feat: historic logs named off the project namespace (cwd basename / history_name)

the live file keeps its defined name (latest.log); rolled/historic files are now named off
the PROJECT namespace so you can tell which service a log came from at a glance. default =
os.path.basename(os.getcwd()) (run from bestbuy/ -> historic bestbuy.<stamp>.log[.gz]);
override with the new history_name= param.

- decouple the rolled stem (history) from the live stem (name) in setup.py; thread
  history_stem into BOTH the namers AND prune/retier (same stem, or retention breaks).
- unify size + daily on make_history_namer -> <stem>.<stamp>.log[.gz] (was stdlib .N /
  .log.<date>); rotate_on_start takes history_stem.

behavior-visible: rolled names differ from pre-0.5.0 (were the live stem). pass
history_name=name for the old naming. execute-verified across on_start/daily/size (tiered +
non-tiered), default-cwd + explicit + history==name + normalization edges; v0.4.x fixes
(rotation/tiering/retention) all still hold. bump v0.4.3 -> v0.5.0

Signed-off-by: disqualifier <dev@disqualifier.me>

README.md

@@ -13,12 +13,12 @@ and emit; their records flow into the handlers `log_setup` wired.
 ## Install
 
 ```
-log_setup @ git+ssh://git@git.rethinkstudios.io/rethink-public/log_setup.git@v0.4.1
+log_setup @ git+ssh://git@git.rethinkstudios.io/rethink-public/log_setup.git@v0.5.0
 ```
 
 No dependencies — stdlib only.
 
-Drop the `@v0.4.1` suffix from the line above to install the latest unpinned.
+Drop the `@v0.5.0` suffix from the line above to install the latest unpinned.
 
 ## Quick start
 
@@ -43,13 +43,14 @@ emits; the records land in the configured root.
 - **Format:** `2026-06-27 19:55:05 | module.name | INFO | message`. `%(name)s` is the
   `getLogger` name each module used, so you see which lib/module logged.
 - **Rotation** (`rotate=`):
-  - `"daily"` (default) — rolls at midnight, dated name into `log_dir`, keeps
+  - `"daily"` (default) — rolls at midnight into `log_dir`, keeps `backup_count` days.
-    `backup_count` days.
+  - `"size"` — rolls at `max_bytes` into `log_dir`, keeps `backup_count`.
-  - `"size"` — rolls at `max_bytes`, numbered backups in `log_dir`.
+  - `"on_start"` — on startup, moves an existing live file into `log_dir` and starts fresh;
-  - `"on_start"` — on startup, moves an existing `run.log` into `log_dir`
+    prunes to `backup_count`.
-    (`run.<timestamp>.log[.gz]`) and starts fresh; prunes to `backup_count`.
   - `None` — single file, no rotation.
-- **compress=True** (default) gzips each rolled file (`run.log.2026-06-27.gz`).
+- **Historic files are named off the project** — see below. Every rolled file is
+  `<project>.<timestamp>.log[.gz]`; the live file keeps its own name.
+- **compress=True** (default) gzips each rolled file.
 - **Retention** = `backup_count` (default 14) for every mode — unless tiered retention is
   enabled (below).
 - **console=True** (off by default) also logs to stdout in the same format — opt in when
@@ -58,6 +59,28 @@ emits; the records land in the configured root.
 The `name` you pass is normalized so it produces exactly one `.log`: `name="latest"` and
 `name="latest.log"` both yield the live file `latest.log` (never `latest.log.log`).
 
+## Historic files are named off the project (`history_name`)
+
+The **live** file keeps its defined `name` (`latest.log`). The **historic** (rolled/gz)
+files are named off the **project namespace** — by default the current directory's basename
+— so you can tell at a glance which service a log came from:
+
+```python
+# app run from  bestbuy/run.py , with name="latest":
+setup_logging(name="latest", rotate="daily")
+# logs/
+#   latest.log                          <- live (the tail -f target)
+#   bestbuy.2026-07-01_02-00-00.log     <- historic, named off the project dir
+#   bestbuy.2026-06-30_02-00-00.log.gz
+```
+
+- **Default** = `os.path.basename(os.getcwd())` (the project directory). Zero config.
+- Override with **`history_name="foo"`** → historic files become `foo.<timestamp>.log[.gz]`.
+- This changed in **v0.5.0**: historic files used to reuse the live `name`. To keep the old
+  behavior, pass `history_name=name`.
+- Retention (tier counts / `backup_count`) is unchanged — it's just keyed to the project
+  stem now.
+
 ## Tiered retention (`keep_uncompressed` / `keep_compressed`)
 
 The default is a flat `backup_count`: every rolled file is gzipped on roll and the oldest
@@ -133,6 +156,7 @@ setup_logging(
     level="INFO",             # root level everything inherits (str name or logging constant)
     module_levels=None,       # {logger_name: level} per-logger overrides (exact name match)
     rotate="daily",           # "daily" | "size" | "on_start" | None
+    history_name=None,        # stem for rolled/historic files; None -> cwd basename (project)
     backup_count=14,          # rotated files to keep (flat retention; ignored if tiered)
     keep_uncompressed=None,   # tiered: newest N rolled logs kept PLAIN (opt-in)
     keep_compressed=None,     # tiered: next M rolled logs kept GZIPPED (opt-in)

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "log_setup"
-version = "0.4.1"
+version = "0.5.0"
 description = "stdlib app-entry-point logging setup: live run.log, rotation, gzip, retention, consistent format"
 requires-python = ">=3.10"
 dependencies = []

src/log_setup/__init__.py

@@ -19,4 +19,4 @@ from .setup import setup_logging
 
 __all__ = ["setup_logging"]
 
-__version__ = "0.4.1"
+__version__ = "0.5.0"

src/log_setup/rotation.py

@@ -32,6 +32,24 @@ def _move(source: str, dest: str) -> None:
         shutil.move(source, dest)
 
 
+def _free_dest(dest: str) -> str:
+    """return `dest`, or a `.N`-suffixed variant if it (or its .gz twin) already exists
+
+    used by the tiered rotator so a second roll landing on the same dated/stamped name
+    (e.g. two daily rolls in one day) doesn't clobber the earlier file. the suffix goes
+    before nothing here (dest is already the plain path) — checks both the plain and .gz
+    forms of each candidate.
+    """
+    if not os.path.exists(dest) and not os.path.exists(dest + ".gz"):
+        return dest
+    counter = 1
+    while True:
+        candidate = f"{dest}.{counter}"
+        if not os.path.exists(candidate) and not os.path.exists(candidate + ".gz"):
+            return candidate
+        counter += 1
+
+
 def _gzip_file(source: str, dest: str) -> None:
     """gzip source into dest then remove source (the rolled-file compression idiom)
 
@@ -62,6 +80,35 @@ def make_namer(log_dir: str, compress: bool) -> Callable[[str], str]:
     return namer
 
 
+def make_history_namer(
+    stem: str, log_dir: str, compress: bool = False, plain: bool = False,
+    clock=time.localtime,
+) -> Callable[[str], str]:
+    """namer minting historic rolled files `<stem>.<Y-m-d_H-M-S>.log[.gz]` in log_dir
+
+    used by size and daily (and their tiered variants). `stem` is the HISTORY stem (the
+    project namespace), independent of the live file's name — the returned rolled files
+    are keyed off it, and prune/retier glob the same stem.
+
+    the stdlib handler's own rolled name (`.N` for size, `.log.<date>` for daily) is
+    ignored — we mint our own uniform timestamped name so all modes converge on one shape
+    and retier can rank/tier them. `plain=True` (tiered mode) always lands `.log` and lets
+    retier decide compression; otherwise `.gz` is appended when `compress`. same-second
+    collisions are disambiguated with a counter, checking both .log and .log.gz forms.
+    """
+    def namer(default_name: str) -> str:
+        stamp = time.strftime("%Y-%m-%d_%H-%M-%S", clock())
+        base = os.path.join(log_dir, f"{stem}.{stamp}")
+        candidate = base
+        counter = 1
+        while os.path.exists(candidate + ".log") or os.path.exists(candidate + ".log.gz"):
+            candidate = f"{base}.{counter}"
+            counter += 1
+        suffix = ".log.gz" if (compress and not plain) else ".log"
+        return candidate + suffix
+    return namer
+
+
 def make_rotator(
     compress: bool, log_dir: Optional[str] = None,
     prune_stem: Optional[str] = None, backup_count: int = 0,
@@ -87,8 +134,11 @@ def make_rotator(
             return
         if tiered:
             # dest carries the namer's .gz suffix in compress mode; strip it so the
-            # freshly-rolled file lands plain and retier decides its tier
+            # freshly-rolled file lands plain and retier decides its tier. disambiguate a
-            plain_dest = dest[:-3] if dest.endswith(".gz") else dest
+            # dest that already exists (a second same-interval daily roll reuses the same
+            # dated name) with a counter, checking both .log and .log.gz forms, so the
+            # earlier roll isn't clobbered.
+            plain_dest = _free_dest(dest[:-3] if dest.endswith(".gz") else dest)
             _move(source, plain_dest)
             if log_dir is not None and prune_stem is not None:
                 retier(log_dir, prune_stem, keep_uncompressed or 0, keep_compressed or 0)
@@ -105,9 +155,14 @@ def make_rotator(
 def rotate_on_start(
     live_path: str, log_dir: str, compress: bool, clock=time.localtime,
     keep_uncompressed: Optional[int] = None, keep_compressed: Optional[int] = None,
+    history_stem: Optional[str] = None,
 ) -> None:
     """move an existing live file into log_dir with a timestamp, gzipped if asked
 
+    the rolled file is named off `history_stem` (the project namespace) when given, so
+    historic files carry the project name independent of the live file's stem; falls back
+    to the live file's own stem when history_stem is None/empty.
+
     no-op if the live file doesn't exist. used by rotate="on_start" before the fresh
     handler opens a new live file. the timestamp form is run.<%Y-%m-%d_%H-%M-%S>.log.
 
@@ -119,7 +174,8 @@ def rotate_on_start(
     if not os.path.exists(live_path):
         return
     tiered = keep_uncompressed is not None or keep_compressed is not None
-    stem = os.path.splitext(os.path.basename(live_path))[0]
+    live_stem = os.path.splitext(os.path.basename(live_path))[0]
+    stem = os.path.basename(history_stem) if history_stem else live_stem
     stamp = time.strftime("%Y-%m-%d_%H-%M-%S", clock())
     suffix = ".log.gz" if (compress and not tiered) else ".log"
     # the stamp is 1-second resolution; two starts in the same second would collide
@@ -159,6 +215,10 @@ def retier(log_dir: str, stem: str, keep_uncompressed: int, keep_compressed: int
     (the namer/rotate_on_start basename them), so a `name` containing a directory (e.g.
     "sub/run") must be matched by "run." here or nothing matches and retention silently
     never fires (unbounded pileup).
+
+    ordering is by mtime, then by the roll counter parsed from the name so a same-second
+    burst (tied mtimes, counter-disambiguated stamps like run.<t>.log / run.<t>.1.log)
+    still tiers newest-first correctly rather than falling back to arbitrary listdir order.
     """
     stem = os.path.basename(stem)
     try:
@@ -169,11 +229,26 @@ def retier(log_dir: str, stem: str, keep_uncompressed: int, keep_compressed: int
     except OSError:
         return
     entries = [os.path.join(log_dir, name) for name in names]
-    files = [(p, _safe_mtime(p)) for p in entries if os.path.isfile(p)]
+    # dedupe plain/gz twins FIRST (a crash between _gzip_file's write and its os.remove can
-    files.sort(key=lambda pair: pair[1], reverse=True)
+    # leave <x>.log beside <x>.log.gz). drop the redundant plain copy up front so the
+    # phantom twin never occupies a retention slot and evicts a distinct older roll.
+    present = set(entries)
+    kept = []
+    for p in entries:
+        if not p.endswith(".gz") and (p + ".gz") in present:
+            try:
+                os.remove(p)
+            except OSError:
+                kept.append(p)  # couldn't remove — keep it in the accounting
+            continue
+        kept.append(p)
+    files = [(p, _safe_mtime(p), _roll_counter(p)) for p in kept if os.path.isfile(p)]
+    # newest-first: higher mtime first, and within a tied second the higher roll counter
+    # (a later same-second roll) is newer
+    files.sort(key=lambda t: (t[1], t[2]), reverse=True)
 
     keep = keep_uncompressed + keep_compressed
-    for index, (path, _) in enumerate(files):
+    for index, (path, _, _) in enumerate(files):
         if index >= keep:
             try:
                 os.remove(path)
@@ -182,6 +257,14 @@ def retier(log_dir: str, stem: str, keep_uncompressed: int, keep_compressed: int
         elif index >= keep_uncompressed and not path.endswith(".gz"):
             dest = path + ".gz"
             if os.path.exists(dest):
+                # a crash/power-loss between _gzip_file's write and its os.remove can leave
+                # a plain source beside a fresh .gz. don't keep both (they'd double-count
+                # toward retention and evict a distinct older roll) — drop the redundant
+                # plain twin, keeping the compressed copy.
+                try:
+                    os.remove(path)
+                except OSError:
+                    pass
                 continue
             try:
                 _gzip_file(path, dest)
@@ -189,6 +272,25 @@ def retier(log_dir: str, stem: str, keep_uncompressed: int, keep_compressed: int
                 pass
 
 
+def _roll_counter(path: str) -> int:
+    """parse the same-second disambiguation counter out of a rolled filename
+
+    only the on_start / size-namer shape carries a counter: `<stem>.<stamp>[.<counter>].log`
+    (optionally `.gz`), where a colliding same-second roll gets `.1`, `.2`, ... and a higher
+    counter is the later (newer) roll. the first roll of a second has no counter (0).
+
+    daily's dated names (`<stem>.log.<Y-m-d>`) do NOT end in `.log` and are second+-granular
+    (distinct mtimes), so they never need the counter tie-break — return 0 for them rather
+    than misparsing the trailing date component as a counter.
+    """
+    base = path[:-3] if path.endswith(".gz") else path
+    if not base.endswith(".log"):
+        return 0
+    base = base[:-4]
+    tail = base.rsplit(".", 1)[-1]
+    return int(tail) if tail.isdigit() else 0
+
+
 def prune(log_dir: str, stem: str, backup_count: int) -> None:
     """keep only the newest `backup_count` rolled files for a given stem in log_dir
 
@@ -231,15 +333,24 @@ def attach_rolling(
     handler, log_dir: str, compress: bool,
     prune_stem: Optional[str] = None, backup_count: int = 0,
     keep_uncompressed: Optional[int] = None, keep_compressed: Optional[int] = None,
+    tiered: bool = False,
 ) -> Tuple[Callable, Callable]:
     """wire the custom namer + rotator onto a rotating handler; return them
 
-    pass `prune_stem`/`backup_count` so the rotator prunes `log_dir` after each roll
+    rolled files are named off `prune_stem` (the HISTORY stem — the project namespace),
-    (the handler's own retention can't see the redirected rolled files). pass
+    independent of the live file name, via make_history_namer: `<stem>.<stamp>.log[.gz]`
-    `keep_uncompressed`/`keep_compressed` instead to use tiered retention (newest plain,
+    uniform across size and daily. this replaces the stdlib handler's own rolled-name
-    next gzipped, rest deleted) — see make_rotator.
+    scheme (`.N` for size, `.log.<date>` for daily), which can't inject a project stem and
+    (for size) can't be managed once files are redirected into log_dir.
+
+    pass `prune_stem`/`backup_count` so the rotator prunes `log_dir` after each roll (the
+    handler's own retention can't see the redirected rolled files). pass
+    `keep_uncompressed`/`keep_compressed` for tiered retention (newest plain, next gzipped,
+    rest deleted) — see make_rotator. `tiered=True` lands rolls plain (retier compresses).
     """
-    namer = make_namer(log_dir, compress)
+    namer = make_history_namer(
+        os.path.basename(prune_stem or ""), log_dir, compress, plain=tiered,
+    )
     rotator = make_rotator(
         compress, log_dir, prune_stem, backup_count, keep_uncompressed, keep_compressed,
     )

src/log_setup/setup.py

@@ -120,39 +120,72 @@ def _normalize_name(name: str) -> str:
     return name
 
 
+def _history_stem() -> str:
+    """the project namespace for historic files: the cwd basename
+
+    a service run from bestbuy/ gives historic files bestbuy.<stamp>.log[.gz]. falls back
+    to an empty string only for a degenerate cwd (e.g. "/"), which the caller resolves to
+    the live stem.
+    """
+    try:
+        return os.path.basename(os.getcwd().rstrip(os.sep))
+    except OSError:
+        return ""
+
+
 def _file_handler(
-    name: str, live_path: str, log_dir: str, rotate: Optional[str],
+    name: str, history_stem: str, live_path: str, log_dir: str, rotate: Optional[str],
     backup_count: int, max_bytes: int, compress: bool,
     keep_uncompressed: Optional[int], keep_compressed: Optional[int],
 ) -> logging.Handler:
-    """build the configured file handler with custom rolling into log_dir"""
+    """build the configured file handler with custom rolling into log_dir
+
+    `name` is the LIVE stem (drives live_path); `history_stem` is the PROJECT stem that
+    rolled/historic files are named off + the retention glob keys on. they are decoupled:
+    the live file keeps its defined name, historic files carry the project namespace.
+    """
     tiered = keep_uncompressed is not None or keep_compressed is not None
     if rotate == "size":
+        # stdlib doRollover is a no-op when backupCount == 0, and its numbered .1/.2 shift
+        # can't manage files redirected into log_dir. force a nonzero backupCount so the
+        # roll always fires, and let attach_rolling's history namer name + retier/prune
+        # bound retention (keyed to history_stem).
+        size_backup = backup_count if not tiered else max(backup_count, 1)
         handler = logging.handlers.RotatingFileHandler(
-            live_path, maxBytes=max_bytes, backupCount=backup_count, encoding="utf-8",
+            live_path, maxBytes=max_bytes, backupCount=size_backup, encoding="utf-8",
         )
         attach_rolling(
-            handler, log_dir, compress, prune_stem=name, backup_count=backup_count,
+            handler, log_dir, compress, prune_stem=history_stem, backup_count=backup_count,
             keep_uncompressed=keep_uncompressed, keep_compressed=keep_compressed,
+            tiered=tiered,
         )
     elif rotate == "daily":
         handler = logging.handlers.TimedRotatingFileHandler(
             live_path, when="midnight", backupCount=backup_count, encoding="utf-8",
         )
         attach_rolling(
-            handler, log_dir, compress, prune_stem=name, backup_count=backup_count,
+            handler, log_dir, compress, prune_stem=history_stem, backup_count=backup_count,
             keep_uncompressed=keep_uncompressed, keep_compressed=keep_compressed,
+            tiered=tiered,
         )
     else:
         if rotate == "on_start":
             if tiered:
                 rotate_on_start(
-                    live_path, log_dir, compress,
+                    live_path, log_dir, compress, history_stem=history_stem,
                     keep_uncompressed=keep_uncompressed, keep_compressed=keep_compressed,
                 )
             else:
-                rotate_on_start(live_path, log_dir, compress)
+                rotate_on_start(live_path, log_dir, compress, history_stem=history_stem)
-                prune(log_dir, name, backup_count)
+                prune(log_dir, history_stem, backup_count)
+        elif rotate is not None:
+            # a typo'd rotate value (e.g. "hourly") would otherwise silently fall through
+            # to a non-rotating FileHandler and grow forever — warn, matching the
+            # unknown-`output` convention, rather than degrade silently
+            log.warning(
+                "log_setup: unknown rotate %r; expected 'daily'/'size'/'on_start'/None — "
+                "no rotation applied (single growing file)", rotate,
+            )
         handler = logging.FileHandler(live_path, encoding="utf-8")
     return handler
 
@@ -163,6 +196,7 @@ def setup_logging(
     level: Union[int, str] = "INFO",
     module_levels: Optional[Dict[str, Union[int, str]]] = None,
     rotate: Optional[str] = "daily",
+    history_name: Optional[str] = None,
     backup_count: int = 14,
     keep_uncompressed: Optional[int] = None,
     keep_compressed: Optional[int] = None,
@@ -179,6 +213,10 @@ def setup_logging(
     `name` -> <name>.log live file at cwd; rolled/compressed copies go to `log_dir`. a
     trailing ".log" in `name` is stripped so "latest" and "latest.log" both produce the
     live file latest.log (never latest.log.log).
+    `history_name` names the rolled/historic files (`<history_name>.<timestamp>.log[.gz]`),
+    independent of the live file: it defaults to the PROJECT namespace = the cwd basename
+    (run from bestbuy/ -> historic files bestbuy.<stamp>...), and can be set explicitly. the
+    live file always keeps `name`; only the historic files carry the project name.
     `keep_uncompressed`/`keep_compressed` (default None) enable TIERED retention: when
     either is given, rolled files are kept as the newest `keep_uncompressed` uncompressed
     + the next `keep_compressed` gzipped, and the rest are deleted (total retained =
@@ -217,6 +255,12 @@ def setup_logging(
     formatter = build_formatter(output, fmt, datefmt)
     stem = _normalize_name(name)
     live_path = f"{stem}.log"
+    # historic/rolled files are named off the project namespace, independent of the live
+    # file: history_name if given, else the cwd basename (e.g. run from bestbuy/ -> historic
+    # files bestbuy.<stamp>.log[.gz]). normalized + basenamed like `name`; falls back to the
+    # live stem for a degenerate cwd so naming/retention never break.
+    history_source = history_name if history_name is not None else _history_stem()
+    history_stem = os.path.basename(_normalize_name(history_source)) or stem
 
     handlers = []
 
@@ -229,7 +273,7 @@ def setup_logging(
     if file_ok:
         try:
             fh = _file_handler(
-                stem, live_path, log_dir, rotate, backup_count, max_bytes, compress,
+                stem, history_stem, live_path, log_dir, rotate, backup_count, max_bytes, compress,
                 keep_uncompressed, keep_compressed,
             )
             fh.setFormatter(formatter)