avoid ByteString when parsing HTTP/2 headers #800
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pjfanning
commented
Sep 26, 2025
pjfanning
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- experiment for Http2 header parser can be made more performant #798
- WIP
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Breaks 1 Http2ClientSpec test |
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jrudolph
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Oct 2, 2025
| httpHeaderParser.parseHeaderLine(pekko.util.ByteString(concHeaderLine))() | ||
| httpHeaderParser.resultHeader | ||
| } else { | ||
| HttpHeader.parse(name, value, httpHeaderParser.settings) match { |
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In general that's really cleaner. I don't expect a performance hit, there's a bit of a difference of how the parsers are looked up between HttpHeader.parse and httpHeaderParser.parseHeaderLine. HttpHeader.parse uses binary search to find the right parser and httpHeaderParser.parseHeaderLine uses kind of a lut / radix lookup once the parser is primed.
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Thanks @jrudolph.
I had to use the startsWith(":") check because HttpHeader.parse doesn't support pseudo headers and 1 test includes a :grpc-status pseudo header.
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But wait, does it even parse it into anything useful?
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I'll debug it later. There is an existing test that relies on the header parser not failing. Whether it needs the parser to actually process the pseudo header at all is something that I haven't yet tested.
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Maybe it's a typo in the test? Is :grpc-status a thing, i.e. is it allowed for gRPC (outside the HTTP/2 spec) to extend the set of : pseudo headers?
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pekko-grpc also doesn't use the colon form so maybe it's just a typo and we could just fix the test.
Added comments to clarify handling of pseudo-headers in the parseHeaderPair method.
He-Pin
reviewed
Oct 2, 2025
| httpHeaderParser.parseHeaderLine(ByteString(concHeaderLine))() | ||
| httpHeaderParser.resultHeader | ||
| import HttpHeader.ParsingResult | ||
| if (name.startsWith(":")) { |
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Maybe just a look ahead char is better
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