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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.use std::collections::HashMap;
// KeyCache stores a pool struct keys mapped to v8,// to minimize allocs and speed up decoding/encoding `v8::Object`s// TODO: experiment with in from_v8/to_v8pub struct KeyCache(HashMap<&'static str, v8::Global<v8::String>>);
// creates an optimized v8::String for a struct field// TODO: experiment with external strings// TODO: evaluate if own KeyCache is better than v8's dedupepub fn v8_struct_key<'s>(  scope: &mut v8::HandleScope<'s>,  field: &'static str,) -> v8::Local<'s, v8::String> {  // Internalized v8 strings are significantly faster than "normal" v8 strings  // since v8 deduplicates re-used strings minimizing new allocations  // see: https://github.com/v8/v8/blob/14ac92e02cc3db38131a57e75e2392529f405f2f/include/v8.h#L3165-L3171  v8::String::new_from_utf8(    scope,    field.as_ref(),    v8::NewStringType::Internalized,  )  .unwrap()
  // TODO: consider external strings later  // right now non-deduped external strings (without KeyCache)  // are slower than the deduped internalized strings by ~2.5x  // since they're a new string in v8's eyes and needs to be hashed, etc...  // v8::String::new_external_onebyte_static(scope, field).unwrap()}