fix: work around PyPI's zipbomb mitigation measures

Author: moriyoshi

.gitignore

@@ -154,3 +154,6 @@ src/jntajis/_version.py
 
 # automatically generated C source
 src/jntajis/_jntajis.c
+
+# Temporary directory used by the coding agent
+.agents/tmp

pyproject.toml

@@ -104,11 +104,12 @@ build = ["cp310-*", "cp311-*",  "cp312-*", "cp313-*"]
 # skip = "pp*"
 
 [tool.cibuildwheel.linux]
-before-build = "find /project -iname '*.so' | xargs rm -f"
+before-build = "find {project} -iname '*.so' | xargs rm -f"
 
 [tool.cibuildwheel.windows]
 before-build = "DEL /S /Q *.pyd"
+repair-wheel-command = "python {project}/tools/repack_wheel.py {wheel} {dest_dir}"
 
 [tool.cibuildwheel.macos]
 archs = ["universal2"]
-before-build = "find . -iname '*.so' | xargs rm -f "
+before-build = "find {project} -iname '*.so' | xargs rm -f "

tools/repack_wheel.py

@@ -0,0 +1,192 @@
+"""Repack wheels to limit per-entry inflation below a threshold.
+
+PyPI rejects wheels where any zip entry inflates over 50x (zip bomb detection).
+This script re-compresses entries that exceed the limit using deflate with
+frequent Z_FULL_FLUSH to reduce compression efficiency while keeping the
+data genuinely compressed.
+
+Usage (cibuildwheel repair-wheel-command):
+    # Single wheel -> dest_dir (Windows, no prior repair step)
+    python tools/repack_wheel.py WHEEL DEST_DIR
+
+    # All wheels in a directory, in-place (after auditwheel/delocate)
+    python tools/repack_wheel.py DEST_DIR
+"""
+
+import os
+import struct
+import sys
+import time
+import zlib
+import zipfile
+
+CHUNK_SIZE = 4096
+MAX_INFLATION = 50
+
+
+def compress_chunked(data, chunk_size):
+    """Compress data with frequent flushes to reduce compression efficiency."""
+    c = zlib.compressobj(1, zlib.DEFLATED, -15)
+    parts = []
+    for i in range(0, len(data), chunk_size):
+        chunk = data[i:i + chunk_size]
+        parts.append(c.compress(chunk))
+        parts.append(c.flush(zlib.Z_FULL_FLUSH))
+    parts.append(c.flush(zlib.Z_FINISH))
+    return b''.join(parts)
+
+
+def make_dos_datetime(dt):
+    mod_time = (dt[3] << 11) | (dt[4] << 5) | (dt[5] // 2)
+    mod_date = ((dt[0] - 1980) << 9) | (dt[1] << 5) | dt[2]
+    return mod_time, mod_date
+
+
+def repack_wheel(src_path, dst_path):
+    """Repack a wheel, limiting per-entry inflation below MAX_INFLATION.
+
+    src_path and dst_path may be the same file (in-place repack).
+    """
+    with zipfile.ZipFile(src_path, 'r') as zin:
+        items_data = [(item, zin.read(item.filename)) for item in zin.infolist()]
+
+    tmp_path = dst_path + '.tmp'
+    needs_repack = False
+
+    with open(tmp_path, 'wb') as f:
+        central_dir = []
+
+        for item, data in items_data:
+            crc = zlib.crc32(data) & 0xFFFFFFFF
+            uncompressed_size = len(data)
+
+            # Compress normally first
+            c = zlib.compressobj(6, zlib.DEFLATED, -15)
+            compressed = c.compress(data) + c.flush()
+
+            # Check if inflation exceeds limit
+            if len(compressed) > 0 and uncompressed_size / len(compressed) >= MAX_INFLATION:
+                needs_repack = True
+                t0 = time.time()
+                compressed = compress_chunked(data, CHUNK_SIZE)
+                elapsed = time.time() - t0
+                inflation = uncompressed_size / len(compressed)
+                print(f'  {item.filename}: {uncompressed_size} -> {len(compressed)} '
+                      f'({len(compressed) / uncompressed_size * 100:.1f}%, {inflation:.1f}x) [{elapsed:.1f}s]')
+
+            compress_type = zipfile.ZIP_DEFLATED
+            compressed_size = len(compressed)
+
+            local_header_offset = f.tell()
+            fname = item.filename.encode('utf-8')
+            mod_time, mod_date = make_dos_datetime(item.date_time)
+
+            # Local file header
+            f.write(struct.pack(
+                '<4sHHHHHIIIHH',
+                b'PK\x03\x04',
+                20,  # version needed
+                0,   # flags
+                compress_type,
+                mod_time,
+                mod_date,
+                crc,
+                compressed_size,
+                uncompressed_size,
+                len(fname),
+                0,   # extra length
+            ))
+            f.write(fname)
+            f.write(compressed)
+
+            central_dir.append((
+                fname, compress_type, mod_time, mod_date,
+                crc, compressed_size, uncompressed_size,
+                local_header_offset, item.external_attr,
+            ))
+
+        # Central directory
+        cd_offset = f.tell()
+        for (fname, ct, mt, md, crc, cs, us, offset, ext_attr) in central_dir:
+            f.write(struct.pack(
+                '<4sHHHHHHIIIHHHHHII',
+                b'PK\x01\x02',
+                20,  # version made by
+                20,  # version needed
+                0,   # flags
+                ct, mt, md, crc, cs, us,
+                len(fname),
+                0,   # extra length
+                0,   # comment length
+                0,   # disk number start
+                0,   # internal attributes
+                ext_attr,
+                offset,
+            ))
+            f.write(fname)
+
+        cd_size = f.tell() - cd_offset
+
+        # End of central directory
+        f.write(struct.pack(
+            '<4sHHHHIIH',
+            b'PK\x05\x06',
+            0, 0,
+            len(central_dir),
+            len(central_dir),
+            cd_size,
+            cd_offset,
+            0,
+        ))
+
+    if needs_repack:
+        os.replace(tmp_path, dst_path)
+    else:
+        os.unlink(tmp_path)
+        if src_path != dst_path:
+            import shutil
+            shutil.copy2(src_path, dst_path)
+
+
+def verify_wheel(whl_path):
+    with zipfile.ZipFile(whl_path, 'r') as zf:
+        max_inflation = 0
+        for info in zf.infolist():
+            if info.compress_size > 0:
+                inf = info.file_size / info.compress_size
+                max_inflation = max(max_inflation, inf)
+        zf.testzip()
+        fsize = os.path.getsize(whl_path)
+        return fsize, max_inflation
+
+
+def main():
+    if len(sys.argv) == 3 and not os.path.isdir(sys.argv[1]):
+        # Mode: repack_wheel.py WHEEL DEST_DIR
+        src_wheel = sys.argv[1]
+        dest_dir = sys.argv[2]
+        basename = os.path.basename(src_wheel)
+        dst_wheel = os.path.join(dest_dir, basename)
+        print(f'Repacking {basename}...')
+        repack_wheel(src_wheel, dst_wheel)
+        fsize, max_inf = verify_wheel(dst_wheel)
+        print(f'  -> {fsize:,} bytes, max entry inflation={max_inf:.1f}x')
+    elif len(sys.argv) == 2 and os.path.isdir(sys.argv[1]):
+        # Mode: repack_wheel.py DEST_DIR (in-place)
+        dest_dir = sys.argv[1]
+        for name in sorted(os.listdir(dest_dir)):
+            if not name.endswith('.whl'):
+                continue
+            path = os.path.join(dest_dir, name)
+            print(f'Repacking {name}...')
+            repack_wheel(path, path)
+            fsize, max_inf = verify_wheel(path)
+            print(f'  -> {fsize:,} bytes, max entry inflation={max_inf:.1f}x')
+    else:
+        print(f'Usage: {sys.argv[0]} WHEEL DEST_DIR', file=sys.stderr)
+        print(f'       {sys.argv[0]} DEST_DIR', file=sys.stderr)
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    main()