npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

@lichtblick/omgidl-serialization

v1.0.0

Published

OMG IDL Schema message serializers and deserializer

Downloads

3,503

Readme

@lichtblick/omgidl-serialization

OMG IDL message serialization, for reading and writing CDR and XCDR2 messages based on .idl schema

npm version

MessageReader

Message reader deserializes CDR, XCDR1 and XCDR2 messages into plain objects. The messages are fully deserialized.

import { parseIDL } from "@lichtblick/omgidl-parser";
import { MessageReader } from "@lichtblick/omgidl-serialization";

const msgDef = `
  module geometry_msgs {
    struct PointStamped {
      Header header;
      Point point;
    };
  };
  struct Header {
    uint32 seq;
    Time stamp;
    string frame_id;
  };
  struct Time {
    uint32 sec;
    uint64 nsec;
  };
  struct Point {
    float x;
    float y;
    float z;
  };
`;

const messageDefinition = parseIDL(msgDef);
const reader = new MessageReader("geometry_msgs::PointStamped", messageDefinition);

// deserialize a buffer into an object
const message = reader.readMessage([0x00, 0x01, ...]);

// access message fields
message.header.stamp;

MessageWriter

Convert an object, array, or primitive value into binary data using CDR message serialization. (XCDR1 and XCDR2 writing is not yet supported.)

import { MessageWriter } from "@lichtblick/omgidl-serialization";

const msgDef = `
  module geometry_msgs {
    struct PointStamped {
      Header header;
      Point point;
    };
  };
  struct Header {
    uint32 seq;
    Time stamp;
    string frame_id;
  };
  struct Time {
    uint32 sec;
    uint64 nsec;
  };
  struct Point {
    float x;
    float y;
    float z;
  };
`;

const messageDefinition = parseIDL(msgDef);

const writer = new MessageWriter("geometry_msgs::PointStamped", messageDefinition, cdrOptions);

// serialize the passed in object to a Uint8Array as a PointStamped message
const uint8Array = writer.writeMessage({
  header: {
    stamp: { sec: 0, nsec: 0 },
    frame_id: ""
  },
  x: 1,
  y: 0,
  z: 0
});

Known Limitations

MessageReader does not support:

  • arrays of variable-size arrays. parseIDL will error if this is detected in the schema to prevent incorrect deserialization.

MessageWriter does not support:

  • does not support writing XCDR1 (PL_CDR) or XCDR2 (PL_CDR2, DELIMITED_CDR2) encoded messages utilizing extensible types. However we can deserialize these encapsulation kinds in MessageReader.

Both do not support:

  • wchar and wstring - These are written and read using custom implementations that are specific to someone's environment. If encountered during deserialization, they will throw an error saying that they are unsupported.

Also see the current IDL parser schema limitations here