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tmadlener
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Apr 7, 2026
| m.SetFastMethod(ROOT.kTRUE) | ||
| m.AddObjectNames("metadata") | ||
| if not m.PartialMerge(ROOT.TFileMerger.kAll | ROOT.TFileMerger.kOnlyListed | ROOT.TFileMerger.kIncremental): | ||
| raise RuntimeError(f"TFileMerger failed adding metadata {fmt_name} to {output_file}") |
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Suggested change
| raise RuntimeError(f"TFileMerger failed adding metadata {fmt_name} to {output_file}") | |
| raise RuntimeError(f"TFileMerger failed adding metadata category to {output_file}") |
Would make it possible to drop the fmt_name from the arguments with essentially the same information.
tmadlener
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Apr 7, 2026
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Looks good to me (minor comments below). I suppose we are not yet at a stage where we have less code if we use the root file merger (that hadd uses internally) directly instead of going through hadd and then "fixing things" afterwards?
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| tmp_fd, tmp_path = tempfile.mkstemp(suffix=".root") | ||
| os.close(tmp_fd) |
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with tempfile.NamedTemporaryFile(suffix=".root", delete=True) as f:
tmp_path = f.namethat way the cleanup below would be automatically done. Or do we need the file handle closed for ROOT?
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Currently
podio-merge-filesreads every Frame and writes it back. This is very slow (between 10x and 100x) compared to usinghadd; I would say unusable. For TTrees and RNTuples, our files can be merged withhadd, producing readable files with the only caveat that there are some categories that may be repeated a few times, like metadata. The new implementation is equivalent to what we had before, but much faster.BEGINRELEASENOTES
haddwith ROOT files inpodio-merge-filesto speed it up and add code to make sure the metadata is set correctly. Keep the old behaviour for the other backends (SIO only).ENDRELEASENOTES
@meleneemil