Defer Snappy decompression of P2P messages until worker thread processing

[pinges]

PR description

• Defer Snappy decompression of inbound P2P
  messages from the Netty I/O thread to the worker
  thread that processes them, reducing memory
  held in the transaction worker queue from
  decompressed size to compressed size
• Add lazy decompression support to RawMessage:
  compressed bytes are stored as-is and only
  decompressed on the first getData() call;
  getSize() reads the Snappy frame header without
  decompressing
• Guard the trace log in ApiHandler with
  isTraceEnabled() to prevent eager getData()
  evaluation on the Netty I/O thread
• Add disconnected-peer check and error handling
  in TransactionsMessageHandler and
  NewPooledTransactionHashesMessageHandler to skip
  work for peers that disconnected while queued,
  and disconnect peers that send malformed
  messages

[Copilot]

Pull request overview

This PR defers Snappy decompression of inbound P2P messages from the Netty I/O thread to worker-thread processing by introducing lazy decompression in RawMessage, reducing queue memory pressure and avoiding accidental eager decompression in trace logging. It also adds worker-side checks/handling for disconnected peers and malformed message payloads.

Changes:

• Add lazy decompression + header-only sizing to RawMessage and relax AbstractMessageData immutability to support it.
• Update Framer to pass compressed payloads through (after initial negotiation/validation) for deferred decompression.
• Guard trace logging and add worker-thread disconnected/malformed-message handling to skip work and disconnect misbehaving peers.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
ethereum/p2p/.../wire/RawMessage.java	Adds lazy Snappy decompression and size calculation from Snappy header.
ethereum/p2p/.../wire/AbstractMessageData.java	Makes data mutable and getSize() overridable to support lazy decode.
ethereum/p2p/.../framing/Framer.java	Stops eagerly decompressing most messages; passes compressed bytes to RawMessage.
ethereum/p2p/.../netty/ApiHandler.java	Avoids evaluating message.getData() on Netty I/O thread when trace is disabled.
ethereum/eth/.../TransactionsMessageHandler.java	Defers decoding to tx worker; adds disconnected-peer skip + malformed-message disconnect.
ethereum/eth/.../NewPooledTransactionHashesMessageHandler.java	Same worker-side skip + malformed-message disconnect for pooled hash messages.

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[Copilot]

Pull request overview

This PR defers Snappy decompression of inbound RLPx P2P messages from the Netty I/O thread to worker threads by introducing lazy decompression in RawMessage, reducing queued-memory pressure and adding additional guards around logging and malformed/queued message handling.

Changes:

• Add lazy Snappy decompression support to RawMessage (decompress on first getData(), size via Snappy frame header).
• Update Framer to emit compressed RawMessage instances (except for first-message fallback / validation logic).
• Avoid eager decompression on the I/O thread via isTraceEnabled() guard and add disconnected/malformed message handling in tx-related message handlers.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/rlpx/wire/RawMessage.java	Introduces lazy decompression and size reporting without full decompression.
ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/rlpx/wire/AbstractMessageData.java	Allows subclasses (e.g., RawMessage) to override getSize().
ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/rlpx/framing/Framer.java	Emits lazily-decompressed RawMessage for subsequent compressed frames.
ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/rlpx/connections/netty/ApiHandler.java	Prevents trace logging from forcing eager getData() evaluation.
ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/transactions/TransactionsMessageHandler.java	Defers message parsing to worker, skips disconnected peers, disconnects on malformed messages.
ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/transactions/NewPooledTransactionHashesMessageHandler.java	Same as above for pooled transaction hash announcements.

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[macfarla]

Could you add a test for the key behavioral change - first message decompresses eagerly, subsequent messages are lazy?

Also maybe a changelog entry?

• Defer Snappy decompression of inbound P2P messages from the Netty I/O thread to the worker thread, reducing memory held in the transaction worker queue to compressed size