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Classes | Public Member Functions | Static Public Member Functions | Protected Member Functions | Friends | List of all members
lsst::afw::table::BaseColumnView Class Reference

Column-wise view into a sequence of records that have been allocated contiguously. More...

#include <BaseColumnView.h>

Inheritance diagram for lsst::afw::table::BaseColumnView:
lsst::afw::table::ColumnViewT< RecordT > lsst::afw::table::SourceColumnViewT< RecordT >

Classes

struct  Impl
 

Public Member Functions

std::shared_ptr< BaseTablegetTable () const
 Return the table that owns the records.
 
Schema getSchema () const
 Return the schema that defines the fields.
 
template<typename T >
ndarray::ArrayRef< T, 1 > const operator[] (Key< T > const &key) const
 Return a 1-d array corresponding to a scalar field (or subfield).
 
template<typename T >
ndarray::ArrayRef< T, 2, 1 > const operator[] (Key< Array< T > > const &key) const
 Return a 2-d array corresponding to an array field.
 
ndarray::result_of::vectorize< detail::FlagExtractor, ndarray::Array< Field< Flag >::Elementconst, 1 > >::type operator[] (Key< Flag > const &key) const
 Return a 1-d array expression corresponding to a flag bit.
 
ndarray::Array< double, 1 > const get_radians_array (Key< Angle > const &key) const
 Return an array column as a double array in radians.
 
BitsColumn getBits (std::vector< Key< Flag > > const &keys) const
 Return an integer array with the given Flag fields repacked into individual bits.
 
BitsColumn getAllBits () const
 Return an integer array with all Flag fields repacked into individual bits.
 
 BaseColumnView (BaseColumnView const &)
 
 BaseColumnView (BaseColumnView &&)
 
BaseColumnViewoperator= (BaseColumnView const &)
 
BaseColumnViewoperator= (BaseColumnView &&)
 
 ~BaseColumnView ()
 

Static Public Member Functions

template<typename InputIterator >
static BaseColumnView make (std::shared_ptr< BaseTable > const &table, InputIterator first, InputIterator last)
 Construct a BaseColumnView from an iterator range.
 
template<typename InputIterator >
static bool isRangeContiguous (std::shared_ptr< BaseTable > const &table, InputIterator first, InputIterator last)
 Return true if the given record iterator range is continuous and the records all belong to the given table.
 

Protected Member Functions

 BaseColumnView (std::shared_ptr< BaseTable > const &table, std::size_t recordCount, void *buf, ndarray::Manager::Ptr const &manager)
 

Friends

class BaseTable
 

Detailed Description

Column-wise view into a sequence of records that have been allocated contiguously.

A BaseColumnView can be created from any iterator range that dereferences to records, as long as those records' field data is contiguous in memory. In practice, that means they must have been created from the same table, and be in the same order they were created (with no deletions). It also requires that those records be allocated in the same block, which can be guaranteed with BaseTable::preallocate().

Geometric (point and shape) fields cannot be accessed through a BaseColumnView, but their scalar components can be.

BaseColumnView and its subclasses are always non-const views into a catalog, and so cannot be obtained from a catalog-of-const (trying this results in an exception, not a compilation error). As a result, all its accessors return arrays of non-const elements, even though they are themselves const member functions. This is no different from a shared_ptr<T>'s get() member function returning a non-const T*, even though get() is a const member function.

Definition at line 83 of file BaseColumnView.h.

Constructor & Destructor Documentation

◆ BaseColumnView() [1/3]

lsst::afw::table::BaseColumnView::BaseColumnView ( BaseColumnView const & )
default

◆ BaseColumnView() [2/3]

lsst::afw::table::BaseColumnView::BaseColumnView ( BaseColumnView && )
default

◆ ~BaseColumnView()

lsst::afw::table::BaseColumnView::~BaseColumnView ( )
default

◆ BaseColumnView() [3/3]

lsst::afw::table::BaseColumnView::BaseColumnView ( std::shared_ptr< BaseTable > const & table,
std::size_t recordCount,
void * buf,
ndarray::Manager::Ptr const & manager )
protected

Definition at line 183 of file BaseColumnView.cc.

185 : _impl(std::make_shared<Impl>(table, recordCount, buf, manager)) {}

Member Function Documentation

◆ get_radians_array()

ndarray::Array< double, 1 > const lsst::afw::table::BaseColumnView::get_radians_array ( Key< Angle > const & key) const

Return an array column as a double array in radians.

Definition at line 117 of file BaseColumnView.cc.

117 {
118 using DoubleArray = ndarray::Array<double, 1>;
119 using AngleArray = ndarray::Array<lsst::geom::Angle, 1>;
120 AngleArray angle_array = (*this)[key];
121 return ndarray::detail::ArrayAccess<DoubleArray>::construct(
122 reinterpret_cast<double *>(angle_array.getData()),
123 ndarray::detail::ArrayAccess<AngleArray>::getCore(angle_array)
124 );
125}

◆ getAllBits()

BitsColumn lsst::afw::table::BaseColumnView::getAllBits ( ) const

Return an integer array with all Flag fields repacked into individual bits.

The returned object contains both the int64 array and accessors to obtain a mask given a Key or field name.

Exceptions
pex::exceptions::LengthErrorif the schema has more than 64 Flag fields.

Definition at line 157 of file BaseColumnView.cc.

157 {
158 BitsColumn result(_impl->recordCount);
159 ExtractFlagItems func = {&result._items};
160 getSchema().forEach(func);
161 if (result._items.size() > sizeof(BitsColumn::SizeT)) {
162 throw LSST_EXCEPT(pex::exceptions::LengthError,
163 (boost::format("Too many Flag keys in schema; %d > %d.") % result._items.size() %
164 sizeof(BitsColumn::SizeT))
165 .str());
166 }
167 ndarray::ArrayRef<BitsColumn::SizeT, 1, 1> array = result._array.deep();
168 BitsColumn::SizeT const size = result._items.size(); // just for unsigned/signed comparisons
169 for (BitsColumn::SizeT i = 0; i < size; ++i) {
170 array |= (BitsColumn::SizeT(1) << i) * (*this)[result._items[i].key];
171 }
172 return result;
173}
py::object result
Definition _schema.cc:429
#define LSST_EXCEPT(type,...)
Create an exception with a given type.
Definition Exception.h:48
Schema getSchema() const
Return the schema that defines the fields.
void forEach(F &func) const
Apply a functor to each SchemaItem in the Schema.
Definition Schema.h:214

◆ getBits()

BitsColumn lsst::afw::table::BaseColumnView::getBits ( std::vector< Key< Flag > > const & keys) const

Return an integer array with the given Flag fields repacked into individual bits.

The returned object contains both the int64 array and accessors to obtain a mask given a Key or field name.

Exceptions
pex::exceptions::LengthErrorif keys.size() > 64

Definition at line 127 of file BaseColumnView.cc.

127 {
128 BitsColumn result(_impl->recordCount);
129 ndarray::ArrayRef<BitsColumn::SizeT, 1, 1> array = result._array.deep();
130 if (keys.size() > sizeof(BitsColumn::SizeT)) {
131 throw LSST_EXCEPT(pex::exceptions::LengthError,
132 (boost::format("Too many keys passed to getBits(); %d > %d.") % keys.size() %
133 sizeof(BitsColumn::SizeT))
134 .str());
135 }
136 BitsColumn::SizeT const size = keys.size(); // just for unsigned/signed comparisons
137 for (BitsColumn::SizeT i = 0; i < size; ++i) {
138 array |= (BitsColumn::SizeT(1) << i) * (*this)[keys[i]];
139 result._items.push_back(getSchema().find(keys[i]));
140 }
141 return result;
142}
SchemaItem< T > find(std::string const &name) const
Find a SchemaItem in the Schema by name.
Definition Schema.cc:467

◆ getSchema()

Schema lsst::afw::table::BaseColumnView::getSchema ( ) const
inline

Return the schema that defines the fields.

Definition at line 89 of file BaseColumnView.h.

89{ return getTable()->getSchema(); }
std::shared_ptr< BaseTable > getTable() const
Return the table that owns the records.

◆ getTable()

std::shared_ptr< BaseTable > lsst::afw::table::BaseColumnView::getTable ( ) const

Return the table that owns the records.

Definition at line 68 of file BaseColumnView.cc.

68{ return _impl->table; }
std::shared_ptr< BaseTable > table

◆ isRangeContiguous()

template<typename InputIterator >
bool lsst::afw::table::BaseColumnView::isRangeContiguous ( std::shared_ptr< BaseTable > const & table,
InputIterator first,
InputIterator last )
static

Return true if the given record iterator range is continuous and the records all belong to the given table.

This tests exactly the same requiremetns needed to construct a column view, so if this test succeeds, BaseColumnView::make should as well.

Definition at line 221 of file BaseColumnView.h.

222 {
223 if (first == last) return true;
224 Schema schema = table->getSchema();
225 std::size_t recordSize = schema.getRecordSize();
226 std::size_t recordCount = 1;
227 void* buf = first->_data;
228 ndarray::Manager::Ptr manager = first->_manager;
229 char* expected = reinterpret_cast<char*>(buf) + recordSize;
230 for (++first; first != last; ++first, ++recordCount, expected += recordSize) {
231 if (first->_data != expected || first->_manager != manager) {
232 return false;
233 }
234 }
235 return true;
236}

◆ make()

template<typename InputIterator >
BaseColumnView lsst::afw::table::BaseColumnView::make ( std::shared_ptr< BaseTable > const & table,
InputIterator first,
InputIterator last )
static

Construct a BaseColumnView from an iterator range.

The iterators must dereference to a reference or const reference to a record. If the record data is not contiguous in memory, throws lsst::pex::exceptions::RuntimeError.

Definition at line 200 of file BaseColumnView.h.

201 {
202 if (first == last) {
203 return BaseColumnView(table, 0, nullptr, ndarray::Manager::Ptr());
204 }
205 Schema schema = table->getSchema();
206 std::size_t recordSize = schema.getRecordSize();
207 std::size_t recordCount = 1;
208 void* buf = first->_data;
209 ndarray::Manager::Ptr manager = first->_manager;
210 char* expected = reinterpret_cast<char*>(buf) + recordSize;
211 for (++first; first != last; ++first, ++recordCount, expected += recordSize) {
212 if (first->_data != expected || first->_manager != manager) {
214 "Record data is not contiguous in memory.");
215 }
216 }
217 return BaseColumnView(table, recordCount, buf, manager);
218}
BaseColumnView(BaseColumnView const &)
Reports errors that are due to events beyond the control of the program.
Definition Runtime.h:104

◆ operator=() [1/2]

BaseColumnView & lsst::afw::table::BaseColumnView::operator= ( BaseColumnView && )
default

◆ operator=() [2/2]

BaseColumnView & lsst::afw::table::BaseColumnView::operator= ( BaseColumnView const & )
default

◆ operator[]() [1/3]

template<typename T >
ndarray::ArrayRef< T, 2, 1 > const lsst::afw::table::BaseColumnView::operator[] ( Key< Array< T > > const & key) const

Return a 2-d array corresponding to an array field.

Definition at line 84 of file BaseColumnView.cc.

84 {
85 if (!key.isValid()) {
86 throw LSST_EXCEPT(
87 pex::exceptions::LogicError,
88 "Key is not valid (if this is a SourceCatalog, make sure slot aliases have been set up).");
89 }
90 if (key.isVariableLength()) {
91 throw LSST_EXCEPT(pex::exceptions::LogicError, "Cannot get columns for variable-length array fields");
92 }
93 return ndarray::external(
94 reinterpret_cast<T *>(reinterpret_cast<char *>(_impl->buf) + key.getOffset()),
95 ndarray::makeVector(_impl->recordCount, key.getSize()),
96 ndarray::makeVector(_impl->table->getSchema().getRecordSize() / sizeof(T), std::size_t(1)),
97 _impl->manager);
98}

◆ operator[]() [2/3]

ndarray::result_of::vectorize< detail::FlagExtractor, ndarray::Array< Field< Flag >::Elementconst, 1 > >::type lsst::afw::table::BaseColumnView::operator[] ( Key< Flag > const & key) const

Return a 1-d array expression corresponding to a flag bit.

In C++, the return value is a lazy ndarray expression template that performs the bitwise & operation on every element when that element is requested. In Python, the result will be copied into a bool NumPy array.

Definition at line 101 of file BaseColumnView.cc.

101 {
102 if (!key.isValid()) {
103 throw LSST_EXCEPT(
104 pex::exceptions::LogicError,
105 "Key is not valid (if this is a SourceCatalog, make sure slot aliases have been set up).");
106 }
107 return ndarray::vectorize(detail::FlagExtractor(key),
108 ndarray::Array<Field<Flag>::Element const, 1>(ndarray::external(
109 reinterpret_cast<Field<Flag>::Element *>(
110 reinterpret_cast<char *>(_impl->buf) + key.getOffset()),
111 ndarray::makeVector(_impl->recordCount),
112 ndarray::makeVector(_impl->table->getSchema().getRecordSize() /
113 sizeof(Field<Flag>::Element)),
114 _impl->manager)));
115}

◆ operator[]() [3/3]

template<typename T >
ndarray::ArrayRef< T, 1 > const lsst::afw::table::BaseColumnView::operator[] ( Key< T > const & key) const

Return a 1-d array corresponding to a scalar field (or subfield).

Definition at line 71 of file BaseColumnView.cc.

71 {
72 if (!key.isValid()) {
73 throw LSST_EXCEPT(
74 pex::exceptions::LogicError,
75 "Key is not valid (if this is a SourceCatalog, make sure slot aliases have been set up).");
76 }
77 return ndarray::external(reinterpret_cast<T *>(reinterpret_cast<char *>(_impl->buf) + key.getOffset()),
78 ndarray::makeVector(_impl->recordCount),
79 ndarray::makeVector(_impl->table->getSchema().getRecordSize() / sizeof(T)),
80 _impl->manager);
81}

Friends And Related Symbol Documentation

◆ BaseTable

Definition at line 165 of file BaseColumnView.h.


The documentation for this class was generated from the following files: