////////////////////////////////////////////////////////////////////////////////
/// @brief edge collection
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2004-2013 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///     http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is triAGENS GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
/// @author Copyright 2011-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#ifndef TRIAGENS_VOC_BASE_EDGE_COLLECTION_H
#define TRIAGENS_VOC_BASE_EDGE_COLLECTION_H 1

#include "VocBase/document-collection.h"

#ifdef __cplusplus
extern "C" {
#endif

// -----------------------------------------------------------------------------
// --SECTION--                                                   EDGE COLLECTION
// -----------------------------------------------------------------------------

// -----------------------------------------------------------------------------
// --SECTION--                                                      public types
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @brief typedef for edge flags
/// the type is an integer which indicates the edge direction (IN/OUT)
/// plus two extra bits that indicate whether the edge is self-reflexive and
/// whether the edge is directed
////////////////////////////////////////////////////////////////////////////////

typedef uint32_t TRI_edge_flags_t;

////////////////////////////////////////////////////////////////////////////////
/// @brief edge from and to
////////////////////////////////////////////////////////////////////////////////

typedef struct TRI_document_edge_s {
  TRI_voc_cid_t _fromCid;
  TRI_voc_key_t _fromKey;

  TRI_voc_cid_t _toCid;
  TRI_voc_key_t _toKey;
}
TRI_document_edge_t;

////////////////////////////////////////////////////////////////////////////////
/// @brief edge direction
////////////////////////////////////////////////////////////////////////////////

typedef enum {
  TRI_EDGE_ANY    = 0, // can only be used for searching
  TRI_EDGE_IN     = 1,
  TRI_EDGE_OUT    = 2
}
TRI_edge_direction_e;

////////////////////////////////////////////////////////////////////////////////
/// @brief index entry for edges
////////////////////////////////////////////////////////////////////////////////

typedef struct TRI_edge_header_s {
  TRI_voc_cid_t _cid; // from or to, depending on the direction
  TRI_voc_key_t _key;
}
TRI_edge_header_t;

// -----------------------------------------------------------------------------
// --SECTION--                                                       EDGES INDEX
// -----------------------------------------------------------------------------

// -----------------------------------------------------------------------------
// --SECTION--                                                  public functions
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @brief looks up edges
////////////////////////////////////////////////////////////////////////////////

TRI_vector_pointer_t TRI_LookupEdgesDocumentCollection (
                                                  TRI_document_collection_t*,
                                                  TRI_edge_direction_e,
                                                  TRI_voc_cid_t,
                                                  TRI_voc_key_t);

#ifdef __cplusplus
}
#endif

#endif

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