Summary: | [JSC] Optimize JSON.parse with small data by changing Identifier pool mechanism | ||||||
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Product: | WebKit | Reporter: | Yusuke Suzuki <ysuzuki> | ||||
Component: | New Bugs | Assignee: | Yusuke Suzuki <ysuzuki> | ||||
Status: | RESOLVED FIXED | ||||||
Severity: | Normal | CC: | ews-watchlist, keith_miller, mark.lam, msaboff, saam, tzagallo, webkit-bug-importer | ||||
Priority: | P2 | Keywords: | InRadar | ||||
Version: | WebKit Nightly Build | ||||||
Hardware: | Unspecified | ||||||
OS: | Unspecified | ||||||
Attachments: |
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Description
Yusuke Suzuki
2021-06-16 16:52:03 PDT
Created attachment 431622 [details]
Patch
Comment on attachment 431622 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=431622&action=review r=me with some suggestions. > Source/JavaScriptCore/ChangeLog:10 > + if JSON.parse is invoked for small data. This patch changes this pool mechanism so that we do not allocate > + Identifiers until we really need. I suggest adding a bit more detail: "This patch changes this pool mechanism so that we do not allocate Identifiers until we really need." => "This patch changes this pool mechanism so that we do not waste effort allocating null Identifiers to pre-populate the recent identifiers pool. Instead, we now use a m_recentIdentifiersIndex uint8_t array to indicate whether there's a cached recent identifier for each given first character." > Source/JavaScriptCore/runtime/LiteralParser.cpp:174 > + if (indexPlusOne) { I see. The reason for using indexPlusOne instead if index is so that 0 can mean no entry. I think this is worth a comment. Comment on attachment 431622 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=431622&action=review Thanks >> Source/JavaScriptCore/ChangeLog:10 >> + Identifiers until we really need. > > I suggest adding a bit more detail: > "This patch changes this pool mechanism so that we do not allocate Identifiers until we really need." => "This patch changes this pool mechanism so that we do not waste effort allocating null Identifiers to pre-populate the recent identifiers pool. Instead, we now use a m_recentIdentifiersIndex uint8_t array to indicate whether there's a cached recent identifier for each given first character." Changed. >> Source/JavaScriptCore/runtime/LiteralParser.cpp:174 >> + if (indexPlusOne) { > > I see. The reason for using indexPlusOne instead if index is so that 0 can mean no entry. I think this is worth a comment. Added. Committed r278971 (238897@main): <https://commits.webkit.org/238897@main> This improved JetStream2/FlightPlanner by 25% in some devices too! |