我正在使用 LZ77 压缩程序，当我尝试压缩 116Kb 文件时，处理时间太长。我的代码有什么问题吗？我怎样才能提高算法的处理时间？
import fileinput
class Assign:
def pattern(self, data):
self.skip = []
self.m = len(data)
for k in range(256): self.skip.append(self.m)
for k in range(self.m - 1): self.skip[ord(data[k])] = self.m - k - 1
self.skip = tuple(self.skip)
self.data = data
def find(self, text):
n = len(text)
if self.m > n: return -1
k = self.m - 1
while k < n:
j = self.m - 1; i = k
while j >= 0 and text[i] == self.data[j]:
j -= 1; i -= 1
if j == -1: return i + 1
k += self.skip[ord(text[k])]
return -1
class LZ77:
def __init__(self, data):
self.position = 0
self.window = ""
self.stream = data
self.streamSize = len(self.stream)
self.search = Assign()
def Encode(self):
p = 0
c = ''
lastresult = 0
found = 0
for i in range(self.streamSize):
self.search.pattern(self.stream[self.position:self.position+i+1])
result = self.search.find(self.window)
if result < 0: break
lastresult = result
found = 1
c = self.stream[self.position+i]
p = lastresult
B = 0
if i > 0: B = self.position - p
L = i
if self.streamSize > 0:
self.position += i + 1
self.streamSize -= i + 1
self.window = self.stream[:self.position]
#print B,L,c
return ((B, L), c)
def Encoder(self):
output = ""
length = self.streamSize
while self.streamSize > 0:
((B, L), C) = self.Encode()
output += str(B) + str(L) + C
return (output)
def aiyoo(#filename):
enter = raw_input("enter the filename to which the original file is to be compressed to")
enter1 = enter
fob1 = open(enter,'wb')
original = ''
print filename
#fob = open(filename,'rb')
#numlines = 0
"""while True:
c = fob.read(1)
if not c:
print "End of file"
break
else :"""
for line in fileinput.input(['hello.txt']): #size of hello.txt is 116kb
original = line
lz = LZ77(original)
stream = lz.Encoder()#, streamSize = lz.Encoder()
fob1.write(stream)
"""for i in fob:
original = i
lz = LZ77(original)
stream = lz.Encoder()#, streamSize = lz.Encoder()
fob1.write(stream)"""
#fob.close()
fob1.close()
return enter