FileInPath.cc

Go to the documentation of this file.

// ----------------------------------------------------------------------
// ----------------------------------------------------------------------

#include <atomic>
#include <cstdlib>
#include <vector>
#include "boost/filesystem/path.hpp"
#include "boost/filesystem/operations.hpp"

#include "FWCore/ParameterSet/interface/FileInPath.h"
#include "FWCore/Utilities/interface/EDMException.h"
#include "FWCore/Utilities/interface/Parse.h"
#include "FWCore/Utilities/interface/resolveSymbolicLinks.h"

namespace bf = boost::filesystem;

namespace
{

  std::atomic<bool> s_fileLookupDisabled{false};


  const std::string PathVariableName("CMSSW_SEARCH_PATH");
  // Environment variables for local and release areas:
  const std::string LOCALTOP("CMSSW_BASE");
  const std::string RELEASETOP("CMSSW_RELEASE_BASE");
  const std::string DATATOP("CMSSW_DATA_PATH");

#if 1
  // Needed for backward compatibility prior to CMSSW_1_5_0_pre3.
  // String to serve as placeholder for release top.
  // Do not change this value.
  const std::string BASE("BASE");
#endif
  const std::string version("V001");

  // Remove symlinks from path
  std::string removeSymLinks(std::string const& envName) {
    char const* const var = getenv(envName.c_str());
    if(var == nullptr) {
      return std::string();
    }
    std::string path = var;
    edm::resolveSymbolicLinks(path);
    return path;
  }

  std::string removeSymLinksSrc(std::string const& envName) {
    char const* const var = getenv(envName.c_str());
    if(var == nullptr) {
      return std::string();
    }
    std::string const src = "/src";
    std::string path = var + src;
    edm::resolveSymbolicLinks(path);
    size_t actualSize = path.size() - src.size();
    assert(path.substr(actualSize, src.size())  == src);
    return path.substr(0, actualSize);
  }

  std::string removeSymLinksTokens(std::string const& envName) {
    char const* const var = getenv(envName.c_str());
    if(var == nullptr) {
      return std::string();
    }
    std::string theSearchPath;
    typedef std::vector<std::string> stringvec_t;
    stringvec_t pathElements = edm::tokenize(std::string(var), ":");
    for(auto& element : pathElements) {
      edm::resolveSymbolicLinks(element);
      if(!theSearchPath.empty()) theSearchPath += ":";
      theSearchPath += element;
    }
    return theSearchPath;
  }

  // Check for existence of a file for the given relative path and
  // 'prefix'.
  // Return true if a file (not directory or symbolic link) is found
  // Return false is *nothing* is found
  // Throw an exception if either a directory or symbolic link is found.
  // If true is returned, then put the
  bool locateFile(bf::path  p,
          std::string const& relative)
  {
    p /= relative;

    if (!bf::exists(p)) return false;

    if (bf::is_directory(p)) {
      throw edm::Exception(edm::errors::FileInPathError)
    << "Path "
    << p.string()
    << " is a directory, not a file\n";
    }

    if (bf::is_symlink(bf::symlink_status(p))) {
      throw edm::Exception(edm::errors::FileInPathError)
    << "Path "
    << p.string()
    << " is a symbolic link, not a file\n";
    }
    return true;
  }
}

namespace edm
{

  FileInPath::FileInPath() :
    relativePath_(),
    canonicalFilename_(),
    location_(Unknown)
  {
    if (s_fileLookupDisabled) {
      return;
    }
    getEnvironment();
  }

  FileInPath::FileInPath(const std::string& r) :
    relativePath_(r),
    canonicalFilename_(),
    location_(Unknown)
  {
    if (s_fileLookupDisabled) {
      return;
    }
    getEnvironment();
    initialize_();
  }

  FileInPath::FileInPath(char const* r) :
    relativePath_(r ? r : ""),
    canonicalFilename_(),
    location_(Unknown)
  {
    if (s_fileLookupDisabled) {
      return;
    }
    if(r == nullptr) {
     throw edm::Exception(edm::errors::FileInPathError) << "Relative path must not be null\n";
    }
    getEnvironment();
    initialize_();
  }

  FileInPath::FileInPath(FileInPath const& other) :
    relativePath_(other.relativePath_),
    canonicalFilename_(other.canonicalFilename_),
    location_(other.location_),
    localTop_(other.localTop_),
    releaseTop_(other.releaseTop_),
    dataTop_(other.dataTop_),
    searchPath_(other.searchPath_)
  {}

  FileInPath::~FileInPath() {}

  FileInPath&
  FileInPath::operator=(FileInPath const& other)
  {
    FileInPath temp(other);
    this->swap(temp);
    return *this;
  }

  void
  FileInPath::swap(FileInPath& other)
  {
    relativePath_.swap(other.relativePath_);
    canonicalFilename_.swap(other.canonicalFilename_);
    std::swap(location_, other.location_);
    localTop_.swap(other.localTop_);
    releaseTop_.swap(other.releaseTop_);
    dataTop_.swap(other.dataTop_);
    searchPath_.swap(other.searchPath_);
  }

  std::string
  FileInPath::relativePath() const
  {
    return relativePath_;
  }


  FileInPath::LocationCode
  FileInPath::location() const
  {
    return location_;
  }

  std::string
  FileInPath::fullPath() const
  {
    return canonicalFilename_;
  }

  void
  FileInPath::write(std::ostream& os) const
  {
    if (location_ == Unknown) {
      os << version << ' ' << relativePath_ << ' ' << location_;
    } else if (location_ == Local) {
      // Guarantee a site independent value by stripping $LOCALTOP.
      if (localTop_.empty()) {
    throw edm::Exception(edm::errors::FileInPathError)
      << "Environment Variable "
      << LOCALTOP
      << " is not set.\n";
      }
      std::string::size_type pos = canonicalFilename_.find(localTop_);
      if (pos != 0) {
    throw edm::Exception(edm::errors::FileInPathError)
      << "Path "
      << canonicalFilename_
      << " is not in the local release area "
      << localTop_
      << "\n";
      }
      os << version << ' ' << relativePath_ << ' ' << location_ << ' ' << canonicalFilename_.substr(localTop_.size());
    } else if (location_ == Release) {
      // Guarantee a site independent value by stripping $RELEASETOP.
      if (releaseTop_.empty()) {
    throw edm::Exception(edm::errors::FileInPathError)
      << "Environment Variable "
      << RELEASETOP
      << " is not set.\n";
      }
      std::string::size_type pos = canonicalFilename_.find(releaseTop_);
      if (pos != 0) {
    throw edm::Exception(edm::errors::FileInPathError)
      << "Path "
      << canonicalFilename_
      << " is not in the base release area "
      << releaseTop_
      << "\n";
      }
      os << version << ' ' << relativePath_ << ' ' << location_ << ' ' << canonicalFilename_.substr(releaseTop_.size());
    } else if (location_ == Data) {
      // Guarantee a site independent value by stripping $DATATOP.
      if (dataTop_.empty()) {
    throw edm::Exception(edm::errors::FileInPathError)
      << "Environment Variable "
      << DATATOP
      << " is not set.\n";
      }
      std::string::size_type pos = canonicalFilename_.find(dataTop_);
      if (pos != 0) {
    throw edm::Exception(edm::errors::FileInPathError)
      << "Path "
      << canonicalFilename_
      << " is not in the data area "
      << dataTop_
      << "\n";
      }
      os << version << ' ' << relativePath_ << ' ' << location_ << ' ' << canonicalFilename_.substr(dataTop_.size());
    }
  }


  void
  FileInPath::read(std::istream& is)
  {
    std::string vsn;
    std::string relname;
    std::string canFilename;
#if 1
    // This #if needed for backward compatibility
    // for files written before CMSSW_1_5_0_pre3.
    is >> vsn;
    if (!is) return;
    bool oldFormat = (version != vsn);
    if (oldFormat) {
      relname = vsn;
      bool local;
      is >> local;
      location_ = (local ? Local : Release);
      is >> canFilename;
    } else {
      // Current format
      int loc;
      is >> relname >> loc;
      location_ = static_cast<FileInPath::LocationCode>(loc);
      if (location_ != Unknown) is >> canFilename;
    }
#else
    is >> vsn >> relname >> loc >> canFilename;
#endif
    if (!is) return;
    relativePath_ = relname;
    if (location_ == Local) {
      if (localTop_.empty()) {
    throw edm::Exception(edm::errors::FileInPathError)
      << "Environment Variable "
      << LOCALTOP
      << " is not set.\n"
      << "Trying to read Local file: " << canFilename << ".\n";
      }
#if 1
      // This #if needed for backward compatibility
      // for files written before CMSSW_1_5_0_pre3.
      if (oldFormat) {
        canonicalFilename_ = canFilename;
      } else
#endif
      canonicalFilename_ = localTop_ + canFilename;
    } else if (location_ == Release) {
      if (releaseTop_.empty()) {
    throw edm::Exception(edm::errors::FileInPathError)
      << "Environment Variable "
      << RELEASETOP
      << " is not set.\n";
      }
#if 1
      // This #if needed for backward compatibility
      // for files written before CMSSW_1_5_0_pre3.
      if (oldFormat) {
         std::string::size_type pos = canFilename.find(BASE);
        if (pos == 0) {
          // Replace the placehoder with the path to the base release (site dependent).
          canonicalFilename_ = releaseTop_ + canFilename.substr(BASE.size());
        } else {
          // Needed for files written before CMSSW_1_2_0_pre2.
          canonicalFilename_ = canFilename;
        }
      } else
#endif
      canonicalFilename_ = releaseTop_ + canFilename;
    } else if (location_ == Data) {
      if (dataTop_.empty()) {
    throw edm::Exception(edm::errors::FileInPathError)
      << "Environment Variable "
      << DATATOP
      << " is not set.\n";
      }
      canonicalFilename_ = dataTop_ + canFilename;
    }
  }

  void
  FileInPath::readFromParameterSetBlob(std::istream& is)
  {
    std::string vsn;
    std::string relname;
    std::string canFilename;
    is >> vsn;
    if (!is) return;
    bool oldFormat = (version != vsn);
    if (oldFormat) {
      relname = vsn;
      bool local;
      is >> local;
      location_ = (local ? Local : Release);
      is >> canFilename;
    } else {
      // Current format
      int loc;
      is >> relname >> loc;
      location_ = static_cast<FileInPath::LocationCode>(loc);
      if (location_ != Unknown) is >> canFilename;
    }
    if (!is) return;
    relativePath_ = relname;
    if (location_ == Local) {
      if (localTop_.empty()) {
    localTop_ = "@LOCAL";
      }
      if (oldFormat) {
        canonicalFilename_ = canFilename;
      } else
      canonicalFilename_ = localTop_ + canFilename;
    } else if (location_ == Release) {
      if (releaseTop_.empty()) {
    releaseTop_="@RELEASE";
      }
      if (oldFormat) {
         std::string::size_type pos = canFilename.find(BASE);
        if (pos == 0) {
          // Replace the placehoder with the path to the base release (site dependent).
          canonicalFilename_ = releaseTop_ + canFilename.substr(BASE.size());
        } else {
          // Needed for files written before CMSSW_1_2_0_pre2.
          canonicalFilename_ = canFilename;
        }
      } else
      canonicalFilename_ = releaseTop_ + canFilename;
    } else if (location_ == Data) {
      if (dataTop_.empty()) {
    throw edm::Exception(edm::errors::FileInPathError)
      << "Environment Variable "
      << DATATOP
      << " is not set.\n";
      }
      canonicalFilename_ = dataTop_ + canFilename;
    }
  }

  //------------------------------------------------------------


  void
  FileInPath::getEnvironment() {
    static std::string const searchPath = removeSymLinksTokens(PathVariableName);
    if (searchPath.empty()) {
      throw edm::Exception(edm::errors::FileInPathError)
    << PathVariableName
    << " must be defined\n";
    }
    searchPath_ = searchPath;

    static std::string const releaseTop = removeSymLinksSrc(RELEASETOP);
    releaseTop_ = releaseTop;

    static std::string const localTop = removeSymLinksSrc(LOCALTOP);
    localTop_ = localTop;

    static std::string const dataTop = removeSymLinks(DATATOP);
    dataTop_ = dataTop;

    if (releaseTop_.empty()) {
      // RELEASETOP was not set.  This means that the environment is set
      // for the base release itself.  So LOCALTOP actually contains the
      // location of the base release.
      releaseTop_ = localTop_;
      localTop_.clear();
    }
    if (releaseTop_ == localTop_) {
      // RELEASETOP is the same as LOCALTOP.  This means that the environment is set
      // for the base release itself.  So LOCALTOP actually contains the
      // location of the base release.
        localTop_.clear();
    }
  }

  void
  FileInPath::initialize_() {
    if (relativePath_.empty()) {
      throw edm::Exception(edm::errors::FileInPathError)
    << "Relative path must not be empty\n";
    }

    // Find the file, based on the value of path variable.
    typedef std::vector<std::string> stringvec_t;
    stringvec_t  pathElements = tokenize(searchPath_, ":");
    for(auto const& element : pathElements) {
      // Set the boost::fs path to the current element of
      // CMSSW_SEARCH_PATH:
      bf::path pathPrefix(element);

      // Does the a file exist? locateFile throws is it finds
      // something goofy.
      if (locateFile(pathPrefix, relativePath_)) {
    // Convert relative path to canonical form, and save it.
    relativePath_ = bf::path(relativePath_).normalize().string();

    // Save the absolute path.
    canonicalFilename_ = bf::absolute(relativePath_, pathPrefix).string();
    if (canonicalFilename_.empty()) {
      throw edm::Exception(edm::errors::FileInPathError)
        << "fullPath is empty"
        << "\nrelativePath() is: " << relativePath_
        << "\npath prefix is: " << pathPrefix.string()
        << '\n';
        }

    // From the current path element, find the branch path (basically the path minus the
    // last directory, e.g. /src or /share):
    for (bf::path br = pathPrefix.branch_path(); !br.normalize().string().empty(); br = br.branch_path()) {

      if (!localTop_.empty()) {
        // Create a path object for our local path LOCALTOP:
        bf::path local_(localTop_);
        // If the branch path matches the local path, the file was found locally:
        if (br == local_) {
          location_ = Local;
          return;
        }
      }

      if (!releaseTop_.empty()) {
        // Create a path object for our release path RELEASETOP:
        bf::path release_(releaseTop_);
        // If the branch path matches the release path, the file was found in the release:
        if (br == release_) {
          location_ = Release;
          return;
        }
      }

      if (!dataTop_.empty()) {
        // Create a path object for our data path DATATOP:
        bf::path data_(dataTop_);
        // If the branch path matches the data path, the file was found in the data area:
        if (br == data_) {
          location_ = Data;
          return;
        }
      }
    }
      }
    }

    // If we got here, we ran out of path elements without finding
    // what we're looking found.
    throw edm::Exception(edm::errors::FileInPathError)
      << "edm::FileInPath unable to find file "
      << relativePath_
      << " anywhere in the search path."
      << "\nThe search path is defined by: "
      << PathVariableName
      << "\n${"
      << PathVariableName
      << "} is: "
      << getenv(PathVariableName.c_str())
      << "\nCurrent directory is: "
      << bf::initial_path().string()
      << "\n";
  }

  void FileInPath::disableFileLookup() {
    s_fileLookupDisabled = true;
  }

}