[ALICE3] Add LUT utilities

[njacazio]

No description provided.

[github-actions]

O2 linter results: ❌ 6 errors, ⚠️ 19 warnings, 🔕 0 disabled

[alibuild]

Auto-approving on behalf of @njacazio.

[alibuild]

Error while checking build/O2Physics/o2 for 7b9b498 at 2026-08-21 16:51:

No log files found

Full log here.

[alibuild]

Error while checking build/O2Physics/staging for 7b9b498 at 2026-08-21 16:51:

No log files found

Full log here.

[alibuild]

Error while checking build/O2Physics/code-check for c9b194c at 2026-08-21 19:57:

## sw/BUILD/O2Physics-latest/log
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatLutEntry.cxx:212:17: error: 'previewHeader' was not declared in this scope; did you mean 'PreviewHeader'?
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatLutEntry.cxx:225:13: error: no declaration matches 'o2::delphes::lutHeader_t o2::delphes::FlatLutData::previewHeader(const uint8_t*, size_t)'
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatLutEntry.cxx:268:13: error: no declaration matches 'o2::delphes::lutHeader_t o2::delphes::FlatLutData::previewHeader(std::ifstream&, const char*)'
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatLutEntry.cxx:284:28: error: 'previewHeader' was not declared in this scope; did you mean 'PreviewHeader'?
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatTrackSmearer.cxx:143:32: error: 'previewHeader' is not a member of 'o2::delphes::FlatLutData'
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatTrackSmearer.cxx:166:32: error: 'previewHeader' is not a member of 'o2::delphes::FlatLutData'
ninja: build stopped: subcommand failed.

Full log here.

[alibuild]

Error while checking build/O2Physics/staging for c9b194c at 2026-08-21 18:21:

## sw/BUILD/O2Physics-latest/log
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatLutEntry.cxx:212:17: error: 'previewHeader' was not declared in this scope; did you mean 'PreviewHeader'?
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatLutEntry.cxx:225:13: error: no declaration matches 'o2::delphes::lutHeader_t o2::delphes::FlatLutData::previewHeader(const uint8_t*, size_t)'
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatLutEntry.cxx:268:13: error: no declaration matches 'o2::delphes::lutHeader_t o2::delphes::FlatLutData::previewHeader(std::ifstream&, const char*)'
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatLutEntry.cxx:284:28: error: 'previewHeader' was not declared in this scope; did you mean 'PreviewHeader'?
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatTrackSmearer.cxx:143:32: error: 'previewHeader' is not a member of 'o2::delphes::FlatLutData'
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatTrackSmearer.cxx:166:32: error: 'previewHeader' is not a member of 'o2::delphes::FlatLutData'
ninja: build stopped: subcommand failed.

Full log here.

[alibuild]

Error while checking build/O2Physics/o2 for c9b194c at 2026-08-23 15:11:

## sw/BUILD/O2Physics-latest/log
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatLutEntry.cxx:212:17: error: 'previewHeader' was not declared in this scope; did you mean 'PreviewHeader'?
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatLutEntry.cxx:225:13: error: no declaration matches 'o2::delphes::lutHeader_t o2::delphes::FlatLutData::previewHeader(const uint8_t*, size_t)'
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatLutEntry.cxx:268:13: error: no declaration matches 'o2::delphes::lutHeader_t o2::delphes::FlatLutData::previewHeader(std::ifstream&, const char*)'
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatLutEntry.cxx:284:28: error: 'previewHeader' was not declared in this scope; did you mean 'PreviewHeader'?
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatTrackSmearer.cxx:143:32: error: 'previewHeader' is not a member of 'o2::delphes::FlatLutData'
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/ALICE3/Core/FlatTrackSmearer.cxx:166:32: error: 'previewHeader' is not a member of 'o2::delphes::FlatLutData'
ninja: build stopped: subcommand failed.

Full log here.

[alibuild]

Auto-approving on behalf of @njacazio.

[alibuild]

Error while checking build/O2Physics/code-check for 059b341 at 2026-08-24 20:25:

## sw/BUILD/O2Physics-latest/log
2026-08-24T20:21:06.358+0200 [23889:140440285834880] [buildboxcommon_grpcretrier.cpp:177] [ERROR] Retry limit (0) exceeded for "ActionCache.GetActionResult()", last gRPC error was [14: failed to connect to all addresses; last error: UNKNOWN: ipv4:127.0.0.1:8980: connection attempt timed out before receiving SETTINGS frame]
2026-08-24T20:21:06.588+0200 [23889:140440285834880] [executioncontext.cpp:544] [ERROR] Error while querying action cache at "http://localhost:8980": 14: failed to connect to all addresses; last error: UNKNOWN: ipv4:127.0.0.1:8980: connection attempt timed out before receiving SETTINGS frame


## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 11 errors and 16 warnings.'
Found 11 errors and 16 warnings.
++ [[ 11 -gt 0 ]]
++ cat /sw/BUILD/97d36561ad292719572f9d9cd96232925f973ca7/O2Physics-code-check/errors.txt
ALICE3/Core/FlatLutEntry.cxx:61:7: error: variable 'bin' is not initialized [cppcoreguidelines-init-variables,-warnings-as-errors]
ALICE3/Core/FlatLutEntry.cxx:76:7: error: variable 'bin' is not initialized [cppcoreguidelines-init-variables,-warnings-as-errors]
ALICE3/Core/FlatLutEntry.cxx:145:10: error: do not use reinterpret_cast [cppcoreguidelines-pro-type-reinterpret-cast,-warnings-as-errors]
ALICE3/Core/FlatLutEntry.cxx:151:10: error: do not use reinterpret_cast [cppcoreguidelines-pro-type-reinterpret-cast,-warnings-as-errors]
ALICE3/Core/FlatLutEntry.cxx:156:11: error: do not use reinterpret_cast [cppcoreguidelines-pro-type-reinterpret-cast,-warnings-as-errors]
ALICE3/Core/FlatLutEntry.cxx:161:11: error: do not use reinterpret_cast [cppcoreguidelines-pro-type-reinterpret-cast,-warnings-as-errors]
ALICE3/Core/FlatLutEntry.cxx:221:24: error: do not use reinterpret_cast [cppcoreguidelines-pro-type-reinterpret-cast,-warnings-as-errors]
ALICE3/Core/FlatLutEntry.cxx:251:25: error: do not use reinterpret_cast [cppcoreguidelines-pro-type-reinterpret-cast,-warnings-as-errors]
ALICE3/Core/FlatLutEntry.cxx:262:13: error: do not use reinterpret_cast [cppcoreguidelines-pro-type-reinterpret-cast,-warnings-as-errors]
ALICE3/Core/FlatLutEntry.cxx:287:13: error: do not use reinterpret_cast [cppcoreguidelines-pro-type-reinterpret-cast,-warnings-as-errors]
ALICE3/Core/FlatLutEntry.h:22:9: error: macro 'LUTCOVM_VERSION' used to declare a constant; consider using a 'constexpr' constant [cppcoreguidelines-macro-usage,-warnings-as-errors]
++ [[ 16 -gt 0 ]]
++ cat /sw/BUILD/97d36561ad292719572f9d9cd96232925f973ca7/O2Physics-code-check/warnings.txt
ALICE3/Core/FlatLutEntry.h:39:3: warning: do not declare C-style arrays, use 'std::array' instead [modernize-avoid-c-arrays]
ALICE3/Core/FlatLutEntry.h:40:3: warning: do not declare C-style arrays, use 'std::array' instead [modernize-avoid-c-arrays]
ALICE3/Core/FlatLutEntry.h:41:3: warning: do not declare C-style arrays, use 'std::array' instead [modernize-avoid-c-arrays]
ALICE3/Core/FlatLutEntry.h:42:3: warning: do not declare C-style arrays, use 'std::array' instead [modernize-avoid-c-arrays]
ALICE3/Core/FlatLutEntry.h:56:3: warning: function 'eval' should be marked [[nodiscard]] [modernize-use-nodiscard]
ALICE3/Core/FlatLutEntry.h:60:13: warning: statement should be inside braces [readability-braces-around-statements]
ALICE3/Core/FlatLutEntry.h:65:3: warning: function 'fracPositionWithinBin' should be marked [[nodiscard]] [modernize-use-nodiscard]
ALICE3/Core/FlatLutEntry.h:66:3: warning: function 'find' should be marked [[nodiscard]] [modernize-use-nodiscard]
ALICE3/Core/FlatLutEntry.h:83:3: warning: function 'check_version' should be marked [[nodiscard]] [modernize-use-nodiscard]
ALICE3/Core/FlatLutEntry.h:107:3: warning: function 'getEntryIndex' should be marked [[nodiscard]] [modernize-use-nodiscard]
ALICE3/Core/FlatLutEntry.h:117:3: warning: function 'getEntryRef' should be marked [[nodiscard]] [modernize-use-nodiscard]
ALICE3/Core/FlatLutEntry.h:127:3: warning: function 'getHeaderRef' should be marked [[nodiscard]] [modernize-use-nodiscard]
ALICE3/Core/FlatLutEntry.h:138:3: warning: function 'data' should be marked [[nodiscard]] [modernize-use-nodiscard]
ALICE3/Core/FlatLutEntry.h:143:3: warning: function 'bytes' should be marked [[nodiscard]] [modernize-use-nodiscard]
ALICE3/Core/FlatLutEntry.h:178:3: warning: function 'isLoaded' should be marked [[nodiscard]] [modernize-use-nodiscard]
ALICE3/Core/FlatLutEntry.h:189:3: warning: function 'getEntryOffset' should be marked [[nodiscard]] [modernize-use-nodiscard]
++ [[ 11 -gt 0 ]]
++ exit 1
--

Full log here.

[alibuild]

Error while checking build/O2Physics/o2 for 059b341 at 2026-08-24 16:50:

## sw/BUILD/O2Physics-latest/log
c++: fatal error: Killed signal terminated program cc1plus
c++: fatal error: Killed signal terminated program cc1plus
c++: fatal error: Killed signal terminated program cc1plus
ninja: build stopped: subcommand failed.

Full log here.