"""probe_gmui_size.py <dump.dmp>

Measure spacing between adjacent gm*UI instances in the same region
to derive a real per-instance allocation size.
"""
import struct, sys
from minidump.minidumpfile import MinidumpFile
from collections import Counter


GM_NOTICE_VT = 0x007ccb60
GM_NOTICE_OFFSET = 0x5f8


def _ei(v):
    if v is None: return 0
    if hasattr(v, 'value'): return int(v.value)
    return int(v)


md = MinidumpFile.parse(sys.argv[1])
reader = md.get_reader().get_buffered_reader()
scan = []
for r in md.memory_info.infos:
    st, ty, pr = _ei(r.State), _ei(r.Type), _ei(r.Protect) & 0xff
    if st != 0x1000 or ty == 0x1000000 or pr not in (0x04, 0x40): continue
    scan.append((r.BaseAddress, r.RegionSize))

# Find outer-object addresses
outers = []
for base, size in scan:
    try:
        reader.move(base); buf = reader.read(size)
    except Exception:
        continue
    if not buf: continue
    end = (len(buf) // 4) * 4
    for off in range(0, end - 4, 4):
        if struct.unpack_from("<I", buf, off)[0] != GM_NOTICE_VT: continue
        outer = (base + off) - GM_NOTICE_OFFSET
        # Read outer vt
        rel = off - GM_NOTICE_OFFSET
        if rel < 0:
            # outer is in previous region; skip
            continue
        outer_vt = struct.unpack_from("<I", buf, rel)[0]
        if outer_vt == 0x007c0498:   # primary gm*UI base vt
            outers.append(outer)

outers.sort()
print(f"gm*UI outers (vt 0x007c0498): {len(outers)}")

# Compute deltas between consecutive outers
deltas = Counter()
for i in range(1, len(outers)):
    d = outers[i] - outers[i-1]
    if d < 0x4000:   # only intra-allocation neighbors
        deltas[d] += 1

print("top inter-instance deltas (bytes between adjacent outers in same region):")
for d, n in deltas.most_common(15):
    print(f"  0x{d:04x} ({d:>6})  x{n}")

# Also probe MEM_PRIVATE region sizes that *contain* gm*UI outers
sizes = Counter()
for o in outers:
    for base, size in scan:
        if base <= o < base + size:
            sizes[size] += 1
            break
print()
print("region sizes containing gm*UI outers:")
for s, n in sizes.most_common(15):
    print(f"  size={s:>9} ({s/1024:>6.1f}KB)  x{n}")