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Jaroslav Sevcik authored
This adds support for integrity level transitions (preventExtensions, seal and freeze) to MapUpdater and Map::TryUpdate. In both cases, we first try to detect whether there were integrity level transitions in the transition tree to the old map and make note of the most restrictive integrity transition and the map just before the transition (integrity-source-map). Then we find an appropriate root (based on integrity-source-map's elements kind) and replay the transitions based on the integrity-source-map's descriptor array. Finally, if we saw an integrity level transition in the beginning, we will find-or-create that transition (on the updated version of integrity-source-map). For the following micro-benchmark, we get about 10x speedup. ``` function C() { this.x = 1; Object.seal(this); this.x = 0.1; } const start = Date.now(); for (let i = 0; i < 1e7; i++) { new C(); } console.log("Reconfigure sealed: " + (Date.now() - start)); ``` Before: > Reconfigure sealed: 5202 After: > Reconfigure sealed: 479 Bug: v8:8538 Change-Id: If695be7469d8b6ccd44ac4528be8aa34b65b3e4d Reviewed-on: https://chromium-review.googlesource.com/c/1442640 Commit-Queue: Jaroslav Sevcik <jarin@chromium.org> Reviewed-by: Igor Sheludko <ishell@chromium.org> Cr-Commit-Position: refs/heads/master@{#59295}
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