Fix HTTP cache checksum mismatch for resources#4886
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Zephkek wants to merge 1 commit intomultitheftauto:masterfrom
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Fix HTTP cache checksum mismatch for resources#4886Zephkek wants to merge 1 commit intomultitheftauto:masterfrom
Zephkek wants to merge 1 commit intomultitheftauto:masterfrom
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Pull request overview
Fixes a race where the server could advertise a checksum from the source resource file but end up serving different bytes from the HTTP cache, most visible with very large client files (issue #4161 / diagnostic #1013).
Changes:
- Introduces a temp-file copy + checksum flow so the checksum is derived from the exact bytes that will be served from the HTTP cache.
- Publishes the refreshed HTTP cache file via an atomic-ish replace step (rename/MoveFileExW) after validation and blocklist checks.
- Defers updating
CResourceFile’s last checksum/size hint until after HTTP cache refresh logic completes.
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| if (MoveFileExW(FromUTF8(strTempPath), FromUTF8(strCachedFilePath), MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH) == 0) | ||
| { | ||
| if (pOutErrorCode) | ||
| *pOutErrorCode = GetLastError(); | ||
| return false; | ||
| } | ||
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| return true; |
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| auto checksumOrError = CChecksum::GenerateChecksumFromFile(strPath); | ||
| if (std::holds_alternative<std::string>(checksumOrError)) | ||
| { | ||
| return SString(std::get<std::string>(checksumOrError)); | ||
| } | ||
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| pResourceFile->SetLastChecksum(std::get<CChecksum>(checksumOrError)); | ||
| pResourceFile->SetLastFileSizeHint(static_cast<uint>(FileSize(strPath))); | ||
| CChecksum checksum = std::get<CChecksum>(checksumOrError); | ||
| uint64 fileSize = FileSize(strPath); | ||
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Summary
Fix HTTP resource file mismatches when large client files are updated.
Motivation
Resolves #4161. The server could advertise a checksum from the source file, then serve different bytes because the HTTP cache was copied in a separate pass. Large files made that race much easier to hit.
Test plan
Checklist