Locate.cxx

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//          
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE_1_0.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)
 
// Please feel free to contact me (krumnack@iastate.edu) for bug
// reports, feature suggestions, praise and complaints.
 
 
//
// includes
//
 
#include <RootCoreUtils/Locate.h>
 
#include <deque>
#include <TSystem.h>
#include <RootCoreUtils/Assert.h>
#include <RootCoreUtils/ShellExec.h>
#include <RootCoreUtils/ThrowMsg.h>
 
//
// method implementations
//
 
namespace RCU
{
  std::string locate (const std::string& locations)
  {
    std::deque<std::string> files;
    {
      std::string::size_type pos = 0, pos2 = 0;
      while ((pos2 = locations.find ("::", pos)) != std::string::npos)
      {
    files.push_back (locations.substr (pos, pos2 - pos));
    pos = pos2 + 2;
      }
      files.push_back (locations.substr (pos));
    }
    std::string name;
    {
      for (std::deque<std::string>::const_iterator file = files.begin(),
         end = files.end(); file != end; ++ file)
      {
    std::string::size_type split = file->rfind ('/');
    if (split == std::string::npos)
      RCU_THROW_MSG ("file name " + *file + " does not contain a \"/\"");
    std::string myname = file->substr (split + 1);
    if (myname.empty())
      RCU_THROW_MSG ("file name " + *file + " should not end with a \"/\"");
    if (name.empty())
      name = std::move(myname);
    else if (name != myname)
      RCU_THROW_MSG ("inconsistent file names " + name + " and " + myname);
      }
    }
    RCU_ASSERT (!name.empty());
 
    files.push_front ("$ROOTCOREBIN/data/RootCoreUtils/download/" + name);
    for (std::deque<std::string>::iterator file = files.begin(),
       end = files.end(); file != end; ++ file)
    {
      TString myfile = *file;
      gSystem->ExpandPathName (myfile);
      *file = myfile.Data();
    }
 
    for (std::deque<std::string>::const_iterator file = files.begin(),
       end = files.end(); file != end; ++ file)
    {
      if (file->find ("http://") == 0)
      {
    try
    {
      Shell::exec ("$ROOTCOREDIR/scripts/download.sh " + Shell::quote (*file) + " " + Shell::quote (files[0]));
      return files[0];
    } catch (...)
    {
      // rationale: ignoring all exceptions, since we might have
      //   more locations to try
    }
      } else
      {
    if (gSystem->AccessPathName (file->c_str()) == 0)
    {
      return *file;
    }
      }
    }
    RCU_THROW_MSG ("failed to find file at " + locations);
    return ""; // compiler dummy
  }
}