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vllm.distributed.kv_transfer.kv_connector.v1.mooncake.store.protocol

Wire-format constants for the LookupKey ZMQ admin channel.

This is the single source of truth shared by LookupKeyClient and LookupKeyServer on the scheduler<->worker rank-0 admin channel.

Wire format (REQ/REP over IPC):

Request: [msg_type: bytes] [payload_frames...]

  msg_type == LOOKUP_MSG:
      frame 1: token_len (u32 big-endian, 4 bytes)
      frame 2: hash_len (u16 big-endian, 2 bytes) — byte length of each
               fixed-size block hash (0 when there are no hashes)
      frame 3: raw block hashes concatenated back-to-back (each hash_len
               bytes); the server splits on hash_len
    Response: [hit_count: u32 big-endian, 4 bytes]

  msg_type == RESET_MSG:
      (no payload frames)
    Response: [RESP_OK] or [RESP_ERR]

The first frame of every request is a named bytes tag (not a numeric sentinel that aliases the data field) so the protocol stays self-describing and extensible: adding new admin commands requires only a new tag and a new dispatch branch.

Mirrors the named-tag convention used by the NIXL connector (see vllm/distributed/kv_transfer/kv_connector/v1/nixl/metadata.py).