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diff --git a/doc-main.txt b/doc-main.txt deleted file mode 100644 index 8a0bc55..0000000 --- a/doc-main.txt +++ /dev/null @@ -1,283 +0,0 @@ -== json - JSON Implementation for Ruby - -=== Description - -This is a implementation of the JSON specification according to RFC 4627 -(http://www.ietf.org/rfc/rfc4627.txt). Starting from version 1.0.0 on there -will be two variants available: - -* A pure ruby variant, that relies on the iconv and the stringscan - extensions, which are both part of the ruby standard library. -* The quite a bit faster C extension variant, which is in parts implemented - in C and comes with its own unicode conversion functions and a parser - generated by the ragel state machine compiler - (http://www.cs.queensu.ca/~thurston/ragel). - -Both variants of the JSON generator escape all non-ASCII an control -characters with \uXXXX escape sequences, and support UTF-16 surrogate pairs -in order to be able to generate the whole range of unicode code points. This -means that generated JSON text is encoded as UTF-8 (because ASCII is a subset -of UTF-8) and at the same time avoids decoding problems for receiving -endpoints, that don't expect UTF-8 encoded texts. On the negative side this -may lead to a bit longer strings than necessarry. - -All strings, that are to be encoded as JSON strings, should be UTF-8 byte -sequences on the Ruby side. To encode raw binary strings, that aren't UTF-8 -encoded, please use the to_json_raw_object method of String (which produces -an object, that contains a byte array) and decode the result on the receiving -endpoint. - -=== Author - -Florian Frank <mailto:flori@ping.de> - -=== License - -This software is distributed under the same license as Ruby itself, see -http://www.ruby-lang.org/en/LICENSE.txt. - -=== Download - -The latest version of this library can be downloaded at - -* http://rubyforge.org/frs?group_id=953 - -Online Documentation should be located at - -* http://json.rubyforge.org - -=== Usage - -To use JSON you can - require 'json' -to load the installed variant (either the extension 'json' or the pure -variant 'json_pure'). If you have installed the extension variant, you can -pick either the extension variant or the pure variant by typing - require 'json/ext' -or - require 'json/pure' - -You can choose to load a set of common additions to ruby core's objects if -you - require 'json/add/core' - -After requiring this you can, e. g., serialise/deserialise Ruby ranges: - - JSON JSON(1..10) # => 1..10 - -To find out how to add JSON support to other or your own classes, read the -Examples section below. - -To get the best compatibility to rails' JSON implementation, you can - require 'json/add/rails' - -Both of the additions attempt to require 'json' (like above) first, if it has -not been required yet. - -=== Speed Comparisons - -I have created some benchmark results (see the benchmarks/data-p4-3Ghz -subdir of the package) for the JSON-parser to estimate the speed up in the C -extension: - - Comparing times (call_time_mean): - 1 ParserBenchmarkExt#parser 900 repeats: - 553.922304770 ( real) -> 21.500x - 0.001805307 - 2 ParserBenchmarkYAML#parser 1000 repeats: - 224.513358139 ( real) -> 8.714x - 0.004454078 - 3 ParserBenchmarkPure#parser 1000 repeats: - 26.755020642 ( real) -> 1.038x - 0.037376163 - 4 ParserBenchmarkRails#parser 1000 repeats: - 25.763381731 ( real) -> 1.000x - 0.038814780 - calls/sec ( time) -> speed covers - secs/call - -In the table above 1 is JSON::Ext::Parser, 2 is YAML.load with YAML -compatbile JSON document, 3 is is JSON::Pure::Parser, and 4 is -ActiveSupport::JSON.decode. The ActiveSupport JSON-decoder converts the -input first to YAML and then uses the YAML-parser, the conversion seems to -slow it down so much that it is only as fast as the JSON::Pure::Parser! - -If you look at the benchmark data you can see that this is mostly caused by -the frequent high outliers - the median of the Rails-parser runs is still -overall smaller than the median of the JSON::Pure::Parser runs: - - Comparing times (call_time_median): - 1 ParserBenchmarkExt#parser 900 repeats: - 800.592479481 ( real) -> 26.936x - 0.001249075 - 2 ParserBenchmarkYAML#parser 1000 repeats: - 271.002390644 ( real) -> 9.118x - 0.003690004 - 3 ParserBenchmarkRails#parser 1000 repeats: - 30.227910865 ( real) -> 1.017x - 0.033082008 - 4 ParserBenchmarkPure#parser 1000 repeats: - 29.722384421 ( real) -> 1.000x - 0.033644676 - calls/sec ( time) -> speed covers - secs/call - -I have benchmarked the JSON-Generator as well. This generated a few more -values, because there are different modes that also influence the achieved -speed: - - Comparing times (call_time_mean): - 1 GeneratorBenchmarkExt#generator_fast 1000 repeats: - 547.354332608 ( real) -> 15.090x - 0.001826970 - 2 GeneratorBenchmarkExt#generator_safe 1000 repeats: - 443.968212317 ( real) -> 12.240x - 0.002252414 - 3 GeneratorBenchmarkExt#generator_pretty 900 repeats: - 375.104545883 ( real) -> 10.341x - 0.002665923 - 4 GeneratorBenchmarkPure#generator_fast 1000 repeats: - 49.978706968 ( real) -> 1.378x - 0.020008521 - 5 GeneratorBenchmarkRails#generator 1000 repeats: - 38.531868759 ( real) -> 1.062x - 0.025952543 - 6 GeneratorBenchmarkPure#generator_safe 1000 repeats: - 36.927649925 ( real) -> 1.018x 7 (>=3859) - 0.027079979 - 7 GeneratorBenchmarkPure#generator_pretty 1000 repeats: - 36.272134441 ( real) -> 1.000x 6 (>=3859) - 0.027569373 - calls/sec ( time) -> speed covers - secs/call - -In the table above 1-3 are JSON::Ext::Generator methods. 4, 6, and 7 are -JSON::Pure::Generator methods and 5 is the Rails JSON generator. It is now a -bit faster than the generator_safe and generator_pretty methods of the pure -variant but slower than the others. - -To achieve the fastest JSON text output, you can use the fast_generate -method. Beware, that this will disable the checking for circular Ruby data -structures, which may cause JSON to go into an infinite loop. - -Here are the median comparisons for completeness' sake: - - Comparing times (call_time_median): - 1 GeneratorBenchmarkExt#generator_fast 1000 repeats: - 708.258020939 ( real) -> 16.547x - 0.001411915 - 2 GeneratorBenchmarkExt#generator_safe 1000 repeats: - 569.105020353 ( real) -> 13.296x - 0.001757145 - 3 GeneratorBenchmarkExt#generator_pretty 900 repeats: - 482.825371244 ( real) -> 11.280x - 0.002071142 - 4 GeneratorBenchmarkPure#generator_fast 1000 repeats: - 62.717626652 ( real) -> 1.465x - 0.015944481 - 5 GeneratorBenchmarkRails#generator 1000 repeats: - 43.965681162 ( real) -> 1.027x - 0.022745013 - 6 GeneratorBenchmarkPure#generator_safe 1000 repeats: - 43.929073409 ( real) -> 1.026x 7 (>=3859) - 0.022763968 - 7 GeneratorBenchmarkPure#generator_pretty 1000 repeats: - 42.802514491 ( real) -> 1.000x 6 (>=3859) - 0.023363113 - calls/sec ( time) -> speed covers - secs/call - -=== Examples - -To create a JSON text from a ruby data structure, you can call JSON.generate -like that: - - json = JSON.generate [1, 2, {"a"=>3.141}, false, true, nil, 4..10] - # => "[1,2,{\"a\":3.141},false,true,null,\"4..10\"]" - -To create a valid JSON text you have to make sure, that the output is -embedded in either a JSON array [] or a JSON object {}. The easiest way to do -this, is by putting your values in a Ruby Array or Hash instance. - -To get back a ruby data structure from a JSON text, you have to call -JSON.parse on it: - - JSON.parse json - # => [1, 2, {"a"=>3.141}, false, true, nil, "4..10"] - -Note, that the range from the original data structure is a simple -string now. The reason for this is, that JSON doesn't support ranges -or arbitrary classes. In this case the json library falls back to call -Object#to_json, which is the same as #to_s.to_json. - -It's possible to add JSON support serialization to arbitrary classes by -simply implementing a more specialized version of the #to_json method, that -should return a JSON object (a hash converted to JSON with #to_json) like -this (don't forget the *a for all the arguments): - - class Range - def to_json(*a) - { - 'json_class' => self.class.name, # = 'Range' - 'data' => [ first, last, exclude_end? ] - }.to_json(*a) - end - end - -The hash key 'json_class' is the class, that will be asked to deserialise the -JSON representation later. In this case it's 'Range', but any namespace of -the form 'A::B' or '::A::B' will do. All other keys are arbitrary and can be -used to store the necessary data to configure the object to be deserialised. - -If a the key 'json_class' is found in a JSON object, the JSON parser checks -if the given class responds to the json_create class method. If so, it is -called with the JSON object converted to a Ruby hash. So a range can -be deserialised by implementing Range.json_create like this: - - class Range - def self.json_create(o) - new(*o['data']) - end - end - -Now it possible to serialise/deserialise ranges as well: - - json = JSON.generate [1, 2, {"a"=>3.141}, false, true, nil, 4..10] - # => "[1,2,{\"a\":3.141},false,true,null,{\"json_class\":\"Range\",\"data\":[4,10,false]}]" - JSON.parse json - # => [1, 2, {"a"=>3.141}, false, true, nil, 4..10] - -JSON.generate always creates the shortest possible string representation of a -ruby data structure in one line. This good for data storage or network -protocols, but not so good for humans to read. Fortunately there's also -JSON.pretty_generate (or JSON.pretty_generate) that creates a more -readable output: - - puts JSON.pretty_generate([1, 2, {"a"=>3.141}, false, true, nil, 4..10]) - [ - 1, - 2, - { - "a": 3.141 - }, - false, - true, - null, - { - "json_class": "Range", - "data": [ - 4, - 10, - false - ] - } - ] - -There are also the methods Kernel#j for generate, and Kernel#jj for -pretty_generate output to the console, that work analogous to Core Ruby's p -and the pp library's pp methods. - -The script tools/server.rb contains a small example if you want to test, how -receiving a JSON object from a webrick server in your browser with the -javasript prototype library (http://www.prototypejs.org) works. - |