[WIP] index header bucket reader async readahead scratch r409 - #16498
[WIP] index header bucket reader async readahead scratch r409#16498francoposa wants to merge 9 commits into
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… sliding unconsumed peekBuf bytes;implement bucket read cancellation for buffer promise release; convert resetReader func from bucket reader to something normal
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Cursor Bugbot has reviewed your changes using default effort and found 2 potential issues.
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| readN, err := io.ReadFull(headPromise, bbar.peekBuf[peekBytesWritten:peekBytesWritten+toRead]) | ||
| peekBytesWritten += readN | ||
| if err != nil { | ||
| return nil, err |
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Failed Peek corrupts buffered state
High Severity
Peek grows peekBuf to the requested length before the fill completes. On a promise error it returns without shrinking peekBuf back to the bytes actually copied. The next Peek, Read, or Skip treats those unfilled bytes as valid data, so a retry can succeed with zeros or stale tail bytes and shift the stream.
Reviewed by Cursor Bugbot for commit ca47b41. Configure here.
| bbar.readOffset += bytesSkipped | ||
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| // Slide any unconsumed bytes from peekBuf to the beginning of the slice and truncate. | ||
| n := copy(bbar.peekBuf, bbar.peekBuf[bytesSkipped:]) |
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Negative Skip and Peek panic
High Severity
Skip and Peek only reject counts larger than Len(), so a negative count passes the check. Skip then slices peekBuf at a negative index and panics; Peek clamps n to a negative value via min and panics on peekBuf[:n]. Decbuf.SkipUvarintBytes can pass a negative int when a corrupt varint overflows, so a bad index header can crash the process.
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Reviewed by Cursor Bugbot for commit ca47b41. Configure here.
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What this PR does
Which issue(s) this PR fixes or relates to
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Checklist
CHANGELOG.mdupdated - the order of entries should be[CHANGE],[FEATURE],[ENHANCEMENT],[BUGFIX]. If changelog entry is not needed, please add thechangelog-not-neededlabel to the PR.about-versioning.mdupdated with experimental features.