store.h

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/**************************************************************
 **
 ** @file data/Store/store.h
 **
 ** Copyright (C) 2012  Xpace, LLC.  All rights reserved
 **
 ** www.xpace.net
 **
 **************************************************************/


#ifndef XPACE_STORE_H
#define XPACE_STORE_H

#include <vector>

#include "data/data.h"

#include "base/sharedimpl.h"

namespace Xpace 
{
  /// A Store is a hierarchically organized dataset, suitable for managing 
  /// structured text and multidimensional (OLAP) data 
  class XPACE_EXPORT Store 
  {
  public:
    static const char* TAG();            ///< Configuration tag for a Store
    static const char* CLASSTREE_TAG;    ///< Configuration tag for a ClassTree
    static const char* NAME_TAG;         ///< Configuration tag for a Store's name

    /// @param config the Store's Configuration
    /// @param access how the Store will be opened
    /// @throw File_Cant_Open
    /// @throw File_Cant_Read
    explicit Store
      (const String& config,
       StoreAccess access = SA_readOnly);

    /// @return true if the store is empty or does not exist
    bool operator!
      ()
      const;

    /// @return the Store's name
    String getName
      ()
      const;

    /// @return the Store's configuration
    String getConfig
      ()
      const;

    /// @return the number of Documents  in the store
    uint64 getDocCount
      ()
      const;

    // ------------------------------ Location and Status -----

    /// A location within a source
    typedef std::vector<uint> Location;   ///< IDs of ancestor nodes and self/target

    /// The result of getting data from a node
    enum Status 
    {
      Continue,       ///< in the middle of content
      Parent,         ///< end of this content and children, parent next
      Child,          ///< end of this content, child next
      Sibling,        ///< end of this content and children, sibling next
      Done            ///< (sub)tree has been traversed; no further movement possible
    };

    // ------------------------------ Sink --------------------

    /// A write-only, forward (by document) cursor into a Store
    class Sink : public Xpace::Sink<const Location&>,    ///< random access, move to Location before writing
                 public Xpace::Sink<const String8&>,     ///< move to child before writing
                 public Xpace::Sink<int>                 ///< move to child before writing
    {
    public:
      using Xpace::Sink<const Location&>::move;
      using Xpace::Sink<const String8&>::move;
      using Xpace::Sink<int>::move;
      using Xpace::Sink<const Location&>::set;
      using Xpace::Sink<const String8&>::set;
      using Xpace::Sink<int>::set;
    };

    /// @return the (only) Sink to this table
    Sink* getSink
      ();

    /// The LOC param to Sink
    enum AddressBy
    {
      AB_location,      ///< LOC = Location
      AB_childName,     ///< LOC = const String&: the node's name (relative to parent)
      AB_childNum       ///< LOC = uint: the node's number (relative to parent) 
    };

    /// Call a Sink for each node in Store order
    /// @param sink called for each node
    /// @param addressBy use this set of callbacks to Sink
    /// @param nodes if not empty, return these nodes in store order
    /// @return true iff sink always returned true, false otherwise
    bool forEach
      (Sink* sink,
       Store::AddressBy addressBy,
       const std::vector<Store::Location>& nodes = std::vector<Store::Location>())
      const;

    DECLARE_IMPL(Store);

    class cantOpen : public Exception
    {
    public :
      cantOpen
        (const String name,  
         const String& config,         
         const Exception reason = Exception());
    };
  }; // Store
} // namespace Xpace

#endif