neo4j: save and load edges separately from nodes.

Edges must be laoded manually by the user, this allow him to control
the way nodes and edges are loaded in memory and avoir out of memory
exception on big graphs.

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>

diff --git a/lib/neo4j/neo4j.nit b/lib/neo4j/neo4j.nit
index f2654e5..58030e4 100644 (file)
--- a/lib/neo4j/neo4j.nit
+++ b/lib/neo4j/neo4j.nit
@@ -768,13 +768,6 @@ class NeoBatch
 
        # Load a node in batch mode also load labels, data and edges
        fun load_node(node: NeoNode) do
-               load_node_data(node)
-               load_node_labels(node)
-               load_node_out_edges(node)
-       end
-
-       # Load data into node
-       private fun load_node_data(node: NeoNode) do
                var job = new_job(node)
                job.action = load_node_data_action
                job.method = "GET"
@@ -783,11 +776,7 @@ class NeoBatch
                else
                        job.to = "\{{node.batch_id.to_s}\}"
                end
-       end
-
-       # Load labels into node
-       private fun load_node_labels(node: NeoNode) do
-               var job = new_job(node)
+               job = new_job(node)
                job.action = load_node_labels_action
                job.method = "GET"
                if node.id != null then
@@ -797,9 +786,17 @@ class NeoBatch
                end
        end
 
-       # Load out edges into node
-       private fun load_node_out_edges(node: NeoNode) do
+       # Load in and out edges into node
+       fun load_node_edges(node: NeoNode) do
                var job = new_job(node)
+               job.action = load_node_in_edges_action
+               job.method = "GET"
+               if node.id != null then
+                       job.to = "/node/{node.id.to_s}/relationships/in"
+               else
+                       job.to = "\{{node.batch_id.to_s}\}/relationships/in"
+               end
+               job = new_job(node)
                job.action = load_node_out_edges_action
                job.method = "GET"
                if node.id != null then
@@ -825,7 +822,7 @@ class NeoBatch
                job.to = "\{{node.batch_id.to_s}\}/labels"
                job.body = new JsonArray.from(node.labels)
                # add edges
-               save_edges(node.out_edges)
+               #save_edges(node.out_edges)
        end
 
        # Create multiple nodes
@@ -898,12 +895,19 @@ class NeoBatch
                                var labels = new Array[String]
                                for l in res["body"].as(JsonArray) do labels.add l.to_s
                                node.internal_labels = labels
+                       else if job.action == load_node_in_edges_action then
+                               var node = job.entity.as(NeoNode)
+                               var edges = res["body"].as(JsonArray)
+                               node.internal_in_edges = new List[NeoEdge]
+                               for edge in edges do
+                                       node.internal_in_edges.add client.load_edge(edge.as(JsonObject)["self"].to_s)
+                               end
                        else if job.action == load_node_out_edges_action then
                                var node = job.entity.as(NeoNode)
                                var edges = res["body"].as(JsonArray)
                                node.internal_out_edges = new List[NeoEdge]
                                for edge in edges do
-                                       node.internal_out_edges.add new NeoEdge.from_json(client, edge.as(JsonObject))
+                                       node.internal_out_edges.add client.load_edge(edge.as(JsonObject)["self"].to_s)
                                end
                        end
                end
@@ -917,7 +921,8 @@ class NeoBatch
        private fun create_edge_action: Int do return 2
        private fun load_node_data_action: Int do return 3
        private fun load_node_labels_action: Int do return 4
-       private fun load_node_out_edges_action: Int do return 5
+       private fun load_node_in_edges_action: Int do return 5
+       private fun load_node_out_edges_action: Int do return 6
 end
 
 # A job that can be executed in a `NeoBatch`