JLargeCalibration Class Reference

The JLargeCalibration class is used to manage local resource files. More...

#include <JLargeCalibration.h>

Collaboration diagram for JLargeCalibration:

Public Member Functions
	JLargeCalibration (std::shared_ptr< JParameterManager > params, JCalibration *jcalib=NULL, string resource_dir="")
template<class T >
bool	Get (string namepath, T &vals, int event_number=0)
string	GetResource (string namepath)
string	GetLocalPathToResource (string namepath)
map< string, string >	GetLocalResources (void)
JCalibration *	GetJCalibration (void)
void	GetResourceFromURL (const string &URL, const string &fullpath)
string	Get_MD5 (string fullpath)

Protected Member Functions
void	ReadResourceInfoFile (void)
void	WriteResourceInfoFile (void)

Protected Attributes
JCalibration *	jcalib
vector< string >	calib_namepaths
JCalibrationFile *	jcalibfile
string	resource_dir
map< string, string >	resources
string	curl_args

Detailed Description

The JLargeCalibration class is used to manage local resource files.

These would typically be larger files that are costly to download every time the program is run. (i.e. if they come from the JCalibration system.) Files are kept in a central location on the local filesystem so only one copy needs to exist.

The JLargeCalibration constructor takes two arguments. The first is a pointer to a JCalibration object. If not NULL, this is used to retrieve the URL of the file's location on the web. This allows the JLargeCalibration to automatically download the file if needed.

If no JCalibration object is supplied (i.e. it's NULL), then it will simply look for a file with the specified namepath relative to the root directory used to hold the resources. The root resource directory can be specified multiple ways. These are, in order of precedence:

1. Passed as second argument to the constructor
2. Specified in JANA:RESOURCE_DIR configuration parameter
3. Specified in JANA_RESOURCE_DIR environment variable
4. Specified in JANA:RESOURCE_DEFAULT_PATH configuration parameter
5. Create a user directory in /tmp called "resources"

Note that in nearly all instances, no second argument should be passed to the constructor so that the value can be changed via run time parameters.

Resource files can be of any format but if they are in an ASCII format compatible with JCalibrationFile then the file can be parsed using the Get(...) methods of JLargeCalibration which map directly to those of JCalibrationFile.

To get the location of a resource on the local file system, use the method:

string GetResource(string namepath);

This will return a string with the full path to the resource file on the local file system. The call will automatically download the resource and install it if it does not already exist locally. The download location will be retrieved using the specified namepath and the JCalibration object passed in to the constructor. The calibration DB should have an entry for the namepath that is a map of key-values with two options for how the URL is specified:

Option 1.) The DB provides a "URL_base" string and a "path" string. These are combined to make the full URL, and the "path" is appended to the resource_dir to generate the local path. Alternatively, "URL_base" may be provided via the JANA:RESOURCE_URL configuration parameter in which case it need not be present in the calib DB. If the config. parameter is supplied, it will be used instead of any "URL_base" values found in the calib DB.

Option 2.) The DB provides a "URL" string only. This is used as the full URL and as a key to the resources map to find the local path. If none exists, this local path is taken to be the namepath specified (appended to resource_dir).

Option 1. takes precedent. If either the "URL_base" or "path" strings are present, then the other must be as well or an exception is thrown. If neither is present, then the URL string is checked and used. If it also does not exist, an exception is thrown.

A text file named "resources" is maintained at the top level of the resources directory tree to record what URLs have been downloaded and where the files are stored. This file is necessary if option 2 above is used to store URLs in the calibration DB, but is only informational if option 1 is used. It is ignored completely if no calibration database is used.

The templated Get(namepath, T vals [, event_number]) method will first call the GetResource() method described above, but will then use a JCalibrationFile object to parse the resource file, filling the container passed in for "vals". See the documentation for the JCalibration class for more info on the allowed types for "vals".

Constructor & Destructor Documentation

JLargeCalibration()

JLargeCalibration::JLargeCalibration	(	std::shared_ptr< JParameterManager >	params,
		JCalibration *	jcalib = NULL,
		string	resource_dir = ""
	)

Creates a new resource manager. See class description for details

Member Function Documentation

Get()

template<class T >

bool JLargeCalibration::Get	(	string	namepath,
		T &	vals,
		int	event_number = 0
	)

Get the specified resource and parse it, placing the values in the specified "vals" container. This first calls GetResource(namepath) to download the resource (if necessary) and then uses a JCalibrationFile::Get() method to parse the file and fill the "vals" container.

References JCalibration::Get().

GetResourceFromURL()

void JLargeCalibration::GetResourceFromURL	(	const string &	URL,
		const string &	fullpath
	)

Download the specified file and place it in the location specified by fullpath. If unsuccessful, a JException will be thrown with an appropriate error message.

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

• JLargeCalibration.h
• JLargeCalibration.cc