Python JSON Benchmark

benchmark.py

'''cjson, jsonlib, simplejson, and yajl also use C code
demjson did not use C code, but was too painfully slow to benchmark
(took about 20 seconds for these tests)

'''
import json
import sys
import time

with open('doc.json') as f:
    decoded = f.read()
encoded = json.loads(decoded)

def test_encodes(modules):    
    encode_times = {}
    
    for json_module in modules:
        start = time.clock()
    
        for _ in xrange(10000):
            json_module.loads(decoded)

        total_time = time.clock() - start
        assert json_module.loads(decoded) == encoded
        encode_times[json_module.__name__] = total_time
    return encode_times

def test_decodes(modules):
    decode_times = {}

    for json_module in modules:
        start = time.clock()

        for _ in xrange(10000):
            json_module.dumps(encoded)

        total_time = time.clock() - start
        assert json.loads(json_module.dumps(encoded)) == encoded
        decode_times[json_module.__name__] = total_time
    return decode_times

def printer(mapping):
    ''' mapping maps module name to time'''
    for k, v in mapping.iteritems():
        print '%s: %ss' % (k, v)


def main():
    print 'JSON Benchmark'
    try:
        import __pypy__
    except ImportError:
        # we are using CPython
        print sys.version
        import cjson, jsonlib, simplejson, ujson, yajl

        jsonlib.loads = jsonlib.read
        jsonlib.dumps = jsonlib.write
        cjson.loads = cjson.decode
        cjson.dumps = cjson.encode
        
        modules = [cjson, json, jsonlib, simplejson, ujson, yajl]
    else:
        # we are using PyPy
        print sys.version
        modules = [json]
    print '-----------------------------'
    print 'ENCODING'
    printer(test_encodes(modules))
    print ''
    print 'DECODING'
    printer(test_decodes(modules))

if __name__ == '__main__':
    main()

doc.json

{
    "web-app": {
        "servlet": [
            {
                "servlet-name": "cofaxCDS",
                "servlet-class": "org.cofax.cds.CDSServlet",
                "init-param": {
                    "configGlossary:installationAt": "Philadelphia, PA",
                    "configGlossary:adminEmail": "ksm@pobox.com",
                    "configGlossary:poweredBy": "Cofax",
                    "configGlossary:poweredByIcon": "/images/cofax.gif",
                    "configGlossary:staticPath": "/content/static",
                    "templateProcessorClass": "org.cofax.WysiwygTemplate",
                    "templateLoaderClass": "org.cofax.FilesTemplateLoader",
                    "templatePath": "templates",
                    "templateOverridePath": "",
                    "defaultListTemplate": "listTemplate.htm",
                    "defaultFileTemplate": "articleTemplate.htm",
                    "useJSP": false,
                    "jspListTemplate": "listTemplate.jsp",
                    "jspFileTemplate": "articleTemplate.jsp",
                    "cachePackageTagsTrack": 200,
                    "cachePackageTagsStore": 200,
                    "cachePackageTagsRefresh": 60,
                    "cacheTemplatesTrack": 100,
                    "cacheTemplatesStore": 50,
                    "cacheTemplatesRefresh": 15,
                    "cachePagesTrack": 200,
                    "cachePagesStore": 100,
                    "cachePagesRefresh": 10,
                    "cachePagesDirtyRead": 10,
                    "searchEngineListTemplate": "forSearchEnginesList.htm",
                    "searchEngineFileTemplate": "forSearchEngines.htm",
                    "dataStoreDriver": "com.microsoft.jdbc.sqlserver.SQLServerDriver",
                    "dataStoreUrl": "jdbc:microsoft:sqlserver://LOCALHOST:1433;DatabaseName=goon",
                    "dataStoreUser": "sa",
                    "dataStorePassword": "dataStoreTestQuery",
                    "dataStoreTestQuery": "SET NOCOUNT ON;select test='test';",
                    "dataStoreLogFile": "/usr/local/tomcat/logs/datastore.log",
                    "dataStoreInitConns": 10,
                    "dataStoreMaxConns": 100,
                    "dataStoreConnUsageLimit": 100,
                    "dataStoreLogLevel": "debug",
                    "maxUrlLength": 500
                }
            },
            {
                "servlet-name": "cofaxEmail",
                "servlet-class": "org.cofax.cds.EmailServlet",
                "init-param": {
                    "mailHost": "mail1",
                    "mailHostOverride": "mail2"
                }
            },
            {
                "servlet-name": "cofaxAdmin",
                "servlet-class": "org.cofax.cds.AdminServlet"
            },
            {
                "servlet-name": "fileServlet",
                "servlet-class": "org.cofax.cds.FileServlet"
            },
            {
                "servlet-name": "cofaxTools",
                "servlet-class": "org.cofax.cms.CofaxToolsServlet",
                "init-param": {
                    "templatePath": "toolstemplates/",
                    "log": 1,
                    "logLocation": "/usr/local/tomcat/logs/CofaxTools.log",
                    "logMaxSize": "",
                    "dataLog": 1,
                    "dataLogLocation": "/usr/local/tomcat/logs/dataLog.log",
                    "dataLogMaxSize": "",
                    "removePageCache": "/content/admin/remove?cache=pages&id=",
                    "removeTemplateCache": "/content/admin/remove?cache=templates&id=",
                    "fileTransferFolder": "/usr/local/tomcat/webapps/content/fileTransferFolder",
                    "lookInContext": 1,
                    "adminGroupID": 4,
                    "betaServer": true
                }
            }
        ],
        "servlet-mapping": {
            "cofaxCDS": "/",
            "cofaxEmail": "/cofaxutil/aemail/*",
            "cofaxAdmin": "/admin/*",
            "fileServlet": "/static/*",
            "cofaxTools": "/tools/*"
        },
        "taglib": {
            "taglib-uri": "cofax.tld",
            "taglib-location": "/WEB-INF/tlds/cofax.tld"
        }
    }
}

requirements.txt

jsonlib==1.6.1
python-cjson==1.0.5
simplejson==2.1.6
ujson==1.4
yajl==0.3.5

results

CPython
JSON Benchmark
2.7.1+ (r271:86832, Apr 11 2011, 18:05:24) 
[GCC 4.5.2]
-----------------------------
ENCODING
simplejson: 0.45s
cjson: 0.45s
ujson: 0.46s
jsonlib: 0.65s
json: 1.02s
yajl: 0.7s

DECODING
simplejson: 0.73s
cjson: 0.83s
ujson: 0.41s
jsonlib: 0.48s
json: 0.6s
yajl: 0.59s

PyPy
JSON Benchmark
2.7.1 (b590cf6de419, Apr 30 2011, 02:00:38)
[PyPy 1.5.0-alpha0 with GCC 4.4.3]
-----------------------------
ENCODING
json: 2.839568s

DECODING
json: 5.551157s