pkg Gp.Search //@}
// BM法検索用ポリシーs
//=========================================================================

//@{ 大文字小文字を区別するポリシー //@}
struct CaseSensitive
{
	static unicode map( unicode c )
		{ return c; }
	static bool not_equal( unicode c1, unicode c2 )
		{ return c1!=c2; }
};

//@{ 大文字小文字を区別しないポリシー //@}
struct IgnoreCase
{
	static unicode map( unicode c )
		{ return (L'a'<=c && c<=L'z' ? c-L'a'+L'A' : c); }
	static bool not_equal( unicode c1, unicode c2 )
		{ return map(c1)!=map(c2); }
};



//=========================================================================
//@{
//	BM法による普通の正方向検索
//@}
//=========================================================================
#ifdef __GNUC__
inline void memFF( void* ptrv, int siz )
	{ BYTE* ptr = (BYTE*)ptrv;
	  for(;siz>3;siz-=4,ptr+=4) *(DWORD*)ptr = 0xffffffff;
	  for(;siz;--siz,++ptr) *ptr = 0xff; }
#endif
template<class ComparisonPolicy> class BMSearch
{
public:
	BMSearch( const unicode* key )
		: keylen_( my_lstrlenW(key) )
		, key_( my_lstrcpyW( new unicode[keylen_+1], key ) )
	{
		memFF( lastAppearance_, sizeof(lastAppearance_) );
		for( int i=0, e=keylen_; i<e; ++i )
			lastAppearance_[ ComparisonPolicy::map(key[i]) ] = i;
	}

	~BMSearch()
	{
		delete [] key_;
	}

	int Search( const unicode* str, int strlen )
	{
		for( int i=0, e=strlen-keylen_, j, t; i<=e; i+=(j>t?j-t:1) )
		{
			for( j=keylen_-1; j>=0; --j )
			{
				if( ComparisonPolicy::not_equal( key_[j], str[i+j] ) )
					break;
			}
			if( j < 0 )
				return i;
			t = lastAppearance_[ ComparisonPolicy::map(str[i+j]) ];
		}
		return -1;
	}

	int keylen() const { return keylen_; }

private:
	int      keylen_;
	unicode* key_;
	int      lastAppearance_[65536];
};



//=========================================================================
//@{
//	BM法による逆方向検索
//@}
//=========================================================================

template<class ComparisonPolicy> class BMSearchRev
{
public:
	BMSearchRev( const unicode* key )
		: keylen_( my_lstrlenW(key) )
		, key_( my_lstrcpyW( new unicode[keylen_+1], key ) )
	{
		memFF( firstAppearance_, sizeof(firstAppearance_) );
		for( int i=keylen_-1; i>=0; --i )
			firstAppearance_[ ComparisonPolicy::map(key[i]) ] = i;
	}

	~BMSearchRev()
	{
		delete [] key_;
	}

	int Search( const unicode* str, int strlen )
	{
		for( int i=strlen-keylen_-1, j, e, t; i>=0; i-=(t>j?t-j:1) )
		{
			for( j=0, e=keylen_; j<e; ++j )
				if( ComparisonPolicy::not_equal( key_[j], str[i+j] ) )
					break;
			if( j >= e )
				return i;
			t = firstAppearance_[ ComparisonPolicy::map(str[i+j]) ];
			if( t == -1 ) t = keylen_;
		}
		return -1;
	}

	int keylen() const { return keylen_; }

private:
	int      keylen_;
	unicode* key_;
	int      firstAppearance_[65536];
};



//=========================================================================
//@{
// Searhcableとしての実装（正方向検索）
//@}
//=========================================================================

template<class CompalisonPolicy>
class NSearch : public Searchable
{
public:
	NSearch( const unicode* key ) : s_(key) {}

private:
	bool Search(
		const unicode* str, ulong len, ulong stt, ulong* mbg, ulong* med )
	{
		int n = s_.Search( str+stt, len-stt );
		if( n < 0 )
			return false;
		*mbg = stt + n;
		*med = stt + n + s_.keylen();
		return true;
	}

private:
	BMSearch<CompalisonPolicy> s_;
};



//=========================================================================
//@{
// Searhcableとしての実装（逆方向検索）
//@}
//=========================================================================

template<class CompalisonPolicy>
class NSearchRev : public Searchable
{
public:
	NSearchRev( const unicode* key ) : s_(key) {}

private:
	bool Search(
		const unicode* str, ulong len, ulong stt, ulong* mbg, ulong* med )
	{
		int n = s_.Search( str, stt+s_.keylen() );
		if( n < 0 )
			return false;
		*mbg = n;
		*med = n + s_.keylen();
		return true;
	}

private:
	BMSearchRev<CompalisonPolicy> s_;
};



//=========================================================================

#endif