src/gromacs/utility/directoryenumerator.cpp

   1 /*
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  36 /*! \internal \file
  37  * \brief
  38  * Implements gmx::DirectoryEnumerator.
  39  *
  40  * \author Erik Lindahl (original C implementation)
  41  * \author Teemu Murtola <teemu.murtola@gmail.com> (C++ wrapper + errno handling)
  42  * \ingroup module_utility
  43  */
  44 #include "gmxpre.h"
  45
  46 #include "directoryenumerator.h"
  47
  48 #include "config.h"
  49
  50 #include <cerrno>
  51 #include <cstdio>
  52
  53 #include <algorithm>
  54 #include <string>
  55 #include <vector>
  56
  57 #if HAVE_DIRENT_H
  58 #    include <dirent.h>
  59 #endif
  60 #if GMX_NATIVE_WINDOWS
  61 #    include <io.h>
  62 #endif
  63
  64 #include "gromacs/utility/exceptions.h"
  65 #include "gromacs/utility/fatalerror.h"
  66 #include "gromacs/utility/futil.h"
  67 #include "gromacs/utility/gmxassert.h"
  68 #include "gromacs/utility/smalloc.h"
  69 #include "gromacs/utility/stringutil.h"
  70
  71 namespace gmx
  72 {
  73
  74 /********************************************************************
  75  * DirectoryEnumerator::Impl
  76  */
  77
  78 // TODO: Consider whether checking the return value of closing would be useful,
  79 // and what could we do if it fails?
  80 #if GMX_NATIVE_WINDOWS
  81 // TODO: Consider if Windows provides more error details through other APIs.
  82 class DirectoryEnumerator::Impl
  83 {
  84 public:
  85     static Impl* init(const char* dirname, bool bThrow)
  86     {
  87         std::string tmpname(dirname);
  88         // Remove possible trailing directory separator.
  89         // TODO: Use a method in gmx::Path instead.
  90         if (tmpname.back() == '/' || tmpname.back() == '\\')
  91         {
  92             tmpname.pop_back();
  93         }
  94
  95         // Add wildcard.
  96         tmpname.append("/*");
  97
  98         errno = 0;
  99         _finddata_t finddata;
 100         intptr_t    handle = _findfirst(tmpname.c_str(), &finddata);
 101         if (handle < 0L)
 102         {
 103             if (errno != ENOENT && bThrow)
 104             {
 105                 const int         code = errno;
 106                 const std::string message =
 107                         formatString("Failed to list files in directory '%s'", dirname);
 108                 GMX_THROW_WITH_ERRNO(FileIOError(message), "_findfirst", code);
 109             }
 110             return NULL;
 111         }
 112         return new Impl(handle, finddata);
 113     }
 114     Impl(intptr_t handle, _finddata_t finddata) :
 115         windows_handle(handle),
 116         finddata(finddata),
 117         bFirst_(true)
 118     {
 119     }
 120     ~Impl() { _findclose(windows_handle); }
 121
 122     bool nextFile(std::string* filename)
 123     {
 124         if (bFirst_)
 125         {
 126             *filename = finddata.name;
 127             bFirst_   = false;
 128             return true;
 129         }
 130         else
 131         {
 132             errno = 0;
 133             if (_findnext(windows_handle, &finddata) != 0)
 134             {
 135                 if (errno == 0 || errno == ENOENT)
 136                 {
 137                     filename->clear();
 138                     return false;
 139                 }
 140                 else
 141                 {
 142                     GMX_THROW_WITH_ERRNO(FileIOError("Failed to list files in a directory"),
 143                                          "_findnext", errno);
 144                 }
 145             }
 146             *filename = finddata.name;
 147             return true;
 148         }
 149     }
 150
 151 private:
 152     intptr_t    windows_handle;
 153     _finddata_t finddata;
 154     bool        bFirst_;
 155 };
 156 #elif HAVE_DIRENT_H
 157 class DirectoryEnumerator::Impl
 158 {
 159 public:
 160     static Impl* init(const char* dirname, bool bThrow)
 161     {
 162         errno       = 0;
 163         DIR* handle = opendir(dirname);
 164         if (handle == nullptr)
 165         {
 166             if (bThrow)
 167             {
 168                 const int         code = errno;
 169                 const std::string message =
 170                         formatString("Failed to list files in directory '%s'", dirname);
 171                 GMX_THROW_WITH_ERRNO(FileIOError(message), "opendir", code);
 172             }
 173             return nullptr;
 174         }
 175         return new Impl(handle);
 176     }
 177     explicit Impl(DIR* handle) : dirent_handle(handle) {}
 178     ~Impl() { closedir(dirent_handle); }
 179
 180     bool nextFile(std::string* filename)
 181     {
 182         errno     = 0;
 183         dirent* p = readdir(dirent_handle);
 184         if (p == nullptr)
 185         {
 186             if (errno == 0)
 187             {
 188                 // All the files have been found.
 189                 filename->clear();
 190                 return false;
 191             }
 192             else
 193             {
 194                 GMX_THROW_WITH_ERRNO(FileIOError("Failed to list files in a directory"), "readdir", errno);
 195             }
 196         }
 197         *filename = p->d_name;
 198         return true;
 199     }
 200
 201 private:
 202     DIR* dirent_handle;
 203 };
 204 #else
 205 class DirectoryEnumerator::Impl
 206 {
 207 public:
 208     static Impl* init(const char* /*dirname*/, bool /*bThrow*/)
 209     {
 210         std::string message(
 211                 "Source compiled without POSIX dirent or Windows support "
 212                 "- cannot scan directories. In the very unlikely event "
 213                 "this is not a compile-time mistake you could consider "
 214                 "implementing support for your platform in "
 215                 "directoryenumerator.cpp, but contact the developers "
 216                 "to make sure it's really necessary!");
 217         GMX_THROW(NotImplementedError(message));
 218     }
 219
 220     bool nextFile(std::string* /*filename*/) { return false; }
 221 };
 222 #endif
 223
 224 /********************************************************************
 225  * DirectoryEnumerator
 226  */
 227
 228 // static
 229 std::vector<std::string> DirectoryEnumerator::enumerateFilesWithExtension(const char* dirname,
 230                                                                           const char* extension,
 231                                                                           bool        bThrow)
 232 {
 233     std::vector<std::string> result;
 234     DirectoryEnumerator      dir(dirname, bThrow);
 235     std::string              nextName;
 236     while (dir.nextFile(&nextName))
 237     {
 238         if (debug)
 239         {
 240             std::fprintf(debug, "dir '%s' file '%s'\n", dirname, nextName.c_str());
 241         }
 242         // TODO: What about case sensitivity?
 243         if (endsWith(nextName, extension))
 244         {
 245             result.push_back(nextName);
 246         }
 247     }
 248
 249     std::sort(result.begin(), result.end());
 250     return result;
 251 }
 252
 253
 254 DirectoryEnumerator::DirectoryEnumerator(const char* dirname, bool bThrow) : impl_(nullptr)
 255 {
 256     GMX_RELEASE_ASSERT(dirname != nullptr && dirname[0] != '\0',
 257                        "Attempted to open empty/null directory path");
 258     impl_.reset(Impl::init(dirname, bThrow));
 259 }
 260
 261 DirectoryEnumerator::DirectoryEnumerator(const std::string& dirname, bool bThrow) : impl_(nullptr)
 262 {
 263     GMX_RELEASE_ASSERT(!dirname.empty(), "Attempted to open empty/null directory path");
 264     impl_.reset(Impl::init(dirname.c_str(), bThrow));
 265 }
 266
 267 DirectoryEnumerator::~DirectoryEnumerator() {}
 268
 269 bool DirectoryEnumerator::nextFile(std::string* filename)
 270 {
 271     if (impl_ == nullptr)
 272     {
 273         filename->clear();
 274         return false;
 275     }
 276     return impl_->nextFile(filename);
 277 }
 278
 279 } // namespace gmx