1. CMS Persistent Event Structure
Vincenzo Innocente
CERN, EP/CMC
RD45 4/98
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2. Top Level Structure Run Event Event RawEvent RecEvent RecEvent
Collection
Event
Collection
Run
In case of re-reconstruction
the original structure is kept.
Event objects are cloned and
new collections created
(classification may change).
Event
Event
RawEvent
RecEvent
Event Header
RecEvent
The Event object could disappear and Event
become just a super-class of Raw&RecEvent
RD45 4/98
Vincenzo Innocente

3. Object Model
RD45 4/98
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4. Object Model
RD45 4/98
Vincenzo Innocente

5. ... Raw Event RawEvent ReadOut ReadOut RawData RawData
Index
RawData are identified by the
corresponding ReadOut.
RawData belonging to different
“detectors” are clustered into
different containers.
The granularity will be adjusted
to optimize I/O performances.
An index at RawEvent level is
used to avoid the access to all
containers in search for a given
RawData.
A range index at RawData level
could be used for fast random
access in complex detectors.
RawEvent
ReadOut
ReadOut
...
RawData
RawData
Vector of Digi
Vector of Digi
Index implemented as an ordered vector of pairs
RD45 4/98
Vincenzo Innocente

6. Reconstructed Objects
RecEvent
Reconstructed Objects
Reconstructed Objects produced by a given
“algorithm” are managed by a Reconstructor.
S-Track
Reconstructor
Track
SecInfo
A Reconstructed Object (Track) is split into several independent persistent objects to allow their clustering according to their access
requirements (physics analysis,
reconstruction, detailed detector studies, etc.).
The top level object acts as a proxy.
Intermediate reconstructed objects
(Hits) are transient and are cashed by value into the final objects .
Track
Constituents
S Track
...
Vector of Hits
S Track
RD45 4/98
Vincenzo Innocente

7. Reconstructed Event New Old RecEvent RecEvent S-Jet Reconstructor
A direct association to previous
RecEvent allows the access to any
obsolete Reconstructor
S-Track
Reconstructor
Old
RecEvent
S-Jet
A Reconstructor has references to
the Reconstructors used to “build”
its RecObjs
“Old”, still valid, Reconstructor
are associated uni-directionally
S-Jet
Reconstructor
My-Jet
RD45 4/98
Vincenzo Innocente

8. Meta-Data Event RecEvent S-Track GRecParam A RecObj is identified
User
Configuration
Meta-Data
A ooGenObj is used to manage
RecParam versions
S-Track
GRecParam
General “job” conditions
(new each transaction?)
Event
A RecObj is identified
by its Type, a Name
and a Version.
Vm.m S-Track
RecParam
RecEvent
Vn.n S-Jet
RecParam
The name (and the version) is always relative to a given context: for instance
the Container of RecParams
S-Track
Reconstructor
A Reconstructor is associated to its
version of RecParam which is used
also to instantiate the correct RecUnit
S-Jet
Reconstructor
S-Jet
RecUnit
RD45 4/98
Vincenzo Innocente