File format¶

An .itar file is a MessagePack-encoded dictionary mapping member paths to metadata:

{
    "path/to/member1.jpg": [
        null,  # shard index (0-based) or null for single archives
        [
            2048,  # metadata byte offset
            2560,  # data byte offset
            1048576,  # file length in bytes
        ],
    ],
    ...
}

• Sharded archives store the shard index in the first position.
• Entries are recorded for files and links; directories are omitted.
• Offsets let itar serve members directly from the underlying tar file(s) without extraction.