fix: handle LineReader buffer wrapparound in LineProtocolFilter (#502) #503
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Thank you for your PR to the influx-cli project! Sorry it has taken so long to review it.
I have a few suggestions for the code which will improve readability, maintainability, and possibly efficiency. If you would like to make the modifications, I will happily re-review. Thanks, again!
| continue | ||
| bytesRead, err := state.lineReader.Read(state.line) | ||
| if err != nil && bytesRead == 0 { | ||
| return 0, err |
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This conditional changes the behavior; in the case where bytes are read, but an error is returned (perhaps EOF from a final line without a newline), this will continue, whereas the existing code will return the bytesRead and the error.
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Is this a fix for a problem you found, or an inadvertent change in behavior?
| @@ -21,24 +25,35 @@ func LineProtocolFilter(reader io.Reader) *LineProtocolFilterReader { | |||
| lineReader.LineNumber = 1 // start counting from 1 | |||
| return &LineProtocolFilterReader{ | |||
| lineReader: lineReader, | |||
| line: make([]byte, 4096), | |||
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4096 should be the defaultBufSize constant, not a literal
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Note: I am suggesting elsewhere that this buffer is unnecessary.
| @@ -21,24 +25,35 @@ func LineProtocolFilter(reader io.Reader) *LineProtocolFilterReader { | |||
| lineReader.LineNumber = 1 // start counting from 1 | |||
| return &LineProtocolFilterReader{ | |||
| lineReader: lineReader, | |||
| line: make([]byte, 4096), | |||
| wrapBuf: make([]byte, 4096), | |||
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4096 should be the defaultBufSize constant, not a literal
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Note: I am suggesting elsewhere that this buffer is not necessary.
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| //read again when we read a partial line at the end of the line reader buffer | ||
| if bytesRead > 0 && state.line[bytesRead-1] != '\n' { | ||
| wrapBytesRead, _ := state.lineReader.Read(state.wrapBuf[0:]) |
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This code ignores any errors from lineReader.Read. Errors need to be handled and returned up the stack.
| return 0, nil | ||
| } | ||
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| copy(b, state.line[0:bytesRead]) |
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This code has an extra copy for every read, and sometimes two extra copies on a line wrap.
Are those copies necessary? Would it be possible to do all the reads into the passed in buffer, b, calling the second read (when there is no \n found) b[bytesRead:] or something like that?
Fix for #502