1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/Index.h	Sun Sep 20 20:39:24 2009 -0700
     1.3 @@ -0,0 +1,76 @@
     1.4 +/*
     1.5 + *  Index.h
     1.6 + *  Ottoman
     1.7 + *
     1.8 + *  Created by Jens Alfke on 8/27/09.
     1.9 + *  Copyright 2009 Jens Alfke. All rights reserved.
    1.10 + *  BSD-Licensed: See the file "LICENSE.txt" for details.
    1.11 + */
    1.12 +
    1.13 +#ifndef _MOOSEYARD_INDEX_
    1.14 +#define _MOOSEYARD_INDEX_
    1.15 +#include "Chunk.h"
    1.16 +#include "Dictionary.h"
    1.17 +
    1.18 +namespace Mooseyard {
    1.19 +    
    1.20 +    class KeyValueChunk;
    1.21 +    
    1.22 +    /** An in-file hash table. This structure is stored directly in the file, memory-mapped.
    1.23 +        Index is normally only used internally by VersionDictionary. */
    1.24 +    class Index :public Chunk {
    1.25 +    public:
    1.26 +        
    1.27 +        class Entry;
    1.28 +        
    1.29 +        static const Index* indexMappedAt (const void*);
    1.30 +        static Index* create (int capacity);
    1.31 +        
    1.32 +        int count() const                                   {return _count;}
    1.33 +        
    1.34 +        Blob get (File *file, Key) const;
    1.35 +        bool put (File *file, Key, FilePosition valuePosition, FilePosition maxPosition);
    1.36 +        bool remove (File *file, Key, FilePosition maxPosition);
    1.37 +        void removeAll();
    1.38 +        
    1.39 +        void copyFrom (File *file, const Index *index);
    1.40 +        
    1.41 +        class Iterator;
    1.42 +        
    1.43 +        void validate() const  throw(File::Error);
    1.44 +        void validateEntries (const File *file) const  throw(File::Error);
    1.45 +        static const uint16_t kChunkType = 2;
    1.46 +        
    1.47 +    private:
    1.48 +        Index (uint32_t tableSize);
    1.49 +        const Entry* table (int index) const;
    1.50 +        Entry* table (int index);
    1.51 +        const KeyValueChunk* _find (File *file, Key) const;
    1.52 +        bool _put (File *file, Key, FilePosition, FilePosition maxPosition);
    1.53 +
    1.54 +        // This is mapped to data in the file! Don't mess with it!
    1.55 +        LittleEndian<uint32_t>  _magicNumber;
    1.56 +        LittleEndian<uint32_t>  _count;
    1.57 +        LittleEndian<uint32_t>  _tableSize;
    1.58 +        char                    _table[0];      // Actually Entry[]
    1.59 +    };
    1.60 +  
    1.61 +    
    1.62 +    
    1.63 +    class Index::Iterator :public Dictionary::Iterator {
    1.64 +    public:
    1.65 +        Iterator (File*, const Index*);
    1.66 +        virtual Key key() const;
    1.67 +        virtual Blob value() const;
    1.68 +        virtual bool next();
    1.69 +        virtual bool hasValue() const;
    1.70 +        
    1.71 +        FilePosition valuePosition();
    1.72 +    private:
    1.73 +        File* const _file;
    1.74 +        const Index::Entry *_current, *_end;
    1.75 +    };
    1.76 +    
    1.77 +}
    1.78 +
    1.79 +#endif //_MOOSEYARD_INDEX_