forked from Imagelibrary/littlefs
8a4f6fcf68
The previous cksum + parity scheme worked, but needing to calculate both
cksum + parity on slightly different sets of metadata felt overly
complicated. After taking a step back, I've realized the problem is that
we're trying to force perturb effects to be implicit via the parity. If we
instead actually implement perturb effects explicitly, things get quite
a bit simpler...
This does add a bit more logic to the read path, but I don't think it's
worse than the mess we needed to parse separate cksum + parity.
Now, the perturb bit has the explicit behavior of inverting all tag
valid bits in the following commit. Which is conveniently the same as
xoring the crc32c with 00000080 before parsing each tag:
.---+---+---+---. . . .---+---+---+---. \ \ \ \
|v| tag | |v| tag | | | | |
+---+---+---+---+ +---+---+---+---+ | | | |
| commit | | commit | | | | |
| | | | +-. | | |
+---+---+---+---+ +---+---+---+---+ / | | | |
|v|p--------------. |v|p| tag | | . . .
+---+---+---+---+ | +---+---+---+---+ | . . .
| cksum | | | cksum | | . . .
+---+---+---+---+ | +---+---+---+---+ | . . .
| padding | | | padding | | . . .
| | | | | | . . .
+---+---+---+---+ | . +---+---+---+---+ | | | |
| erased | +-> |v------------------' | | |
| | | +---+---+---+---+ | | |
. . | | commit | +-. | +- rbyd
. . | | | | | | | cksum
| +---+---+---+---+ / | +-. /
'-> |v----------------------' | |
+---+---+---+---+ / |
| cksum ----------------'
+---+---+---+---+
| padding |
| |
+---+---+---+---+
| erased |
| |
. .
. .
With this scheme, we don't need to calculate a separate parity, because
each valid bit effectively validates the current state of the perturb
bit.
We also don't need extra logic to omit valid bits from the cksum,
because flipping all valid bits effectively makes perturb=0 the
canonical metadata encoding and cksum.
---
I also considered only inverting the first valid bit, which would have
the additional benefit of allowing entire commits to be crc32ced at
once, but since we don't actually track when we've started a commit
this turned out to be quite a bit more complicated than I thought.
We need someway to validate the first valid bit, otherwise it could be
flipped by a failed prog and we'd never notice. This is fine, we can
store a copy of the previous perturb bit in the next cksum tag, but it
does mean we need to track the perturb bit for the duration of the
commit. So we'd end up needing to track both start-of-commit and the
perturb bit state, which starts getting difficult to fit into our rbyd
struct...
It's easier and simpler to just flip every valid bit. As a plus this
means every valid bit contributes to validating the perturb bit.
---
Also renamed LFSR_TAG_PERTURB -> LFSR_TAG_NOISE just to avoid confusion.
Though not sure if this tag should stick around...
The end result is a nice bit of code/stack savings, which is what we'd
expect with a simpler scheme:
code stack
before: 33746 2600
after: 33570 (-0.5%) 2592 (-0.3%)
1136 lines
37 KiB
Python
Executable File
1136 lines
37 KiB
Python
Executable File
#!/usr/bin/env python3
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import bisect
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import collections as co
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import itertools as it
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import math as m
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import os
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import struct
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COLORS = [
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'34', # blue
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'31', # red
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'32', # green
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'35', # purple
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'33', # yellow
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'36', # cyan
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]
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TAG_NULL = 0x0000
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TAG_CONFIG = 0x0000
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TAG_MAGIC = 0x0003
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TAG_VERSION = 0x0004
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TAG_RCOMPAT = 0x0005
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TAG_WCOMPAT = 0x0006
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TAG_OCOMPAT = 0x0007
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TAG_GEOMETRY = 0x0009
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TAG_NAMELIMIT = 0x000c
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TAG_FILELIMIT = 0x000d
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TAG_GDELTA = 0x0100
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TAG_GRMDELTA = 0x0100
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TAG_NAME = 0x0200
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TAG_REG = 0x0201
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TAG_DIR = 0x0202
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TAG_BOOKMARK = 0x0204
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TAG_ORPHAN = 0x0205
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TAG_STRUCT = 0x0300
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TAG_DATA = 0x0300
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TAG_BLOCK = 0x0304
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TAG_BSHRUB = 0x0308
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TAG_BTREE = 0x030c
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TAG_MROOT = 0x0311
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TAG_MDIR = 0x0315
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TAG_MTREE = 0x031c
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TAG_DID = 0x0320
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TAG_BRANCH = 0x032c
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TAG_UATTR = 0x0400
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TAG_SATTR = 0x0600
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TAG_SHRUB = 0x1000
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TAG_ALT = 0x4000
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TAG_B = 0x0000
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TAG_R = 0x2000
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TAG_LE = 0x0000
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TAG_GT = 0x1000
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TAG_CKSUM = 0x3000
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TAG_Q = 0x0000
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TAG_P = 0x0001
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TAG_NOISE = 0x3100
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TAG_ECKSUM = 0x3200
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# some ways of block geometry representations
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# 512 -> 512
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# 512x16 -> (512, 16)
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# 0x200x10 -> (512, 16)
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def bdgeom(s):
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s = s.strip()
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b = 10
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if s.startswith('0x') or s.startswith('0X'):
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s = s[2:]
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b = 16
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elif s.startswith('0o') or s.startswith('0O'):
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s = s[2:]
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b = 8
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elif s.startswith('0b') or s.startswith('0B'):
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s = s[2:]
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b = 2
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if 'x' in s:
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s, s_ = s.split('x', 1)
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return (int(s, b), int(s_, b))
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else:
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return int(s, b)
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# parse some rbyd addr encodings
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# 0xa -> [0xa]
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# 0xa.c -> [(0xa, 0xc)]
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# 0x{a,b} -> [0xa, 0xb]
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# 0x{a,b}.c -> [(0xa, 0xc), (0xb, 0xc)]
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def rbydaddr(s):
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s = s.strip()
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b = 10
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if s.startswith('0x') or s.startswith('0X'):
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s = s[2:]
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b = 16
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elif s.startswith('0o') or s.startswith('0O'):
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s = s[2:]
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b = 8
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elif s.startswith('0b') or s.startswith('0B'):
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s = s[2:]
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b = 2
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trunk = None
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if '.' in s:
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s, s_ = s.split('.', 1)
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trunk = int(s_, b)
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if s.startswith('{') and '}' in s:
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ss = s[1:s.find('}')].split(',')
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else:
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ss = [s]
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addr = []
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for s in ss:
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if trunk is not None:
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addr.append((int(s, b), trunk))
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else:
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addr.append(int(s, b))
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return addr
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def crc32c(data, crc=0):
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crc ^= 0xffffffff
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for b in data:
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crc ^= b
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for j in range(8):
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crc = (crc >> 1) ^ ((crc & 1) * 0x82f63b78)
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return 0xffffffff ^ crc
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def popc(x):
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return bin(x).count('1')
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def parity(x):
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return popc(x) & 1
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def fromle32(data):
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return struct.unpack('<I', data[0:4].ljust(4, b'\0'))[0]
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def fromleb128(data):
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word = 0
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for i, b in enumerate(data):
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word |= ((b & 0x7f) << 7*i)
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word &= 0xffffffff
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if not b & 0x80:
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return word, i+1
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return word, len(data)
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def fromtag(data):
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data = data.ljust(4, b'\0')
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tag = (data[0] << 8) | data[1]
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weight, d = fromleb128(data[2:])
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size, d_ = fromleb128(data[2+d:])
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return tag>>15, tag&0x7fff, weight, size, 2+d+d_
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def xxd(data, width=16):
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for i in range(0, len(data), width):
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yield '%-*s %-*s' % (
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3*width,
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' '.join('%02x' % b for b in data[i:i+width]),
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width,
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''.join(
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b if b >= ' ' and b <= '~' else '.'
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for b in map(chr, data[i:i+width])))
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def tagrepr(tag, w=None, size=None, off=None):
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if (tag & 0x6fff) == TAG_NULL:
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return '%snull%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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' w%d' % w if w else '',
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' %d' % size if size else '')
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elif (tag & 0x6f00) == TAG_CONFIG:
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return '%s%s%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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'magic' if (tag & 0xfff) == TAG_MAGIC
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else 'version' if (tag & 0xfff) == TAG_VERSION
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else 'rcompat' if (tag & 0xfff) == TAG_RCOMPAT
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else 'wcompat' if (tag & 0xfff) == TAG_WCOMPAT
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else 'ocompat' if (tag & 0xfff) == TAG_OCOMPAT
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else 'geometry' if (tag & 0xfff) == TAG_GEOMETRY
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else 'namelimit' if (tag & 0xfff) == TAG_NAMELIMIT
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else 'filelimit' if (tag & 0xfff) == TAG_FILELIMIT
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else 'config 0x%02x' % (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x6f00) == TAG_GDELTA:
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return '%s%s%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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'grmdelta' if (tag & 0xfff) == TAG_GRMDELTA
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else 'gdelta 0x%02x' % (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x6f00) == TAG_NAME:
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return '%s%s%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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'name' if (tag & 0xfff) == TAG_NAME
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else 'reg' if (tag & 0xfff) == TAG_REG
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else 'dir' if (tag & 0xfff) == TAG_DIR
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else 'orphan' if (tag & 0xfff) == TAG_ORPHAN
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else 'bookmark' if (tag & 0xfff) == TAG_BOOKMARK
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else 'name 0x%02x' % (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x6f00) == TAG_STRUCT:
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return '%s%s%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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'data' if (tag & 0xfff) == TAG_DATA
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else 'block' if (tag & 0xfff) == TAG_BLOCK
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else 'bshrub' if (tag & 0xfff) == TAG_BSHRUB
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else 'btree' if (tag & 0xfff) == TAG_BTREE
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else 'mroot' if (tag & 0xfff) == TAG_MROOT
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else 'mdir' if (tag & 0xfff) == TAG_MDIR
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else 'mtree' if (tag & 0xfff) == TAG_MTREE
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else 'did' if (tag & 0xfff) == TAG_DID
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else 'branch' if (tag & 0xfff) == TAG_BRANCH
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else 'struct 0x%02x' % (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x6e00) == TAG_UATTR:
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return '%suattr 0x%02x%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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((tag & 0x100) >> 1) | (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x6e00) == TAG_SATTR:
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return '%ssattr 0x%02x%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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((tag & 0x100) >> 1) | (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif tag & TAG_ALT:
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return 'alt%s%s%s%s%s' % (
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'r' if tag & TAG_R else 'b',
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'a' if tag & 0x0fff == 0 and tag & TAG_GT
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else 'n' if tag & 0x0fff == 0
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else 'gt' if tag & TAG_GT
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else 'le',
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' 0x%x' % (tag & 0x0fff) if tag & 0x0fff != 0 else '',
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' w%d' % w if w is not None else '',
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' 0x%x' % (0xffffffff & (off-size))
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if size and off is not None
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else ' -%d' % size if size
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else '')
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elif (tag & 0x7f00) == TAG_CKSUM:
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return 'cksum%s%s%s' % (
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'p' if tag & 0xff == TAG_P
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else 'q' if tag & 0xff == TAG_Q
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else ' 0x%02x' % (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x7f00) == TAG_NOISE:
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return 'noise%s%s%s' % (
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' 0x%02x' % (tag & 0xff) if tag & 0xff else '',
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x7f00) == TAG_ECKSUM:
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return 'ecksum%s%s%s' % (
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' 0x%02x' % (tag & 0xff) if tag & 0xff else '',
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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else:
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return '0x%04x%s%s' % (
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tag,
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' w%d' % w if w is not None else '',
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' %d' % size if size is not None else '')
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def dbg_log(data, block_size, rev, eoff, weight, *,
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color=False,
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**args):
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# preprocess jumps
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if args.get('jumps'):
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jumps = []
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j_ = 4
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while j_ < (block_size if args.get('all') else eoff):
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j = j_
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v, tag, w, size, d = fromtag(data[j_:])
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j_ += d
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if not tag & TAG_ALT:
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j_ += size
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if tag & TAG_ALT and size:
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# figure out which alt color
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if tag & TAG_R:
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_, ntag, _, _, _ = fromtag(data[j_:])
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if ntag & TAG_R:
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jumps.append((j, j-size, 0, 'y'))
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else:
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jumps.append((j, j-size, 0, 'r'))
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else:
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jumps.append((j, j-size, 0, 'b'))
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# figure out x-offsets to avoid collisions between jumps
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for j in range(len(jumps)):
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a, b, _, c = jumps[j]
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x = 0
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while any(
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max(a, b) >= min(a_, b_)
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and max(a_, b_) >= min(a, b)
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and x == x_
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for a_, b_, x_, _ in jumps[:j]):
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x += 1
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jumps[j] = a, b, x, c
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def jumprepr(j):
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# render jumps
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chars = {}
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for a, b, x, c in jumps:
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c_start = (
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'\x1b[33m' if color and c == 'y'
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else '\x1b[31m' if color and c == 'r'
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else '\x1b[90m' if color
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else '')
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c_stop = '\x1b[m' if color else ''
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if j == a:
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for x_ in range(2*x+1):
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chars[x_] = '%s-%s' % (c_start, c_stop)
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chars[2*x+1] = '%s\'%s' % (c_start, c_stop)
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elif j == b:
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for x_ in range(2*x+1):
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chars[x_] = '%s-%s' % (c_start, c_stop)
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chars[2*x+1] = '%s.%s' % (c_start, c_stop)
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chars[0] = '%s<%s' % (c_start, c_stop)
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elif j >= min(a, b) and j <= max(a, b):
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chars[2*x+1] = '%s|%s' % (c_start, c_stop)
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return ''.join(chars.get(x, ' ')
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for x in range(max(chars.keys(), default=0)+1))
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# preprocess lifetimes
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lifetime_width = 0
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if args.get('lifetimes'):
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class Lifetime:
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color_i = 0
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def __init__(self, j):
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self.origin = j
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self.tags = set()
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self.color = COLORS[self.__class__.color_i]
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self.__class__.color_i = (
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self.__class__.color_i + 1) % len(COLORS)
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def add(self, j):
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self.tags.add(j)
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def __bool__(self):
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return bool(self.tags)
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# first figure out where each rid comes from
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weights = []
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lifetimes = []
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def index(weights, rid):
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for i, w in enumerate(weights):
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if rid < w:
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return i, rid
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rid -= w
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return len(weights), 0
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checkpoint_js = [0]
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checkpoints = [([], [], set(), set(), set())]
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def checkpoint(j, weights, lifetimes, grows, shrinks, tags):
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checkpoint_js.append(j)
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checkpoints.append((
|
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weights.copy(), lifetimes.copy(),
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grows, shrinks, tags))
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lower_, upper_ = 0, 0
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weight_ = 0
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trunk_ = 0
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j_ = 4
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while j_ < (block_size if args.get('all') else eoff):
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j = j_
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v, tag, w, size, d = fromtag(data[j_:])
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j_ += d
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if not tag & TAG_ALT:
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j_ += size
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|
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# evaluate trunks
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if (tag & 0xf000) != TAG_CKSUM:
|
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if not trunk_:
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trunk_ = j_-d
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lower_, upper_ = 0, 0
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|
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if tag & TAG_ALT and not tag & TAG_GT:
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lower_ += w
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else:
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upper_ += w
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|
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if not tag & TAG_ALT:
|
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# derive the current tag's rid from alt weights
|
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delta = (lower_+upper_) - weight_
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weight_ = lower_+upper_
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rid = lower_ + w-1
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trunk_ = 0
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|
|
|
if (tag & 0xf000) != TAG_CKSUM and not tag & TAG_ALT:
|
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# note we ignore out-of-bounds here for debugging
|
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if delta > 0:
|
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# grow lifetimes
|
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i, rid_ = index(weights, lower_)
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if rid_ > 0:
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weights[i:i+1] = [rid_, delta, weights[i]-rid_]
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lifetimes[i:i+1] = [
|
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lifetimes[i], Lifetime(j), lifetimes[i]]
|
|
else:
|
|
weights[i:i] = [delta]
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lifetimes[i:i] = [Lifetime(j)]
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|
|
checkpoint(j, weights, lifetimes, {i}, set(), {i})
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|
|
|
elif delta < 0:
|
|
# shrink lifetimes
|
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i, rid_ = index(weights, lower_)
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delta_ = -delta
|
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weights_ = weights.copy()
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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
|
|
trunk_ = 0
|
|
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 & 0xf000) != TAG_CKSUM:
|
|
if not trunk_:
|
|
trunk_ = j_-d
|
|
weight__ = 0
|
|
|
|
weight__ += w
|
|
|
|
if not tag & TAG_ALT:
|
|
# found new weight?
|
|
weight_ = max(weight_, weight__)
|
|
trunk_ = 0
|
|
|
|
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
|
|
cksum = crc32c(data[0:4])
|
|
cksum_ = cksum
|
|
perturb = False
|
|
lower_, upper_ = 0, 0
|
|
trunk_ = 0
|
|
j_ = 4
|
|
while j_ < (block_size if args.get('all') else eoff):
|
|
notes = []
|
|
|
|
# perturb?
|
|
if perturb:
|
|
cksum_ ^= 0x00000080
|
|
|
|
# read next tag
|
|
j = j_
|
|
v, tag, w, size, d = fromtag(data[j_:])
|
|
if v != parity(cksum_):
|
|
notes.append('v!=%x' % parity(cksum_))
|
|
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__)
|
|
# update perturb bit
|
|
perturb = tag & TAG_P
|
|
# revert to data cksum
|
|
cksum_ = cksum
|
|
j_ += size
|
|
|
|
# evaluate trunks
|
|
if (tag & 0xf000) != TAG_CKSUM:
|
|
if not trunk_:
|
|
trunk_ = j_-d
|
|
lower_, upper_ = 0, 0
|
|
|
|
if tag & TAG_ALT and not tag & TAG_GT:
|
|
lower_ += w
|
|
else:
|
|
upper_ += w
|
|
|
|
if not tag & TAG_ALT:
|
|
# update data checksum
|
|
cksum = cksum_
|
|
# derive the current tag's rid from alt weights
|
|
rid = lower_ + w-1
|
|
trunk_ = 0
|
|
|
|
# show human-readable tag representation
|
|
print('%s%08x:%s %*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),
|
|
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 ''),
|
|
' (%s)' % ', '.join(notes) if notes else '',
|
|
'\x1b[m' if color and j >= eoff else '',
|
|
' %s' % jumprepr(j)
|
|
if args.get('jumps') and not notes 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):
|
|
tag = max(tag, 0x1)
|
|
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') or args.get('rbyd'):
|
|
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}
|
|
|
|
if args.get('rbyd'):
|
|
# treat unreachable alts as converging paths
|
|
for j_, alt in alts.items():
|
|
if 'f' not in alt:
|
|
alt['f'] = alt['nf']
|
|
elif 'nf' not in alt:
|
|
alt['nf'] = alt['f']
|
|
|
|
else:
|
|
# 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
|
|
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'],
|
|
))
|
|
if alt['ft'] != alt['nft']:
|
|
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 %-*s %s' % (
|
|
j,
|
|
treerepr(rid, tag)
|
|
if args.get('tree') or args.get('rbyd') else '',
|
|
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),
|
|
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 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,
|
|
block_count=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
|
|
|
|
# is bd geometry specified?
|
|
if isinstance(block_size, tuple):
|
|
block_size, block_count_ = block_size
|
|
if block_count is None:
|
|
block_count = block_count_
|
|
|
|
# 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])
|
|
cksum__ = cksum_
|
|
perturb = False
|
|
eoff = 0
|
|
eoff_ = None
|
|
j_ = 4
|
|
trunk_ = 0
|
|
trunk__ = 0
|
|
trunk___ = 0
|
|
weight = 0
|
|
weight_ = 0
|
|
weight__ = 0
|
|
while j_ < len(data) and (not trunk or eoff <= trunk):
|
|
# perturb?
|
|
if perturb:
|
|
cksum__ ^= 0x00000080
|
|
|
|
# read next tag
|
|
v, tag, w, size, d = fromtag(data[j_:])
|
|
if v != parity(cksum__):
|
|
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 = eoff_ if eoff_ else j_ + size
|
|
cksum = cksum_
|
|
trunk_ = trunk__
|
|
weight = weight_
|
|
# update perturb bit
|
|
perturb = tag & TAG_P
|
|
# revert to data cksum
|
|
cksum__ = cksum_
|
|
|
|
# evaluate trunks
|
|
if (tag & 0xf000) != TAG_CKSUM and (
|
|
not trunk or j_-d <= trunk or trunk___):
|
|
# new trunk?
|
|
if not trunk___:
|
|
trunk___ = j_-d
|
|
weight__ = 0
|
|
|
|
# keep track of weight
|
|
weight__ += w
|
|
|
|
# end of trunk?
|
|
if not tag & TAG_ALT:
|
|
# update data checksum
|
|
cksum_ = cksum__
|
|
# 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__ = trunk___
|
|
weight_ = weight__
|
|
# keep track of eoff for best matching trunk
|
|
if trunk and j_ + size > trunk:
|
|
eoff_ = j_ + size
|
|
eoff = eoff_
|
|
cksum = cksum_
|
|
trunk_ = trunk__
|
|
weight = weight_
|
|
trunk___ = 0
|
|
|
|
if not tag & TAG_ALT:
|
|
j_ += size
|
|
|
|
return rev, eoff, trunk_, weight, cksum
|
|
|
|
revs, eoffs, trunks_, weights, cksums = [], [], [], [], []
|
|
i = 0
|
|
for i_, (data, trunk_) in enumerate(zip(datas, trunks)):
|
|
rev, eoff, trunk_, weight, cksum = fetch(data, trunk_)
|
|
revs.append(rev)
|
|
eoffs.append(eoff)
|
|
trunks_.append(trunk_)
|
|
weights.append(weight)
|
|
cksums.append(cksum)
|
|
|
|
# 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, cksum = (
|
|
blocks[i],
|
|
datas[i],
|
|
revs[i],
|
|
eoffs[i],
|
|
trunks_[i],
|
|
weights[i],
|
|
cksums[i])
|
|
|
|
print('rbyd %s w%d, rev %08x, size %d, cksum %08x' % (
|
|
'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_),
|
|
weight,
|
|
rev,
|
|
eoff,
|
|
cksum))
|
|
|
|
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=bdgeom,
|
|
help="Block size/geometry in bytes.")
|
|
parser.add_argument(
|
|
'--block-count',
|
|
type=lambda x: int(x, 0),
|
|
help="Block count in blocks.")
|
|
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(
|
|
'-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(
|
|
'-R', '--rbyd',
|
|
action='store_true',
|
|
help="Show the full 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}))
|