tests with python2.6 and python3 show that it's much quicker to get
the handles after the inser/deleted index and upgrade those
(because random-access in a hash-table is super fast)
Here is the code use for tests:
import string,random,sys
import timeit
def id_generator(size=6, chars=string.ascii_lowercase):
return ''.join(random.choice(chars) for _ in range(size))
num_items=80000
handle_sizes=10
num_operation=2000
setup="""
from __main__ import id_generator,string,num_items,handle_sizes,random
_index2hndl=[("",id_generator(handle_sizes)) for e in range (num_items)]
_hndl2index=dict([key[1], index]
for index, key in enumerate(_index2hndl))
"""
add0='''
h=id_generator(handle_sizes)
insert_pos= random.randrange(len(_hndl2index))
srtkey_hndl=("",h)
_index2hndl.insert(insert_pos, srtkey_hndl)
for hndl, index in _hndl2index.iteritems():
if index >= insert_pos:
_hndl2index[hndl] += 1
_hndl2index[h]=insert_pos
'''
add1='''
h=id_generator(handle_sizes)
insert_pos= random.randrange(len(_hndl2index))
srtkey_hndl=("",h)
_index2hndl.insert(insert_pos, srtkey_hndl)
for hndl, index in _hndl2index.items():
if index >= insert_pos:
_hndl2index[hndl] += 1
_hndl2index[h]=insert_pos
'''
add2='''
h=id_generator(handle_sizes)
insert_pos= random.randrange(len(_hndl2index))
srtkey_hndl=("",h)
_index2hndl.insert(insert_pos, srtkey_hndl)
for srt_key,hndl in _index2hndl[insert_pos+1:]:
_hndl2index[hndl] += 1
_hndl2index[h]=insert_pos
'''
del0='''
index= random.randrange(len(_hndl2index))
srt_key,handle=_index2hndl[index]
del _index2hndl[index]
del _hndl2index[handle]
for key, val in _hndl2index.iteritems():
if val > index:
_hndl2index[key] -= 1
'''
del1='''
index= random.randrange(len(_hndl2index))
srt_key,handle=_index2hndl[index]
del _index2hndl[index]
del _hndl2index[handle]
for key, val in _hndl2index.items():
if val > index:
_hndl2index[key] -= 1
'''
del2='''
index= random.randrange(len(_hndl2index))
srt_key,handle=_index2hndl[index]
del _index2hndl[index]
del _hndl2index[handle]
for srt_key,hndl in _index2hndl[index:]:
_hndl2index[hndl] -= 1
'''
if sys.version_info[0] < 3:
cmds=[add0,add1,add2,del0,del1,del2]
else:
cmds=[add1,add2,del1,del2]
for c in cmds:
print(c)
random.seed(1)
t=timeit.Timer(c, setup=setup).timeit(num_operation)
print(num_operation,"ops in ", t, "seconds. avg:",t/num_operation,"seconds")
