Files
littlefs/scripts/dbgbtree.py
Christopher Haster a897b875d3 Implemented lfsr_btree_update and added more tests
This was a rather simple exercise. lfsr_btree_commit does most of the
work already, so all this needed was setting up the pending attributes
correctly.

Also:
- Tweaked dbgrbyd.py's tree rendering to match dbgbtree.py's.
- Added a print to each B-tree test to help find the resulting B-tree
  when debugging.
2023-03-17 14:20:40 -05:00

608 lines
21 KiB
Python
Executable File

#!/usr/bin/env python3
import bisect
import itertools as it
import math as m
import os
import struct
def blocklim(s):
if '.' in s:
s = s.strip()
b = 10
if s.startswith('0x') or s.startswith('0X'):
s = s[2:]
b = 16
elif s.startswith('0o') or s.startswith('0O'):
s = s[2:]
b = 8
elif s.startswith('0b') or s.startswith('0B'):
s = s[2:]
b = 2
s0, s1 = s.split('.', 1)
return int(s0, b), int(s1, b)
else:
return int(s, 0)
def crc32c(data, crc=0):
crc ^= 0xffffffff
for b in data:
crc ^= b
for j in range(8):
crc = (crc >> 1) ^ ((crc & 1) * 0x82f63b78)
return 0xffffffff ^ crc
def fromleb128(data):
word = 0
for i, b in enumerate(data):
word |= ((b & 0x7f) << 7*i)
word &= 0xffffffff
if not b & 0x80:
return word, i+1
return word, len(data)
def fromtag(data):
tag, delta = fromleb128(data)
id, delta_ = fromleb128(data[delta:])
size, delta__ = fromleb128(data[delta+delta_:])
return tag&1, tag&~1, id if tag&0x8 else id-1, size, delta+delta_+delta__
def popc(x):
return bin(x).count('1')
def xxd(data, width=16, crc=False):
for i in range(0, len(data), width):
yield '%-*s %-*s' % (
3*width,
' '.join('%02x' % b for b in data[i:i+width]),
width,
''.join(
b if b >= ' ' and b <= '~' else '.'
for b in map(chr, data[i:i+width])))
def tagrepr(tag, id, size, off=None):
if (tag & ~0x3f0) == 0x0400:
return 'mk%s id%d %d' % (
'branch' if ((tag & 0x3f0) >> 4) == 0x00
else 'reg' if ((tag & 0x3f0) >> 4) == 0x01
else 'dir' if ((tag & 0x3f0) >> 4) == 0x02
else ' 0x%02x' % ((tag & 0x3f0) >> 4),
id,
size)
elif tag == 0x0800:
return 'inlined id%d %d' % (id, size)
elif tag == 0x0810:
return 'block id%d %d' % (id, size)
elif tag == 0x0820:
return 'btree id%d %d' % (id, size)
elif tag == 0x0830:
return 'branch id%d %d' % (id, size)
elif (tag & ~0xff2) == 0x2000:
return '%suattr 0x%02x%s%s' % (
'rm' if tag & 0x2 else '',
(tag & 0xff0) >> 4,
' id%d' % id if id != -1 else '',
' %d' % size if not tag & 0x2 or size else '')
elif tag == 0x0006:
return 'grow id%d w%d' % (
id,
size)
elif tag == 0x0016:
return 'shrink id%d w%d' % (
id,
size)
elif (tag & ~0x10) == 0x0004:
return 'crc%x%s %d' % (
1 if tag & 0x10 else 0,
' 0x%02x' % id if id != -1 else '',
size)
elif tag == 0x0024:
return 'fcrc%s %d' % (
' 0x%02x' % id if id != -1 else '',
size)
elif tag & 0x8:
return 'alt%s%s 0x%x w%d %s' % (
'r' if tag & 0x2 else 'b',
'gt' if tag & 0x4 else 'le',
tag & 0x3ff0,
id,
'0x%x' % (0xffffffff & (off-size))
if off is not None
else '-%d' % off)
else:
return '0x%04x id%d %d' % (tag, id, size)
class Rbyd:
def __init__(self, block, limit, data, rev, off, trunk, weight):
self.block = block
self.limit = limit
self.data = data
self.rev = rev
self.off = off
self.trunk = trunk
self.weight = weight
@classmethod
def fetch(cls, f, block_size, block, limit):
# seek to the block
f.seek(block * block_size)
data = f.read(limit)
# fetch the rbyd
rev, = struct.unpack('<I', data[0:4].ljust(4, b'\0'))
crc = crc32c(data[0:4])
off = 0
j_ = 4
trunk = None
trunk_ = None
weight = 0
weight_ = 0
wastrunk = False
while j_ < limit:
v, tag, id, size, delta = fromtag(data[j_:])
if v != (popc(crc) & 1):
break
crc = crc32c(data[j_:j_+delta], crc)
j_ += delta
# find trunk
if not wastrunk and (tag & 0xe) != 0x4:
trunk_ = j_ - delta
wastrunk = not not tag & 0x8
# keep track of weight
if tag == 0x0006:
weight_ += size
elif tag == 0x0016:
weight_ = max(weight_ - size, 0)
# take care of crcs
if (tag & 0xe) <= 0x4:
if (tag & ~0x10) != 0x04:
crc = crc32c(data[j_:j_+size], crc)
# found a crc?
else:
crc_, = struct.unpack('<I', data[j_:j_+4].ljust(4, b'\0'))
if crc != crc_:
break
# commit what we have
off = j_ + size
trunk = trunk_
weight = weight_
j_ += size
return Rbyd(block, limit, data, rev, off, trunk, weight)
def lookup(self, tag, id):
if not self:
return True, 0, -1, 0, 0, 0, b''
lower = -1
upper = self.weight
# descend down tree
j = self.trunk
while True:
_, alt, weight_, jump, delta = fromtag(self.data[j:])
# found an alt?
if alt & 0x8:
# follow?
if ((id, tag & ~0xf) > (upper-weight_-1, alt & ~0xf)
if alt & 0x4
else ((id, tag & ~0xf) <= (lower+weight_, alt & ~0xf))):
lower += upper-lower-1-weight_ if alt & 0x4 else 0
upper -= upper-lower-1-weight_ if not alt & 0x4 else 0
j = j - jump
# stay on path
else:
lower += weight_ if not alt & 0x4 else 0
upper -= weight_ if alt & 0x4 else 0
j = j + delta
# found tag
else:
tag_ = alt
id_ = upper-1
w_ = id_-lower
done = (id_, tag_) < (id, tag) or tag_ & 2
return (done, tag_, id_, w_,
j, delta, self.data[j+delta:j+delta+jump])
def __bool__(self):
return self.trunk is not None
def __eq__(self, other):
return self.block == other.block and self.limit == other.limit
def __ne__(self, other):
return not self.__eq__(other)
def __iter__(self):
tag = 0
id = 0
while True:
done, tag, id, w, j, d, data = self.lookup(tag+0x10, id)
if done:
break
yield tag, id, w, j, d, data
def main(disk, block_size=None, trunk=0, limit=None, *,
color='auto',
**args):
# figure out what color should be
if color == 'auto':
color = sys.stdout.isatty()
elif color == 'always':
color = True
else:
color = False
# trunk may include a limit
if isinstance(trunk, tuple):
if limit is None:
limit = trunk[1]
trunk = trunk[0]
# we seek around a bunch, so just keep the disk open
with open(disk, 'rb') as f:
# if block_size is omitted, assume the block device is one big block
if block_size is None:
f.seek(0, os.SEEK_END)
block_size = f.tell()
# default limit to the block_size
if limit is None:
limit = block_size
# fetch the trunk
trunk = Rbyd.fetch(f, block_size, trunk, limit)
print('btree 0x%x.%x, rev %d, weight %d' % (
trunk.block, trunk.limit, trunk.rev, trunk.weight))
# look up an id, while keeping track of the search path
def lookup(id, depth=None):
rbyd = trunk
rid = id
depth_ = 1
path = []
# corrupted? return a corrupted block once
if not rbyd:
return (id > 0, id, 0, rbyd, -1, 0,
0, 0, b'',
0, 0, b'',
path)
while True:
# first lookup id/name
(done, _, rid_, w,
name_j, name_d, name) = rbyd.lookup(0x400, rid)
if done:
return True, id, 0, rbyd, -1, 0, 0, 0, b'', 0, 0, b'', path
# then lookup struct
(done, tag, _, _,
struct_j, struct_d, struct_) = rbyd.lookup(0x800, rid_)
if done:
return True, id, 0, rbyd, -1, 0, 0, 0, b'', 0, 0, b'', path
path.append((id + (rid_-rid), w, rbyd, rid_, tag,
name_j, name_d, name,
struct_j, struct_d, struct_))
# is it another branch? continue down tree
if tag == 0x830 and (depth is None or depth_ < depth):
block, delta = fromleb128(struct_)
limit, _ = fromleb128(struct_[delta:])
rbyd = Rbyd.fetch(f, block_size, block, limit)
# corrupted? bail here so we can keep traversing the tree
if not rbyd:
return (False, id + (rid_-rid), w, rbyd, -1, 0,
0, 0, b'',
0, 0, b'',
path)
rid -= (rid_-(w-1))
depth_ += 1
else:
return (False, id + (rid_-rid), w, rbyd, rid_, tag,
name_j, name_d, name,
struct_j, struct_d, struct_,
path)
# if we're printing the tree, first find the max depth so we know how
# much space to reserve
t_width = 0
if args.get('tree'):
t_depth = 0
id = -1
while True:
(done, id, w, rbyd, rid, tag,
name_j, name_d, name,
struct_j, struct_d, struct_,
path) = (lookup(id+1, depth=args.get('depth')))
if done:
break
t_depth = max(t_depth, len(path))
t_width = 2*t_depth+2 if t_depth > 0 else 0
t_branches = [(0, trunk.weight)]
def t_repr(id, w, d=None):
branches_ = []
for i in range(len(t_branches)):
if d is not None and d == i-1:
branches_.append('+')
elif i+1 < len(t_branches):
if (id-(w-1) == t_branches[i+1][0]
and t_branches[i][0] == t_branches[i+1][0]
and (not args.get('inner')
or (i == 0 and d == 0))):
branches_.append('+-')
elif (id-(w-1) == t_branches[i+1][0]
and t_branches[i][1] == t_branches[i+1][1]
and (not args.get('inner') or d == i)):
branches_.append('\'-')
elif (id-(w-1) == t_branches[i+1][0]
and (not args.get('inner') or d == i)):
branches_.append('|-')
elif (id-(w-1) >= t_branches[i][0]
and id-(w-1) < t_branches[i][1]
and t_branches[i][1] != t_branches[i+1][1]):
branches_.append('| ')
else:
branches_.append(' ')
else:
if (id-(w-1) == t_branches[i][0]
and (not args.get('inner') or i == 0)):
branches_.append('+-%s> ' % ('-'*2*(t_depth-i-1)))
elif id == t_branches[i][1]-1:
branches_.append('\'-%s> ' % ('-'*2*(t_depth-i-1)))
elif (id >= t_branches[i][0]
and id-(w-1) < t_branches[i][1]):
branches_.append('|-%s> ' % ('-'*2*(t_depth-i-1)))
return '%s%-*s%s' % (
'\x1b[90m' if color else '',
t_width, ''.join(branches_),
'\x1b[m' if color else '')
# print header
w_width = 2*m.ceil(m.log10(max(1, trunk.weight)+1))+1
print('%-9s %*s%-*s %-8s %-22s %s' % (
'block',
t_width, '',
w_width, 'ids',
'name',
'tag',
'data (truncated)'
if not args.get('no_truncate') else ''))
# traverse and print entries
id = -1
prbyd = None
ppath = []
corrupted = False
while True:
(done, id, w, rbyd, rid, tag,
name_j, name_d, name,
struct_j, struct_d, struct_,
path) = (lookup(id+1, depth=args.get('depth')))
if done:
break
if args.get('inner') or args.get('tree'):
t_branches = [(0, trunk.weight)]
changed = False
for i, (x, px) in enumerate(
it.zip_longest(path[:-1], ppath[:-1])):
if x is None:
break
(id_, w_, rbyd_, rid_, tag_,
name_j_, name_d_, name_,
struct_j_, struct_d_, struct__) = x
t_branches.append((id_-(w_-1), id_+1))
if args.get('inner'):
if not (changed or px is None or x != px):
continue
changed = True
# show human-readable representation
print('%10s %s%*s %-8s %-22s %s' % (
'%04x.%04x:' % (rbyd_.block, rbyd_.limit)
if prbyd is None or rbyd_ != prbyd
else '',
t_repr(id_, w_, i) if args.get('tree') else '',
w_width, '%d-%d' % (id_-(w_-1), id_)
if w_ > 1 else id_
if w_ > 0 else '',
''.join(
b if b >= ' ' and b <= '~' else '.'
for b in map(chr, name_)),
tagrepr(tag_, rid_, len(struct__), None),
next(xxd(struct__, 8), '')
if not args.get('no_truncate') else ''))
# show in-device representation
if args.get('device'):
print('%9s %*s%*s %8s %-22s%s' % (
'',
t_width, '',
w_width, '',
'',
'%04x %08x %07x' % (
tag_, 0xffffffff & rid_, len(struct__)),
' %s' % ' '.join(
'%08x' % struct.unpack('<I',
rbyd_.data[struct_j_+struct_d_+i*4
: struct_j_+struct_d_
+ min(i*4+4,len(struct__))]
.ljust(4, b'\0'))
for i in range(
min(m.ceil(len(struct__)/4), 3)))[:23]))
# show on-disk encoding of tags/data
for j, d, data in [
(name_j_, name_d_, name_),
(struct_j_, struct_d_, struct__)]:
if args.get('raw'):
for o, line in enumerate(
xxd(rbyd_.data[j:j+d])):
print('%9s: %s' % (
'%04x' % (j + o*16),
line))
# show on-disk encoding of tags
if args.get('raw') or args.get('no_truncate'):
for o, line in enumerate(xxd(data)):
print('%9s: %s' % (
'%04x' % (j+d + o*16),
line))
# prbyd here means the last rendered rbyd, we update
# here to always print interleaved addresses
prbyd = rbyd_
# corrupted? try to keep printing the tree
if not rbyd:
print('%04x.%04x: %s%s%s%s' % (
rbyd.block, rbyd.limit,
t_repr(id, w) if args.get('tree') else '',
'\x1b[31m' if color else '',
'(corrupted rbyd 0x%x.%x)' % (rbyd.block, rbyd.limit),
'\x1b[m' if color else ''))
prbyd = rbyd
ppath = path
corrupted = True
continue
# show human-readable representation
print('%10s %s%*s %-8s %-22s %s' % (
'%04x.%04x:' % (rbyd.block, rbyd.limit)
if prbyd is None or rbyd != prbyd
else '',
t_repr(id, w) if args.get('tree') else '',
w_width, '%d-%d' % (id-(w-1), id)
if w > 1 else id
if w > 0 else '',
''.join(
b if b >= ' ' and b <= '~' else '.'
for b in map(chr, name)),
tagrepr(tag, rid, len(struct_), None),
next(xxd(struct_, 8), '')
if not args.get('no_truncate') else ''))
# show in-device representation
if args.get('device'):
print('%9s %*s%*s %8s %-22s%s' % (
'',
t_width, '',
w_width, '',
'',
'%04x %08x %07x' % (
tag, 0xffffffff & rid, len(struct_)),
' %s' % ' '.join(
'%08x' % struct.unpack('<I',
rbyd.data[struct_j+struct_d+i*4
: struct_j+struct_d
+ min(i*4+4,len(struct_))]
.ljust(4, b'\0'))
for i in range(
min(m.ceil(len(struct_)/4), 3)))[:23]))
# show on-disk encoding of tags/data
for j, d, data in [
(name_j, name_d, name),
(struct_j, struct_d, struct_)]:
if args.get('raw'):
for o, line in enumerate(xxd(rbyd.data[j:j+d])):
print('%9s: %s' % (
'%04x' % (j + o*16),
line))
# show on-disk encoding of tags
if args.get('raw') or args.get('no_truncate'):
for o, line in enumerate(xxd(data)):
print('%9s: %s' % (
'%04x' % (j+d + o*16),
line))
prbyd = rbyd
ppath = path
if args.get('error_on_corrupt') and corrupted:
sys.exit(2)
if __name__ == "__main__":
import argparse
import sys
parser = argparse.ArgumentParser(
description="Debug rbyd B-trees.",
allow_abbrev=False)
parser.add_argument(
'disk',
help="File containing the block device.")
parser.add_argument(
'trunk',
nargs='?',
type=blocklim,
help="Block address of the trunk of the tree.")
parser.add_argument(
'-B', '--block-size',
type=lambda x: int(x, 0),
help="Block size in bytes.")
parser.add_argument(
'-L', '--limit',
type=lambda x: int(x, 0),
help="Rbyd limit of the trunk of the tree (alias).")
parser.add_argument(
'--color',
choices=['never', 'always', 'auto'],
default='auto',
help="When to use terminal colors. Defaults to 'auto'.")
parser.add_argument(
'-r', '--raw',
action='store_true',
help="Show the raw data including tag encodings.")
parser.add_argument(
'-x', '--device',
action='store_true',
help="Show the device-side representation of tags.")
parser.add_argument(
'-T', '--no-truncate',
action='store_true',
help="Don't truncate, show the full contents.")
parser.add_argument(
'-i', '--inner',
action='store_true',
help="Show inner branches.")
parser.add_argument(
'-t', '--tree',
action='store_true',
help="Show the underlying B-tree.")
parser.add_argument(
'-Z', '--depth',
type=lambda x: int(x, 0),
help="Depth of tree to show.")
parser.add_argument(
'-e', '--error-on-corrupt',
action='store_true',
help="Error if B-tree is corrupt.")
sys.exit(main(**{k: v
for k, v in vars(parser.parse_intermixed_args()).items()
if v is not None}))