mirror of
https://opendev.org/x/pyghmi
synced 2025-03-19 09:57:43 +00:00
Switch to faster EFI decompressor
The pure python EFI decompressor was extraordinarily slow. Dramatically improve performance by switching to the C version of the function. Change-Id: Ib931d46a4b5b4937cb8dfc3d37bfa63b92e84ead
This commit is contained in:
Jarrod Johnson
parent
22133c4aca
commit
d61f6d5e6e
@ -1,199 +0,0 @@
|
||||
# Licensed under the Apache License, Version 2.0 (the "License");
|
||||
# you may not use this file except in compliance with the License.
|
||||
# You may obtain a copy of the License at
|
||||
#
|
||||
# http://www.apache.org/licenses/LICENSE-2.0
|
||||
#
|
||||
# Unless required by applicable law or agreed to in writing, software
|
||||
# distributed under the License is distributed on an "AS IS" BASIS,
|
||||
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
# See the License for the specific language governing permissions and
|
||||
# limitations under the License.
|
||||
|
||||
import struct
|
||||
|
||||
try:
|
||||
range = xrange
|
||||
except NameError:
|
||||
pass
|
||||
|
||||
|
||||
class BitArray(object):
|
||||
def __init__(self, data):
|
||||
self._Data = bytearray(data)
|
||||
|
||||
self._DataBitsLeft = len(data) * 8
|
||||
|
||||
self._ByteIdx = 0
|
||||
self._BitIdx = 0
|
||||
|
||||
@staticmethod
|
||||
def mask(bitcount):
|
||||
return (1 << bitcount) - 1
|
||||
|
||||
def read(self, bitsleftcount):
|
||||
|
||||
result = 0
|
||||
while bitsleftcount:
|
||||
curbitsleftcount = 8 - self._BitIdx
|
||||
curdata = self._Data[self._ByteIdx] & self.mask(
|
||||
curbitsleftcount)
|
||||
|
||||
if curbitsleftcount >= bitsleftcount:
|
||||
result <<= bitsleftcount
|
||||
result |= curdata >> (curbitsleftcount - bitsleftcount)
|
||||
self._BitIdx += bitsleftcount
|
||||
bitsleftcount = 0
|
||||
else:
|
||||
result <<= curbitsleftcount
|
||||
result |= curdata
|
||||
bitsleftcount -= curbitsleftcount
|
||||
self._BitIdx += curbitsleftcount
|
||||
|
||||
if self._BitIdx >= 8:
|
||||
self._BitIdx = 0
|
||||
self._ByteIdx += 1
|
||||
|
||||
return result
|
||||
|
||||
|
||||
def loadhuffmansyms(bits, symscountbits, zeroskipidx):
|
||||
symscount = bits.read(symscountbits)
|
||||
if symscount == 0:
|
||||
v = bits.read(symscountbits)
|
||||
huffsyms = [[v, 1, 0], [v, 1, 1]]
|
||||
else:
|
||||
# Decode the horrible bit length encoding thing!
|
||||
huffsyms = []
|
||||
idx = 0
|
||||
while idx < symscount:
|
||||
bitlen = bits.read(3)
|
||||
if bitlen == 7:
|
||||
while bits.read(1):
|
||||
bitlen += 1
|
||||
if bitlen != 0:
|
||||
huffsyms += ([idx, bitlen, None],)
|
||||
idx += 1
|
||||
|
||||
# decode the extra special nasty zero-skip hack!
|
||||
if idx == zeroskipidx:
|
||||
idx += bits.read(2)
|
||||
|
||||
# Now, sort them by bit length
|
||||
huffsyms = sorted(huffsyms, key=lambda length: length[1])
|
||||
|
||||
# Allocate huffman codes to the length-ordered symbols
|
||||
huffsyms[0][2] = 0
|
||||
for idx in range(1, len(huffsyms)):
|
||||
huffsyms[idx][2] = (huffsyms[idx - 1][2] + 1) << (
|
||||
huffsyms[idx][1] - huffsyms[idx - 1][1])
|
||||
|
||||
return huffsyms
|
||||
|
||||
|
||||
def buildhuffmantree(huffsyms):
|
||||
hufftree = [None, None]
|
||||
for huffsym in huffsyms:
|
||||
symbol = huffsym[0]
|
||||
bitlen = huffsym[1]
|
||||
huffcode = huffsym[2]
|
||||
if bitlen == 0:
|
||||
continue
|
||||
|
||||
huffsubtree = hufftree
|
||||
for bit in range(0, bitlen):
|
||||
lr = huffcode & (1 << (bitlen - bit - 1)) != 0
|
||||
|
||||
if bit < bitlen - 1:
|
||||
if huffsubtree[lr] is None:
|
||||
huffsubtree[lr] = [None, None]
|
||||
huffsubtree = huffsubtree[lr]
|
||||
else:
|
||||
huffsubtree[lr] = symbol
|
||||
return hufftree
|
||||
|
||||
|
||||
def huffmandecode(hufftree, bits):
|
||||
while type(hufftree) == list:
|
||||
hufftree = hufftree[bits.read(1)]
|
||||
return hufftree
|
||||
|
||||
|
||||
def loadcharlenhuffmansyms(bits, extra_hufftree):
|
||||
symscount = bits.read(9)
|
||||
|
||||
if symscount == 0:
|
||||
v = bits.read(9)
|
||||
huffsyms = [[v, 1, 0], [v, 1, 1]]
|
||||
else:
|
||||
# Decode the horrible bit length encoding thing!
|
||||
huffsyms = []
|
||||
idx = 0
|
||||
while idx < symscount:
|
||||
bitlen = huffmandecode(extra_hufftree, bits)
|
||||
|
||||
if bitlen == 0:
|
||||
bitlen = 0
|
||||
elif bitlen == 1:
|
||||
idx += bits.read(4) + 3 - 1
|
||||
bitlen = 0
|
||||
elif bitlen == 2:
|
||||
idx += bits.read(9) + 20 - 1
|
||||
bitlen = 0
|
||||
else:
|
||||
bitlen -= 2
|
||||
|
||||
if bitlen != 0:
|
||||
huffsyms += ([idx, bitlen, None],)
|
||||
|
||||
idx += 1
|
||||
|
||||
# Now, sort them by bit length
|
||||
huffsyms = sorted(huffsyms, key=lambda length: length[1])
|
||||
|
||||
# Allocate huffman codes to the length-ordered symbols
|
||||
huffsyms[0][2] = 0
|
||||
for idx in range(1, len(huffsyms)):
|
||||
huffsyms[idx][2] = (huffsyms[idx - 1][2] + 1) << (
|
||||
huffsyms[idx][1] - huffsyms[idx - 1][1])
|
||||
|
||||
return huffsyms
|
||||
|
||||
|
||||
def decompress(buf):
|
||||
(compressed_size, decompressed_size) = struct.unpack("<II", buf[0:8])
|
||||
bits = BitArray(buf[8:])
|
||||
|
||||
outbuf = bytearray()
|
||||
blocksize = 0
|
||||
charlen_hufftree = None
|
||||
positionset_hufftree = None
|
||||
while decompressed_size:
|
||||
if blocksize == 0:
|
||||
blocksize = bits.read(16)
|
||||
extra_hufftree = buildhuffmantree(loadhuffmansyms(bits, 5, 3))
|
||||
charlen_hufftree = buildhuffmantree(
|
||||
loadcharlenhuffmansyms(bits, extra_hufftree))
|
||||
|
||||
positionset_hufftree = buildhuffmantree(
|
||||
loadhuffmansyms(bits, 5, -1))
|
||||
|
||||
c = huffmandecode(charlen_hufftree, bits)
|
||||
blocksize -= 1
|
||||
if c < 256:
|
||||
outbuf.append(c)
|
||||
decompressed_size -= 1
|
||||
else:
|
||||
data_length = (c & 0xff) + 3
|
||||
pos_bitlen = huffmandecode(positionset_hufftree, bits)
|
||||
data_offset = pos_bitlen
|
||||
if pos_bitlen > 1:
|
||||
data_offset = (1 << (pos_bitlen - 1)) + bits.read(
|
||||
pos_bitlen - 1)
|
||||
data_idx = len(outbuf) - data_offset - 1
|
||||
|
||||
for i in range(0, data_length):
|
||||
outbuf.append(outbuf[data_idx + i])
|
||||
decompressed_size -= data_length
|
||||
|
||||
return bytes(outbuf)
|
||||
@ -24,7 +24,6 @@ import struct
|
||||
import six
|
||||
|
||||
import pyghmi.exceptions as pygexc
|
||||
from pyghmi.ipmi.oem.lenovo import EfiDecompressor
|
||||
|
||||
try:
|
||||
import EfiCompressor
|
||||
@ -260,7 +259,7 @@ class LenovoFirmwareConfig(object):
|
||||
size = self.imm_size(cfgfilename)
|
||||
data = self.imm_read(filehandle, size)
|
||||
self.imm_close(filehandle)
|
||||
data = EfiDecompressor.decompress(data)
|
||||
data = EfiCompressor.FrameworkDecompress(data, len(data))
|
||||
if len(data) != 0:
|
||||
break
|
||||
self.connection.ipmi_session.pause(2)
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user