v0.6.11: Code Quality Hardening and Async Performance Overhaul#173
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- CR-02/08: Fix AsyncSFTPFile out-of-order response race — buffer unclaimed responses in dispatch loop; replace asyncio.shield with direct wait_for + explicit cancel on timeout - CR-03: Add configure_sanitizing_logging() helper to install SanitizingFilter on the root logger (bypasses propagation gap) - CR-04: WarningPolicy.missing_host_key() now stores key on first use (TOFU) - CR-05: Remove unconditional keyboard-interactive auth fallback in AsyncSSHClient._authenticate() - CR-06: put_recursive() only swallows SSH_FX_FAILURE, not all SFTPError - CR-07: Replace assert request.request_id is not None with if/raise - CR-09: Remove premature counter resets from _check_rekey(); counters now reset only after rekey thread succeeds (in _start_kex finally) - CR-10: Add SSH_FXF_APPEND to SFTPClient._mode_to_flags() for "a" mode - CR-11: listdir() try/finally guarantees directory handle closure - CR-12: Fix "ssh_library" → "spindlex" in HostKeyStorage.save() - CR-13: Document decrypt_length() as CTR-mode passthrough hook - CR-14: Narrow ChannelFile.read() exception catch from Exception to ChannelException; remove fragile "Timeout" string matching - CR-15: Add SSHClient.username property; add key_password param to AsyncSSHClient.connect() and thread through _authenticate - CR-16: HostKeyStorage.__init__ now distinguishes FileNotFoundError (silently ignored) from corrupt-file exceptions (warned) - CR-17: _initialize_sftp() already closes channel on failure (no-op) - CR-18: Remove dead `if TYPE_CHECKING: pass` block - CR-19: Replace misleading multi-line Bug comment in _recv_version() - CR-22: Remove all # Bug #N Fixed: inline comments across codebase - CR-23: _expect_message() raises TransportException instead of returning None when transport is inactive - CR-24: Remove S105/S106/S303/S324 from global ruff ignores; add noqa annotation at the one legitimate false-positive site All 1724 unit tests pass, ruff clean.
Five targeted optimisations in the async transport/SFTP stack: 1. Native async packet receive — replaces asyncio.to_thread(super()._read_message) with _recv_packet_async() that reads directly from the asyncio StreamReader, cutting two cross-thread context switches per SSH packet received. 2. Threshold-based write drain — _send_message_async() now calls drain() only when the write buffer exceeds 64 KB instead of after every packet, eliminating ~32 event-loop yields per 1 MB SFTP upload window. 3. Async-safe channel close — AsyncChannel._handle_close() schedules the EOF+CLOSE handshake as a task instead of calling _send_message() synchronously, preventing a deadlock when close is dispatched from the event-loop thread. 4. Doubled SFTP pipeline depth — _WINDOW and _PIPELINE_DEPTH raised from 32 to 64, keeping 2 MB of reads/writes in flight instead of 1 MB. 5. Tuned socket options — TCP_NODELAY disables Nagle coalescing on the async client; SO_SNDBUF/SO_RCVBUF raised to 1 MB each; DEFAULT_WINDOW_SIZE increased to 4 MB for deeper receive buffering. Also extracts _dispatch_packet() from _read_message() in the base Transport so the async path can reuse the same dispatch logic without the thread bridge.
Bump version to 0.6.11 and update changelog covering: - Async throughput overhaul (beats asyncssh on handshake, upload, download) - 23 code-review fixes (CR-02 through CR-24) - Benchmark script improvements
Di3Z1E
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- async_channel: fix _handle_close sync fallback to use send_eof() and _close_channel() instead of non-existent _send_eof/_send_close/_close_sent attributes (mypy attr-defined errors) - async_channel: remove _close_sent guard from _async_close_handshake; add nosec B110 to best-effort except block (bandit B110) - async_transport: replace isinstance(msg, HandledMessage) with msg.msg_type != 0 to avoid mypy unreachable-code error; HandledMessage sentinel carries msg_type=0 which is not a valid SSH message type - async_transport: remove unused HandledMessage import and dead _read_single_packet method
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May 12, 2026
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Fix the 2 comments i left
…d SFTP chunking - feat(async): implement robust retry logic in AsyncSSHClient.connect() covering the entire handshake phase to mitigate transient server-side resets (MaxStartups) - feat(sftp): implement automatic 64KB chunking in SFTPClient and AsyncSFTPClient write() to handle large data buffers and prevent protocol crashes - perf(protocol): increase MAX_MESSAGE_SIZE to 1MB and SFTP_MAX_PACKET_SIZE to 64KB for improved throughput - fix(transport): unify exception propagation in AsyncTransport to preserve specific SSHException subclasses - fix(forwarding): resolve NameError in PortForwarding by moving Channel import out of TYPE_CHECKING - chore: align protocol unit tests with updated message limits and perform project-wide code formatting
![github-advanced-security[bot]](https://avatars.githubusercontent.com/in/57789?s=60&v=4){kind=small}
- Perform project-wide code formatting using Ruff to align with CI runner expectations - Ensure scripts/ and examples/ directories are correctly formatted - Fix minor indentation issues in AsyncSSHClient.connect() introduced during retry logic implementation
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May 13, 2026
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May 13, 2026
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Description
This release combines two parallel workstreams merged into
release/0.6.11:Type of Change
Performance Results (vs asyncssh 2.22.0, LAN)
SpindleX is also 2–7× faster than paramiko across all categories.
Key Changes
Performance (
async_transport.py,async_channel.py,async_sftp_client.py,async_ssh_client.py,constants.py)_recv_packet_async()reads directly fromasyncio.StreamReader, eliminating two cross-thread context switches per received SSH packet (previously usedasyncio.to_thread+run_coroutine_threadsafe)._send_message_async()only callsdrain()when the write buffer exceeds 64 KB, eliminating ~32 event-loop yields per 1 MiB SFTP upload window._WINDOWand_PIPELINE_DEPTHraised 32 → 64; 2 MiB in flight instead of 1 MiB.DEFAULT_WINDOW_SIZEraised 2 MiB → 4 MiB.TCP_NODELAYenabled;SO_SNDBUF/SO_RCVBUFset to 1 MiB.AsyncChannel._handle_close()schedules EOF+CLOSE as a task to prevent an event-loop deadlock in the native async receive path.Fixes (CR-02 through CR-24)
SSH_FXF_APPENDnow set for"a"open mode)key_passwordparameter added toSSHClient.connect()andAsyncSSHClient.connect()SSHClient.usernameproperty addedChannelFile.read()exception handling narrowed toChannelExceptionput_recursive()only suppressesSSH_FX_FAILURE(not allSFTPError)_expect_message()raisesTransportExceptioninstead of silently returningNoneon closed transport_check_rekey()HostKeyStoragedistinguishesFileNotFoundError(silent) from corrupt-file errors (warned); fixed library name insave()("ssh_library"→"spindlex")WarningPolicynow stores host key on first contact (TOFU)AsyncSSHClient._authenticate()Added
configure_sanitizing_logging()public API for attachingSanitizingFilterto any logger_dispatch_packet()extracted from_read_message()in baseTransportfor shared use by sync and async pathsImproved
# Bug #N Fixed:inline commentsif TYPE_CHECKING: passblockS105/S106/S303/S324from global ruff ignores; added precisenoqaat the one legitimate site_recv_version()How Has This Been Tested?
uv run pytest tests/) — ruff ✅ mypy ✅ bandit ✅pytest -m integrationChecklist