mirror of
https://github.com/python/cpython.git
synced 2025-10-31 10:26:02 +00:00
d316607732
* Several modules: change "class C(): ..." to "class C: ...". * flp.py: support for frozen forms. * Added string.find() which is like index but returns -1 if not found
297 lines
7.6 KiB
Python
Executable file
297 lines
7.6 KiB
Python
Executable file
# persist.py
|
|
#
|
|
# Implement limited persistence.
|
|
#
|
|
# Simple interface:
|
|
# persist.save() save __main__ module on file (overwrite)
|
|
# persist.load() load __main__ module from file (merge)
|
|
#
|
|
# These use the filename persist.defaultfile, initialized to 'wsrestore.py'.
|
|
#
|
|
# A raw interface also exists:
|
|
# persist.writedict(dict, fp) save dictionary to open file
|
|
# persist.readdict(dict, fp) read (merge) dictionary from open file
|
|
#
|
|
# Internally, the function dump() and a whole bunch of support of functions
|
|
# traverse a graph of objects and print them in a restorable form
|
|
# (which happens to be a Python module).
|
|
#
|
|
# XXX Limitations:
|
|
# - Volatile objects are dumped as strings:
|
|
# - open files, windows etc.
|
|
# - Other 'obscure' objects are dumped as strings:
|
|
# - classes, instances and methods
|
|
# - compiled regular expressions
|
|
# - anything else reasonably obscure (e.g., capabilities)
|
|
# - type objects for obscure objects
|
|
# - It's slow when there are many of lists or dictionaries
|
|
# (This could be fixed if there were a quick way to compute a hash
|
|
# function of any object, even if recursive)
|
|
|
|
defaultfile = 'wsrestore.py'
|
|
|
|
def save():
|
|
import __main__
|
|
import os
|
|
# XXX On SYSV, if len(defaultfile) >= 14, this is wrong!
|
|
backup = defaultfile + '~'
|
|
try:
|
|
os.unlink(backup)
|
|
except os.error:
|
|
pass
|
|
try:
|
|
os.rename(defaultfile, backup)
|
|
except os.error:
|
|
pass
|
|
fp = open(defaultfile, 'w')
|
|
writedict(__main__.__dict__, fp)
|
|
fp.close()
|
|
|
|
def load():
|
|
import __main__
|
|
fp = open(defaultfile, 'r')
|
|
readdict(__main__.__dict__, fp)
|
|
|
|
def writedict(dict, fp):
|
|
import sys
|
|
savestdout = sys.stdout
|
|
try:
|
|
sys.stdout = fp
|
|
dump(dict) # Writes to sys.stdout
|
|
finally:
|
|
sys.stdout = savestdout
|
|
|
|
def readdict(dict, fp):
|
|
contents = fp.read()
|
|
globals = {}
|
|
exec(contents, globals)
|
|
top = globals['top']
|
|
for key in top.keys():
|
|
if dict.has_key(key):
|
|
print 'warning:', key, 'not overwritten'
|
|
else:
|
|
dict[key] = top[key]
|
|
|
|
|
|
# Function dump(x) prints (on sys.stdout!) a sequence of Python statements
|
|
# that, when executed in an empty environment, will reconstruct the
|
|
# contents of an arbitrary dictionary.
|
|
|
|
import sys
|
|
|
|
# Name used for objects dict on output.
|
|
#
|
|
FUNNYNAME = FN = 'A'
|
|
|
|
# Top-level function. Call with the object you want to dump.
|
|
#
|
|
def dump(x):
|
|
types = {}
|
|
stack = [] # Used by test for recursive objects
|
|
print FN, '= {}'
|
|
topuid = dumpobject(x, types, stack)
|
|
print 'top =', FN, '[', `topuid`, ']'
|
|
|
|
# Generic function to dump any object.
|
|
#
|
|
dumpswitch = {}
|
|
#
|
|
def dumpobject(x, types, stack):
|
|
typerepr = `type(x)`
|
|
if not types.has_key(typerepr):
|
|
types[typerepr] = {}
|
|
typedict = types[typerepr]
|
|
if dumpswitch.has_key(typerepr):
|
|
return dumpswitch[typerepr](x, typedict, types, stack)
|
|
else:
|
|
return dumpbadvalue(x, typedict, types, stack)
|
|
|
|
# Generic function to dump unknown values.
|
|
# This assumes that the Python interpreter prints such values as
|
|
# <foo object at xxxxxxxx>.
|
|
# The object will be read back as a string: '<foo object at xxxxxxxx>'.
|
|
# In some cases it may be possible to fix the dump manually;
|
|
# to ease the editing, these cases are labeled with an XXX comment.
|
|
#
|
|
def dumpbadvalue(x, typedict, types, stack):
|
|
xrepr = `x`
|
|
if typedict.has_key(xrepr):
|
|
return typedict[xrepr]
|
|
uid = genuid()
|
|
typedict[xrepr] = uid
|
|
print FN, '[', `uid`, '] =', `xrepr`, '# XXX'
|
|
return uid
|
|
|
|
# Generic function to dump pure, simple values, except strings
|
|
#
|
|
def dumpvalue(x, typedict, types, stack):
|
|
xrepr = `x`
|
|
if typedict.has_key(xrepr):
|
|
return typedict[xrepr]
|
|
uid = genuid()
|
|
typedict[xrepr] = uid
|
|
print FN, '[', `uid`, '] =', `x`
|
|
return uid
|
|
|
|
# Functions to dump string objects
|
|
#
|
|
def dumpstring(x, typedict, types, stack):
|
|
# XXX This can break if strings have embedded '\0' bytes
|
|
# XXX because of a bug in the dictionary module
|
|
if typedict.has_key(x):
|
|
return typedict[x]
|
|
uid = genuid()
|
|
typedict[x] = uid
|
|
print FN, '[', `uid`, '] =', `x`
|
|
return uid
|
|
|
|
# Function to dump type objects
|
|
#
|
|
typeswitch = {}
|
|
class some_class:
|
|
def method(self): pass
|
|
some_instance = some_class()
|
|
#
|
|
def dumptype(x, typedict, types, stack):
|
|
xrepr = `x`
|
|
if typedict.has_key(xrepr):
|
|
return typedict[xrepr]
|
|
uid = genuid()
|
|
typedict[xrepr] = uid
|
|
if typeswitch.has_key(xrepr):
|
|
print FN, '[', `uid`, '] =', typeswitch[xrepr]
|
|
elif x == type(sys):
|
|
print 'import sys'
|
|
print FN, '[', `uid`, '] = type(sys)'
|
|
elif x == type(sys.stderr):
|
|
print 'import sys'
|
|
print FN, '[', `uid`, '] = type(sys.stderr)'
|
|
elif x == type(dumptype):
|
|
print 'def some_function(): pass'
|
|
print FN, '[', `uid`, '] = type(some_function)'
|
|
elif x == type(some_class):
|
|
print 'class some_class: pass'
|
|
print FN, '[', `uid`, '] = type(some_class)'
|
|
elif x == type(some_instance):
|
|
print 'class another_class: pass'
|
|
print 'some_instance = another_class()'
|
|
print FN, '[', `uid`, '] = type(some_instance)'
|
|
elif x == type(some_instance.method):
|
|
print 'class yet_another_class:'
|
|
print ' def method(): pass'
|
|
print 'another_instance = yet_another_class()'
|
|
print FN, '[', `uid`, '] = type(another_instance.method)'
|
|
else:
|
|
# Unknown type
|
|
print FN, '[', `uid`, '] =', `xrepr`, '# XXX'
|
|
return uid
|
|
|
|
# Initialize the typeswitch
|
|
#
|
|
for x in None, 0, 0.0, '', (), [], {}:
|
|
typeswitch[`type(x)`] = 'type(' + `x` + ')'
|
|
for s in 'type(0)', 'abs', '[].append':
|
|
typeswitch[`type(eval(s))`] = 'type(' + s + ')'
|
|
|
|
# Dump a tuple object
|
|
#
|
|
def dumptuple(x, typedict, types, stack):
|
|
item_uids = []
|
|
xrepr = ''
|
|
for item in x:
|
|
item_uid = dumpobject(item, types, stack)
|
|
item_uids.append(item_uid)
|
|
xrepr = xrepr + ' ' + item_uid
|
|
del stack[-1:]
|
|
if typedict.has_key(xrepr):
|
|
return typedict[xrepr]
|
|
uid = genuid()
|
|
typedict[xrepr] = uid
|
|
print FN, '[', `uid`, '] = (',
|
|
for item_uid in item_uids:
|
|
print FN, '[', `item_uid`, '],',
|
|
print ')'
|
|
return uid
|
|
|
|
# Dump a list object
|
|
#
|
|
def dumplist(x, typedict, types, stack):
|
|
# Check for recursion
|
|
for x1, uid1 in stack:
|
|
if x is x1: return uid1
|
|
# Check for occurrence elsewhere in the typedict
|
|
for uid1 in typedict.keys():
|
|
if x is typedict[uid1]: return uid1
|
|
# This uses typedict differently!
|
|
uid = genuid()
|
|
typedict[uid] = x
|
|
print FN, '[', `uid`, '] = []'
|
|
stack.append(x, uid)
|
|
item_uids = []
|
|
for item in x:
|
|
item_uid = dumpobject(item, types, stack)
|
|
item_uids.append(item_uid)
|
|
del stack[-1:]
|
|
for item_uid in item_uids:
|
|
print FN, '[', `uid`, '].append(', FN, '[', `item_uid`, '])'
|
|
return uid
|
|
|
|
# Dump a dictionary object
|
|
#
|
|
def dumpdict(x, typedict, types, stack):
|
|
# Check for recursion
|
|
for x1, uid1 in stack:
|
|
if x is x1: return uid1
|
|
# Check for occurrence elsewhere in the typedict
|
|
for uid1 in typedict.keys():
|
|
if x is typedict[uid1]: return uid1
|
|
# This uses typedict differently!
|
|
uid = genuid()
|
|
typedict[uid] = x
|
|
print FN, '[', `uid`, '] = {}'
|
|
stack.append(x, uid)
|
|
item_uids = []
|
|
for key in x.keys():
|
|
val_uid = dumpobject(x[key], types, stack)
|
|
item_uids.append(key, val_uid)
|
|
del stack[-1:]
|
|
for key, val_uid in item_uids:
|
|
print FN, '[', `uid`, '][', `key`, '] =',
|
|
print FN, '[', `val_uid`, ']'
|
|
return uid
|
|
|
|
# Dump a module object
|
|
#
|
|
def dumpmodule(x, typedict, types, stack):
|
|
xrepr = `x`
|
|
if typedict.has_key(xrepr):
|
|
return typedict[xrepr]
|
|
from string import split
|
|
# `x` has the form <module 'foo'>
|
|
name = xrepr[9:-2]
|
|
uid = genuid()
|
|
typedict[xrepr] = uid
|
|
print 'import', name
|
|
print FN, '[', `uid`, '] =', name
|
|
return uid
|
|
|
|
|
|
# Initialize dumpswitch, a table of functions to dump various objects,
|
|
# indexed by `type(x)`.
|
|
#
|
|
for x in None, 0, 0.0:
|
|
dumpswitch[`type(x)`] = dumpvalue
|
|
for x, f in ('', dumpstring), (type(0), dumptype), ((), dumptuple), \
|
|
([], dumplist), ({}, dumpdict), (sys, dumpmodule):
|
|
dumpswitch[`type(x)`] = f
|
|
|
|
|
|
# Generate the next unique id; a string consisting of digits.
|
|
# The seed is stored as seed[0].
|
|
#
|
|
seed = [0]
|
|
#
|
|
def genuid():
|
|
x = seed[0]
|
|
seed[0] = seed[0] + 1
|
|
return `x`
|