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improve json decoding performance #51700

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pitrou opened this issue Dec 7, 2009 · 11 comments
Closed

improve json decoding performance #51700

pitrou opened this issue Dec 7, 2009 · 11 comments
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performance Performance or resource usage stdlib Python modules in the Lib dir

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@pitrou
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pitrou commented Dec 7, 2009

BPO 7451
Nosy @rhettinger, @etrepum, @pitrou, @benjaminp
Files
  • json-opts2.patch
  • json-opts3.patch
  • json-opts4.patch
    		•

    Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.

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    GitHub fields:

    assignee = None
closed_at = <Date 2010-09-04.20:17:11.093>
created_at = <Date 2009-12-07.23:08:18.891>
labels = ['library', 'performance']
title = 'improve json decoding performance'
updated_at = <Date 2010-09-04.20:17:11.091>
user = 'https://github.com/pitrou'

    bugs.python.org fields:

    activity = <Date 2010-09-04.20:17:11.091>
actor = 'pitrou'
assignee = 'none'
closed = True
closed_date = <Date 2010-09-04.20:17:11.093>
closer = 'pitrou'
components = ['Library (Lib)']
creation = <Date 2009-12-07.23:08:18.891>
creator = 'pitrou'
dependencies = []
files = ['15478', '15484', '18755']
hgrepos = []
issue_num = 7451
keywords = ['patch']
message_count = 11.0
messages = ['96082', '96093', '96097', '96098', '96099', '96169', '96171', '96903', '96908', '115611', '115612']
nosy_count = 5.0
nosy_names = ['rhettinger', 'bob.ippolito', 'pitrou', 'benjamin.peterson', 'vkuznet']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'performance'
url = 'https://bugs.python.org/issue7451'
versions = ['Python 3.2']
    @pitrou
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    pitrou commented Dec 7, 2009

    This patch does two things:

    • it speeds up decoding of JSON objects by doing fewer temporary allocations
    • it reduces memory use of decoded JSON objects by reusing key strings
      when they appear several times in a JSON string

    @pitrou pitrou added stdlib Python modules in the Lib dir performance Performance or resource usage labels Dec 7, 2009
    @benjaminp
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    The problem with this is that it makes json in Python diverge even more
    from the simplejson trunk.

    @pitrou
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    pitrou commented Dec 8, 2009

    Unless Bob applies it to simplejson as well, that is.

    @pitrou
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    pitrou commented Dec 8, 2009

    I've just noticed that there is a persistent decoder instance in
    json._default_decoder. To avoid keeping references to past keys
    forever, this updated patch clears the memo dict when a string has
    finished decoding.

    @pitrou
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    pitrou commented Dec 8, 2009

    Here is the patch.

    @vkuznet
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    Mannequin

    vkuznet mannequin commented Dec 9, 2009

    I wonder if you can make a patch for 2.6 python branch.

    @pitrou
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    pitrou commented Dec 9, 2009

    I wonder if you can make a patch for 2.6 python branch.

    No, 2.6 doesn't have the same C accelerator in the first place.

    @etrepum
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    Mannequin

    etrepum mannequin commented Dec 27, 2009

    I applied most of this patch to r206 of simplejson trunk

    @pitrou
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    pitrou commented Dec 27, 2009

    Le dimanche 27 décembre 2009 à 11:10 +0000, Bob Ippolito a écrit :

    Bob Ippolito <bob@redivi.com> added the comment:

    I applied most of this patch to r206 of simplejson trunk

    Thank you. Will you port it to CPython yourself or would you prefer
    someone else to do it?

    @pitrou
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    pitrou commented Sep 4, 2010

    Updated patch against py3k.

    @pitrou
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    pitrou commented Sep 4, 2010

    Committed in r84505.

    @pitrou pitrou closed this as completed Sep 4, 2010
    @ezio-melotti ezio-melotti transferred this issue from another repository Apr 10, 2022
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