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arangodb/js/server/modules/org/arangodb/graph.js

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JavaScript

/*jslint indent: 2, nomen: true, maxlen: 100, sloppy: true, vars: true, white: true, plusplus: true */
/*global require, exports */
////////////////////////////////////////////////////////////////////////////////
/// @brief Graph functionality
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2010-2012 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, Lucas Dohmen
/// @author Copyright 2011-2012, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
var arangodb = require("org/arangodb"),
is = require("org/arangodb/is"),
db = arangodb.db,
ArangoCollection = arangodb.ArangoCollection,
common = require("org/arangodb/graph-common"),
Edge = common.Edge,
Graph = common.Graph,
Vertex = common.Vertex,
GraphArray = common.GraphArray,
Iterator = common.Iterator;
// -----------------------------------------------------------------------------
// --SECTION-- module "org/arangodb/graph"
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// --SECTION-- private functions
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup ArangoGraph
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief find or create a collection by name
////////////////////////////////////////////////////////////////////////////////
var findOrCreateCollectionByName = function (name) {
var col = db._collection(name);
if (col === null) {
col = db._create(name);
} else if (!(col instanceof ArangoCollection) || col.type() !== ArangoCollection.TYPE_DOCUMENT) {
throw "<" + name + "> must be a document collection";
}
if (col === null) {
throw "collection '" + name + "' has vanished";
}
return col;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief find or create an edge collection by name
////////////////////////////////////////////////////////////////////////////////
var findOrCreateEdgeCollectionByName = function (name) {
var col = db._collection(name);
if (col === null) {
col = db._createEdgeCollection(name);
} else if (!(col instanceof ArangoCollection) || col.type() !== ArangoCollection.TYPE_EDGE) {
throw "<" + name + "> must be an edge collection";
}
if (col === null) {
throw "collection '" + name + "' has vanished";
}
return col;
};
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup ArangoGraph
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief changes a property of an edge
///
/// @FUN{@FA{edge}.setProperty(@FA{name}, @FA{value})}
///
/// Changes or sets the property @FA{name} an @FA{edges} to @FA{value}.
///
/// @EXAMPLES
///
/// @verbinclude graph-edge-set-property
////////////////////////////////////////////////////////////////////////////////
Edge.prototype.setProperty = function (name, value) {
var shallow = this._properties._shallowCopy;
var id;
// Could potentially change the weight of edges
this._graph.emptyCachedPredecessors();
shallow.$label = this._properties.$label;
shallow[name] = value;
// TODO use "update" if this becomes available
id = this._graph._edges.replace(this._properties, shallow);
this._properties = this._graph._edges.document(id);
return value;
};
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- Vertex
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup ArangoGraph
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief constructs a new vertex object
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup ArangoGraph
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief inbound and outbound edges
///
/// @FUN{@FA{vertex}.edges()}
///
/// Returns a list of in- or outbound edges of the @FA{vertex}.
///
/// @EXAMPLES
///
/// @verbinclude graph-vertex-edges
////////////////////////////////////////////////////////////////////////////////
Vertex.prototype.edges = function () {
var graph = this._graph;
return graph._edges.edges(this._properties._id).map(function (result) {
return graph.constructEdge(result);
});
};
////////////////////////////////////////////////////////////////////////////////
/// @brief inbound edges with given label
///
/// @FUN{@FA{vertex}.getInEdges(@FA{label}, ...)}
///
/// Returns a list of inbound edges of the @FA{vertex} with given label(s).
///
/// @EXAMPLES
///
/// @verbinclude graph-vertex-get-in-edges
////////////////////////////////////////////////////////////////////////////////
Vertex.prototype.getInEdges = function () {
var labels = Array.prototype.slice.call(arguments);
var result = this.inbound();
if (labels.length > 0) {
result = result.filter(function (edge) {
return (labels.lastIndexOf(edge.getLabel()) > -1);
});
}
return result;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief outbound edges with given label
///
/// @FUN{@FA{vertex}.getOutEdges(@FA{label}, ...)}
///
/// Returns a list of outbound edges of the @FA{vertex} with given label(s).
///
/// @EXAMPLES
///
/// @verbinclude graph-vertex-get-out-edges
////////////////////////////////////////////////////////////////////////////////
Vertex.prototype.getOutEdges = function () {
var labels = Array.prototype.slice.call(arguments);
var result = this.outbound();
if (labels.length > 0) {
result = result.filter(function (edge) {
return (labels.lastIndexOf(edge.getLabel()) > -1);
});
}
return result;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief in- or outbound edges with given label
///
/// @FUN{@FA{vertex}.getEdges(@FA{label}, ...)}
///
/// Returns a list of in- or outbound edges of the @FA{vertex} with given
/// label(s).
////////////////////////////////////////////////////////////////////////////////
Vertex.prototype.getEdges = function () {
var labels = Array.prototype.slice.call(arguments);
var result = this.edges();
if (labels.length > 0) {
result = result.filter(function (edge) {
return (labels.lastIndexOf(edge.getLabel()) > -1);
});
}
return result;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief inbound edges
///
/// @FUN{@FA{vertex}.inbound()}
///
/// Returns a list of inbound edges of the @FA{vertex}.
///
/// @EXAMPLES
///
/// @verbinclude graph-vertex-inbound
////////////////////////////////////////////////////////////////////////////////
Vertex.prototype.inbound = function () {
var graph = this._graph;
return graph._edges.inEdges(this._properties._id).map(function (result) {
return graph.constructEdge(result);
});
};
////////////////////////////////////////////////////////////////////////////////
/// @brief outbound edges
///
/// @FUN{@FA{vertex}.outbound()}
///
/// Returns a list of outbound edges of the @FA{vertex}.
///
/// @EXAMPLES
///
/// @verbinclude graph-vertex-outbound
////////////////////////////////////////////////////////////////////////////////
Vertex.prototype.outbound = function () {
var graph = this._graph;
return graph._edges.outEdges(this._properties._id).map(function (result) {
return graph.constructEdge(result);
});
};
////////////////////////////////////////////////////////////////////////////////
/// @brief changes a property of a vertex
///
/// @FUN{@FA{vertex}.setProperty(@FA{name}, @FA{value})}
///
/// Changes or sets the property @FA{name} a @FA{vertex} to @FA{value}.
///
/// @EXAMPLES
///
/// @verbinclude graph-vertex-set-property
////////////////////////////////////////////////////////////////////////////////
Vertex.prototype.setProperty = function (name, value) {
var shallow = this._properties._shallowCopy;
var id;
shallow[name] = value;
// TODO use "update" if this becomes available
id = this._graph._vertices.replace(this._properties, shallow);
this._properties = this._graph._vertices.document(id);
return value;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the number of edges
////////////////////////////////////////////////////////////////////////////////
Vertex.prototype.degree = function () {
return this.getEdges().length;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the number of in-edges
////////////////////////////////////////////////////////////////////////////////
Vertex.prototype.inDegree = function () {
return this.getInEdges().length;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the number of out-edges
////////////////////////////////////////////////////////////////////////////////
Vertex.prototype.outDegree = function () {
return this.getOutEdges().length;
};
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup ArangoGraph
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief constructs a new graph object
///
/// @FUN{Graph(@FA{name}, @FA{vertices}, @FA{edges})}
///
/// Constructs a new graph object using the collection @FA{vertices} for all
/// vertices and the collection @FA{edges} for all edges. Note that it is
/// possible to construct two graphs with the same vertex set, but different
/// edge sets.
///
/// @FUN{Graph(@FA{name})}
///
/// Returns a known graph.
///
/// @EXAMPLES
///
/// @verbinclude graph-constructor
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.initialize = function (name, vertices, edges, waitForSync) {
var gdb = db._collection("_graphs");
var graphProperties;
var graphPropertiesId;
if (gdb === null) {
throw "_graphs collection does not exist.";
}
if (typeof name !== "string" || name === "") {
throw "<name> must be a string";
}
if (vertices === undefined && edges === undefined) {
// Find an existing graph
try {
graphProperties = gdb.document(name);
}
catch (e) {
throw "no graph named '" + name + "' found";
}
if (graphProperties === null) {
throw "no graph named '" + name + "' found";
}
vertices = db._collection(graphProperties.vertices);
if (vertices === null) {
throw "vertex collection '" + graphProperties.vertices + "' has vanished";
}
edges = db._collection(graphProperties.edges);
if (edges === null) {
throw "edge collection '" + graphProperties.edges + "' has vanished";
}
}
else if (typeof vertices !== "string" || vertices === "") {
throw "<vertices> must be a string or null";
}
else if (typeof edges !== "string" || edges === "") {
throw "<edges> must be a string or null";
}
else {
// Create a new graph or get an existing graph
vertices = findOrCreateCollectionByName(vertices);
edges = findOrCreateEdgeCollectionByName(edges);
try {
graphProperties = gdb.document(name);
}
catch (e1) {
graphProperties = null;
}
// Graph doesn't exist yet
if (graphProperties === null) {
// check if know that graph
graphProperties = gdb.firstExample(
'vertices', vertices.name(),
'edges', edges.name()
);
if (graphProperties === null) {
// check if edge is used in a graph
graphProperties = gdb.firstExample('edges', edges.name());
if (graphProperties === null) {
graphPropertiesId = gdb.save({
'vertices' : vertices.name(),
'edges' : edges.name(),
'_key' : name
}, waitForSync);
graphProperties = gdb.document(graphPropertiesId);
}
else {
throw "edge collection already used";
}
}
else {
throw "found graph but has different <name>";
}
}
else {
throw "graph with that name already exists";
//if (graphProperties.vertices !== vertices.name()) {
// throw "found graph but has different <vertices>";
//}
//if (graphProperties.edges !== edges.name()) {
// throw "found graph but has different <edges>";
//}
}
}
this._properties = graphProperties;
// and store the collections
this._gdb = gdb;
this._vertices = vertices;
this._edges = edges;
// and dictionary for vertices and edges
this._verticesCache = {};
this._edgesCache = {};
// and store the cashes
this.predecessors = {};
this.distances = {};
};
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup ArangoGraph
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @fn JSF_graph_getAll
/// @brief returns all available graphs
///
/// @FUN{@FA{graph}.getAll()}
///
/// Returns all available graphs.
////////////////////////////////////////////////////////////////////////////////
function getAllGraphs () {
var gdb = db._collection("_graphs"),
graphs = [ ];
gdb.toArray().forEach(function(doc) {
try {
var g = new Graph(doc._key);
if (g._properties !== null) {
graphs.push(g._properties);
}
}
catch (err) {
// if there's a problem, we just skip this graph
}
});
return graphs;
}
Graph.getAll = getAllGraphs;
////////////////////////////////////////////////////////////////////////////////
/// @brief drops the graph, the vertices, and the edges
///
/// @FUN{@FA{graph}.drop(@FA{waitForSync})}
///
/// Drops the graph, the vertices, and the edges. Handle with care.
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.drop = function (waitForSync) {
var gdb = db._collection("_graphs");
gdb.remove(this._properties, true, waitForSync);
this._vertices.drop();
this._edges.drop();
};
////////////////////////////////////////////////////////////////////////////////
/// @brief saves an edge to the graph
////////////////////////////////////////////////////////////////////////////////
Graph.prototype._saveEdge = function(id, out_vertex_id, in_vertex_id, shallow, waitForSync) {
this.emptyCachedPredecessors();
if (id !== undefined && id !== null) {
shallow._key = String(id);
}
var ref = this._edges.save(out_vertex_id,
in_vertex_id,
shallow,
waitForSync);
return this.constructEdge(ref._id);
};
////////////////////////////////////////////////////////////////////////////////
/// @brief saves a vertex to the graph
////////////////////////////////////////////////////////////////////////////////
Graph.prototype._saveVertex = function (id, shallow, waitForSync) {
var ref;
if (is.existy(id)) {
shallow._key = String(id);
}
ref = this._vertices.save(shallow, waitForSync);
return this.constructVertex(ref._id);
};
////////////////////////////////////////////////////////////////////////////////
/// @brief replaces a vertex to the graph
////////////////////////////////////////////////////////////////////////////////
Graph.prototype._replaceVertex = function (vertex_id, data) {
var result = this._vertices.replace(vertex_id, data);
};
////////////////////////////////////////////////////////////////////////////////
/// @brief replaces an edge in the graph
////////////////////////////////////////////////////////////////////////////////
Graph.prototype._replaceEdge = function (edge_id, data) {
var result = this._edges.replace(edge_id, data);
};
////////////////////////////////////////////////////////////////////////////////
/// @brief returns a vertex given its id
///
/// @FUN{@FA{graph}.getVertex(@FA{id})}
///
/// Returns the vertex identified by @FA{id} or @LIT{null}.
///
/// @EXAMPLES
///
/// @verbinclude graph-graph-get-vertex
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.getVertex = function (id) {
var ref, vertex;
try {
ref = this._vertices.document(id);
} catch (e) {
ref = null;
}
if (ref !== null) {
vertex = this.constructVertex(ref);
} else {
try {
vertex = this.constructVertex(id);
} catch (e1) {
vertex = null;
}
}
return vertex;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief returns an iterator for all vertices
///
/// @FUN{@FA{graph}.getVertices()}
///
/// Returns an iterator for all vertices of the graph. The iterator supports the
/// methods @FN{hasNext} and @FN{next}.
///
/// @EXAMPLES
///
/// @verbinclude graph-graph-get-vertices
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.getVertices = function () {
var all = this._vertices.all(),
graph = this,
wrapper = function(object) {
return graph.constructVertex(object);
};
return new Iterator(wrapper, graph.constructVertex, "[edge iterator]");
};
////////////////////////////////////////////////////////////////////////////////
/// @brief returns an edge given its id
///
/// @FUN{@FA{graph}.getEdge(@FA{id})}
///
/// Returns the edge identified by @FA{id} or @LIT{null}.
///
/// @EXAMPLES
///
/// @verbinclude graph-graph-get-edge
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.getEdge = function (id) {
var ref, edge;
try {
ref = this._edges.document(id);
} catch (e) {
ref = null;
}
if (ref !== null) {
edge = this.constructEdge(ref);
} else {
try {
edge = this.constructEdge(id);
} catch (e1) {
edge = null;
}
}
return edge;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief returns an iterator for all edges
///
/// @FUN{@FA{graph}.getEdges()}
///
/// Returns an iterator for all edges of the graph. The iterator supports the
/// methods @FN{hasNext} and @FN{next}.
///
/// @EXAMPLES
///
/// @verbinclude graph-graph-get-edges
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.getEdges = function () {
var all = this._edges.all(),
graph = this,
wrapper = function(object) {
return graph.constructEdge(object);
};
return new Iterator(wrapper, all, "[edge iterator]");
};
////////////////////////////////////////////////////////////////////////////////
/// @brief removes a vertex and all in- or out-bound edges
///
/// @FUN{@FA{graph}.removeVertex(@FA{vertex},@FA{waitForSync})}
///
/// Deletes the @FA{vertex} and all its edges.
///
/// @EXAMPLES
///
/// @verbinclude graph-graph-remove-vertex
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.removeVertex = function (vertex, waitForSync) {
var result, graph = this;
this.emptyCachedPredecessors();
if (vertex._properties) {
result = this._vertices.remove(vertex._properties, true, waitForSync);
if (!result) {
throw "cannot delete vertex";
}
vertex.edges().forEach(function (edge) {
graph.removeEdge(edge, waitForSync);
});
vertex._properties = undefined;
}
};
////////////////////////////////////////////////////////////////////////////////
/// @brief removes an edge
///
/// @FUN{@FA{graph}.removeEdge(@FA{vertex},@FA{waitForSync})}
///
/// Deletes the @FA{edge}. Note that the in and out vertices are left untouched.
///
/// @EXAMPLES
///
/// @verbinclude graph-graph-remove-edge
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.removeEdge = function (edge, waitForSync) {
var result;
this.emptyCachedPredecessors();
if (edge._properties) {
result = this._edges.remove(edge._properties, true, waitForSync);
if (! result) {
throw "cannot delete edge";
}
this._edgesCache[edge._properties._id] = undefined;
edge._properties = undefined;
}
};
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- private methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup ArangoGraph
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief empties the internal cache for Predecessors
///
/// @FUN{@FA{graph}.emptyCachedPredecessors()}
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.emptyCachedPredecessors = function () {
this.predecessors = {};
};
////////////////////////////////////////////////////////////////////////////////
/// @brief gets Predecessors for a pair from the internal cache
///
/// @FUN{@FA{graph}.getCachedPredecessors(@FA{target}), @FA{source})}
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.getCachedPredecessors = function (target, source) {
var predecessors;
if (this.predecessors[target.getId()]) {
predecessors = this.predecessors[target.getId()][source.getId()];
}
return predecessors;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief sets Predecessors for a pair in the internal cache
///
/// @FUN{@FA{graph}.setCachedPredecessors(@FA{target}), @FA{source}, @FA{value})}
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.setCachedPredecessors = function (target, source, value) {
if (!this.predecessors[target.getId()]) {
this.predecessors[target.getId()] = {};
}
this.predecessors[target.getId()][source.getId()] = value;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief constructs a vertex
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.constructVertex = function (data) {
var id, rev;
if (typeof data === "string") {
id = data;
} else {
id = data._id;
rev = data._rev;
}
var vertex = this._verticesCache[id];
if (vertex === undefined || vertex._rev !== rev) {
var properties = this._vertices.document(id);
if (! properties) {
throw "accessing a deleted vertex";
}
this._verticesCache[id] = vertex = new Vertex(this, properties);
}
return vertex;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief constructs an edge
////////////////////////////////////////////////////////////////////////////////
Graph.prototype.constructEdge = function (data) {
var id, edge, properties;
if (typeof data === "string") {
id = data;
} else {
id = data._id;
rev = data._rev;
}
edge = this._edgesCache[id];
if (edge === undefined || edge._rev !== rev) {
properties = this._edges.document(id);
if (!properties) {
throw "accessing a deleted edge";
}
this._edgesCache[id] = edge = new Edge(this, properties);
}
return edge;
};
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- MODULE EXPORTS
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup ArangoGraph
/// @{
////////////////////////////////////////////////////////////////////////////////
exports.Edge = Edge;
exports.Graph = Graph;
exports.Vertex = Vertex;
exports.GraphArray = GraphArray;
// TODO: Remove Monkey Patch
require("org/arangodb/graph/algorithms");
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
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