go/src/encoding/json/encode.go, branch fix-runtime-test-GOMAXPROCS

encoding/json: add security section to doc

2025-06-27T20:38:47Z

Add a section to the package doc which details the security considerations of using encoding/json, in particular with respect to parser misalignment issues. Additionally, clarify previously ambiguous statement in the Unmarshal doc about how case is used when matching keys in objects, and add a note about how duplicate keys are handled. Fixes #14750 Change-Id: I66f9b845efd98c86a684d7333b3aa8a456564922 Reviewed-on: https://go-review.googlesource.com/c/go/+/684315 LUCI-TryBot-Result: Go LUCI Reviewed-by: Joseph Tsai Auto-Submit: Roland Shoemaker Reviewed-by: Damien Neil

encoding/json: avoid supurious synctest deadlock detection

2025-05-20T22:46:07Z

Use a sync.OnceValue rather than a sync.WaitGroup to coordinate access to encoderCache entries. The OnceValue better expresses the intent of the code (we want to initialize the cache entry only once). However, the motivation for this change is to avoid testing/synctest incorrectly reporting a deadlock when multiple bubbles call Marshal at the same time. Goroutines blocked on WaitGroup.Wait are "durably blocked", causing confusion when a goroutine in one bubble Waits for a goroutine in a different bubble. Goroutines blocked on OnceValue are not durably blocked, avoiding the problem. Fixes #73733 For #67434 Change-Id: I81cddda80af67cf5c280fd4327620bc37e7a6fe6 Reviewed-on: https://go-review.googlesource.com/c/go/+/673335 Auto-Submit: Damien Neil Reviewed-by: Michael Pratt LUCI-TryBot-Result: Go LUCI

encoding/json: add json/v2 with GOEXPERIMENT=jsonv2 guard

2025-04-18T15:24:07Z

This imports the proposed new v2 JSON API implemented in github.com/go-json-experiment/json as of commit d3c622f1b874954c355e60c8e6b6baa5f60d2fed. When GOEXPERIMENT=jsonv2 is set, the encoding/json/v2 and encoding/jsontext packages are visible, the encoding/json package is implemented in terms of encoding/json/v2, and the encoding/json package include various additional APIs. (See #71497 for details.) When GOEXPERIMENT=jsonv2 is not set, the new API is not present and the encoding/json package is unchanged. The experimental API is not bound by the Go compatibility promise and is expected to evolve as updates are made to the json/v2 proposal. The contents of encoding/json/internal/jsontest/testdata are compressed with zstd v1.5.7 with the -19 option. Fixes #71845 For #71497 Change-Id: Ib8c94e5f0586b6aaa22833190b41cf6ef59f4f01 Reviewed-on: https://go-review.googlesource.com/c/go/+/665796 Auto-Submit: Damien Neil LUCI-TryBot-Result: Go LUCI Reviewed-by: Michael Pratt Reviewed-by: Joseph Tsai Reviewed-by: Dmitri Shuralyov

encoding/json: use builtin min function in appendString

2025-02-25T19:49:13Z

To make code a bit simpler. Change-Id: I59fca1d5760e304abd53873ecf9ca8b2903e02e8 GitHub-Last-Rev: 1369df6da16121c342a4e678efe3e5b082485b74 GitHub-Pull-Request: golang/go#71873 Reviewed-on: https://go-review.googlesource.com/c/go/+/651355 Reviewed-by: Ian Lance Taylor Auto-Submit: Ian Lance Taylor LUCI-TryBot-Result: Go LUCI Reviewed-by: Michael Pratt

encoding/json: clarify omitempty option for {array,slice,map,string}

2024-10-23T15:18:51Z

This CL is inspired by: https://github.com/golang/go/issues/29310#issuecomment-758768325 When I read omitempty option in encoding/xml package, I find it's a bit different than encoding/json package. I think it's more precise to say: "any array, slice, map, or string of length zero." Update #29310 Change-Id: Ia77167c3155411640224b349d4b34d0bb91ee11e GitHub-Last-Rev: a4cf00dcc75067bd259bc600f288c9de4b5393cf GitHub-Pull-Request: golang/go#69984 Reviewed-on: https://go-review.googlesource.com/c/go/+/621835 Auto-Submit: Ian Lance Taylor LUCI-TryBot-Result: Go LUCI Reviewed-by: Ian Lance Taylor Reviewed-by: Joseph Tsai Reviewed-by: Michael Pratt

encoding/json: add omitzero option

2024-10-02T14:22:27Z

Fixes #45669 Change-Id: Ic13523c0b3acdfc5b3e29a717bc62fde302ed8fd GitHub-Last-Rev: 57030f26b0062fa8eda21b3a73b7665deab88c76 GitHub-Pull-Request: golang/go#69622 Reviewed-on: https://go-review.googlesource.com/c/go/+/615676 LUCI-TryBot-Result: Go LUCI Auto-Submit: Ian Lance Taylor Reviewed-by: Ian Lance Taylor Reviewed-by: Joseph Tsai Reviewed-by: Michael Knyszek

encoding/json: rewrite interface{} to any

2024-07-24T00:40:06Z

For #49884 Change-Id: I1623201c47c820a152773d2f43d0072a1466d3bf Reviewed-on: https://go-review.googlesource.com/c/go/+/588118 LUCI-TryBot-Result: Go LUCI Reviewed-by: Emmanuel Odeke Reviewed-by: Ian Lance Taylor Commit-Queue: Ian Lance Taylor Reviewed-by: Dmitri Shuralyov Reviewed-by: Mauri de Souza Meneguzzo Reviewed-by: Joseph Tsai Auto-Submit: Ian Lance Taylor Commit-Queue: Ian Lance Taylor Auto-Submit: Ian Lance Taylor

encoding/json: clarify the map's key type for Unmarshal

2024-06-21T18:42:18Z

While here, also fix doc link for encoding.TextMarshaler. Fixes #67495 Change-Id: Ia2a674c5c35b5a849ce8f5eef3d34d165b3195b6 Reviewed-on: https://go-review.googlesource.com/c/go/+/593335 LUCI-TryBot-Result: Go LUCI Reviewed-by: Joseph Tsai Reviewed-by: David Chase Auto-Submit: Ian Lance Taylor Reviewed-by: Ian Lance Taylor

all: document legacy //go:linkname for modules with ≥20,000 dependents

2024-05-23T00:18:55Z

For #67401. Change-Id: Icc10ede72547d8020c0ba45e89d954822a4b2455 Reviewed-on: https://go-review.googlesource.com/c/go/+/587218 Auto-Submit: Russ Cox Reviewed-by: Cherry Mui LUCI-TryBot-Result: Go LUCI

encoding/json: optimize field sorting with slices and cmp

2024-04-29T14:01:21Z

Refactor field sorting in typeFields to use slices.SortFunc and cmp.Compare, resulting in performance improvements in cache misses and slight increases in hit latency. Memory allocation and operation counts also reduced significantly for cache misses. goos: darwin goarch: arm64 pkg: encoding/json cpu: Apple M2 Max │ old.txt │ new.txt │ │ sec/op │ sec/op vs base │ TypeFieldsCache/MissTypes1-12 5.068µ ± 2% 5.032µ ± 1% ~ (p=0.055 n=10) TypeFieldsCache/MissTypes10-12 15.22µ ± 2% 14.79µ ± 2% -2.84% (p=0.000 n=10) TypeFieldsCache/MissTypes100-12 98.40µ ± 3% 94.72µ ± 1% -3.73% (p=0.002 n=10) TypeFieldsCache/MissTypes1000-12 860.3µ ± 3% 840.7µ ± 1% ~ (p=0.105 n=10) TypeFieldsCache/MissTypes10000-12 8.092m ± 3% 7.987m ± 4% ~ (p=0.280 n=10) TypeFieldsCache/MissTypes100000-12 80.90m ± 9% 80.62m ± 2% ~ (p=0.631 n=10) TypeFieldsCache/MissTypes1000000-12 1009.5m ± 7% 933.8m ± 7% -7.50% (p=0.011 n=10) TypeFieldsCache/HitTypes1-12 1.554n ± 3% 1.617n ± 3% +4.05% (p=0.004 n=10) TypeFieldsCache/HitTypes10-12 1.575n ± 1% 1.624n ± 6% +3.14% (p=0.000 n=10) TypeFieldsCache/HitTypes100-12 1.566n ± 1% 1.627n ± 5% +3.86% (p=0.000 n=10) TypeFieldsCache/HitTypes1000-12 1.526n ± 4% 1.596n ± 3% +4.55% (p=0.001 n=10) TypeFieldsCache/HitTypes10000-12 1.506n ± 0% 1.573n ± 3% +4.41% (p=0.000 n=10) TypeFieldsCache/HitTypes100000-12 1.480n ± 1% 1.529n ± 7% +3.35% (p=0.001 n=10) TypeFieldsCache/HitTypes1000000-12 1.473n ± 2% 1.468n ± 2% ~ (p=0.739 n=10) geomean 1.371µ 1.374µ +0.25% │ old.txt │ new.txt │ │ B/op │ B/op vs base │ TypeFieldsCache/MissTypes1-12 2.023Ki ± 0% 2.000Ki ± 0% -1.16% (p=0.000 n=10) TypeFieldsCache/MissTypes10-12 10.95Ki ± 0% 10.71Ki ± 0% -2.17% (p=0.000 n=10) TypeFieldsCache/MissTypes100-12 101.91Ki ± 0% 99.53Ki ± 0% -2.34% (p=0.000 n=10) TypeFieldsCache/MissTypes1000-12 1044.3Ki ± 0% 1020.8Ki ± 0% -2.25% (p=0.000 n=10) TypeFieldsCache/MissTypes10000-12 9.957Mi ± 0% 9.730Mi ± 0% -2.29% (p=0.000 n=10) TypeFieldsCache/MissTypes100000-12 97.79Mi ± 0% 95.50Mi ± 0% -2.34% (p=0.000 n=10) TypeFieldsCache/MissTypes1000000-12 1018.4Mi ± 0% 995.5Mi ± 0% -2.25% (p=0.000 n=10) TypeFieldsCache/HitTypes1-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ TypeFieldsCache/HitTypes10-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ TypeFieldsCache/HitTypes100-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ TypeFieldsCache/HitTypes1000-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ TypeFieldsCache/HitTypes10000-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ TypeFieldsCache/HitTypes100000-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ TypeFieldsCache/HitTypes1000000-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ geomean ² -1.06% ² ¹ all samples are equal ² summaries must be >0 to compute geomean │ old.txt │ new.txt │ │ allocs/op │ allocs/op vs base │ TypeFieldsCache/MissTypes1-12 46.00 ± 0% 45.00 ± 0% -2.17% (p=0.000 n=10) TypeFieldsCache/MissTypes10-12 215.0 ± 0% 205.0 ± 0% -4.65% (p=0.000 n=10) TypeFieldsCache/MissTypes100-12 1.845k ± 0% 1.745k ± 0% -5.42% (p=0.000 n=10) TypeFieldsCache/MissTypes1000-12 18.08k ± 0% 17.08k ± 0% -5.53% (p=0.000 n=10) TypeFieldsCache/MissTypes10000-12 180.3k ± 0% 170.3k ± 0% -5.55% (p=0.000 n=10) TypeFieldsCache/MissTypes100000-12 1.804M ± 0% 1.704M ± 0% -5.54% (p=0.000 n=10) TypeFieldsCache/MissTypes1000000-12 18.04M ± 0% 17.04M ± 0% -5.54% (p=0.000 n=10) TypeFieldsCache/HitTypes1-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ TypeFieldsCache/HitTypes10-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ TypeFieldsCache/HitTypes100-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ TypeFieldsCache/HitTypes1000-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ TypeFieldsCache/HitTypes10000-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ TypeFieldsCache/HitTypes100000-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ TypeFieldsCache/HitTypes1000000-12 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹ geomean ² -2.49% ² ¹ all samples are equal ² summaries must be >0 to compute geomean Change-Id: I62b8f524f5747f4f1b9241a1d849efeef1851049 GitHub-Last-Rev: d16772d4fb44f76e2688e15f1bdfc7db14bb55c6 GitHub-Pull-Request: golang/go#67046 Reviewed-on: https://go-review.googlesource.com/c/go/+/581895 LUCI-TryBot-Result: Go LUCI Auto-Submit: Ian Lance Taylor Reviewed-by: Ian Lance Taylor Reviewed-by: Joedian Reid