backend-infra-engineer: Post v0.3.9-hotfix7 snapshot (build cleanup)

tools/decode_sprname.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python3
+"""Decode hmagic sprname.dat standard format into JSON.
+
+Format (standard):
+- byte 0: flag (0 = standard, non-zero = alt)
+- bytes 1-4: little-endian size of payload
+- payload: 0x11c entries, each [len (1 byte), name bytes]
+Alt format not implemented here (would be 256 entries of 9 bytes each if flag!=0).
+"""
+import json
+import struct
+import sys
+from pathlib import Path
+
+
+def decode_standard(data: bytes):
+    if len(data) < 5:
+        raise ValueError("file too small")
+    flag = data[0]
+    size = struct.unpack_from('<I', data, 1)[0]
+    buf = data[5:5 + size]
+    if flag != 0:
+        raise ValueError("non-zero flag: alt format not handled here")
+    names = []
+    pos = 0
+    for i in range(0x11C):
+        if pos >= len(buf):
+            raise ValueError(f"truncated at entry {i}")
+        name_len = buf[pos]
+        pos += 1
+        if name_len > 15:
+            raise ValueError(f"name too long at entry {i}: {name_len}")
+        if pos + name_len > len(buf):
+            raise ValueError(f"truncated payload at entry {i}")
+        name = buf[pos:pos + name_len].decode('latin1')
+        pos += name_len
+        names.append(name)
+    return names
+
+
+def main():
+    if len(sys.argv) != 2:
+        print("Usage: decode_sprname.py <sprname.dat>")
+        sys.exit(1)
+    path = Path(sys.argv[1])
+    data = path.read_bytes()
+    names = decode_standard(data)
+    print(json.dumps(names, indent=2))
+
+
+if __name__ == "__main__":
+    main()