src/backend/utils/graph_generation.c

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

#include "postgres.h"

#include "access/xact.h"
#include "access/genam.h"
#include "access/heapam.h"
#include "catalog/dependency.h"
#include "catalog/objectaddress.h"
#include "commands/defrem.h"
#include "commands/schemacmds.h"
#include "commands/tablecmds.h"
#include "fmgr.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodes.h"
#include "nodes/parsenodes.h"
#include "nodes/pg_list.h"
#include "nodes/value.h"
#include "parser/parser.h"
#include "utils/fmgroids.h"
#include "utils/relcache.h"
#include "utils/rel.h"

#include "catalog/ag_graph.h"
#include "catalog/ag_label.h"
#include "commands/label_commands.h"
#include "utils/graphid.h"
#include "commands/graph_commands.h"
#include "utils/load/age_load.h"
#include "utils/load/ag_load_edges.h"
#include "utils/load/ag_load_labels.h"


PG_FUNCTION_INFO_V1(create_complete_graph);

/*
* SELECT * FROM ag_catalog.create_complete_graph('graph_name',no_of_nodes, 'edge_label', 'node_label'=NULL);
*/

Datum create_complete_graph(PG_FUNCTION_ARGS)
{   
    Oid graph_id;
    Name graph_name;

    int64 no_vertices;
    int64 i,j,vid = 1, eid, start_vid, end_vid;

    Name vtx_label_name = NULL;
    Name edge_label_name;
    int32 vtx_label_id;
    int32 edge_label_id;

    agtype *props = NULL;
    graphid object_graph_id;
    graphid start_vertex_graph_id;
    graphid end_vertex_graph_id;

    Oid vtx_seq_id;
    Oid edge_seq_id;

    char* graph_name_str;
    char* vtx_name_str;
    char* edge_name_str;

    graph_cache_data *graph_cache;
    label_cache_data *vertex_cache;
    label_cache_data *edge_cache;

    Oid nsp_id;
    Name vtx_seq_name;
    char *vtx_seq_name_str;

    Name edge_seq_name;
    char *edge_seq_name_str;

    int64 lid; 

    if (PG_ARGISNULL(0))
    {
        ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                        errmsg("graph name can not be NULL")));
    }

    if (PG_ARGISNULL(1))
    {
        ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                errmsg("number of nodes can not be NULL")));
    }
    
    if (PG_ARGISNULL(2))
    {
        ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                errmsg("edge label can not be NULL")));
    }


    graph_name = PG_GETARG_NAME(0);
    no_vertices = (int64) PG_GETARG_INT64(1);
    edge_label_name = PG_GETARG_NAME(2);
    namestrcpy(vtx_label_name, AG_DEFAULT_LABEL_VERTEX);

    graph_name_str = NameStr(*graph_name);
    vtx_name_str = AG_DEFAULT_LABEL_VERTEX;
    edge_name_str = NameStr(*edge_label_name);


    if (!graph_exists(graph_name_str))
    {
        DirectFunctionCall1(create_graph, CStringGetDatum(graph_name));

    }

    graph_id = get_graph_oid(graph_name_str);

    
    
    if (!PG_ARGISNULL(3))
    {
        vtx_label_name = PG_GETARG_NAME(3);
        vtx_name_str = NameStr(*vtx_label_name);
        // Check if label with the input name already exists
        if (!label_exists(vtx_name_str, graph_id))
        {
            DirectFunctionCall2(create_vlabel, CStringGetDatum(graph_name), CStringGetDatum(vtx_label_name));
        }
    }

    if (!label_exists(edge_name_str, graph_id))
    {
        DirectFunctionCall2(create_elabel, CStringGetDatum(graph_name), CStringGetDatum(edge_label_name));   
    }

    vtx_label_id = get_label_id(vtx_name_str, graph_id);
    edge_label_id = get_label_id(edge_name_str, graph_id);

    graph_cache = search_graph_name_cache(graph_name_str);
    vertex_cache = search_label_name_graph_cache(vtx_name_str,graph_id);
    edge_cache = search_label_name_graph_cache(edge_name_str,graph_id);

    nsp_id = graph_cache->namespace;
    vtx_seq_name = &(vertex_cache->seq_name);
    vtx_seq_name_str = NameStr(*vtx_seq_name);

    edge_seq_name = &(edge_cache->seq_name);
    edge_seq_name_str = NameStr(*edge_seq_name);

    vtx_seq_id = get_relname_relid(vtx_seq_name_str, nsp_id);
    edge_seq_id = get_relname_relid(edge_seq_name_str, nsp_id);

    /* Creating vertices*/
    for (i=(int64)1;i<=no_vertices;i++)
    {   
        vid = nextval_internal(vtx_seq_id, true);
        object_graph_id = make_graphid(vtx_label_id, vid);
        props = create_empty_agtype();
        insert_vertex_simple(graph_id,vtx_name_str,object_graph_id,props);
    }

    lid = vid;
    
    /* Creating edges*/
    for (i = 1;i<=no_vertices-1;i++)
    {   
        start_vid = lid-no_vertices+i;
        for(j=i+1;j<=no_vertices;j++)
        {  
            end_vid = lid-no_vertices+j;
            eid = nextval_internal(edge_seq_id, true);
            object_graph_id = make_graphid(edge_label_id, eid);

            start_vertex_graph_id = make_graphid(vtx_label_id, start_vid);
            end_vertex_graph_id = make_graphid(vtx_label_id, end_vid);

            props = create_empty_agtype();

            insert_edge_simple(graph_id, edge_name_str,
                            object_graph_id, start_vertex_graph_id,
                            end_vertex_graph_id, props);
            
        }
    }

    PG_RETURN_VOID();
}