llar Artifact Binary Format

LLAR Binary Artifact

Archive

artifact.tar.gz
  .llar/
    metadata.json
  ...

The default archive type is tar.gz. The archive root is the artifact install directory. .llar/ is reserved for LLAR files. Other files are package payload.

C/C++ example:

artifact.tar.gz
  .llar/
    metadata.json
  include/
    zlib.h
    zconf.h
  lib/
    libz.a
    pkgconfig/
      zlib.pc

.llar/metadata.json

{
  "metadata": "-I{{.InstallDir}}/include -L{{.InstallDir}}/lib -lz",
  "deps": [
    "madler/zlib@v1.3.1"
  ]
}

Field	Type	Required	Description
metadata	string	yes	LLAR build metadata, same semantic value as formula.BuildResult.Metadata().
deps	string[]	no	Artifact dependencies in module@version form.

No version field is defined.

Path Placeholder

Use {{.InstallDir}} for this artifact's install directory inside metadata.

/tmp/llard/work/madler/zlib/install/include
{{.InstallDir}}/include

llar install expands it to the local install directory before writing .cache.json.

Rules

Producer:

• archive the install directory as the archive root;
• include .llar/metadata.json;
• replace this artifact's build-time install directory with {{.InstallDir}}.

Installer:

• verify and extract the archive;
• read .llar/metadata.json;
• expand {{.InstallDir}};
• write metadata into .cache.json.

Invalid Artifacts

Case	Reason
missing .llar/metadata.json	no LLAR metadata
invalid .llar/metadata.json	cannot decode metadata
missing metadata	cannot determine this artifact's usage information, such as include paths and libraries, for the selected matrix