DeserializationError too frequent when HistoPath is specified in HiFa XML

[kratsg]

Summary

When a <Sample> specifies the HistoPath and it's not empty, we will run into very frequent deserialization errors from uproot which is very slow to raise an exception (see scikit-hep/uproot5#504).

pyhf needs to fix this to be a bit smarter in how to check valid keys, and in particular, fix up its logic to not hit a/rely on DeserializationError.

OS / Environment

$ system_profiler -detailLevel mini SPSoftwareDataType | head -n 6
Software:

    System Software Overview:

      System Version: macOS 10.14.6 (18G9323)
      Kernel Version: Darwin 18.7.0

Steps to Reproduce

See #1687 for the fundamental issue. It's reproducible using private workspaces for now, but can be confirmed reproducible.

$ time pyhf xml2json monotop_twmetComb0L1LBoosted_allCRs_normDStoDR_unblind_sigTheo_envelope__pmoder_sig_a250_DM10_H900_tb1_st0p7/NormalMeasurement.xml --basedir monotop_twmetComb0L1LBoosted_allCRs_normDStoDR_unblind_sigTheo_envelope__pmoder_sig_a250_DM10_H900_tb1_st0p7
Processing ./NormalMeasurement_CR_0LBoosted_ttbar_cuts.xml:   0%|                           | 0/1 [00:00<?, ?channel/smonotop_twmetComb0L1LBoosted_allCRs_normDStoDR_unblind_sigTheo_envelope__pmoder_sig_a250_DM10_H900_tb1_st0p7/results/monotop_twmetComb0L1LBoosted_allCRs_normDStoDR_unblind_sigTheo_envelope__pmoder_sig_a250_DM10_H900_tb1_st0p7/Exclusion_combined_NormalMeasurement_model.root not in filecache
path=CR_0LBoosted_ttbar_cuts_hists/data, name=hData_CR_0LBoosted_ttbar_obs_cuts
deserialization error, trying fullname=CR_0LBoosted_ttbar_cuts_hists/data/hData_CR_0LBoosted_ttbar_obs_cuts instead
                                                                                                                      monotop_twmetComb0L1LBoosted_allCRs_normDStoDR_unblind_sigTheo_envelope__pmoder_sig_a250_DM10_H900_tb1_st0p7/results/monotop_twmetComb0L1LBoosted_allCRs_normDStoDR_unblind_sigTheo_envelope__pmoder_sig_a250_DM10_H900_tb1_st0p7/Exclusion_combined_NormalMeasurement_model.root in filecache
path=CR_0LBoosted_ttbar_cuts_hists/Top0LBoosted, name=hTop0LBoostedNom_CR_0LBoosted_ttbar_obs_cuts
deserialization error, trying fullname=CR_0LBoosted_ttbar_cuts_hists/Top0LBoosted/hTop0LBoostedNom_CR_0LBoosted_ttbar_obs_cuts instead
                                                                                                                      monotop_twmetComb0L1LBoosted_allCRs_normDStoDR_unblind_sigTheo_envelope__pmoder_sig_a250_DM10_H900_tb1_st0p7/results/monotop_twmetComb0L1LBoosted_allCRs_normDStoDR_unblind_sigTheo_envelope__pmoder_sig_a250_DM10_H900_tb1_st0p7/Exclusion_combined_NormalMeasurement_model.root in filecache
path=CR_0LBoosted_ttbar_cuts_hists/Top0LBoosted, name=hTop0LBoostedEG_EffLow_CR_0LBoosted_ttbar_obs_cutsNorm
deserialization error, trying fullname=CR_0LBoosted_ttbar_cuts_hists/Top0LBoosted/hTop0LBoostedEG_EffLow_CR_0LBoosted_ttbar_obs_cutsNorm instead

File Upload (optional)

No response

Expected Results

pyhf xml2json should be fast.

Actual Results

`pyhf xml2json` is slow.

pyhf Version

This impacts all pyhf versions up to 0.6.4.

Code of Conduct

• I agree to follow the Code of Conduct