Ninja
disk_interface.cc
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00001 // Copyright 2011 Google Inc. All Rights Reserved.
00002 //
00003 // Licensed under the Apache License, Version 2.0 (the "License");
00004 // you may not use this file except in compliance with the License.
00005 // You may obtain a copy of the License at
00006 //
00007 //     http://www.apache.org/licenses/LICENSE-2.0
00008 //
00009 // Unless required by applicable law or agreed to in writing, software
00010 // distributed under the License is distributed on an "AS IS" BASIS,
00011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00012 // See the License for the specific language governing permissions and
00013 // limitations under the License.
00014 
00015 #include "disk_interface.h"
00016 
00017 #include <errno.h>
00018 #include <stdio.h>
00019 #include <string.h>
00020 #include <sys/stat.h>
00021 #include <sys/types.h>
00022 
00023 #ifdef _WIN32
00024 #include <windows.h>
00025 #include <direct.h>  // _mkdir
00026 #endif
00027 
00028 #include "util.h"
00029 
00030 namespace {
00031 
00032 string DirName(const string& path) {
00033 #ifdef _WIN32
00034   const char kPathSeparator = '\\';
00035 #else
00036   const char kPathSeparator = '/';
00037 #endif
00038 
00039   string::size_type slash_pos = path.rfind(kPathSeparator);
00040   if (slash_pos == string::npos)
00041     return string();  // Nothing to do.
00042   while (slash_pos > 0 && path[slash_pos - 1] == kPathSeparator)
00043     --slash_pos;
00044   return path.substr(0, slash_pos);
00045 }
00046 
00047 int MakeDir(const string& path) {
00048 #ifdef _WIN32
00049   return _mkdir(path.c_str());
00050 #else
00051   return mkdir(path.c_str(), 0777);
00052 #endif
00053 }
00054 
00055 }  // namespace
00056 
00057 // DiskInterface ---------------------------------------------------------------
00058 
00059 bool DiskInterface::MakeDirs(const string& path) {
00060   string dir = DirName(path);
00061   if (dir.empty())
00062     return true;  // Reached root; assume it's there.
00063   TimeStamp mtime = Stat(dir);
00064   if (mtime < 0)
00065     return false;  // Error.
00066   if (mtime > 0)
00067     return true;  // Exists already; we're done.
00068 
00069   // Directory doesn't exist.  Try creating its parent first.
00070   bool success = MakeDirs(dir);
00071   if (!success)
00072     return false;
00073   return MakeDir(dir);
00074 }
00075 
00076 // RealDiskInterface -----------------------------------------------------------
00077 
00078 TimeStamp RealDiskInterface::Stat(const string& path) {
00079 #ifdef _WIN32
00080   // MSDN: "Naming Files, Paths, and Namespaces"
00081   // http://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx
00082   if (!path.empty() && path[0] != '\\' && path.size() > MAX_PATH) {
00083     if (!quiet_) {
00084       Error("Stat(%s): Filename longer than %i characters",
00085             path.c_str(), MAX_PATH);
00086     }
00087     return -1;
00088   }
00089   WIN32_FILE_ATTRIBUTE_DATA attrs;
00090   if (!GetFileAttributesEx(path.c_str(), GetFileExInfoStandard, &attrs)) {
00091     DWORD err = GetLastError();
00092     if (err == ERROR_FILE_NOT_FOUND || err == ERROR_PATH_NOT_FOUND)
00093       return 0;
00094     if (!quiet_) {
00095       Error("GetFileAttributesEx(%s): %s", path.c_str(),
00096             GetLastErrorString().c_str());
00097     }
00098     return -1;
00099   }
00100   const FILETIME& filetime = attrs.ftLastWriteTime;
00101   // FILETIME is in 100-nanosecond increments since the Windows epoch.
00102   // We don't much care about epoch correctness but we do want the
00103   // resulting value to fit in an integer.
00104   uint64_t mtime = ((uint64_t)filetime.dwHighDateTime << 32) |
00105     ((uint64_t)filetime.dwLowDateTime);
00106   mtime /= 1000000000LL / 100; // 100ns -> s.
00107   mtime -= 12622770400LL;  // 1600 epoch -> 2000 epoch (subtract 400 years).
00108   return (TimeStamp)mtime;
00109 #else
00110   struct stat st;
00111   if (stat(path.c_str(), &st) < 0) {
00112     if (errno == ENOENT || errno == ENOTDIR)
00113       return 0;
00114     if (!quiet_) {
00115       Error("stat(%s): %s", path.c_str(), strerror(errno));
00116     }
00117     return -1;
00118   }
00119   return st.st_mtime;
00120 #endif
00121 }
00122 
00123 bool RealDiskInterface::WriteFile(const string& path, const string& contents) {
00124   FILE* fp = fopen(path.c_str(), "w");
00125   if (fp == NULL) {
00126     Error("WriteFile(%s): Unable to create file. %s",
00127           path.c_str(), strerror(errno));
00128     return false;
00129   }
00130 
00131   if (fwrite(contents.data(), 1, contents.length(), fp) < contents.length())  {
00132     Error("WriteFile(%s): Unable to write to the file. %s",
00133           path.c_str(), strerror(errno));
00134     fclose(fp);
00135     return false;
00136   }
00137 
00138   if (fclose(fp) == EOF) {
00139     Error("WriteFile(%s): Unable to close the file. %s",
00140           path.c_str(), strerror(errno));
00141     return false;
00142   }
00143 
00144   return true;
00145 }
00146 
00147 bool RealDiskInterface::MakeDir(const string& path) {
00148   if (::MakeDir(path) < 0) {
00149     Error("mkdir(%s): %s", path.c_str(), strerror(errno));
00150     return false;
00151   }
00152   return true;
00153 }
00154 
00155 string RealDiskInterface::ReadFile(const string& path, string* err) {
00156   string contents;
00157   int ret = ::ReadFile(path, &contents, err);
00158   if (ret == -ENOENT) {
00159     // Swallow ENOENT.
00160     err->clear();
00161   }
00162   return contents;
00163 }
00164 
00165 int RealDiskInterface::RemoveFile(const string& path) {
00166   if (remove(path.c_str()) < 0) {
00167     switch (errno) {
00168       case ENOENT:
00169         return 1;
00170       default:
00171         Error("remove(%s): %s", path.c_str(), strerror(errno));
00172         return -1;
00173     }
00174   } else {
00175     return 0;
00176   }
00177 }