A simple data-source implementation, for demo purposes.
Constructing an RDataFrame as RDataFrame(nEntries)
is a superior alternative.
Definition at line 24 of file RTrivialDS.hxx.
Public Member Functions | |
RTrivialDS () | |
This ctor produces a data-source that returns infinite entries. | |
RTrivialDS (ULong64_t size, bool skipEvenEntries=false) | |
~RTrivialDS () | |
const std::vector< std::string > & | GetColumnNames () const |
Returns a reference to the collection of the dataset's column names. | |
std::vector< std::pair< ULong64_t, ULong64_t > > | GetEntryRanges () |
Return ranges of entries to distribute to tasks. | |
std::string | GetLabel () |
Return a string representation of the datasource type. | |
std::string | GetTypeName (std::string_view) const |
Type of a column as a string, e.g. | |
bool | HasColumn (std::string_view colName) const |
Checks if the dataset has a certain column. | |
void | Initialise () |
Convenience method called before starting an event-loop. | |
bool | SetEntry (unsigned int slot, ULong64_t entry) |
Advance the "cursors" returned by GetColumnReaders to the selected entry for a particular slot. | |
void | SetNSlots (unsigned int nSlots) |
Inform RDataSource of the number of processing slots (i.e. | |
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virtual | ~RDataSource ()=default |
virtual void | Finalise () |
Convenience method called after concluding an event-loop. | |
virtual void | FinaliseSlot (unsigned int) |
Convenience method called at the end of the data processing associated to a slot. | |
template<typename T > | |
std::vector< T ** > | GetColumnReaders (std::string_view columnName) |
Called at most once per column by RDF. | |
virtual std::unique_ptr< ROOT::Detail::RDF::RColumnReaderBase > | GetColumnReaders (unsigned int, std::string_view, const std::type_info &) |
If the other GetColumnReaders overload returns an empty vector, this overload will be called instead. | |
virtual void | InitSlot (unsigned int, ULong64_t) |
Convenience method called at the start of the data processing associated to a slot. | |
Protected Member Functions | |
std::string | AsString () |
Private Member Functions | |
std::vector< void * > | GetColumnReadersImpl (std::string_view name, const std::type_info &) |
type-erased vector of pointers to pointers to column values - one per slot | |
Private Attributes | |
std::vector< std::string > | fColNames {"col0"} |
std::vector< ULong64_t > | fCounter |
std::vector< ULong64_t * > | fCounterAddr |
std::vector< std::pair< ULong64_t, ULong64_t > > | fEntryRanges |
unsigned int | fNSlots = 0U |
ULong64_t | fSize = 0ULL |
bool | fSkipEvenEntries = false |
Additional Inherited Members | |
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using | Record_t = std::vector< void * > |
#include <ROOT/RTrivialDS.hxx>
Definition at line 35 of file RTrivialDS.cxx.
ROOT::RDF::RTrivialDS::RTrivialDS | ( | ) |
This ctor produces a data-source that returns infinite entries.
Definition at line 39 of file RTrivialDS.cxx.
ROOT::RDF::RTrivialDS::~RTrivialDS | ( | ) |
Definition at line 43 of file RTrivialDS.cxx.
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inlineprotectedvirtual |
Reimplemented from ROOT::RDF::RDataSource.
Definition at line 36 of file RTrivialDS.hxx.
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virtual |
Returns a reference to the collection of the dataset's column names.
Implements ROOT::RDF::RDataSource.
Definition at line 47 of file RTrivialDS.cxx.
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privatevirtual |
type-erased vector of pointers to pointers to column values - one per slot
Implements ROOT::RDF::RDataSource.
Definition at line 21 of file RTrivialDS.cxx.
Return ranges of entries to distribute to tasks.
They are required to be contiguous intervals with no entries skipped. Supposing a dataset with nEntries, the intervals must start at 0 and end at nEntries, e.g. [0-5],[5-10] for 10 entries. This function will be invoked repeatedly by RDataFrame as it needs additional entries to process. The same entry range should not be returned more than once. Returning an empty collection of ranges signals to RDataFrame that the processing can stop.
Implements ROOT::RDF::RDataSource.
Definition at line 62 of file RTrivialDS.cxx.
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virtual |
Return a string representation of the datasource type.
The returned string will be used by ROOT::RDF::SaveGraph() to represent the datasource in the visualization of the computation graph. Concrete datasources can override the default implementation.
Reimplemented from ROOT::RDF::RDataSource.
Definition at line 119 of file RTrivialDS.cxx.
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virtual |
Type of a column as a string, e.g.
GetTypeName("x") == "double"
. Required for jitting e.g. df.Filter("x>0")
.
[in] | colName | The name of the column |
Implements ROOT::RDF::RDataSource.
Definition at line 57 of file RTrivialDS.cxx.
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virtual |
Checks if the dataset has a certain column.
[in] | colName | The name of the column |
Implements ROOT::RDF::RDataSource.
Definition at line 52 of file RTrivialDS.cxx.
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virtual |
Convenience method called before starting an event-loop.
This method might be called multiple times over the lifetime of a RDataSource, since users can run multiple event-loops with the same RDataFrame. Ideally, Initialise
should set the state of the RDataSource so that multiple identical event-loops will produce identical results.
Reimplemented from ROOT::RDF::RDataSource.
Definition at line 98 of file RTrivialDS.cxx.
Advance the "cursors" returned by GetColumnReaders to the selected entry for a particular slot.
[in] | slot | The data processing slot that needs to be considered |
[in] | entry | The entry which needs to be pointed to by the reader pointers Slots are adopted to accommodate parallel data processing. Different workers will loop over different ranges and will be labelled by different "slot" values. Returns true if the entry has to be processed, false otherwise. |
Implements ROOT::RDF::RDataSource.
Definition at line 80 of file RTrivialDS.cxx.
Inform RDataSource of the number of processing slots (i.e.
worker threads) used by the associated RDataFrame. Slots numbers are used to simplify parallel execution: RDataFrame guarantees that different threads will always pass different slot values when calling methods concurrently.
Implements ROOT::RDF::RDataSource.
Definition at line 89 of file RTrivialDS.cxx.
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private |
Definition at line 30 of file RTrivialDS.hxx.
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private |
Definition at line 31 of file RTrivialDS.hxx.
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private |
Definition at line 32 of file RTrivialDS.hxx.
Definition at line 29 of file RTrivialDS.hxx.
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private |
Definition at line 26 of file RTrivialDS.hxx.
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private |
Definition at line 27 of file RTrivialDS.hxx.
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private |
Definition at line 28 of file RTrivialDS.hxx.