Package Format

[ricochet]

Goal: define the format for a package

• Should work with the content-digest field
• multi-file bundling or how to associate recognized package types with each other.
• Should this include component validation? For example if the package type is a Component, then it should adhere to binary spec of the Component Model. The same is true for a core module (like the cpython interpreter).

Note: Signature formats do not need to be defined as a part of this (covered by #26).

[lann]

@lukewagner has proposed a "wasm2dir" (ref #9 (reply in thread)) tool/spec that could bundle (and unbundle!) arbitrary other file data into .wasm section(s). As long as that bundling process is deterministically reversible (to allow for content digesting) it could be used for this purpose.

[lann]

Another consideration here is package metadata (assuming we even need it!). If we have multi-file packages of some sort then that could just be a particular filename like wasm-component.json, but it also could be a separate (bincoded?) .wasm section.

[lukewagner]

For package metadata (not accessible at runtime to the component), in the single-.wasm-format, one idea is that these could go into custom sections (with the file name in the custom section name) and then the tree-ified version would explode custom sections out into files. (Then, if we want JSON metadata, it would be JSON in the custom section.)