[jython] Problem with an huge dictionary

[keobox]

Hi,
I apologize if this is not the right group for posting question
related to jython.
Please give me the right directions if this is the case.

The question is:
Is there a limit on the number of entries a dictionary can have i
jython?

I wrote a little app where my data is stored in a huge dictionary
(11746 entries) generated with a python script.
When I try to import the dictionary, jython complains with the
following message:

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\ceplacan\My Documents\Documents\Source\source
\Python\j
moco-test>jython
Jython 2.5.1 (Release_2_5_1:6813, Sep 26 2009, 13:47:54)
[Java HotSpot(TM) Client VM (Sun Microsystems Inc.)] on java1.5.0_13
Type "help", "copyright", "credits" or "license" for more information.Traceback (most recent call last):
File "<stdin>", line 1, in <module>
java.lang.ClassFormatError: Invalid this class index 3241 in constant
pool in cl
ass file _1076
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at org.python.core.BytecodeLoader
$Loader.loadClassFromBytes(BytecodeLoad
er.java:119)
at
org.python.core.BytecodeLoader.makeClass(BytecodeLoader.java:37)
at org.python.core.BytecodeLoader.makeCode(BytecodeLoader.java:
67)
at org.python.core.imp.createFromSource(imp.java:288)
at org.python.core.imp.loadFromSource(imp.java:514)
at org.python.core.imp.find_module(imp.java:411)
at org.python.core.imp.import_next(imp.java:635)
at org.python.core.imp.import_name(imp.java:746)
at org.python.core.imp.importName(imp.java:806)
at org.python.core.ImportFunction.__call__(__builtin__.java:
1232)
at org.python.core.PyObject.__call__(PyObject.java:367)
at org.python.core.__builtin__.__import__(__builtin__.java:
1202)
at org.python.core.__builtin__.__import__(__builtin__.java:
1185)
at org.python.core.imp.importOne(imp.java:817)
at org.python.pycode._pyx1.f$0(<stdin>:1)
at org.python.pycode._pyx1.call_function(<stdin>)
at org.python.core.PyTableCode.call(PyTableCode.java:165)
at org.python.core.PyCode.call(PyCode.java:18)
at org.python.core.Py.runCode(Py.java:1204)
at org.python.core.Py.exec(Py.java:1248)
at
org.python.util.PythonInterpreter.exec(PythonInterpreter.java:181)
at
org.python.util.InteractiveInterpreter.runcode(InteractiveInterpreter
..java:89)
at
org.python.util.InteractiveInterpreter.runsource(InteractiveInterpret
er.java:70)
at
org.python.util.InteractiveInterpreter.runsource(InteractiveInterpret
er.java:46)
at
org.python.util.InteractiveConsole.push(InteractiveConsole.java:110)
at
org.python.util.InteractiveConsole.interact(InteractiveConsole.java:9
0)
at org.python.util.jython.run(jython.java:316)
at org.python.util.jython.main(jython.java:129)

java.lang.ClassFormatError: java.lang.ClassFormatError: Invalid this
class index
3241 in constant pool in class file _1076

What can I do to avoid this?

Regards,
Cesare

 

[Thomas Lehmann]

The question is:
Is there a limit on the number of entries a dictionary can have i
jython?

I wrote a little app where my data is stored in a huge dictionary
(11746 entries) generated with a python script.
When I try to import the dictionary, jython complains with the
following message:

1) You did not say what you have saved (content of your dictionary).
2) You did not say how you have saved.

From the callstack - also I have never used jython - it looks like
that
there is a try to create a class. It looks like - I may be wrong -
that
you have saved user objects in your dictionary - have you?

If so you might fail on loading those objects - especially when your
program
does not have the code for it.

More details are required...

 

[keobox]

1) You did not say what you have saved (content of your dictionary).

- As you can see I received the error when I tried to import
jmoco_event_data.py module from the jython interpreter prompt.
- The "import" will cause the module compilation, jython will produce
a .class file instead of .pyc.
- jmoco_event_data.py contains 4 dictionaries:

typesValToName={
220:'EMS_EVENT_EMS_INTERNAL_BASE',
221:'EMS_EVENT_INTERNAL_TYPE_BASE',
222:'EMS_EVENT_INTERNAL_N_E_P_M_EVENT',
223:'EMS_EVENT_INTERNAL_N_E_ALARM_RCVD',
224:'EMS_EVENT_NE_SPECIFIC_BASE',
.... 11746 entries int key: string value
}

typesNameToVal={
'EMS_EVENT_EMS_INTERNAL_BASE':220,
'EMS_EVENT_INTERNAL_TYPE_BASE':221,
'EMS_EVENT_INTERNAL_N_E_P_M_EVENT':222,
'EMS_EVENT_INTERNAL_N_E_ALARM_RCVD':223,
'EMS_EVENT_NE_SPECIFIC_BASE':224,
.... total 11746 entries string key: int value
}

causesValToName={
0:'NOT_APPLICABLE_UNKNOWN',
1:'SOFTWARE_CAUSE_UNKNOWN',
2:'ABSENT_MODULE',
3:'FAULTY_MODULE',
.... 483 entries int key: string value
}

causesNameToVal={
'NOT_APPLICABLE_UNKNOWN':0,
'SOFTWARE_CAUSE_UNKNOWN':1,
'ABSENT_MODULE':2,
'FAULTY_MODULE':3,
.... 483 entries string key: int value
}

2) You did not say how you have saved.

The dictionaries are in the jmoco_event_data.py module.

From the callstack - also I have never used jython - it looks like
that
there is a try to create a class. It looks like - I may be wrong -
that
you have saved user objects in your dictionary - have you?

Nope, the dictionaries are only int to string mappings and string to
int mappings

If so you might fail on loading those objects - especially when your
program
does not have the code for it.

The failure happens during module's import, so my question is: Is
jython able to handle such big dictionaries?

More details are required...

jmoco_event_data.py has a size of roughly 700KB.

 

[Peter Otten]

- As you can see I received the error when I tried to import
jmoco_event_data.py module from the jython interpreter prompt.
- The "import" will cause the module compilation, jython will produce
a .class file instead of .pyc.
- jmoco_event_data.py contains 4 dictionaries:

typesValToName={
220:'EMS_EVENT_EMS_INTERNAL_BASE',
221:'EMS_EVENT_INTERNAL_TYPE_BASE',
222:'EMS_EVENT_INTERNAL_N_E_P_M_EVENT',
223:'EMS_EVENT_INTERNAL_N_E_ALARM_RCVD',
224:'EMS_EVENT_NE_SPECIFIC_BASE',
... 11746 entries int key: string value
}

typesNameToVal={
'EMS_EVENT_EMS_INTERNAL_BASE':220,
'EMS_EVENT_INTERNAL_TYPE_BASE':221,
'EMS_EVENT_INTERNAL_N_E_P_M_EVENT':222,
'EMS_EVENT_INTERNAL_N_E_ALARM_RCVD':223,
'EMS_EVENT_NE_SPECIFIC_BASE':224,
... total 11746 entries string key: int value
}

causesValToName={
0:'NOT_APPLICABLE_UNKNOWN',
1:'SOFTWARE_CAUSE_UNKNOWN',
2:'ABSENT_MODULE',
3:'FAULTY_MODULE',
... 483 entries int key: string value
}

causesNameToVal={
'NOT_APPLICABLE_UNKNOWN':0,
'SOFTWARE_CAUSE_UNKNOWN':1,
'ABSENT_MODULE':2,
'FAULTY_MODULE':3,
... 483 entries string key: int value
}


The dictionaries are in the jmoco_event_data.py module.


Nope, the dictionaries are only int to string mappings and string to
int mappings


The failure happens during module's import, so my question is: Is
jython able to handle such big dictionaries?

The problem seems to be the size of the code, i. e. the dict literal rather
than the size of the dictionary. With a slightly smaller dict I get

$ cat make_dict_source.py
from itertools import chain, count, islice

def main():
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("n", type=int, default=100)
parser.add_argument("py")

args = parser.parse_args()

prefix = ["data = {\n"]
suffix = ["}\n"]
pairs = ("'enum_whatever_{0}': {0},\n".format(i) for i in count())
pairs = islice(pairs, args.n)
with open(args.py, "w") as outstream:
lines = chain(prefix, pairs, suffix)
outstream.writelines(lines)

if __name__ == "__main__":
main()
$ python make_dict_source.py 4000 tmp.py
$ jython tmp.py
Traceback (innermost last):
(no code object) at line 0
java.lang.ClassFormatError: Invalid method Code length 71912 in class file
org/python/pycode/_pyx0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:632)
at org.python.core.BytecodeLoader2.loadClassFromBytes(Unknown
Source)
at org.python.core.BytecodeLoader.makeClass(Unknown Source)
at org.python.core.BytecodeLoader.makeCode(Unknown Source)
at org.python.core.Py.compile_flags(Unknown Source)
at org.python.core.Py.compile_flags(Unknown Source)
at org.python.core.__builtin__.execfile_flags(Unknown Source)
at org.python.util.PythonInterpreter.execfile(Unknown Source)
at org.python.util.jython.main(Unknown Source)

java.lang.ClassFormatError: java.lang.ClassFormatError: Invalid method Code
length 71912 in class file org/python/pycode/_pyx0
$ jython --version
Jython 2.2.1 on java1.6.0_0

Jython seems to generate a method that is bigger than the 64K allowed by
Java.

The simplest workaround is probably to let your module read the dict data
from a separate file in e. g. csv format.

Peter