Micro-optimisations to perform better on JSON and String processing #1280
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* free_token is general Javascript deallocation, json_free_token creates a special case with reduced evaluation
Contributor
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Can you share some before/after performance numbers? I note there are some unrelated changes in your PR. |
Author
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The focus of this is specifically JSON parsing - Thus I base my work off kraken-1.0/json-parse-financial. I modified the benchmark to run 100x to magnify the impact which is only marginally visible in original. 
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Author
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The performance data is in "Instruments" format |
Author
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I have cleaned up the mix ups with other pieces of code |
bnoordhuis
approved these changes
Dec 28, 2025
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LGTM module some style issues, thanks for the PR!
quickjs.c
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| if (p >= s->buf_end) { | ||
| goto end_of_input; | ||
| } |
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Suggested change
| if (p >= s->buf_end) { | |
| goto end_of_input; | |
| } | |
| if (p >= s->buf_end) | |
| goto end_of_input; |
quickjs.c
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| case TOK_NUMBER: | ||
| JS_FreeValue(s->ctx, token->u.num.val); | ||
| break; | ||
| case TOK_STRING: | ||
| JS_FreeValue(s->ctx, token->u.str.str); | ||
| break; | ||
| case TOK_IDENT: | ||
| JS_FreeAtom(s->ctx, token->u.ident.atom); | ||
| break; |
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Suggested change
| case TOK_NUMBER: | |
| JS_FreeValue(s->ctx, token->u.num.val); | |
| break; | |
| case TOK_STRING: | |
| JS_FreeValue(s->ctx, token->u.str.str); | |
| break; | |
| case TOK_IDENT: | |
| JS_FreeAtom(s->ctx, token->u.ident.atom); | |
| break; | |
| case TOK_NUMBER: | |
| JS_FreeValue(s->ctx, token->u.num.val); | |
| break; | |
| case TOK_STRING: | |
| JS_FreeValue(s->ctx, token->u.str.str); | |
| break; | |
| case TOK_IDENT: | |
| JS_FreeAtom(s->ctx, token->u.ident.atom); | |
| break; |
djinn
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Dec 29, 2025
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djinn
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Updated according to convention
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free_tokenis general Javascript deallocation,json_free_tokencreates a special case with reduced evaluation for JSON objects