imageContentKey function

String imageContentKey(
  1. ImageContent image
)

Content key of an image: SHA-256 over the canonical payload string (data:<mime>;base64,<data>). Same bytes under a different mime are distinct entries (re-encoded occurrences dedup-miss — correct but suboptimal, learn.ai's resilient-lookup semantics).

Implementation

String imageContentKey(ImageContent image) => sha256
    .convert(utf8.encode('data:${image.mimeType};base64,${image.data}'))
    .toString();