Compiling and Running a Custom PGX Algorithm

4.9.2 Compiling and Running a Custom PGX Algorithm

To be able to compile and run a custom PGX algorithm, you must perform the following actions:

Set the following two configuration parameters in the conf/pgx.conf file:
- Set the graph_algorithm_language option to JAVA.
- Set the java_home_dir option to the path to your Java home (use <system-java-home-dir> to have PGX infer Java home from the system properties).
```
{
  "graph_algorithm_language": "JAVA",
  "java_home_dir": "<system-java-home-dir>"
}
```

Create a session.

cd /opt/oracle/graph
./bin/opg4j

import oracle.pgx.algorithm.*;
PgxSession session = Pgx.createSession("my-session");

session = instance.create_session("my-session")

Compile a PGX Algorithm. For example:

opg4j> var myAlgorithm = session.compileProgram("/path/to/MyAlgorithm.java")
myAlgorithm ==> CompiledProgram[name=MyAlgorithm]

import oracle.pgx.algorithm.CompiledProgram;
CompiledProgram myAlgorithm = session.compileProgram("/path/to/MyAlgorithm.java");

my_algorithm = session.compile_program("/path/to/MyAlgorithm.java")

Run the algorithm. For example:

opg4j> var graph =session.readGraphWithProperties("/path/to/bank_graph_analytics.json")
graph ==> PgxGraph[name=bank_graph_analytics,N=1000,E=5001,created=1633504705054]
opg4j> var property = graph.createVertexProperty(PropertyType.INTEGER)
property ==> VertexProperty[name=vertex_prop_integer_9,type=integer,graph=bank_graph_analytics]
opg4j> myAlgorithm.run(graph, property)
$6 ==> {
  "success" : true,
  "canceled" : false,
  "exception" : null,
  "returnValue" : 42,
  "executionTimeMs" : 0
}

import oracle.pgx.algorithm.VertexProperty;
PgxGraph graph = session.readGraphWithProperties("/path/to/bank_graph_analytics.json");
VertexProperty property = graph.createVertexProperty(PropertyType.INTEGER);
myAlgorithm.run(graph, property);

graph = session.read_graph_with_properties("/path/to/bank_graph_analytics.json")
property = graph.create_vertex_property("integer")
my_algorithm.run(graph, property)
{'success': True, 'canceled': False, 'exception': None, 'return_value': 42, 'execution_time(ms)': 1}

Parent topic: Using Custom PGX Graph Algorithms