Software Heritage - Indexer

Tools to compute multiple indexes on SWH's raw contents:

• content:
  • mimetype
  • fossology-license
  • metadata
• origin:
  • metadata (intrinsic, using the content indexer; and extrinsic)

An indexer is in charge of:

• looking up objects
• extracting information from those objects
• store those information in the swh-indexer db

There are multiple indexers working on different object types:

• content indexer: works with content sha1 hashes
• revision indexer: works with revision sha1 hashes
• origin indexer: works with origin identifiers

Indexation procedure:

• receive batch of ids
• retrieve the associated data depending on object type
• compute for that object some index
• store the result to swh's storage

Current content indexers:

• mimetype (queue swh_indexer_content_mimetype): detect the encoding and mimetype
• fossology-license (queue swh_indexer_fossology_license): compute the license
• metadata: translate file from an ecosystem-specific formats to JSON-LD (using schema.org/CodeMeta vocabulary)

Current origin indexers:

• metadata: translate file from an ecosystem-specific formats to JSON-LD (using schema.org/CodeMeta and ForgeFed vocabularies)