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865477d7e1406e4d30ff5b5edc00551ee213b409
littlefs/scripts/dbgrbyd.py
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Christopher Haster 865477d7e1 Changing coalesce strategy, reimplemented shrub/btree carve 
Note this is already showing better code reuse, which is a good sign,
though maybe that's just the benefit of reimplementing similar logic
multiple times.

Now both reading and carving end up in the same lfsr_btree_readnext and
lfsr_btree_buildcarve functions for both btrees and shrubs. Both btrees
and shrubs are fundamentally rbyds, so we can share a lot of
functionality as long as we redirect to the correct commit function at
the last minute. This surprising opportunity for deduplication was
noticed while putting together the dbg scripts.

Planned logic (not actual function names):

  lfsr_file_readnext -> lfsr_shrub_readnext
            |                    |
            |                    v
            '---------> lfsr_btree_readnext

  lfsr_file_flushbuffer -> lfsr_shrub_carve ------------.
            .---------------------'                     |
            v                                           v
  lfsr_file_flushshrub  -> lfsr_btree_carve -> lfsr_btree_buildcarve

Though the btree part of the above statement is only a hypothetical at
the moment. Not even the shrubs can survive compaction now.

The reason is the new SLICE tag which needs low-level support in rbyd
compact. SLICE introduces indirect refernces to data located in the same
rbyd, which removes any copying cost associated with coalescing.
Previously, a large coalesce_size risked O(n^2) runtime when
incrementally append small amounts of data, but with SLICEs we can defer
coalescing to compaction time, where the copy is effectively free.

This compaction-time-coalescing is also hypothetical, which is why our
tests are failing. But the theory is promising.

I was originally against this idea because of how it crosses abstraction
layers, requiring some very low-level code that absolutely can not be
omitted in a simpler littlefs driver. But after working on the actual
file writing code for a while I've become convinced the tradeoff is
worth it.

Note coalesce_size will likely still need to be configurable. Data in
fragmenting/sparse btrees is still susceptible to coalescing, and it's
not clear the impacts of internal fragmentation when data sizes approach
the hard block_size/2 limit.
2023-10-17 23:21:18 -05:00

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#!/usr/bin/env python3
import bisect
import collections as co
import itertools as it
import math as m
import os
import struct
COLORS = [
'34', # blue
'31', # red
'32', # green
'35', # purple
'33', # yellow
'36', # cyan
]
TAG_NULL = 0x0000
TAG_CONFIG = 0x0000
TAG_MAGIC = 0x0003
TAG_VERSION = 0x0004
TAG_FLAGS = 0x0005
TAG_CKSUMTYPE = 0x0006
TAG_REDUNDTYPE = 0x0007
TAG_BLOCKLIMIT = 0x0008
TAG_DISKLIMIT = 0x0009
TAG_MLEAFLIMIT = 0x000a
TAG_SIZELIMIT = 0x000b
TAG_NAMELIMIT = 0x000c
TAG_UTAGLIMIT = 0x000d
TAG_UATTRLIMIT = 0x000e
TAG_GSTATE = 0x0100
TAG_GRM = 0x0100
TAG_NAME = 0x0200
TAG_BNAME = 0x0200
TAG_BOOKMARK = 0x0201
TAG_REG = 0x0202
TAG_DIR = 0x0203
TAG_STRUCT = 0x0300
TAG_DATA = 0x0300
TAG_SLICE = 0x0304
TAG_TRUNK = 0x0308
TAG_DID = 0x030c
TAG_BLOCK = 0x0310
TAG_BTREE = 0x0314
TAG_MDIR = 0x0321
TAG_MTREE = 0x0324
TAG_MROOT = 0x0329
TAG_BRANCH = 0x032c
TAG_UATTR = 0x0400
TAG_SATTR = 0x0600
TAG_SHRUB = 0x1000
TAG_CKSUM = 0x2000
TAG_ECKSUM = 0x2100
TAG_ALT = 0x4000
TAG_GT = 0x2000
TAG_R = 0x1000
# parse some rbyd addr encodings
# 0xa -> [0xa]
# 0xa.b -> ([0xa], b)
# 0x{a,b} -> [0xa, 0xb]
def rbydaddr(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
trunk = None
if '.' in s:
s, s_ = s.split('.', 1)
trunk = int(s_, b)
if s.startswith('{') and '}' in s:
ss = s[1:s.find('}')].split(',')
else:
ss = [s]
addr = []
for s in ss:
if trunk is not None:
addr.append((int(s, b), trunk))
else:
addr.append(int(s, b))
return addr
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 fromle32(data):
return struct.unpack('<I', data[0:4].ljust(4, b'\0'))[0]
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):
data = data.ljust(4, b'\0')
tag = (data[0] << 8) | data[1]
weight, d = fromleb128(data[2:])
size, d_ = fromleb128(data[2+d:])
return tag>>15, tag&0x7fff, weight, size, 2+d+d_
def popc(x):
return bin(x).count('1')
def xxd(data, width=16):
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, w, size, off=None):
if (tag & 0xefff) == TAG_NULL:
return '%snull%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
' w%d' % w if w else '',
' %d' % size if size else '')
elif (tag & 0xef00) == TAG_CONFIG:
return '%s%s%s %d' % (
'shrub' if tag & TAG_SHRUB else '',
'magic' if (tag & 0xfff) == TAG_MAGIC
else 'version' if (tag & 0xfff) == TAG_VERSION
else 'flags' if (tag & 0xfff) == TAG_FLAGS
else 'cksumtype' if (tag & 0xfff) == TAG_CKSUMTYPE
else 'redundtype' if (tag & 0xfff) == TAG_REDUNDTYPE
else 'blocklimit' if (tag & 0xfff) == TAG_BLOCKLIMIT
else 'disklimit' if (tag & 0xfff) == TAG_DISKLIMIT
else 'mleaflimit' if (tag & 0xfff) == TAG_MLEAFLIMIT
else 'sizelimit' if (tag & 0xfff) == TAG_SIZELIMIT
else 'namelimit' if (tag & 0xfff) == TAG_NAMELIMIT
else 'utaglimit' if (tag & 0xfff) == TAG_UTAGLIMIT
else 'uattrlimit' if (tag & 0xfff) == TAG_UATTRLIMIT
else 'config 0x%02x' % (tag & 0xff),
' w%d' % w if w else '',
size)
elif (tag & 0xef00) == TAG_GSTATE:
return '%s%s%s %d' % (
'shrub' if tag & TAG_SHRUB else '',
'grm' if (tag & 0xfff) == TAG_GRM
else 'gstate 0x%02x' % (tag & 0xff),
' w%d' % w if w else '',
size)
elif (tag & 0xef00) == TAG_NAME:
return '%s%s%s %d' % (
'shrub' if tag & TAG_SHRUB else '',
'bname' if (tag & 0xfff) == TAG_BNAME
else 'bookmark' if (tag & 0xfff) == TAG_BOOKMARK
else 'reg' if (tag & 0xfff) == TAG_REG
else 'dir' if (tag & 0xfff) == TAG_DIR
else 'name 0x%02x' % (tag & 0xff),
' w%d' % w if w else '',
size)
elif (tag & 0xef00) == TAG_STRUCT:
return '%s%s%s %d' % (
'shrub' if tag & TAG_SHRUB else '',
'data' if (tag & 0xfff) == TAG_DATA
else 'slice' if (tag & 0xfff) == TAG_SLICE
else 'trunk' if (tag & 0xfff) == TAG_TRUNK
else 'did' if (tag & 0xfff) == TAG_DID
else 'block' if (tag & 0xfff) == TAG_BLOCK
else 'btree' if (tag & 0xfff) == TAG_BTREE
else 'mdir' if (tag & 0xfff) == TAG_MDIR
else 'mtree' if (tag & 0xfff) == TAG_MTREE
else 'mroot' if (tag & 0xfff) == TAG_MROOT
else 'branch' if (tag & 0xfff) == TAG_BRANCH
else 'struct 0x%02x' % (tag & 0xff),
' w%d' % w if w else '',
size)
elif (tag & 0xef00) == TAG_UATTR:
return '%suattr 0x%02x%s %d' % (
'shrub' if tag & TAG_SHRUB else '',
((tag & 0x100) >> 1) | (tag & 0xff),
' w%d' % w if w else '',
size)
elif (tag & 0xef00) == TAG_SATTR:
return '%ssattr 0x%02x%s %d' % (
'shrub' if tag & TAG_SHRUB else '',
((tag & 0x100) >> 1) | (tag & 0xff),
' w%d' % w if w else '',
size)
elif (tag & 0xff00) == TAG_CKSUM:
return 'cksum 0x%02x%s %d' % (
tag & 0xff,
' w%d' % w if w > 0 else '',
size)
elif (tag & 0xff00) == TAG_ECKSUM:
return 'ecksum%s%s %d' % (
' 0x%02x' % (tag & 0xff) if tag & 0xff else '',
' w%d' % w if w > 0 else '',
size)
elif tag & TAG_ALT:
return 'alt%s%s 0x%x w%d %s' % (
'r' if tag & TAG_R else 'b',
'gt' if tag & TAG_GT else 'le',
tag & 0x0fff,
w,
'0x%x' % (0xffffffff & (off-size))
if off is not None
else '-%d' % off)
else:
return '0x%04x w%d %d' % (tag, w, size)
def dbg_log(data, block_size, rev, eoff, weight, *,
color=False,
**args):
cksum = crc32c(data[0:4])
# preprocess jumps
if args.get('jumps'):
jumps = []
j_ = 4
while j_ < (block_size if args.get('all') else eoff):
j = j_
v, tag, w, size, d = fromtag(data[j_:])
j_ += d
if not tag & TAG_ALT:
j_ += size
if tag & TAG_ALT:
# figure out which alt color
if tag & TAG_R:
_, ntag, _, _, _ = fromtag(data[j_:])
if ntag & TAG_R:
jumps.append((j, j-size, 0, 'y'))
else:
jumps.append((j, j-size, 0, 'r'))
else:
jumps.append((j, j-size, 0, 'b'))
# figure out x-offsets to avoid collisions between jumps
for j in range(len(jumps)):
a, b, _, c = jumps[j]
x = 0
while any(
max(a, b) >= min(a_, b_)
and max(a_, b_) >= min(a, b)
and x == x_
for a_, b_, x_, _ in jumps[:j]):
x += 1
jumps[j] = a, b, x, c
def jumprepr(j):
# render jumps
chars = {}
for a, b, x, c in jumps:
c_start = (
'\x1b[33m' if color and c == 'y'
else '\x1b[31m' if color and c == 'r'
else '\x1b[90m' if color
else '')
c_stop = '\x1b[m' if color else ''
if j == a:
for x_ in range(2*x+1):
chars[x_] = '%s-%s' % (c_start, c_stop)
chars[2*x+1] = '%s\'%s' % (c_start, c_stop)
elif j == b:
for x_ in range(2*x+1):
chars[x_] = '%s-%s' % (c_start, c_stop)
chars[2*x+1] = '%s.%s' % (c_start, c_stop)
chars[0] = '%s<%s' % (c_start, c_stop)
elif j >= min(a, b) and j <= max(a, b):
chars[2*x+1] = '%s|%s' % (c_start, c_stop)
return ''.join(chars.get(x, ' ')
for x in range(max(chars.keys(), default=0)+1))
# preprocess lifetimes
lifetime_width = 0
if args.get('lifetimes'):
class Lifetime:
color_i = 0
def __init__(self, j):
self.origin = j
self.tags = set()
self.color = COLORS[self.__class__.color_i]
self.__class__.color_i = (
self.__class__.color_i + 1) % len(COLORS)
def add(self, j):
self.tags.add(j)
def __bool__(self):
return bool(self.tags)
# first figure out where each rid comes from
weights = []
lifetimes = []
def index(weights, rid):
for i, w in enumerate(weights):
if rid < w:
return i, rid
rid -= w
return len(weights), 0
checkpoint_js = [0]
checkpoints = [([], [], set(), set(), set())]
def checkpoint(j, weights, lifetimes, grows, shrinks, tags):
checkpoint_js.append(j)
checkpoints.append((
weights.copy(), lifetimes.copy(),
grows, shrinks, tags))
lower_, upper_ = 0, 0
weight_ = 0
wastrunk = False
j_ = 4
while j_ < (block_size if args.get('all') else eoff):
j = j_
v, tag, w, size, d = fromtag(data[j_:])
j_ += d
if not tag & TAG_ALT:
j_ += size
# evaluate trunks
if (tag & 0xe000) != TAG_CKSUM:
if not wastrunk:
wastrunk = True
lower_, upper_ = 0, 0
if (tag & 0xe000) == TAG_ALT:
lower_ += w
else:
upper_ += w
if not tag & TAG_ALT:
wastrunk = False
# derive the current tag's rid from alt weights
delta = (lower_+upper_) - weight_
weight_ = lower_+upper_
rid = lower_ + w-1
if (tag & 0xe000) != TAG_CKSUM and not tag & TAG_ALT:
# note we ignore out-of-bounds here for debugging
if delta > 0:
# grow lifetimes
i, rid_ = index(weights, lower_)
if rid_ > 0:
weights[i:i+1] = [rid_, delta, weights[i]-rid_]
lifetimes[i:i+1] = [
lifetimes[i], Lifetime(j), lifetimes[i]]
else:
weights[i:i] = [delta]
lifetimes[i:i] = [Lifetime(j)]
checkpoint(j, weights, lifetimes, {i}, set(), {i})
elif delta < 0:
# shrink lifetimes
i, rid_ = index(weights, lower_)
delta_ = -delta
weights_ = weights.copy()
lifetimes_ = lifetimes.copy()
shrinks = set()
while delta_ > 0 and i < len(weights_):
if weights_[i] > delta_:
delta__ = min(delta_, weights_[i]-rid_)
delta_ -= delta__
weights_[i] -= delta__
i += 1
rid_ = 0
else:
delta_ -= weights_[i]
weights_[i:i+1] = []
lifetimes_[i:i+1] = []
shrinks.add(i + len(shrinks))
checkpoint(j, weights, lifetimes, set(), shrinks, {i})
weights = weights_
lifetimes = lifetimes_
if rid >= 0:
# attach tag to lifetime
i, rid_ = index(weights, rid)
if i < len(weights):
lifetimes[i].add(j)
if delta == 0:
checkpoint(j, weights, lifetimes, set(), set(), {i})
lifetime_width = 2*max((
sum(1 for lifetime in lifetimes if lifetime)
for _, lifetimes, _, _, _ in checkpoints),
default=0)
def lifetimerepr(j):
x = bisect.bisect(checkpoint_js, j)-1
j_ = checkpoint_js[x]
weights, lifetimes, grows, shrinks, tags = checkpoints[x]
reprs = []
colors = []
was = None
for i, (w, lifetime) in enumerate(zip(weights, lifetimes)):
# skip lifetimes with no tags and shrinks
if not lifetime or (j != j_ and i in shrinks):
if i in grows or i in shrinks or i in tags:
tags = tags.copy()
tags.add(i+1)
continue
if j == j_ and i in grows:
reprs.append('.')
was = 'grow'
elif j == j_ and i in shrinks:
reprs.append('\'')
was = 'shrink'
elif j == j_ and i in tags:
reprs.append('* ')
elif was == 'grow':
reprs.append('\\ ')
elif was == 'shrink':
reprs.append('/ ')
else:
reprs.append('| ')
colors.append(lifetime.color)
return '%s%*s' % (
''.join('%s%s%s' % (
'\x1b[%sm' % c if color else '',
r,
'\x1b[m' if color else '')
for r, c in zip(reprs, colors)),
lifetime_width - sum(len(r) for r in reprs), '')
# dynamically size the id field
#
# we need to do an additional pass to find this since our rbyd weight
# does not include any shrub trees
weight_ = 0
weight__ = 0
wastrunk = False
j_ = 4
while j_ < (block_size if args.get('all') else eoff):
j = j_
v, tag, w, size, d = fromtag(data[j_:])
j_ += d
if not tag & TAG_ALT:
j_ += size
# evaluate trunks
if (tag & 0xe000) != TAG_CKSUM:
if not wastrunk:
wastrunk = True
weight__ = 0
weight__ += w
if not tag & TAG_ALT:
wastrunk = False
# found new weight?
weight_ = max(weight_, weight__)
w_width = m.ceil(m.log10(max(1, weight_)+1))
# print revision count
if args.get('raw'):
print('%8s: %*s%*s %s' % (
'%04x' % 0,
lifetime_width, '',
2*w_width+1, '',
next(xxd(data[0:4]))))
# print tags
lower_, upper_ = 0, 0
wastrunk = False
j_ = 4
while j_ < (block_size if args.get('all') else eoff):
notes = []
j = j_
v, tag, w, size, d = fromtag(data[j_:])
if v != (popc(cksum) & 1):
notes.append('v!=%x' % (popc(cksum) & 1))
cksum = crc32c(data[j_:j_+d], cksum)
j_ += d
# take care of cksums
if not tag & TAG_ALT:
if (tag & 0xff00) != TAG_CKSUM:
cksum = crc32c(data[j_:j_+size], cksum)
# found a cksum?
else:
cksum_ = fromle32(data[j_:j_+4])
if cksum != cksum_:
notes.append('cksum!=%08x' % cksum)
j_ += size
# evaluate trunks
if (tag & 0xe000) != TAG_CKSUM:
if not wastrunk:
wastrunk = True
lower_, upper_ = 0, 0
if (tag & 0xe000) == TAG_ALT:
lower_ += w
else:
upper_ += w
if not tag & TAG_ALT:
wastrunk = False
# derive the current tag's rid from alt weights
rid = lower_ + w-1
# show human-readable tag representation
print('%s%08x:%s %*s%s%*s %-*s%s%s' % (
'\x1b[90m' if color and j >= eoff else '',
j,
'\x1b[m' if color and j >= eoff else '',
lifetime_width, lifetimerepr(j) if args.get('lifetimes') else '',
'\x1b[90m' if color and j >= eoff else '',
2*w_width+1, '' if (tag & 0xe000) != 0x0000
else '%d-%d' % (rid-(w-1), rid) if w > 1
else rid,
56+w_width, '%-*s%s' % (
21+w_width, tagrepr(tag, w, size, j),
' %s' % next(xxd(
data[j+d:j+d+min(size, 8)], 8), '')
if not args.get('raw') and not args.get('no_truncate')
and not tag & TAG_ALT else ''),
'\x1b[m' if color and j >= eoff else '',
' (%s)' % ', '.join(notes) if notes
else ' %s' % jumprepr(j)
if args.get('jumps')
else ''))
# show in-device representation, including some extra
# cksum/parity info
if args.get('device'):
print('%s%8s %*s%*s %-*s %08x %x%s' % (
'\x1b[90m' if color and j >= eoff else '',
'',
lifetime_width, '',
2*w_width+1, '',
21+w_width, '%04x %08x %07x' % (tag, w, size),
cksum,
popc(cksum) & 1,
'\x1b[m' if color and j >= eoff else ''))
# show on-disk encoding of tags
if args.get('raw'):
for o, line in enumerate(xxd(data[j:j+d])):
print('%s%8s: %*s%*s %s%s' % (
'\x1b[90m' if color and j >= eoff else '',
'%04x' % (j + o*16),
lifetime_width, '',
2*w_width+1, '',
line,
'\x1b[m' if color and j >= eoff else ''))
if args.get('raw') or args.get('no_truncate'):
if not tag & TAG_ALT:
for o, line in enumerate(xxd(data[j+d:j+d+size])):
print('%s%8s: %*s%*s %s%s' % (
'\x1b[90m' if color and j >= eoff else '',
'%04x' % (j+d + o*16),
lifetime_width, '',
2*w_width+1, '',
line,
'\x1b[m' if color and j >= eoff else ''))
def dbg_tree(data, block_size, rev, trunk, weight, *,
color=False,
**args):
if not trunk:
return
# lookup a tag, returning also the search path for decoration
# purposes
def lookup(rid, tag):
lower = 0
upper = weight
path = []
# descend down tree
j = trunk
while True:
_, alt, w, jump, d = fromtag(data[j:])
# found an alt?
if alt & TAG_ALT:
# follow?
if ((rid, tag & 0xfff) > (upper-w-1, alt & 0xfff)
if alt & TAG_GT
else ((rid, tag & 0xfff) <= (lower+w-1, alt & 0xfff))):
lower += upper-lower-w if alt & TAG_GT else 0
upper -= upper-lower-w if not alt & TAG_GT else 0
j = j - jump
# figure out which color
if alt & TAG_R:
_, nalt, _, _, _ = fromtag(data[j+jump+d:])
if nalt & TAG_R:
path.append((j+jump, j, True, 'y'))
else:
path.append((j+jump, j, True, 'r'))
else:
path.append((j+jump, j, True, 'b'))
# stay on path
else:
lower += w if not alt & TAG_GT else 0
upper -= w if alt & TAG_GT else 0
j = j + d
# figure out which color
if alt & TAG_R:
_, nalt, _, _, _ = fromtag(data[j:])
if nalt & TAG_R:
path.append((j-d, j, False, 'y'))
else:
path.append((j-d, j, False, 'r'))
else:
path.append((j-d, j, False, 'b'))
# found tag
else:
rid_ = upper-1
tag_ = alt
w_ = upper-lower
done = not tag_ or (rid_, tag_) < (rid, tag)
return done, rid_, tag_, w_, j, d, jump, path
# precompute tree
t_width = 0
if args.get('tree'):
trunks = co.defaultdict(lambda: (-1, 0))
alts = co.defaultdict(lambda: {})
rid, tag = -1, 0
while True:
done, rid, tag, w, j, d, size, path = lookup(rid, tag+0x1)
# found end of tree?
if done:
break
# keep track of trunks/alts
trunks[j] = (rid, tag)
for j_, j__, followed, c in path:
if followed:
alts[j_] |= {'f': j__, 'c': c}
else:
alts[j_] |= {'nf': j__, 'c': c}
# prune any alts with unreachable edges
pruned = {}
for j_, alt in alts.items():
if 'f' not in alt:
pruned[j_] = alt['nf']
elif 'nf' not in alt:
pruned[j_] = alt['f']
for j_ in pruned.keys():
del alts[j_]
for j_, alt in alts.items():
while alt['f'] in pruned:
alt['f'] = pruned[alt['f']]
while alt['nf'] in pruned:
alt['nf'] = pruned[alt['nf']]
# find the trunk and depth of each alt, assuming pruned alts
# didn't exist
def rec_trunk(j_):
if j_ not in alts:
return trunks[j_]
else:
if 'nft' not in alts[j_]:
alts[j_]['nft'] = rec_trunk(alts[j_]['nf'])
return alts[j_]['nft']
for j_ in alts.keys():
rec_trunk(j_)
for j_, alt in alts.items():
if alt['f'] in alts:
alt['ft'] = alts[alt['f']]['nft']
else:
alt['ft'] = trunks[alt['f']]
def rec_height(j_):
if j_ not in alts:
return 0
else:
if 'h' not in alts[j_]:
alts[j_]['h'] = max(
rec_height(alts[j_]['f']),
rec_height(alts[j_]['nf'])) + 1
return alts[j_]['h']
for j_ in alts.keys():
rec_height(j_)
t_depth = max((alt['h']+1 for alt in alts.values()), default=0)
# convert to more general tree representation
TBranch = co.namedtuple('TBranch', 'a, b, d, c')
tree = set()
for j, alt in alts.items():
# note all non-trunk edges should be black
tree.add(TBranch(
a=alt['nft'],
b=alt['nft'],
d=t_depth-1 - alt['h'],
c=alt['c'],
))
tree.add(TBranch(
a=alt['nft'],
b=alt['ft'],
d=t_depth-1 - alt['h'],
c='b',
))
# find the max depth from the tree
t_depth = max((branch.d+1 for branch in tree), default=0)
if t_depth > 0:
t_width = 2*t_depth + 2
def treerepr(rid, tag):
if t_depth == 0:
return ''
def branchrepr(x, d, was):
for branch in tree:
if branch.d == d and branch.b == x:
if any(branch.d == d and branch.a == x
for branch in tree):
return '+-', branch.c, branch.c
elif any(branch.d == d
and x > min(branch.a, branch.b)
and x < max(branch.a, branch.b)
for branch in tree):
return '|-', branch.c, branch.c
elif branch.a < branch.b:
return '\'-', branch.c, branch.c
else:
return '.-', branch.c, branch.c
for branch in tree:
if branch.d == d and branch.a == x:
return '+ ', branch.c, None
for branch in tree:
if (branch.d == d
and x > min(branch.a, branch.b)
and x < max(branch.a, branch.b)):
return '| ', branch.c, was
if was:
return '--', was, was
return ' ', None, None
trunk = []
was = None
for d in range(t_depth):
t, c, was = branchrepr((rid, tag), d, was)
trunk.append('%s%s%s%s' % (
'\x1b[33m' if color and c == 'y'
else '\x1b[31m' if color and c == 'r'
else '\x1b[90m' if color and c == 'b'
else '',
t,
('>' if was else ' ') if d == t_depth-1 else '',
'\x1b[m' if color and c else ''))
return '%s ' % ''.join(trunk)
# dynamically size the id field
w_width = m.ceil(m.log10(max(1, weight)+1))
rid, tag = -1, 0
for i in it.count():
done, rid, tag, w, j, d, size, path = lookup(rid, tag+0x1)
# found end of tree?
if done:
break
# show human-readable tag representation
print('%08x: %s%s' % (
j,
treerepr(rid, tag) if args.get('tree') else '',
'%*s %-*s%s' % (
2*w_width+1, '%d-%d' % (rid-(w-1), rid)
if w > 1 else rid
if w > 0 or i == 0 else '',
21+w_width, tagrepr(tag, w, size, j),
' %s' % next(xxd(
data[j+d:j+d+min(size, 8)], 8), '')
if not args.get('raw') and not args.get('no_truncate')
and not tag & TAG_ALT else '')))
# show in-device representation
if args.get('device'):
print('%8s %*s%*s %04x %08x %07x' % (
'',
t_width, '',
2*w_width+1, '',
tag, w, size))
# show on-disk encoding of tags
if args.get('raw'):
for o, line in enumerate(xxd(data[j:j+d])):
print('%8s: %*s%*s %s' % (
'%04x' % (j + o*16),
t_width, '',
2*w_width+1, '',
line))
if args.get('raw') or args.get('no_truncate'):
if not tag & TAG_ALT:
for o, line in enumerate(xxd(data[j+d:j+d+size])):
print('%8s: %*s%*s %s' % (
'%04x' % (j+d + o*16),
t_width, '',
2*w_width+1, '',
line))
def main(disk, blocks=None, *,
block_size=None,
trunk=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
# flatten blocks, default to block 0
if not blocks:
blocks = [[0]]
blocks = [block for blocks_ in blocks for block in blocks_]
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()
# blocks may also encode trunks
blocks, trunks = (
[block[0] if isinstance(block, tuple) else block
for block in blocks],
[trunk if trunk is not None
else block[1] if isinstance(block, tuple)
else None
for block in blocks])
# read each block
datas = []
for block in blocks:
f.seek(block * block_size)
datas.append(f.read(block_size))
# first figure out which block as the most recent revision
def fetch(data, trunk):
rev = fromle32(data[0:4])
cksum = 0
cksum_ = crc32c(data[0:4])
eoff = 0
j_ = 4
trunk_ = 0
trunk__ = 0
trunk___ = 0
weight = 0
weight_ = 0
weight__ = 0
wastrunk = False
trunkeoff = None
while j_ < len(data) and (not trunk or eoff <= trunk):
v, tag, w, size, d = fromtag(data[j_:])
if v != (popc(cksum_) & 1):
break
cksum_ = crc32c(data[j_:j_+d], cksum_)
j_ += d
if not tag & TAG_ALT and j_ + size > len(data):
break
# take care of cksums
if not tag & TAG_ALT:
if (tag & 0xff00) != TAG_CKSUM:
cksum_ = crc32c(data[j_:j_+size], cksum_)
# found a cksum?
else:
cksum__ = fromle32(data[j_:j_+4])
if cksum_ != cksum__:
break
# commit what we have
eoff = trunkeoff if trunkeoff else j_ + size
cksum = cksum_
trunk_ = trunk__
weight = weight_
# evaluate trunks
if (tag & 0xe000) != TAG_CKSUM and (
not trunk or trunk >= j_-d or wastrunk):
# new trunk?
if not wastrunk:
wastrunk = True
trunk___ = j_-d
weight__ = 0
# keep track of weight
weight__ += w
# end of trunk?
if not tag & TAG_ALT:
wastrunk = False
# update trunk/weight unless we found a shrub or an
# explicit trunk (which may be a shrub) is requested
if not tag & TAG_SHRUB or trunk:
trunk__ = trunk___
weight_ = weight__
# keep track of eoff for best matching trunk
if trunk and j_ + size > trunk:
trunkeoff = j_ + size
if not tag & TAG_ALT:
j_ += size
return rev, eoff, trunk_, weight
revs, eoffs, trunks_, weights = [], [], [], []
i = 0
for i_, (data, trunk_) in enumerate(zip(datas, trunks)):
rev, eoff, trunk_, weight = fetch(data, trunk_)
revs.append(rev)
eoffs.append(eoff)
trunks_.append(trunk_)
weights.append(weight)
# compare with sequence arithmetic
if trunk_ and (
not trunks_[i]
or not ((rev - revs[i]) & 0x80000000)
or (rev == revs[i] and trunk_ > trunks_[i])):
i = i_
# print contents of the winning metadata block
block, data, rev, eoff, trunk_, weight = (
blocks[i], datas[i], revs[i], eoffs[i], trunks_[i], weights[i])
print('rbyd %s, rev %d, size %d, weight %d' % (
'0x%x.%x' % (block, trunk_)
if len(blocks) == 1
else '0x{%x,%s}.%x' % (
block,
','.join('%x' % blocks[(i+1+j) % len(blocks)]
for j in range(len(blocks)-1)),
trunk_),
rev, eoff, weight))
if args.get('log'):
dbg_log(data, block_size, rev, eoff, weight,
color=color,
**args)
else:
dbg_tree(data, block_size, rev, trunk_, weight,
color=color,
**args)
if args.get('error_on_corrupt') and eoff == 0:
sys.exit(2)
if __name__ == "__main__":
import argparse
import sys
parser = argparse.ArgumentParser(
description="Debug rbyd metadata.",
allow_abbrev=False)
parser.add_argument(
'disk',
help="File containing the block device.")
parser.add_argument(
'blocks',
nargs='*',
type=rbydaddr,
help="Block address of metadata blocks.")
parser.add_argument(
'-B', '--block-size',
type=lambda x: int(x, 0),
help="Block size in bytes.")
parser.add_argument(
'--trunk',
type=lambda x: int(x, 0),
help="Use this offset as the trunk of the tree.")
parser.add_argument(
'--color',
choices=['never', 'always', 'auto'],
default='auto',
help="When to use terminal colors. Defaults to 'auto'.")
parser.add_argument(
'-a', '--all',
action='store_true',
help="Don't stop parsing on bad commits.")
parser.add_argument(
'-l', '--log',
action='store_true',
help="Show the raw tags as they appear in the log.")
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(
'-t', '--tree',
action='store_true',
help="Show the rbyd tree.")
parser.add_argument(
'-j', '--jumps',
action='store_true',
help="Show alt pointer jumps in the margin.")
parser.add_argument(
'-g', '--lifetimes',
action='store_true',
help="Show inserts/deletes of ids in the margin.")
parser.add_argument(
'-e', '--error-on-corrupt',
action='store_true',
help="Error if no valid commit is found.")
sys.exit(main(**{k: v
for k, v in vars(parser.parse_intermixed_args()).items()
if v is not None}))
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