Crate hpr_format 

The hpr open design format: a rocket design as one JSON document, with its JSON Schema.

Guide: the format’s page says what a document holds, how it is versioned, and how it was checked. Version 0.1 is a draft until hpr’s first release: it can change in place, so keep the source .ork too.

A document is a DesignFile: a header naming the format (FORMAT), its version (VERSION) and where the design came from (Provenance), then the design as hpr_io::ork reads it from a .ork, then every other entry of that file’s archive, such as an embedded thrust curve or a decal image. The design holds the rocket, every motor configuration, the recovery events, the simulations stored with it, and what the source file holds that hpr does not model, kept under a namespaced extension (x-openrocket). A .ork written from a document is the .ork hpr writes from the file it was read from, byte for byte, as checked on the 73 designs hpr’s .ork checks read (ADR-111).

to_json writes the canonical text: two-space indents, keys in the order the types declare them, and a final newline, so the same design always gives the same bytes and a change shows as a small diff. from_json reads it back to the same value, takes a document of an older version to the current one (migrate), and refuses one of another format or a newer version with the reason. schema is the document’s JSON Schema, committed as schema/format/hpr-design-0.2.schema.json beside the older versions’ schemas. A container (.hprz) carries a design with other files, such as its flight logs.

Generated TypeScript and Python types come with the format’s third step, M3.3c.

use hpr_format::{DesignFile, Provenance, from_json, to_json};

let bytes = include_bytes!("../../../validation/fixtures/ork/loft-demo/demo-stable.ork");
let read = DesignFile::from_ork(bytes)?;
let text = to_json(&read.value)?;
assert!(text.starts_with("{\n  \"format\": \"hpr-design\",\n  \"version\": \"0.2\","));
assert_eq!(from_json(&text)?, read.value);

Modules

container

The .hprz container: a design and the files that go with it, such as flight logs, results and photographs, in one zip archive (ADR-112).

migrate

Migrations: a document of an older version rewritten into the current version’s shape.

Structs

DesignFile

A design as one document of the hpr design format.

Opened

A document read, and the version it was written in.

Provenance

Which program wrote a document, and from what.

Source

The file a design was read from: its format and its SHA-256, which name it without its path, and whether its rocket was read exactly as written.

SourceFile

One of the source file’s other files: its name, and its contents as text where they are UTF-8, or else as base64 (RFC 4648, section 4).

Version

A version of the format, written major.minor (ADR-111).

Enums

Content

A file’s contents: text, or base64 for bytes that are not UTF-8.

Format

The format’s name: a document holds only hpr-design.

FormatError

Why a document could not be written or read.

SourceFormat

The formats a design can be read from.

Constants

CONTAINER_EXTENSION

The extension of the zip container of a design and its attachments (container): .hprz.

EXTENSION

The extension of a design written as plain JSON (ADR-111): .hpr.

FORMAT

The format’s name, the value of every document’s format key.

VERSION

The version this crate writes and reads.

Functions

from_json

Reads a document from its JSON text, taking one of an older version to the current one.

read_json

Reads a document from its JSON text, and says which version it was written in.

schema

The document’s JSON Schema (draft 2020-12), as committed under schema/format/.

schema_json

schema as the canonical text committed: two-space indents and a final newline.

to_json

The canonical JSON text of document: two-space indents, keys in declared order, a final newline.