mirror of https://github.com/PCSX2/pcsx2.git
671 lines
24 KiB
C++
671 lines
24 KiB
C++
#pragma once
|
|
|
|
#include <google/type_traits.h>
|
|
#include <google/dense_hash_set>
|
|
#include <google/dense_hash_map>
|
|
#include <google/sparsehash/densehashtable.h>
|
|
|
|
#include <wx/string.h>
|
|
|
|
namespace HashTools {
|
|
|
|
#define HashFriend(Key,T) friend class HashMap<Key,T>
|
|
|
|
/// Defines an equality comparison unary method.
|
|
/// Generally intended for internal use only.
|
|
#define _EQUALS_UNARY_OP( Type ) bool operator()(const Type s1, const Type s2) const { return s1.Equals( s2 ); }
|
|
|
|
/// Defines a hash code unary method
|
|
/// Generally intended for internal use only.
|
|
#define _HASHCODE_UNARY_OP( Type ) hash_key_t operator()( const Type& val ) const { return val.GetHashCode(); }
|
|
|
|
/// <summary>
|
|
/// Defines an equality comparison method within an encapsulating struct, using the 'unary method' approach.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// <para>
|
|
/// This macro is a shortcut helper to implementing types usable as keys in <see cref="HashMap"/>s.
|
|
/// Normally you will want to use <see cref="DEFINE_HASH_API"/> instead as it defines both
|
|
/// the HashCode predicate and Compare predicate.
|
|
/// </para>
|
|
/// The code generated by this macro is equivalent to this:
|
|
/// <code>
|
|
/// // where 'Type' is the parameter used in the macro.
|
|
/// struct UnaryEquals
|
|
/// {
|
|
/// bool operator()(const Type s1, const Type s2) const
|
|
/// {
|
|
/// return s1.Equals( s2 ); // this operator must be implemented by the user.
|
|
/// }
|
|
/// };
|
|
/// </code>
|
|
/// Note:
|
|
/// In C++, the term 'unary method' refers to a method that is implemented as an overload of the
|
|
/// <c>operator ()</c>, such that the object instance itself acts as a method.
|
|
/// Note:
|
|
/// This methodology is similar to C# / .NET's <c>object.Equals()</c> method: The class member method
|
|
/// implementation of <c>Equals</c> should *not* throw exceptions -- it should instead return <c>false</c>
|
|
/// if either side of the comparison is not a matching type. See <see cref="IHashable" /> for details.
|
|
/// Note:
|
|
/// The reason for this (perhaps seemingly) hogwash red tape is because you can define custom
|
|
/// equality behavior for individual hashmaps, which are independent of the type used. The only
|
|
/// obvious scenario where such a feature is useful is in
|
|
/// </remarks>
|
|
/// <seealso cref="DEFINE_HASHCODE_UNARY"/>
|
|
/// <seealso cref="DEFINE_HASH_API"/>
|
|
/// <seealso cref="IHashable"/>
|
|
/// <seealso cref="HashMap"/>
|
|
#define DEFINE_EQUALS_UNARY( Type ) struct UnaryEquals{ _EQUALS_UNARY_OP( Type ) }
|
|
|
|
/// <summary>
|
|
/// Defines a hash code predicate within an encapsulating struct; for use in hashable user datatypes
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// <para>
|
|
/// This macro is a shortcut helper to implementing types usable as keys in <see cref="HashMap"/>s.
|
|
/// Normally you will want to use <see cref="DEFINE_HASH_API"/> instead as it defines both
|
|
/// the HashCode predicate and Compare predicate.
|
|
/// </para>
|
|
/// The code generated by this macro is equivalent to this:
|
|
/// <code>
|
|
/// // where 'Type' is the parameter used in the macro.
|
|
/// struct UnaryHashCode
|
|
/// {
|
|
/// hash_key_t operator()( const Type& val ) const
|
|
/// {
|
|
/// return val.GetHashCode(); // this member function must be implemented by the user.
|
|
/// }
|
|
/// };
|
|
/// </code>
|
|
/// </remarks>
|
|
/// <seealso cref="DEFINE_EQUALS_UNARY"/>
|
|
/// <seealso cref="DEFINE_HASH_API"/>
|
|
/// <seealso cref="IHashable"/>
|
|
/// <seealso cref="HashMap"/>
|
|
#define DEFINE_HASHCODE_UNARY( Type ) struct UnaryHashCode{ _HASHCODE_UNARY_OP( Type ) }
|
|
|
|
/// <summary>
|
|
/// Defines the API for hashcode and comparison unary methods; for use in hashable user datatypes
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// This macro creates APIs that allow the class or struct to be used as a key in a <see cref="HashMap"/>.
|
|
/// It requires that the data type implement the following items:
|
|
/// * An equality test via an <c>operator==</c> overload.
|
|
/// * A public instance member method <c>GetHashCode.</c>
|
|
/// The code generated by this macro is equivalent to this:
|
|
/// <code>
|
|
/// // where 'Type' is the parameter used in the macro.
|
|
/// struct UnaryHashCode
|
|
/// {
|
|
/// hash_key_t operator()( const Type& val ) const
|
|
/// {
|
|
/// return val.GetHashCode(); // this member function must be implemented by the user.
|
|
/// }
|
|
/// };
|
|
///
|
|
/// struct UnaryEquals
|
|
/// {
|
|
/// bool operator()(const Type s1, const Type s2) const
|
|
/// {
|
|
/// return s1.Equals( s2 ); // this operator must be implemented by the user.
|
|
/// }
|
|
/// };
|
|
/// </code>
|
|
/// Note:
|
|
/// In C++, the term 'unary method' refers to a method that is implemented as an overload of the
|
|
/// <c>operator ()</c>, such that the object instance itself acts as a method.
|
|
/// Note:
|
|
/// For class types you can use the <see cref="IHashable"/> interface, which also allows you to group
|
|
/// multiple types of objects into a single complex HashMap.
|
|
/// Note:
|
|
/// Generally speaking, you do not use the <c>IHashable</c> interface on simple C-style structs, since it
|
|
/// would incur the overhead of a vtbl and could potentially break code that assumes the structs to have
|
|
/// 1-to-1 data-to-declaration coorlations.
|
|
/// Note:
|
|
/// Internally, using this macro is functionally equivalent to using both <see cref="DEFINE_HASHCODE_CLASS"/>
|
|
/// and <see cref="DEFINE_EQUALS_CLASS"/>.
|
|
/// </remarks>
|
|
/// <seealso cref="IHashable"/>
|
|
/// <seealso cref="DEFINE_HASHCODE_CLASS"/>
|
|
/// <seealso cref="DEFINE_COMPARE_CLASS"/>
|
|
/// <seealso cref="DEFINE_HASH_API"/>
|
|
/// <seealso cref="HashMap"/>
|
|
#define DEFINE_HASH_API( Type ) DEFINE_HASHCODE_UNARY( Type ); DEFINE_EQUALS_UNARY( Type );
|
|
|
|
/// <summary>
|
|
/// A helper macro for creating custom types that can be used as <see cref="HashMap" /> keys.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// Use of this macro is only needed if the hashable type in question is a struct that is a private
|
|
/// local to the namespace of a containing class.
|
|
/// </remarks>
|
|
#define PRIVATE_HASHMAP( Key, T ) \
|
|
typedef SpecializedHashMap<Key, T> Key##HashMap; \
|
|
friend Key##HashMap;
|
|
|
|
/// <summary>
|
|
/// Type that represents a hashcode; returned by all hash functions.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// In theory this could be changed to a 64 bit value in the future, although many of the hash algorithms
|
|
/// would have to be changed to take advantage of the larger data type.
|
|
/// </remarks>
|
|
typedef u32 hash_key_t;
|
|
|
|
hash_key_t Hash(const char* data, int len);
|
|
|
|
struct CommonHashClass;
|
|
extern const CommonHashClass GetCommonHash;
|
|
|
|
/// <summary>
|
|
/// A unary-style set of methods for getting the hash code of C++ fundamental types.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// This class is used to pass hash functions into the <see cref="HashMap"/> class and
|
|
/// it's siblings. It houses methods for most of the fundamental types of C++ and the STL,
|
|
/// such as all int and float types, and also <c>std::string</c>. All functions can be
|
|
/// accessed via the () overload on an instance of the class, such as:
|
|
/// <code>
|
|
/// const CommonHashClass GetHash;
|
|
/// int v = 27;
|
|
/// std::string s = "Joe's World!";
|
|
/// hash_key_t hashV = GetHash( v );
|
|
/// hash_key_t hashS = GetHash( s );
|
|
/// </code>
|
|
/// Note:
|
|
/// In C++, the term 'unary method' refers to a method that is implemented as an overload of the
|
|
/// <c>operator ()</c>, such that the object instance itself acts as a method.
|
|
/// </remarks>
|
|
/// <seealso cref="GetCommonHash"/>
|
|
struct CommonHashClass
|
|
{
|
|
public:
|
|
// GCC needs empty constructors on const instances, because it likes pointlessness.
|
|
CommonHashClass() {}
|
|
|
|
hash_key_t DoInt( u32 val ) const
|
|
{
|
|
u32 key = val;
|
|
key = ~key + (key << 15);
|
|
key = key ^ (key >> 12);
|
|
key = key + (key << 2);
|
|
key = key ^ (key >> 4);
|
|
key = key * 2057;
|
|
key = key ^ (key >> 16);
|
|
|
|
return val;
|
|
}
|
|
|
|
hash_key_t operator()(const std::string& src) const
|
|
{
|
|
return Hash( src.data(), src.length() );
|
|
}
|
|
|
|
hash_key_t operator()( const std::wstring& src ) const
|
|
{
|
|
return Hash( (const char *)src.data(), src.length() * sizeof( wchar_t ) );
|
|
}
|
|
|
|
hash_key_t operator()( const wxString& src ) const
|
|
{
|
|
return Hash( (const char *)src.data(), src.length() * sizeof( wxChar ) );
|
|
}
|
|
|
|
// Returns a hashcode for a character.
|
|
// This has function has been optimized to return an even distribution
|
|
// across the range of an int value. In theory that should be more rewarding
|
|
// to hastable performance than a straight up char lookup.
|
|
hash_key_t operator()( const char c1 ) const
|
|
{
|
|
// Most chars contain values between 0 and 128, so let's mix it up a bit:
|
|
int cs = (int)( c1 + (char)64 );
|
|
return ( cs + ( cs<<8 ) + ( cs << 16 ) + (cs << 24 ) );
|
|
}
|
|
|
|
hash_key_t operator()( const wchar_t wc1 ) const
|
|
{
|
|
// Most unicode values are between 0 and 128, with 0-1024
|
|
// making up the bulk of the rest. Everything else is spatially used.
|
|
/*int wcs = (int) ( wc1 + 0x2000 );
|
|
return wcs ^ ( wcs + 0x19000 );*/
|
|
|
|
// or maybe I'll just feed it into the int hash:
|
|
return GetCommonHash( (u32)wc1 );
|
|
}
|
|
|
|
/// <summary>
|
|
/// Gets the hash code for a 32 bit integer.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// This method performs a very fast algorithm optimized for typical integral
|
|
/// dispersion patterns (which tend to favor a bit heavy on the lower-range of values while
|
|
/// leaving the extremes un-used).
|
|
/// Note:
|
|
/// Implementation is based on an article found here: http://www.concentric.net/~Ttwang/tech/inthash.htm
|
|
/// </remarks>
|
|
hash_key_t operator()( const u32 val ) const
|
|
{
|
|
return DoInt(val);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Gets the hash code for a 32 bit integer.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// This method performs a very fast algorithm optimized for typical integral
|
|
/// dispersion patterns (which tend to favor a bit heavy on the lower-range of values while
|
|
/// leaving the extremes un-used).
|
|
/// Note:
|
|
/// Implementation is based on an article found here: http://www.concentric.net/~Ttwang/tech/inthash.htm
|
|
/// </remarks>
|
|
hash_key_t operator()( const s32 val ) const
|
|
{
|
|
return DoInt(val);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Gets the hash code for a 64 bit integer.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// This method performs a very fast algorithm optimized for typical integral
|
|
/// dispersion patterns (which tend to favor a bit heavy on the lower-range of values while
|
|
/// leaving the extremes un-used).
|
|
/// Note:
|
|
/// Implementation is based on an article found here: http://www.concentric.net/~Ttwang/tech/inthash.htm
|
|
/// </remarks>
|
|
hash_key_t operator()( const u64 val ) const
|
|
{
|
|
u64 key = val;
|
|
key = (~key) + (key << 18);
|
|
key = key ^ (key >> 31);
|
|
key = key * 21; // key = (key + (key << 2)) + (key << 4);
|
|
key = key ^ (key >> 11);
|
|
key = key + (key << 6);
|
|
key = key ^ (key >> 22);
|
|
return (u32) key;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Gets the hash code for a 64 bit integer.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// This method performs a very fast algorithm optimized for typical integral
|
|
/// dispersion patterns (which tend to favor a bit heavy on the lower-range of values while
|
|
/// leaving the extremes un-used).
|
|
/// Note:
|
|
/// Implementation is based on an article found here: http://www.concentric.net/~Ttwang/tech/inthash.htm
|
|
/// </remarks>
|
|
hash_key_t operator()( const s64 val ) const
|
|
{
|
|
return GetCommonHash((u64)val);
|
|
}
|
|
|
|
hash_key_t operator()( const float val ) const
|
|
{
|
|
// floats do a fine enough job of being scattered about
|
|
// the universe:
|
|
return *((hash_key_t *)&val);
|
|
}
|
|
|
|
hash_key_t operator()( const double val ) const
|
|
{
|
|
// doubles have to be compressed into a 32 bit value:
|
|
return GetCommonHash( *((u64*)&val) );
|
|
}
|
|
|
|
/// <summary>
|
|
/// Calculates the hash of a pointer.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// This method has been optimized to give typical 32 bit pointers a reasonably
|
|
/// wide spread across the integer spectrum.
|
|
/// Note:
|
|
/// This method is optimized for 32 bit pointers only. 64 bit pointer support
|
|
/// has not been implemented, and thus on 64 bit platforms performance could be poor or,
|
|
/// worse yet, results may not have a high degree of uniqueness.
|
|
/// </remarks>
|
|
hash_key_t operator()( const void* addr ) const
|
|
{
|
|
hash_key_t key = (hash_key_t) addr;
|
|
return (hash_key_t)((key >> 3) * 2654435761ul);
|
|
}
|
|
|
|
|
|
};
|
|
|
|
/// <summary>
|
|
/// This class contains comparison methods for most fundamental types; and is used by the CommonHashMap class.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// The predicates of this class do standard equality comparisons between fundamental C/STL types such as
|
|
/// <c>int, float</c>, and <c>std::string.</c> Usefulness of this class outside the <see cref="CommonHashMap"/>
|
|
/// class is limited.
|
|
/// </remarks>
|
|
/// <seealso cref="CommonHashMap">
|
|
struct CommonComparisonClass
|
|
{
|
|
bool operator()(const char* s1, const char* s2) const
|
|
{
|
|
return (s1 == s2) || (s1 && s2 && strcmp(s1, s2) == 0);
|
|
}
|
|
};
|
|
|
|
/// <summary>
|
|
/// An interface for classes that implement hashmap functionality.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// This class provides interface methods for getting th hashcode of a class and checking for object
|
|
/// equality. It's general intent is for use in situations where you have to store *non-similar objects*
|
|
/// in a single unified hash map. As all object instances derive from this type, it allows the equality
|
|
/// comparison to use typeid or dynamic casting to check for type similarity, and then use more detailed
|
|
/// equality checks for similar types.
|
|
/// </remarks>
|
|
class IHashable
|
|
{
|
|
public:
|
|
/// Obligatory Virtual destructor mess!
|
|
virtual ~IHashable() {};
|
|
|
|
/// <summary>
|
|
/// Your basic no-thrills equality comparison; using a pointer comparison by default.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// This method uses a pointer comparison by default, which is the only way to really compare objects
|
|
/// of unrelated types or of derrived types. When implementing this method, you may want to use typeid comparisons
|
|
/// if you want derived types to register as being non-equal, or <c>dynamic_cast</c> for a more robust
|
|
/// base-class comparison (illustrated in the example below).
|
|
/// Note:
|
|
/// It's recommended important to always do a pointer comparison as the first step of any object equality check.
|
|
/// It is fast and easy, and 100% reliable.
|
|
/// </remarks>
|
|
/// <example>
|
|
/// Performing non-pointer comparisons:
|
|
/// <code>
|
|
/// class Hasher : IHashable
|
|
/// {
|
|
/// int someValue;
|
|
///
|
|
/// virtual bool Equals( const IHashable& right ) const
|
|
/// {
|
|
/// // Use pointer comparison first since it's fast and accurate:
|
|
/// if( &right == this ) return true;
|
|
///
|
|
/// Hasher* them = dynamic_cast<Hasher*>( right );
|
|
/// if( them == NULL ) return false;
|
|
/// return someValue == them->SomeValue;
|
|
/// }
|
|
/// }
|
|
/// </code>
|
|
/// </example>
|
|
virtual bool Equals( const IHashable& right ) const
|
|
{
|
|
return ( &right == this ); // pointer comparison.
|
|
}
|
|
|
|
/// <summary>
|
|
/// Returns a hash value for this object; by default the hash of its pointer address.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// </remarks>
|
|
/// <seealso cref="HashMap"/>
|
|
virtual hash_key_t GetHashCode() const
|
|
{
|
|
return GetCommonHash( this );
|
|
}
|
|
};
|
|
|
|
template< typename Key >
|
|
class HashSet : public google::dense_hash_set< Key, CommonHashClass >
|
|
{
|
|
public:
|
|
/// <summary>
|
|
/// Constructor.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// Both the <c>emptyKey</c>a nd c>deletedKey</c> parameters must be unique values that
|
|
/// are *not* used as actual values in the set.
|
|
/// </remarks>
|
|
HashSet( Key emptyKey, Key deletedKey, int initialCapacity=33 ) :
|
|
google::dense_hash_set<Key, CommonHashClass>( initialCapacity )
|
|
{
|
|
set_empty_key( emptyKey );
|
|
set_deleted_key( deletedKey );
|
|
}
|
|
};
|
|
|
|
/// <summary>
|
|
/// Defines a hashed collection of objects and provides methods for adding, removing, and reading items.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// <para>This class is for hashing out a set data using objects as keys. Objects should derive from the
|
|
/// <see cref="IHashable"/> type, and in either case *must* implement the UnaryHashCode and UnaryEquals
|
|
/// unary classes.</para>
|
|
/// <para>*Details On Implementing Key Types*</para>
|
|
/// <para>
|
|
/// Custom hash keying uses what I consider a somewhat contrived method of implementing the Key type;
|
|
/// involving a handful of macros in the best case, and a great deal of syntaxical red tape in
|
|
/// the worst case. Most cases should fall within the realm of the macros, which make life a lot easier,
|
|
/// so that's the only implementation I will cover in detail here (see below for example).
|
|
/// </para>
|
|
/// Note:
|
|
/// For most hashs based on common or fundamental types or types that can be adequately compared using
|
|
/// the default equality operator ==, such as <c>int</c> or structs that have no padding alignment concerns,
|
|
/// use <see cref="HashMap" /> instead. For string-based hashs, use <see cref="Dictionary" /> or <see cref="UnicodeDictionary" />.
|
|
/// </remarks>
|
|
/// <example>
|
|
/// This is an example of making a hashable type out of a struct. This is useful in situations where
|
|
/// inheriting the <see cref="IHashable"/> type would cause unnecessary overhead and/or broken C/C++
|
|
/// compatability.
|
|
/// <code>
|
|
/// struct Point
|
|
/// {
|
|
/// int x, y;
|
|
///
|
|
/// // Empty constructor is necessary for HashMap.
|
|
/// // This can either be initialized to zero, or uninitialized as here:
|
|
/// Point() {}
|
|
///
|
|
/// // Copy Constructor is just always necessary.
|
|
/// Point( const Point& src ) : first( src.first ), second( src.second ) {}
|
|
///
|
|
/// // Standard content constructor (Not needed by HashMap)
|
|
/// Point( int xpos, int ypos ) : x( xpos ), y( ypos ) {}
|
|
///
|
|
/// /**** Begin Hashmap Interface Implementation ****/
|
|
///
|
|
/// // HashMap Requires both GetEmptyKey() and GetDeleteKey() instance member
|
|
/// // methods to be defined. These act as defaults. The actual values used
|
|
/// // can be overridden on an individual HashMap basis via the HashMap constructor.
|
|
///
|
|
/// static Point GetEmptyKey() { return Point( -0xffffff, 0xffffff ); }
|
|
/// static Point GetDeletedKey() { return Kerning( -0xffffee, 0xffffee ); }
|
|
///
|
|
/// // HashMap Requires an Equality Overload.
|
|
/// // The inequality overload is not required but is probably a good idea since
|
|
/// // orphaned equality (without sibling inequality) operator overloads are ugly code.
|
|
///
|
|
/// bool Equals( const Point& right ) const
|
|
/// {
|
|
/// return ( x == right.x ) && ( y == right.y );
|
|
/// }
|
|
///
|
|
/// hash_key_t GetHashCode() const
|
|
/// {
|
|
/// // This is a decent "universal" hash method for when you have multiple int types:
|
|
/// return GetCommonHash( x ) ^ GetCommonHash( y );
|
|
/// }
|
|
///
|
|
/// // Use a macro to expose the hash API to the HashMap templates.
|
|
/// // This macro creates MakeHashCode and Compare structs, which use the ()
|
|
/// // operator to create "unary methods" for the GetHashCode and == operator above.
|
|
/// // Feeling dizzy yet? Don't worry. Just follow this template. It works!
|
|
///
|
|
/// DEFINE_HASH_API( Point );
|
|
///
|
|
/// /**** End HashMap Interface Implementation ****/
|
|
/// };
|
|
/// </code>
|
|
/// </example>
|
|
template< class Key, class T >
|
|
class SpecializedHashMap : public google::dense_hash_map<Key, T, typename Key::UnaryHashCode, typename Key::UnaryEquals>
|
|
{
|
|
public:
|
|
virtual ~SpecializedHashMap() {}
|
|
SpecializedHashMap( int initialCapacity=33, Key emptyKey=Key::GetEmptyKey(), Key deletedKey=Key::GetDeletedKey() ) :
|
|
google::dense_hash_map<Key, T, typename Key::UnaryHashCode, typename Key::UnaryEquals>( initialCapacity )
|
|
{
|
|
set_empty_key( emptyKey );
|
|
set_deleted_key( deletedKey );
|
|
}
|
|
|
|
/// <summary>
|
|
/// Tries to get a value from this hashmap; or does nothing if the Key does not exist.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// If found, the value associated with the requested key is copied into the <c>outval</c>
|
|
/// parameter. This is a more favorable alternative to the indexer operator since the
|
|
/// indexer implementation can and will create new entries for every request that
|
|
/// </remarks>
|
|
/*void TryGetValue( const Key& key, T& outval ) const
|
|
{
|
|
// GCC doesn't like this for some reason -- says const_iterator can't be found.
|
|
// Fortunately nothing uses these functions yet, so I just commented them out. --air
|
|
const_iterator iter = find( key );
|
|
if( iter != end() )
|
|
outval = iter->second;
|
|
}*/
|
|
|
|
const T& GetValue( Key key ) const
|
|
{
|
|
return (find( key ))->second;
|
|
}
|
|
};
|
|
|
|
/// <summary>
|
|
/// This class implements a hashmap that uses fundamental types such as <c>int</c> or <c>std::string</c>
|
|
/// as keys.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// This class is provided so that you don't have to jump through hoops in order to use fundamental types as
|
|
/// hash keys. The <see cref="HashMap" /> class isn't suited to the task since it requires the key type to
|
|
/// include a set of unary methods. Obviously predicates cannot be added to fundamentals after the fact. :)
|
|
/// Note:
|
|
/// Do not use <c>char *</c> or <c>wchar_t *</c> as key types. Use <c>std::string</c> and <c>std::wstring</c>
|
|
/// instead, as performance of those types will generally be superior due to string length caching. For that
|
|
/// matter, don't use this class at all! Use the string-specialized classes <see cref="Dictionary" /> and
|
|
/// <see cref="UnicodeDictionary" />.
|
|
/// </remarks>
|
|
template< class Key, class T, class HashFunctor=CommonHashClass >
|
|
class HashMap : public google::dense_hash_map<Key, T, HashFunctor>
|
|
{
|
|
DeclareNoncopyableObject( HashMap );
|
|
|
|
typedef typename google::dense_hash_map<Key, T, HashFunctor> _parent;
|
|
|
|
public:
|
|
using _parent::operator[];
|
|
using _parent::end;
|
|
typedef typename _parent::const_iterator const_iterator;
|
|
|
|
virtual ~HashMap() {}
|
|
|
|
/// <summary>
|
|
/// Constructor.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// Both the <c>emptyKey</c>a nd c>deletedKey</c> parameters must be unique values that
|
|
/// are *not* used as actual values in the set.
|
|
/// </remarks>
|
|
HashMap( const Key& emptyKey, const Key& deletedKey, int initialCapacity=33 ) :
|
|
google::dense_hash_map<Key, T, HashFunctor>( initialCapacity )
|
|
{
|
|
set_empty_key( emptyKey );
|
|
set_deleted_key( deletedKey );
|
|
}
|
|
|
|
/// <summary>
|
|
/// Tries to get a value from this hashmap; or does nothing if the Key does not exist.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// If found, the value associated with the requested key is copied into the <c>outval</c>
|
|
/// parameter. This is a more favorable alternative to the indexer operator since the
|
|
/// indexer implementation can and will create new entries for every request that
|
|
/// </remarks>
|
|
bool TryGetValue( const Key& key, T& outval ) const
|
|
{
|
|
const_iterator iter( find(key) );
|
|
if( iter != end() )
|
|
{
|
|
outval = iter->second;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
const T& GetValue( Key key ) const
|
|
{
|
|
return (find( key ))->second;
|
|
}
|
|
|
|
bool Find( Key key ) const
|
|
{
|
|
return find(key) != end();
|
|
}
|
|
};
|
|
|
|
/// <summary>
|
|
/// A shortcut class for easy implementation of string-based hash maps.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// Note:
|
|
/// This class does not support Unicode character sets natively. To use Unicode strings as keys,
|
|
/// use <see cref="UnicodeDictionary"/> instead.
|
|
/// </remarks>
|
|
template< class T >
|
|
class Dictionary : public HashMap<std::string, T>
|
|
{
|
|
public:
|
|
virtual ~Dictionary() {}
|
|
|
|
Dictionary( int initialCapacity=33, const std::string& emptyKey = "@@-EMPTY-@@", const std::string& deletedKey = "@@-DELETED-@@" )
|
|
: HashMap<std::string, T>( emptyKey, deletedKey, initialCapacity)
|
|
{
|
|
}
|
|
};
|
|
|
|
/// <summary>
|
|
/// A shortcut class for easy implementation of string-based hash maps.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// Note:
|
|
/// This class does incur some amount of additional overhead over <see cref="Dictionary"/>, as it
|
|
/// requires twice as much memory and much hash twice as much data.
|
|
/// If you're only using the hash for friendly named array access (via string constants)
|
|
/// then you should probably just stick to using the regular dictionary.
|
|
/// </remarks>
|
|
template< class T >
|
|
class UnicodeDictionary : public HashMap<std::wstring, T>
|
|
{
|
|
public:
|
|
virtual ~UnicodeDictionary() {}
|
|
|
|
UnicodeDictionary( int initialCapacity=33, const std::wstring& emptyKey = L"@@-EMPTY-@@", const std::wstring& deletedKey = L"@@-DELETED-@@" )
|
|
: HashMap<std::wstring, T>( emptyKey, deletedKey, initialCapacity)
|
|
{
|
|
}
|
|
};
|
|
|
|
}
|
|
|
|
template< class T, class HashFunctor=HashTools::CommonHashClass >
|
|
class pxDictionary : public HashTools::HashMap<wxString, T, HashFunctor>
|
|
{
|
|
public:
|
|
virtual ~pxDictionary() {}
|
|
|
|
pxDictionary( int initialCapacity=33, const wxString& emptyKey = L"@@-EMPTY-@@", const wxString& deletedKey = L"@@-DELETED-@@" )
|
|
: HashTools::HashMap<wxString, T, HashFunctor>( emptyKey, deletedKey, initialCapacity)
|
|
{
|
|
}
|
|
};
|