golded-ftn-squish

Repository: golded-ftn-squish-python. The distribution remains golded-ftn-squish; imports use golded_ftn_squish. The source is public on GitHub. This package has not been released on PyPI.

Strict reader and offline writer for classic Squish .SQD and .SQI message areas. Python 3.12+; plain Python, using the models and text helpers from golded-ftn. Version 1.2.0 is prepared locally; these writer changes are unreleased.

from pathlib import Path
from golded_ftn_squish import SquishReader

base = Path("messages/general")  # basename, without an extension
for message in SquishReader().read(base):
    print(message.msgno, message.from_name, message.subject)

For a local checkout:

git clone https://github.com/golded-dev/golded-ftn-python.git
git clone https://github.com/golded-dev/golded-ftn-squish-python.git
cd golded-ftn-squish-python
uv sync --locked

uv uses the sibling ../golded-ftn-python repository. Wheels and source distributions declare only golded-ftn>=1.2.0,<2; the development source override and lock file are excluded from the sdist.

Reading an area

SquishReader.read(path, options=None) implements MessageBaseReader. Pass an area basename and optionally core ReaderOptions(fallback_charset="CP850"). Extensions are matched case-insensitively; ambiguous candidates fail. Both files must be regular files. Missing files and wrong file types raise filesystem errors. Malformed records and decoding failures raise ParserException with the actual file path, byte offset and chained cause. All active records are validated before the result is returned; a damaged later record never produces a partial result.

Read a stable area without concurrent writes. The two files are read separately, without locking: this does not create an atomic snapshot.

The supported layout has a 256-byte area header, 28-byte frame header, 238-byte message header and 12-byte index records. Extended layouts, compressed frames and frames being updated are rejected. The area header's message count selects the active index prefix; preallocated index tail records are ignored. Active records must have increasing, positive unique UIDs and distinct, non-overlapping frames. UID gaps and arbitrary unused allocation bytes within a frame are accepted. Unindexed old and free frames are ignored; an active record pointing to a free frame is an error. .SQL lastread data is not used.

Message mapping

• msgno is the persistent index UID, not its relative index position. Header UID is checked against it only when the MSGUID attribute marks it as valid.
• Names, subject and body decode strictly through core helpers. Charset controls in the separate control block precede body declarations. Conflicting declarations fail; otherwise core charset aliases and CP850 fallback apply. Mojibake repair is left to callers.
• body_text contains only the normalized body payload. Separate header controls are preserved in control_lines, before body controls. Controls are separated by SOH bytes. A final NUL is optional inside the declared length; after the first NUL only NUL padding is accepted. Empty controls, trailing SOH and line breaks in the control block are rejected. Repeated controls remain in source order.
• Header and body MSGID/REPLY values must agree; identical repetitions are accepted. external_id is MSGID, otherwise a core synthetic ID over decoded, normalized fields. Routing metadata comes from the combined control parser.
• Binary addresses preserve node 0 and nonzero points. Incomplete components may be supplemented by INTL/FMPT/TOPT, following the MSG package's conflict rules. Unresolvable addresses become None; binary Squish addresses have no domain.
• Valid packed DateWritten is timezone-aware UTC. The signed writer UTC offset does not change it. A zero packed date permits a valid FTSC-date fallback, which is timezone-naive. Invalid dates become None, without calendar normalization. Binary UTC offset and arrival time have no dedicated core fields; existing TZUTC controls remain available as metadata.
• Attributes remain raw. reply_to_msgno and reply1st_msgno preserve header UIDs, with zero mapped to None. reply_next_msgno is None: the remaining eight reply slots form a reply list, not a next-sibling pointer. The core model cannot represent that full list.
• Provenance records source type squish, the actual SQD path, UID as text and frame byte offset. Area metadata and other unknown fields remain None.

Area discovery, packing, repair and databases are outside this package.

Development

Run uv run pytest, uv run ruff check ., uv run ruff format --check ., uv run mypy and uv run python -m mypy.stubtest golded_ftn_squish. Build with uv build; then run uv run twine check dist/* and uv run python scripts/verify_distribution.py. The distribution check rebuilds from sdist and tests both wheels with a local core wheel in separate environments outside the repositories. CI runs these checks on Linux Python 3.12–3.14 and tests on Windows/macOS Python 3.14. Local results do not establish a passing CI run.

Format references

The binary layout is documented in the original Maximus Squish structures and MsgAPI headers. Index allocation explains the unused tail. GoldED's gmosqsh.h and its reader/writer provide a second implementation reference. The PHP laravel-ftn-squish reader and tests provide compatibility context; its silent truncation and corruption handling are not copied. Tests use independent synthetic bytes, never private message archives.

MIT license. See CONTRIBUTING.md, SECURITY.md and release instructions.

Archive mode

Strict reading remains the default. Archive mode requires a report callback:

from golded_ftn import ReaderIssue, ReaderOptions

issues: list[ReaderIssue] = []
options = ReaderOptions(archive_mode=True, on_issue=issues.append)
# Pass options to SquishReader().read(source, options).

Issues carry recovered, skipped or stopped, the actual filename, record identity and physical offset. Their detail contains no message contents. A stop means the traversal is incomplete; a validated prefix may still be returned. Multiple issues can describe one record, including recovery followed by a skip. Filesystem errors and callback exceptions propagate. Files must remain stable.

The index UID wins over a disagreeing header UID and empty SOH control segments are ignored, both with reports. Failed indexed frames or messages are skipped using the next index slot. Duplicate offsets, overlapping frame extents, invalid UID order and truncated indices stop traversal. Metadata conflicts are skipped.

If declared ASCII cannot decode a payload, the configured fallback is tried strictly and reported. The original charset control stays unchanged. Other decoding failures are skipped; there is no lossy decoding or mojibake repair.

Writing an area

SquishWriter.create(path) creates .SQD, .SQI and an empty .SQL lastread file. Existing files are rejected. The base header stores the basename, with no extension, in its 80-byte name field. The first new UID is 2, following GoldED's initialization. Existing .SQL bytes remain untouched by editing.

from pathlib import Path

from golded_ftn import MessagePatch, OutgoingMessage
from golded_ftn_squish import SquishWriter

writer = SquishWriter()
Path("messages").mkdir(exist_ok=True)
writer.create("messages/new-area")
with writer.open("messages/new-area") as session:
    created = session.append(
        OutgoingMessage(
            from_name="Alice",
            to_name="Bob",
            subject="Hello",
            body_text="Body",
        )
    )
    current = session.read(created.identity.msgno)
    changed = session.update(
        current.identity, MessagePatch(subject="Revised"), current.revision
    )
    session.delete(changed.identity, changed.revision)

Sessions acquire byte 0 of .SQD per operation, reread the whole base and validate the physical frames, both linked lists and the active index before writing. Revision tokens include the identity, frame offset and raw message bytes; neighbor frame links are excluded because an unrelated append changes them. A changed or missing target raises ConflictError. Unrelated message changes do not invalidate the token. Omitted patch fields retain their values; explicit None clears only fields the format can represent as absent.

Content changes append a new frame and move the old frame to the free list. UIDs stay fixed. Free frames are kept for other tools; this writer does not recycle, merge or pack them. Header patches preserve omitted raw metadata, all nine replies, arrival time, UTC offset and unknown attribute bits. Attribute-only changes preserve the original control and text bytes. A body-only patch preserves omitted SEEN-BY and PATH routing. Explicit control replacement replaces the control block while preserving an omitted external_id; conflicting MSGID controls are rejected. New names and subjects require room for their trailing NUL; oversized fields and unencodable text fail instead of being truncated. WriterOptions selects the strict encoding, CP850 by default. Charset declarations must agree when text is serialized. Routing and MSGID are explicit caller data.

One operation is the rollback unit. Injected write, truncate and flush failures restore watched files in place under the lock. A failed rollback raises RollbackError and makes the session unusable. This does not promise recovery from process termination or power loss. A configured maxmsgs limit rejects an append at capacity; editing never purges other messages automatically.

Use Squish offline with GoldED closed. concurrent=True is rejected on every platform. macOS is the only runtime tested in this checkout. POSIX record locks serialize cooperating Python writers; Linux execution remains unverified. Windows has a byte-lock implementation but has not been exercised here. GoldED build tests, concurrent reading and refresh checks are deferred, so no GoldED build is certified. See writer source notes.