Add DecodeFieldPriorityFirstWin option

[goccy]

Summary

In the default behavior, go-json, like encoding/json, will reflect the result of the last evaluation when a field with the same name exists. I've added new options to allow you to change this behavior. json.DecodeFieldPriorityFirstWin option reflects the result of the first evaluation if a field with the same name exists. This behavior has a performance advantage as it allows the subsequent strings to be skipped if all fields have been evaluated.

Benchmark

Results

goos: darwin
goarch: amd64
pkg: benchmark
Benchmark_Decode_SmallStruct_Unmarshal_EncodingJson-16                            418848              2395 ns/op             400 B/op         10 allocs/op
Benchmark_Decode_SmallStruct_Unmarshal_FastJson-16                                720466              1624 ns/op            3376 B/op         11 allocs/op
Benchmark_Decode_SmallStruct_Unmarshal_JsonIter-16                               1602945               745 ns/op             208 B/op         13 allocs/op
Benchmark_Decode_SmallStruct_Unmarshal_GoJay-16                                  2604565               455 ns/op             256 B/op          2 allocs/op
Benchmark_Decode_SmallStruct_Unmarshal_GoJayUnsafe-16                            3026695               397 ns/op             112 B/op          1 allocs/op
Benchmark_Decode_SmallStruct_Unmarshal_SegmentioJson-16                          1260757               959 ns/op             192 B/op          5 allocs/op
Benchmark_Decode_SmallStruct_Unmarshal_GoJson-16                                 2852440               417 ns/op             256 B/op          2 allocs/op
Benchmark_Decode_SmallStruct_Unmarshal_GoJsonNoEscape-16                         3440616               348 ns/op             144 B/op          1 allocs/op
Benchmark_Decode_SmallStruct_Stream_EncodingJson-16                               429216              2710 ns/op            1104 B/op         12 allocs/op
Benchmark_Decode_SmallStruct_Stream_JsonIter-16                                  1236762               969 ns/op             872 B/op         16 allocs/op
Benchmark_Decode_SmallStruct_Stream_GoJay-16                                     2147300               562 ns/op             720 B/op          3 allocs/op
Benchmark_Decode_SmallStruct_Stream_SegmentioJson-16                              208017              5250 ns/op           32960 B/op          6 allocs/op
Benchmark_Decode_SmallStruct_Stream_GoJson-16                                    1919298               613 ns/op             728 B/op          4 allocs/op
Benchmark_Decode_MediumStruct_Unmarshal_EncodingJson-16                            79514             14821 ns/op             696 B/op         19 allocs/op
Benchmark_Decode_MediumStruct_Unmarshal_FastJson-16                               115572              9728 ns/op           17304 B/op         54 allocs/op
Benchmark_Decode_MediumStruct_Unmarshal_JsonIter-16                               214368              5383 ns/op             792 B/op         82 allocs/op
Benchmark_Decode_MediumStruct_Unmarshal_GoJay-16                                  361904              3341 ns/op            2449 B/op          8 allocs/op
Benchmark_Decode_MediumStruct_Unmarshal_GoJayUnsafe-16                            391798              2793 ns/op             144 B/op          7 allocs/op
Benchmark_Decode_MediumStruct_Unmarshal_SegmentioJson-16                          220917              5706 ns/op             296 B/op          9 allocs/op
Benchmark_Decode_MediumStruct_Unmarshal_GoJson-16                                 297412              3448 ns/op            2451 B/op          8 allocs/op
Benchmark_Decode_MediumStruct_Unmarshal_GoJsonNoEscape-16                         381306              3220 ns/op            2419 B/op          7 allocs/op
Benchmark_Decode_MediumStruct_Stream_EncodingJson-16                               65142             18784 ns/op            7136 B/op         26 allocs/op
Benchmark_Decode_MediumStruct_Stream_JsonIter-16                                  182212              6607 ns/op            1792 B/op         91 allocs/op
Benchmark_Decode_MediumStruct_Stream_GoJay-16                                     270672              4545 ns/op            7920 B/op         12 allocs/op
Benchmark_Decode_MediumStruct_Stream_SegmentioJson-16                              78078             14739 ns/op           33064 B/op         10 allocs/op
Benchmark_Decode_MediumStruct_Stream_GoJson-16                                    277111              4223 ns/op            3834 B/op         12 allocs/op
Benchmark_Decode_LargeStruct_Unmarshal_EncodingJson-16                              5744            204362 ns/op            6240 B/op        191 allocs/op
Benchmark_Decode_LargeStruct_Unmarshal_FastJson-16                                  7574            134493 ns/op          283204 B/op        540 allocs/op
Benchmark_Decode_LargeStruct_Unmarshal_JsonIter-16                                 10000            102447 ns/op           17179 B/op       1271 allocs/op
Benchmark_Decode_LargeStruct_Unmarshal_GoJay-16                                    29066             39675 ns/op           31252 B/op         77 allocs/op
Benchmark_Decode_LargeStruct_Unmarshal_GoJayUnsafe-16                              36532             32485 ns/op            2561 B/op         76 allocs/op
Benchmark_Decode_LargeStruct_Unmarshal_SegmentioJson-16                            13063             90192 ns/op            4400 B/op        132 allocs/op
Benchmark_Decode_LargeStruct_Unmarshal_GoJson-16                                   23830             44974 ns/op           30792 B/op         67 allocs/op
Benchmark_Decode_LargeStruct_Unmarshal_GoJsonNoEscape-16                           26092             45308 ns/op           30759 B/op         66 allocs/op
Benchmark_Decode_LargeStruct_Unmarshal_GoJsonFirstWinMode-16                       27903             38975 ns/op           30792 B/op         67 allocs/op
Benchmark_Decode_LargeStruct_Unmarshal_GoJsonNoEscapeFirstWinMode-16               30661             39387 ns/op           30760 B/op         66 allocs/op
Benchmark_Decode_LargeStruct_Stream_EncodingJson-16                                 4974            229413 ns/op           70016 B/op        201 allocs/op
Benchmark_Decode_LargeStruct_Stream_JsonIter-16                                     9038            110930 ns/op           21320 B/op       1398 allocs/op
Benchmark_Decode_LargeStruct_Stream_GoJay-16                                       25328             47193 ns/op           67680 B/op         84 allocs/op
Benchmark_Decode_LargeStruct_Stream_SegmentioJson-16                                7567            152554 ns/op           37168 B/op        133 allocs/op
Benchmark_Decode_LargeStruct_Stream_GoJson-16                                      21698             54857 ns/op           34464 B/op         74 allocs/op
Benchmark_Decode_LargeStruct_Stream_GoJsonFirstWinMode-16                          24721             48504 ns/op           34465 B/op         74 allocs/op
Benchmark_Decode_SlowReader_EncodingJson/chunksize_16384-16                         4630            259097 ns/op          114516 B/op        403 allocs/op
Benchmark_Decode_SlowReader_EncodingJson/chunksize_4096-16                          4366            255513 ns/op          110429 B/op        406 allocs/op
Benchmark_Decode_SlowReader_EncodingJson/chunksize_1024-16                          4538            261276 ns/op          110418 B/op        425 allocs/op
Benchmark_Decode_SlowReader_EncodingJson/chunksize_256-16                           4420            268734 ns/op          110428 B/op        507 allocs/op
Benchmark_Decode_SlowReader_EncodingJson/chunksize_64-16                            3378            306652 ns/op          110403 B/op        836 allocs/op
Benchmark_Decode_SlowReader_GoJson/chunksize_16384-16                              13065             93375 ns/op           79034 B/op        276 allocs/op
Benchmark_Decode_SlowReader_GoJson/chunksize_4096-16                               13022             91710 ns/op           79034 B/op        280 allocs/op
Benchmark_Decode_SlowReader_GoJson/chunksize_1024-16                               12795             92556 ns/op           75957 B/op        299 allocs/op
Benchmark_Decode_SlowReader_GoJson/chunksize_256-16                                12289             97962 ns/op           75011 B/op        381 allocs/op
Benchmark_Decode_SlowReader_GoJson/chunksize_64-16                                 10000            117662 ns/op           74938 B/op        711 allocs/op

[codecov-commenter]

Codecov Report

Merging #242 (5c39787) into master (7d7af9f) will decrease coverage by 0.10%.
The diff coverage is 65.06%.

@@            Coverage Diff             @@
##           master     #242      +/-   ##
==========================================
- Coverage   81.61%   81.51%   -0.11%     
==========================================
  Files          46       46              
  Lines       14449    14537      +88     
==========================================
+ Hits        11793    11850      +57     
- Misses       2113     2141      +28     
- Partials      543      546       +3