perf: ensure full write buffer for *File.ReadFrom#623
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In `*File.ReadFrom`, ensure that the buffer is filled to capacity (`maxPacket` length) before performing the write. Prior to this change, the amount of data read into the buffer was dictated by the `io.Reader`'s `Read` implementation, and write performance would suffer when the Read would return less than maxPacket bytes of data. An example source would be a `net/http` response `Body` from a TLS server, which seems to cap each read to 16384 bytes -- half the default max packet size of 32768 bytes.
puellanivis
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Mar 24, 2025
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This does look like a solid improvement.
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In
*File.ReadFrom, ensure that the buffer is filled to capacity (maxPacketlength) before performing the write.Prior to this change, the amount of data read into the buffer was dictated by the
io.Reader'sReadimplementation, and write performance would suffer when the Read would return less than maxPacket bytes of data. An example source would be anet/httpresponseBodyfrom a TLS server, which seems to cap each read to 16384 bytes -- half the default max packet size of 32768 bytes.