donau

check-db-naming.py (5221B)

---

 #!/usr/bin/env python3
 """Enforce the database layer naming convention.
 
 Rules checked (see the commit series "database naming cleanup"):
 
   1. every public function's name starts with the name of the file it lives in
   2. the file's own name uses a prefix from the closed set, or is exempt
   3. iterate_ iff the function takes a caller-supplied callback; get_ iff not
   4. a .h exists beside every .c, and a .sql (if any) shares the name
   5. every prepared statement is named after the function preparing it
   6. no prepared statement name is used in two files
   7. no numeric suffixes and no repeated library prefix
 
 Run from the top of the source tree; exits non-zero on any violation.
 """
 import re
 import sys
 import pathlib
 
 # ---------------------------------------------------------------- CONFIG --
 # (impl dir, header dir, symbol prefix, .c basename prefix)
 LAYERS = [
     ("src/donaudb", "src/include/donau-database", "DONAUDB_", ""),
 ]
 
 # Prefixes that describe what the caller gets.
 PREFIXES = ("get_", "get_count_", "get_exists_", "iterate_",
             "insert_", "update_", "update_to_", "delete_", "do_")
 
 # Not CRUD: transaction control, DDL, events, memory, session plumbing,
 # cancellable handle APIs, and multi-function helper modules.  Keep this list
 # short and justified -- every entry is a rule the checker stops enforcing.
 EXEMPT = {
     "start", "start_read_only", "start_read_committed", "commit", "rollback",
     "preflight", "create_tables", "drop_tables",
     "event_listen", "event_listen_cancel", "event_notify",
 }
 
 # Files that are not part of the API surface at all.  plugin_donaudb_postgres.c
 # is not a plugin vtable despite the name; it holds the connect/disconnect and
 # reconnect plumbing, and is skipped by the plugin_ rule below.
 SKIP = {"helper", "pg_template"}
 # ------------------------------------------------------------ END CONFIG --
 
 PREP = re.compile(r'PREPARE\s*\(\s*\w+\s*,\s*"([A-Za-z0-9_]+)"', re.S)
 
 errors = []
 
 
 def check_layer(impl_dir, hdr_dir, prefix, fpfx):
     impl, hdr = pathlib.Path(impl_dir), pathlib.Path(hdr_dir)
     if not impl.is_dir():
         return
     decl = re.compile(r"^" + re.escape(prefix) + r"(\w+)\s*\((.*?)\)\s*;",
                       re.S | re.M)
     stmt_owner = {}
 
     for c in sorted(impl.glob("*.c")):
         if c.stem in SKIP or c.stem.startswith("test_") \
            or c.stem.startswith("plugin_"):
             continue
         if fpfx and not c.stem.startswith(fpfx):
             continue
         stem = c.stem[len(fpfx):] if fpfx else c.stem
 
         # 2. prefix from the closed set, or exempt
         if stem not in EXEMPT and not stem.startswith(PREFIXES):
             errors.append(f"{c}: '{stem}' uses no approved prefix")
 
         # 7. numeric suffix
         if re.search(r"\d$", stem):
             errors.append(f"{c}: '{stem}' ends in a digit")
 
         # 4. matching header
         h = hdr / (stem + ".h")
         if stem not in EXEMPT and not h.exists():
             errors.append(f"{c}: no matching header {h}")
 
         text = c.read_text(errors="replace")
 
         # 5. prepared statements named after the function
         for s in dict.fromkeys(PREP.findall(text)):
             if s != stem and not s.startswith(stem + "_"):
                 errors.append(
                     f"{c}: prepared statement '{s}' is not named after "
                     f"'{stem}'")
             # 6. cross-file uniqueness
             if s in stmt_owner and stmt_owner[s] != str(c):
                 errors.append(
                     f"{c}: prepared statement '{s}' also prepared in "
                     f"{stmt_owner[s]}")
             stmt_owner[s] = str(c)
 
         if not h.exists():
             continue
         htext = re.sub(r"/\*.*?\*/", "", h.read_text(errors="replace"),
                        flags=re.S)
         for name, params in decl.findall(htext):
             # 1. declared names belong to their file.  Exempt entries are the
             # documented multi-function modules, so this does not apply there.
             if (stem not in EXEMPT
                     and name != stem and not name.startswith(stem + "_")):
                 errors.append(
                     f"{h}: declares '{name}', which does not belong to "
                     f"'{stem}'")
             # 3. iterate_ iff callback
             has_cb = bool(re.search(r"\w*(Callback|Iterator)\s+\w+", params))
             if name.startswith("iterate_") and not has_cb:
                 errors.append(
                     f"{h}: '{name}' is iterate_ but takes no callback")
             if name.startswith("get_") and has_cb:
                 errors.append(f"{h}: '{name}' takes a callback; use iterate_")
 
     # 7. repeated library prefix anywhere in the tree
     head = prefix.split("_")[0]
     for f in list(impl.glob("*.[ch]")) + list(hdr.glob("*.h")):
         if "unc-backup" in f.name:
             continue
         if re.search(r"\b" + re.escape(head) + r"_" + re.escape(prefix),
                      f.read_text(errors="replace")):
             errors.append(f"{f}: repeated '{prefix}' prefix")
 
 
 for a in LAYERS:
     check_layer(*a)
 
 for e in errors:
     print("ERROR:", e)
 print(f"\ndb-naming: {len(errors)} violation(s)")
 sys.exit(1 if errors else 0)