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# This file is part of daf_butler. 

# 

# Developed for the LSST Data Management System. 

# This product includes software developed by the LSST Project 

# (http://www.lsst.org). 

# See the COPYRIGHT file at the top-level directory of this distribution 

# for details of code ownership. 

# 

# This program is free software: you can redistribute it and/or modify 

# it under the terms of the GNU General Public License as published by 

# the Free Software Foundation, either version 3 of the License, or 

# (at your option) any later version. 

# 

# This program is distributed in the hope that it will be useful, 

# but WITHOUT ANY WARRANTY; without even the implied warranty of 

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

# GNU General Public License for more details. 

# 

# You should have received a copy of the GNU General Public License 

# along with this program. If not, see <http://www.gnu.org/licenses/>. 

 

__all__ = ("FitsExposureFormatter", ) 

 

import copy 

 

from astro_metadata_translator import fix_header 

from lsst.daf.butler import Formatter 

 

 

class FitsExposureFormatter(Formatter): 

"""Interface for reading and writing Exposures to and from FITS files. 

""" 

extension = ".fits" 

 

def readImageComponent(self, fileDescriptor, component): 

"""Read the image, mask, or variance component of an Exposure. 

 

Parameters 

---------- 

fileDescriptor : `FileDescriptor` 

Identifies the file to read and parameters to be used for reading. 

component : `str`, optional 

Component to read from the file. Always one of "image", 

"variance", or "mask". 

 

Returns 

------- 

image : `~lsst.afw.image.Image` or `~lsst.afw.image.Mask` 

In-memory image, variance, or mask component. 

""" 

# TODO: could be made more efficient *if* Exposure type objects 

# held the class objects of their components. 

full = self.readFull(fileDescriptor, fileDescriptor.parameters) 

return fileDescriptor.storageClass.assembler().getComponent(full, component) 

 

def readMetadata(self, fileDescriptor): 

"""Read all header metadata directly into a PropertyList. 

 

Parameters 

---------- 

fileDescriptor : `FileDescriptor` 

Identifies the file to read and parameters to be used for reading. 

 

Returns 

------- 

metadata : `~lsst.daf.base.PropertyList` 

Header metadata. 

""" 

from lsst.afw.image import readMetadata 

md = readMetadata(fileDescriptor.location.path) 

fix_header(md) 

return md 

 

def stripMetadata(self, metadata): 

"""Remove metadata entries that are parsed into components. 

 

This is only called when just the metadata is requested; stripping 

entries there forces code that wants other components to ask for those 

components directly rather than trying to extract them from the 

metadata manually, which is fragile. This behavior is an intentional 

change from Gen2. 

 

Parameters 

---------- 

metadata : `~lsst.daf.base.PropertyList` 

Header metadata, to be modified in-place. 

""" 

# TODO: make sure this covers everything, by delegating to something 

# that doesn't yet exist in afw.image.ExposureInfo. 

from lsst.afw.image import bboxFromMetadata 

from lsst.afw.geom import makeSkyWcs 

bboxFromMetadata(metadata) # always strips 

makeSkyWcs(metadata, strip=True) 

 

def readInfoComponent(self, fileDescriptor, component): 

"""Read a component held by ExposureInfo. 

 

Parameters 

---------- 

fileDescriptor : `FileDescriptor` 

Identifies the file to read and parameters to be used for reading. 

component : `str`, optional 

Component to read from the file. 

 

Returns 

------- 

obj : component-dependent 

In-memory component object. 

""" 

from lsst.afw.image import LOCAL 

from lsst.geom import Box2I, Point2I 

parameters = dict(bbox=Box2I(minimum=Point2I(0, 0), maximum=Point2I(0, 0)), origin=LOCAL) 

tiny = self.readFull(fileDescriptor, parameters) 

return fileDescriptor.storageClass.assembler().getComponent(tiny, component) 

 

def readFull(self, fileDescriptor, parameters=None): 

"""Read the full Exposure object. 

 

Parameters 

---------- 

fileDescriptor : `FileDescriptor` 

Identifies the file to read and parameters to be used for reading. 

parameters : `dict`, optional 

If specified a dictionary of slicing parameters that overrides 

those in ``fileDescriptor`. 

 

Returns 

------- 

exposure : `~lsst.afw.image.Exposure` 

Complete in-memory exposure. 

""" 

if parameters is None: 

parameters = fileDescriptor.parameters 

if parameters is None: 

parameters = {} 

fileDescriptor.storageClass.validateParameters(parameters) 

return fileDescriptor.storageClass.pytype(fileDescriptor.location.path, **parameters) 

 

def read(self, fileDescriptor, component=None): 

"""Read data from a file. 

 

Parameters 

---------- 

fileDescriptor : `FileDescriptor` 

Identifies the file to read, type to read it into and parameters 

to be used for reading. 

component : `str`, optional 

Component to read from the file. Only used if the `StorageClass` 

for reading differed from the `StorageClass` used to write the 

file. 

 

Returns 

------- 

inMemoryDataset : `object` 

The requested data as a Python object. The type of object 

is controlled by the specific formatter. 

 

Raises 

------ 

ValueError 

Component requested but this file does not seem to be a concrete 

composite. 

KeyError 

Raised when parameters passed with fileDescriptor are not 

supported. 

""" 

if fileDescriptor.readStorageClass != fileDescriptor.storageClass: 

168 ↛ 169line 168 didn't jump to line 169, because the condition on line 168 was never true if component == "metadata": 

md = self.readMetadata(fileDescriptor) 

self.stripMetadata(md) 

return md 

elif component in ("image", "variance", "mask"): 

return self.readImageComponent(fileDescriptor, component) 

174 ↛ 177line 174 didn't jump to line 177, because the condition on line 174 was never false elif component is not None: 

return self.readInfoComponent(fileDescriptor, component) 

else: 

raise ValueError("Storage class inconsistency ({} vs {}) but no" 

" component requested".format(fileDescriptor.readStorageClass.name, 

fileDescriptor.storageClass.name)) 

return self.readFull(fileDescriptor) 

 

def write(self, inMemoryDataset, fileDescriptor): 

"""Write a Python object to a file. 

 

Parameters 

---------- 

inMemoryDataset : `object` 

The Python object to store. 

fileDescriptor : `FileDescriptor` 

Identifies the file to read, type to read it into and parameters 

to be used for reading. 

 

Returns 

------- 

path : `str` 

The `URI` where the primary file is stored. 

""" 

# Update the location with the formatter-preferred file extension 

fileDescriptor.location.updateExtension(self.extension) 

inMemoryDataset.writeFits(fileDescriptor.location.path) 

return fileDescriptor.location.pathInStore 

 

def predictPath(self, location): 

"""Return the path that would be returned by write, without actually 

writing. 

 

Parameters 

---------- 

location : `Location` 

The location to simulate writing to. 

""" 

location = copy.deepcopy(location) 

location.updateExtension(self.extension) 

return location.pathInStore