Remove deprecated EventStore based I/O functionality

CMakeLists.txt

@@ -191,11 +191,20 @@ add_subdirectory(src)
 SET(podio_PYTHON_DIR ${PROJECT_SOURCE_DIR}/python CACHE PATH "Path to the podio python directory")
 
 if(BUILD_TESTING)
+  include(ExternalData)
+  list(APPEND ExternalData_URL_TEMPLATES
+    "https://key4hep.web.cern.ch:443/testFiles/podio/%(hash)"
+  )
   include(cmake/podioTest.cmake)
   add_subdirectory(tests)
 endif()
 add_subdirectory(tools)
 add_subdirectory(python)
 
+
+if(BUILD_TESTING)
+  # Make sure to fetch all data, after all legacy test cases have been added
+  ExternalData_Add_Target(legacy_test_cases)
+endif()
 #--- add CMake infrastructure --------------------------------------------------
 include(cmake/podioCreateConfig.cmake)

cmake/podioTest.cmake

@@ -3,9 +3,8 @@
 function(PODIO_SET_TEST_ENV test)
   # We need to convert this into a list of arguments that can be used as environment variable
   list(JOIN PODIO_IO_HANDLERS " " IO_HANDLERS)
-  set_property(TEST ${test}
-    PROPERTY ENVIRONMENT
-      LD_LIBRARY_PATH=${PROJECT_BINARY_DIR}/tests:${PROJECT_BINARY_DIR}/src:$<TARGET_FILE_DIR:ROOT::Tree>:$<$<TARGET_EXISTS:SIO::sio>:$<TARGET_FILE_DIR:SIO::sio>>:$ENV{LD_LIBRARY_PATH}
+  set(test_environment
+    LD_LIBRARY_PATH=${PROJECT_BINARY_DIR}/tests:${PROJECT_BINARY_DIR}/src:$<TARGET_FILE_DIR:ROOT::Tree>:$<$<TARGET_EXISTS:SIO::sio>:$<TARGET_FILE_DIR:SIO::sio>>:$ENV{LD_LIBRARY_PATH}
       PYTHONPATH=${PROJECT_SOURCE_DIR}/python:$ENV{PYTHONPATH}
       PODIO_SIOBLOCK_PATH=${PROJECT_BINARY_DIR}/tests
       ROOT_INCLUDE_PATH=${PROJECT_BINARY_DIR}/tests/datamodel:${PROJECT_SOURCE_DIR}/include
@@ -14,6 +13,10 @@ function(PODIO_SET_TEST_ENV test)
       PODIO_USE_CLANG_FORMAT=${PODIO_USE_CLANG_FORMAT}
       PODIO_BASE=${PROJECT_SOURCE_DIR}
       ENABLE_SIO=${ENABLE_SIO}
+      PODIO_BUILD_BASE=${PROJECT_BINARY_DIR}
+  )
+  set_property(TEST ${test}
+    PROPERTY ENVIRONMENT "${test_environment}"
   )
 endfunction()
 

doc/advanced_topics.md

@@ -32,26 +32,14 @@ Before writing out a collection, the data need to be put into the proper structu
 
 ### Reading Back-End
 
-There are two possibilities to implement a reading-back end. In case one uses the `podio::EventStore`, one simply has to implement the `IReader` interface.
-
-If not taking advantage of this implementation, the data reader or the event store have to implement the `ICollectionProvider` interface. Reading of a collection happens then similar to:
-
-```cpp
-    // ...
-    // your creation of the collection and reading of the PODs from disk
-    // ...
-    collection->setBuffer(buffer);
-    auto refCollections = collection->referenceCollections();
-    // ...
-    // your filling of refCollections from disk
-    // ...
-    collection->setID( <collection ID read from disk> );
-    collection->prepareAfterRead();
-    // ...
-    collection->setReferences( &collectionProvider );
-```
-
-The strong assumption here is that all references are being followed up directly and no later on-demand reading is done.
+The main requirement for a reading backend is its capability of reading back all
+the necessary data from which a collection can be constructed in the form of
+`podio::CollectionReadBuffers`. From thes buffers collections can then be
+constructed. Each instance has to contain the (type erased) POD buffers (as a
+`std::vector`), the (possibly empty) vectors of `podio::ObjectID`s that contain
+the relation information as well the (possibly empty) vectors for the vector
+member buffers, which are currently stored as pairs of the type (as a
+`std::string`) and (type erased) data buffers in the form of `std::vector`s.
 
 ### Dumping JSON
 
@@ -94,12 +82,9 @@ As explained in the section about mutability of data, thread-safety is only guar
 During the calls of `prepareForWriting` and `prepareAfterReading` on collections other operations like object creation or addition will lead to an inconsistent state.
 
 ### Not-thread-safe components
-The example event store provided with PODIO is as of writing not thread-safe. Neither is the chosen serialization.
-
-## Implementing a transient Event Class
-
-PODIO contains one example `podio::EventStore` class.
-To implement your own transient event store, the only requirement is to set the collectionID of each collection to a unique ID on creation.
+The Readers and Writers that ship with podio are assumed to run on a single
+thread only (more precisely we assume that each Reader or Writer doesn't have to
+synchronize with any other for file operations).
 
 ## Running pre-commit
 

doc/examples.md

@@ -102,28 +102,30 @@ Passing in a size argument is optional; If no argument is passed all elements wi
 if an argument is passed only as many elements as requested will be returned.
 If the collection holds less elements than are requested, only as elements as are available will be returned.
 
-### EventStore functionality
+### `podio::Frame` container
 
-The event store contained in the package is for *educational* purposes and kept very minimal. It has two main methods:
+The `podio::Frame` is the main container for containing and grouping collections
+together. It has two main methods:
 
 ```cpp
-    /// create a new collection
+    /// Store a collection
     template<typename T>
-    T& create(const std::string& name);
+    const T& put(T&& coll, const std::string& name);
 
-    /// access a collection.
+    /// access a collection
     template<typename T>
-    const T& get(const std::string& name);
+    const& T get(const std::string& name);
 ```
 
-Please note that a `put` method for collections is not foreseen.
+Note that for `put`ting collections into the Frame an explicit `std::move` is
+necessary to highlight the change of ownership that happens in this case.
 
 ### Object Retrieval
 
 Collections can be retrieved explicitly:
 
 ```cpp
-    auto& hits = store.get<HitCollection>("hits");
+    auto& hits = frame.get<HitCollection>("hits");
     if (hits.isValid()) { ... }
 ```
 
@@ -135,51 +137,19 @@ Or implicitly when following an object reference. In both cases the access to da
 Sometimes it is necessary or useful to store additional data that is not directly foreseen in the EDM.
 This could be configuration parameters of simulation jobs, or parameter descriptions like cell-ID encoding etc. PODIO currently allows to store such meta data in terms of a `GenericParameters` class that
 holds an arbitrary number of named parameters of type `int, float, string` or vectors if these.
-Meta data can be stored and retrieved from the `EventStore` for runs, collections and events via
-the three methods:
-```cpp
-virtual GenericParameters& EventStore::getRunMetaData(int runID);
-virtual GenericParameters& EventStore::getEventMetaData();
-virtual GenericParameters& EventStore::getCollectionMetaData(int colID);
-```
-
-- example for writing event data:
-```cpp
-auto& evtMD = store.getEventMetaData() ;
-evtMD.setValue( "UserEventWeight" , (float) 100.*i ) ;
-```
-- example for reading event data:
-```cpp
-auto& evtMD = store.getEventMetaData() ;
-float evtWeight = evtMD.getFloatVal( "UserEventWeight" ) ;
-
-```
-
-- example for writing collection meta data:
-
-```cpp
-auto& hits = store.create<ExampleHitCollection>("hits");
-// ...
-auto& colMD = store.getCollectionMetaData( hits.getID() );
-colMD.setValue("CellIDEncodingString","system:8,barrel:3,layer:6,slice:5,x:-16,y:-16");
-```
-
-- example for reading collection meta data
-
-```cpp
-auto colMD = store.getCollectionMetaData( hits.getID() );
-std::string es = colMD.getStringVal("CellIDEncodingString") ;
-```
-
+Meta data can be stored and retrieved from the `Frame` via the templated `putParameter` and `getParameter` methods.
 
 #### Python Interface
 
-The class `EventStore` provides all the necessary (read) access to event files. It can be used as follows:
+The `Reader` and `Writer` classes in the `root_io` and `sio_io` submodules
+provide all the necessary functionality to read and write event files. An
+example of reading files looks like this:
+
 
 ```python
-    from EventStore import EventStore
-    store = EventStore(<list of files>)
-    for event in store:
+    from podio.root_io import Reader
+    reader = Reader("one or many input files")
+    for event in reader.get("events"):
       hits = store.get("hits")
       for hit in hits:
         # ...

doc/userdata.md

@@ -6,17 +6,18 @@ data* via the `podio::UserDataCollection`. It gives the user access to a
 the data stored in the EDM classes for each event.
 
 ## Example usage
-Creating or getting a `UserDataCollection` via the `EventStore` works the same
-as with any other collection of the EDM via the `create` or `get` functions:
+Creating or getting a `UserDataCollection` via the `Frame` works the same
+as with any other collection of the EDM via the `put` or `get` functions:
 
 ```cpp
 #include "podio/UserDataCollection.h"
 
-// Create a collection
-auto& userFloats = store.create<podio::UserDataCollection<float>>("userFloats");
+// Create a collection and put it into a Frame
+userFloats = podio::UserDataCollection<float>();
+frame.put(std::move(userFloats), "userFloats");
 
 // get a collection
-const auto& userData = store.get<podio::UserDataCollection<float>>("userFloats");
+const auto& userData = frame.get<podio::UserDataCollection<float>>("userFloats");
 ```
 
 The interface of the `UserDataCollection` is similar to a basic version of the