columnar::ColumnarModeArray Struct Reference

#include <ColumnarDef.h>

Collaboration diagram for columnar::ColumnarModeArray:

Public Types
using	LinkIndexType = std::size_t
	the type used for columns that represent element links
using	LinkKeyType = std::uint8_t
	the type used for the key column

Static Public Member Functions
static LinkKeyType	getLinkKey (LinkIndexType link)
	get the key value from a link value
static LinkIndexType	getLinkIndex (LinkIndexType link)
	get the index value from a link value
static LinkIndexType	mergeLinkKeyIndex (LinkIndexType key, LinkIndexType index)
	merge a key and index value into a link value

Static Public Attributes
static constexpr bool	isColumnarMode = true
	Whather this is a columnar mode.
static constexpr bool	isXAOD = false
	Whether this is the xAOD mode.
static constexpr bool	isArrayMode = true
	Whether this is an array mode.
static constexpr bool	hasTypedLinks = false
	Whether links have an intrinsic type.
static constexpr bool	useNestedVectors = false
	Whether we use nested vectors for std::vector<...> columns.
static constexpr bool	inPlaceReplace = false
	Whether for this columnar mode decorators that replace the original column will also refer to the input column.
static constexpr LinkIndexType	invalidLinkValue = static_cast<LinkIndexType>(-1)
	the value used for an invalid link (a.k.a. empty/null link)
static constexpr unsigned	linkKeyBits = 8
	the number of bits used for the key inside the link
static constexpr unsigned	linkIndexBits = 8 * sizeof(LinkIndexType) - linkKeyBits
	various helper definitions
static constexpr LinkIndexType	linkIndexMask = (static_cast<LinkIndexType>(1) << linkIndexBits) - 1

Detailed Description

Definition at line 45 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

Member Typedef Documentation

LinkIndexType

using columnar::ColumnarModeArray::LinkIndexType = std::size_t

the type used for columns that represent element links

Element Link Definition

In general links are just represented by an integer index into the target container. However, for variant links (i.e. links pointing into one of multiple containers) we need to be able to identify the target container. This happens by using the top couple of bits of the index to identify the target container.

For variant links there is also an additional column that contains the keys for the target containers for each link, in the order the tool defined. If there are multiple accessors for the same variant link column, they will share the same key column and as such need to define the variant in the same way.

There are a couple of configurable aspects to this, like the exact types involved, as well as the number of bits used for the key, all of which can be configured through the columnar mode. Beyond that there are also a couple of helper functions and convenience definitions to avoid bit packing/unpacking code being repeated in multiple places.

Definition at line 93 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

LinkKeyType

using columnar::ColumnarModeArray::LinkKeyType = std::uint8_t

the type used for the key column

Definition at line 102 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

Member Function Documentation

getLinkIndex()

LinkIndexType columnar::ColumnarModeArray::getLinkIndex ( LinkIndexType link )

inlinestatic

get the index value from a link value

Definition at line 116 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

                                                                  {
      return link & linkIndexMask;
    }

getLinkKey()

LinkKeyType columnar::ColumnarModeArray::getLinkKey ( LinkIndexType link )

inlinestatic

get the key value from a link value

Definition at line 111 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

                                                              {
      return link >> linkIndexBits;
    }

mergeLinkKeyIndex()

LinkIndexType columnar::ColumnarModeArray::mergeLinkKeyIndex ( LinkIndexType key, LinkIndexType index )

inlinestatic

merge a key and index value into a link value

Definition at line 121 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

                                                                                           {
      if (key >= (static_cast<LinkIndexType>(1) << linkKeyBits))
        throw std::runtime_error ("link key too large to fit in link: " + std::to_string(key));
      if (index & ~linkIndexMask)
        throw std::runtime_error ("index too large to fit in link: " + std::to_string(index));
      return index | (key << linkIndexBits);
    }

Member Data Documentation

hasTypedLinks

bool columnar::ColumnarModeArray::hasTypedLinks = false

staticconstexpr

Whether links have an intrinsic type.

Definition at line 57 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

inPlaceReplace

bool columnar::ColumnarModeArray::inPlaceReplace = false

staticconstexpr

Whether for this columnar mode decorators that replace the original column will also refer to the input column.

This is very obscure, but can be queried if it avoids copying over the input column in the tool first.

Definition at line 67 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

invalidLinkValue

LinkIndexType columnar::ColumnarModeArray::invalidLinkValue = static_cast<LinkIndexType>(-1)

staticconstexpr

the value used for an invalid link (a.k.a. empty/null link)

Definition at line 96 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

isArrayMode

bool columnar::ColumnarModeArray::isArrayMode = true

staticconstexpr

Whether this is an array mode.

Definition at line 54 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

isColumnarMode

bool columnar::ColumnarModeArray::isColumnarMode = true

staticconstexpr

Whather this is a columnar mode.

Definition at line 48 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

isXAOD

bool columnar::ColumnarModeArray::isXAOD = false

staticconstexpr

Whether this is the xAOD mode.

Definition at line 51 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

linkIndexBits

unsigned columnar::ColumnarModeArray::linkIndexBits = 8 * sizeof(LinkIndexType) - linkKeyBits

staticconstexpr

various helper definitions

Definition at line 107 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

linkIndexMask

LinkIndexType columnar::ColumnarModeArray::linkIndexMask = (static_cast<LinkIndexType>(1) << linkIndexBits) - 1

staticconstexpr

Definition at line 108 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

linkKeyBits

unsigned columnar::ColumnarModeArray::linkKeyBits = 8

staticconstexpr

the number of bits used for the key inside the link

Definition at line 99 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

useNestedVectors

bool columnar::ColumnarModeArray::useNestedVectors = false

staticconstexpr

Whether we use nested vectors for std::vector<...> columns.

Definition at line 60 of file ColumnarCore/ColumnarCore/ColumnarDef.h.

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The documentation for this struct was generated from the following file:

• ColumnarCore/ColumnarCore/ColumnarDef.h