VFSSvc Class Reference

Simple service that allows to read files independently from the storage. More...

#include <src/component/VFSSvc.h>

Inheritance diagram for VFSSvc:

Collaboration diagram for VFSSvc:

Public Member Functions
StatusCode	initialize () override
	Initialize Service. More...
StatusCode	finalize () override
	Finalize Service. More...
std::unique_ptr< std::istream >	open (const std::string &url) override
const std::vector< std::string > &	protocols () const override
	VFSSvc (const std::string &name, ISvcLocator *svcloc)
	Standard constructor. More...
	~VFSSvc () override=default
	Destructor. More...
Public Member Functions inherited from extends< BASE, Interfaces >
void *	i_cast (const InterfaceID &tid) const override
	Implementation of IInterface::i_cast. More...
StatusCode	queryInterface (const InterfaceID &ti, void **pp) override
	Implementation of IInterface::queryInterface. More...
std::vector< std::string >	getInterfaceNames () const override
	Implementation of IInterface::getInterfaceNames. More...
	~extends () override=default
	Virtual destructor. More...
void *	i_cast (const InterfaceID &tid) const override
	Implementation of IInterface::i_cast. More...
StatusCode	queryInterface (const InterfaceID &ti, void **pp) override
	Implementation of IInterface::queryInterface. More...
std::vector< std::string >	getInterfaceNames () const override
	Implementation of IInterface::getInterfaceNames. More...
	~extends () override=default
	Virtual destructor. More...
Public Member Functions inherited from extend_interfaces< Interfaces...>
	~extend_interfaces () override=default
	Virtual destructor. More...
	~extend_interfaces () override=default
	Virtual destructor. More...

Private Attributes
std::vector< std::string >	m_urlHandlersNames = { { {"FileReadTool"} } }
	Names of the handlers to use. More...
std::vector< std::string >	m_protocols
	Protocols registered. More...
std::string	m_fallBackProtocol
	Protocol to use in case there is not a specific tool to handle the URL. More...
GaudiUtils::HashMap< std::string, IFileAccess * >	m_urlHandlers
	Map of the tools handling the known protocols. More...
SmartIF< IToolSvc >	m_toolSvc
	Handle to the tool service. More...
std::vector< IAlgTool * >	m_acquiredTools
	List of acquired tools (needed to release them). More...

Additional Inherited Members
Public Types inherited from extends< BASE, Interfaces >
typedef extends	base_class
	Typedef to this class. More...
typedef extend_interfaces< Interfaces...>	extend_interfaces_base
	Typedef to the base of this class. More...
typedef extends	base_class
	Typedef to this class. More...
typedef extend_interfaces< Interfaces...>	extend_interfaces_base
	Typedef to the base of this class. More...
Public Types inherited from extend_interfaces< Interfaces...>
using	ext_iids = typename Gaudi::interface_list_cat< typename Interfaces::ext_iids...>::type
	take union of the ext_iids of all Interfaces... More...
using	ext_iids = typename Gaudi::interface_list_cat< typename Interfaces::ext_iids...>::type
	take union of the ext_iids of all Interfaces... More...

Detailed Description

Simple service that allows to read files independently from the storage.

The service uses tools to resolve URLs and serve the files as input streams. The basic implementations read from the filesystem, and simple extensions allow to read from databases, web...

Author

Marco Clemencic

Date

2008-01-18

Definition at line 26 of file VFSSvc.h.

Constructor & Destructor Documentation

VFSSvc::VFSSvc	(	const std::string &	name,
		ISvcLocator *	svcloc
	)

Standard constructor.

Definition at line 10 of file VFSSvc.cpp.

                                                     :
  base_class(name,svc)
{
  declareProperty("FileAccessTools",m_urlHandlersNames,
                  "List of tools implementing the IFileAccess interface.");

  declareProperty("FallBackProtocol",m_fallBackProtocol = "file",
                  "URL prefix to use if the prefix is not present.");
}

VFSSvc::~VFSSvc ( )

overridedefault

Destructor.

Member Function Documentation

StatusCode VFSSvc::finalize ( )

override

Finalize Service.

Definition at line 64 of file VFSSvc.cpp.

                            {
  m_urlHandlers.clear(); // clear the map
  m_protocols.clear();

  if (m_toolSvc) {
    // release the acquired tools (from the last acquired one)
    while ( !m_acquiredTools.empty()  ){
      m_toolSvc->releaseTool(m_acquiredTools.back()).ignore();
      m_acquiredTools.pop_back();
    }
    m_toolSvc.reset() ; // release the tool service
  }
  return Service::finalize();
}

StatusCode VFSSvc::initialize ( )

override

Initialize Service.

Definition at line 20 of file VFSSvc.cpp.

                              {
  StatusCode sc = Service::initialize();
  if (sc.isFailure()) return sc;

  MsgStream log(msgSvc(), name());

  m_toolSvc = serviceLocator()->service("ToolSvc");
  if (!m_toolSvc){
    log << MSG::ERROR << "Cannot locate ToolSvc" << endmsg;
    return StatusCode::FAILURE;
  }

  IAlgTool *tool;
  for(const auto& i : m_urlHandlersNames) {
    // retrieve the tool and the pointer to the interface
    sc = m_toolSvc->retrieve(i,IAlgTool::interfaceID(),tool,0,true);
    if (sc.isFailure()){
      log << MSG::ERROR << "Cannot get tool " << i << endmsg;
      return sc;
    }
    m_acquiredTools.push_back(tool); // this is one tool that we will have to release
    auto hndlr = SmartIF<IFileAccess>(tool);
    if (!hndlr){
      log << MSG::ERROR << i << " does not implement IFileAccess" << endmsg;
      return StatusCode::FAILURE;
    }
    // We do not need to increase the reference count for the IFileAccess interface
    // because we hold the tool by its IAlgTool interface.
    // loop over the list of supported protocols and add them to the map (for quick access)
    for ( const auto& prot : hndlr->protocols() ) m_urlHandlers[prot] = hndlr.get();
  }

  // Now let's check if we can handle the fallback protocol
  if ( m_urlHandlers.find(m_fallBackProtocol) == m_urlHandlers.end() ) {
    log << MSG::ERROR << "No handler specified for fallback protocol prefix "
        << m_fallBackProtocol << endmsg;
    return StatusCode::FAILURE;
  }

  // Note: the list of handled protocols will be filled only if requested

  return sc;
}

std::unique_ptr< std::istream > VFSSvc::open ( const std::string &  url )

override

See also

IFileAccess::open

Definition at line 79 of file VFSSvc.cpp.

                                                          {

  // get the url prefix endpos
  auto pos = url.find("://");

  if (std::string::npos == pos) { // no url prefix
    return m_urlHandlers[m_fallBackProtocol]->open(url);
  }

  std::string url_prefix(url,0,pos);
  if ( m_urlHandlers.find(url_prefix) == m_urlHandlers.end() ) {
    // if we do not have a handler for the URL prefix,
    // use the fall back one and pass only the path
    return m_urlHandlers[m_fallBackProtocol]->open(url.substr(pos+3));
  }
  return m_urlHandlers[url_prefix]->open(url);
}

const std::vector< std::string > & VFSSvc::protocols ( ) const

override

See also

IFileAccess::protocols

Definition at line 107 of file VFSSvc.cpp.

{
  if (m_protocols.empty()){
    // prepare the list of handled protocols
    std::transform( m_urlHandlers.begin(),m_urlHandlers.end(),
                    std::back_inserter(const_cast<VFSSvc*>(this)->m_protocols),
                    select1st );
  }
  return m_protocols;
}

Member Data Documentation

std::vector<IAlgTool*> VFSSvc::m_acquiredTools

private

List of acquired tools (needed to release them).

Definition at line 62 of file VFSSvc.h.

std::string VFSSvc::m_fallBackProtocol

private

Protocol to use in case there is not a specific tool to handle the URL.

Definition at line 53 of file VFSSvc.h.

std::vector<std::string> VFSSvc::m_protocols

private

Protocols registered.

Definition at line 50 of file VFSSvc.h.

SmartIF<IToolSvc> VFSSvc::m_toolSvc

private

Handle to the tool service.

Definition at line 59 of file VFSSvc.h.

GaudiUtils::HashMap<std::string,IFileAccess*> VFSSvc::m_urlHandlers

private

Map of the tools handling the known protocols.

Definition at line 56 of file VFSSvc.h.

std::vector<std::string> VFSSvc::m_urlHandlersNames = { { {"FileReadTool"} } }

private

Names of the handlers to use.

Definition at line 47 of file VFSSvc.h.

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

• GaudiUtils/src/component/VFSSvc.h
• GaudiUtils/src/component/VFSSvc.cpp