Crate rsmgp_sys

Source
Expand description

A library to simplify implementation of Memgraph Query Modules.

Example

use c_str_macro::c_str;
// All possible rsmgp modules (probably not all will be required).
use rsmgp_sys::edge::*;
use rsmgp_sys::list::*;
use rsmgp_sys::map::*;
use rsmgp_sys::memgraph::*;
use rsmgp_sys::mgp::*;
use rsmgp_sys::path::*;
use rsmgp_sys::property::*;
use rsmgp_sys::result::*;
use rsmgp_sys::rsmgp::*;
use rsmgp_sys::value::*;
use rsmgp_sys::vertex::*;
use rsmgp_sys::{close_module, define_procedure, define_type, init_module};
// The following are required because of used macros.
use std::ffi::CString;
use std::os::raw::c_int;
use std::panic;

init_module!(|memgraph: &Memgraph| -> MgpResult<()> {
    memgraph.add_read_procedure(
        basic, // Has to be the same as specified in the `define_procedure!`.
        c_str!("basic"), // Name under which Memgraph will register the procedure.
        &[define_type!("input_string", Type::String)],  // Required arguments.
        &[],                                            // Optional arguments.
        &[define_type!("output_string", Type::String)], // Return fields.
    )?;
    Ok(())
});

define_procedure!(basic, |memgraph: &Memgraph| -> MgpResult<()> {
    let result = memgraph.result_record()?;
    let args = memgraph.args()?;
    let output_string = args.value_at(0)?;
    result.insert_mgp_value(
        c_str!("output_string"),
        &output_string.to_mgp_value(&memgraph)?,
    )?;
    Ok(())
});

close_module!(|| -> MgpResult<()> { Ok(()) });

Modules§

  • edge
    All edge (relationship) related.
  • list
    All related to the list datatype.
  • map
    All related to the map (dictionary) datatype.
  • memgraph
    Abstraction to interact with Memgraph.
  • mgp
    Auto-generated bindings (don’t use directly, except top-level pointer data types).
  • path
    All related to a graph path.
  • property
    All related to the property graph property (data key-value pair).
  • result
    Simplifies returning results to Memgraph and then to the client.
  • rsmgp
    Macro definitions and top level data structures.
  • value
    All related to the value (container for any data type).
  • vertex
    All vertex (node) related.

Macros§