ENH: During file installation treat the source file as a dependency of the installed file. Install the file only if the destination is older than the source. Set the file times on the installed file to match those of the source file. This should greatly improve the speed of repeated installations because it removes the comparison of file contents. This addresses bug#3349.

1 files changed, 45 insertions, 18 deletions

diff --git a/Source/cmFileCommand.cxx b/Source/cmFileCommand.cxx
index 9330bb455a..3a31a3fee2 100644
--- a/Source/cmFileCommand.cxx
+++ b/Source/cmFileCommand.cxx
@@ -17,9 +17,11 @@
 #include "cmFileCommand.h"
 #include "cmake.h"
 #include "cmHexFileConverter.h"
+#include "cmFileTimeComparison.h"
 
 #include <sys/types.h>
 #include <sys/stat.h>
+
 #include <cmsys/Directory.hxx>
 #include <cmsys/Glob.hxx>
 #include <cmsys/RegularExpression.hxx>
@@ -716,6 +718,7 @@ struct cmFileInstaller
 private:
   cmFileCommand* FileCommand;
   cmMakefile* Makefile;
+  cmFileTimeComparison FileTimes;
 public:
 
   // The length of the destdir setting.
@@ -807,11 +810,6 @@ private:
 bool cmFileInstaller::InstallSymlink(const char* fromFile, const char* toFile,
                                      bool always)
 {
-  // Inform the user about this file installation.
-  std::string message = "Installing ";
-  message += toFile;
-  this->Makefile->DisplayStatus(message.c_str(), -1);
-
   // Read the original symlink.
   std::string symlinkTarget;
   if(!cmSystemTools::ReadSymlink(fromFile, symlinkTarget))
@@ -825,6 +823,7 @@ bool cmFileInstaller::InstallSymlink(const char* fromFile, const char* toFile,
 
   // Compare the symlink value to that at the destination if not
   // always installing.
+  bool copy = true;
   if(!always)
     {
     std::string oldSymlinkTarget;
@@ -832,22 +831,30 @@ bool cmFileInstaller::InstallSymlink(const char* fromFile, const char* toFile,
       {
       if(symlinkTarget == oldSymlinkTarget)
         {
-        return true;
+        copy = false;
         }
       }
     }
 
-  // Remove the destination file so we can always create the symlink.
-  cmSystemTools::RemoveFile(toFile);
+  // Inform the user about this file installation.
+  std::string message = (copy? "Installing: " : "Up-to-date: ");
+  message += toFile;
+  this->Makefile->DisplayStatus(message.c_str(), -1);
 
-  // Create the symlink.
-  if(!cmSystemTools::CreateSymlink(symlinkTarget.c_str(), toFile))
+  if(copy)
     {
-    cmOStringStream e;
-    e << "INSTALL cannot duplicate symlink \"" << fromFile
-      << "\" at \"" << toFile << "\".";
-    this->FileCommand->SetError(e.str().c_str());
-    return false;
+    // Remove the destination file so we can always create the symlink.
+    cmSystemTools::RemoveFile(toFile);
+
+    // Create the symlink.
+    if(!cmSystemTools::CreateSymlink(symlinkTarget.c_str(), toFile))
+      {
+      cmOStringStream e;
+      e << "INSTALL cannot duplicate symlink \"" << fromFile
+        << "\" at \"" << toFile << "\".";
+      this->FileCommand->SetError(e.str().c_str());
+      return false;
+      }
     }
 
   // Add the file to the manifest.
@@ -875,13 +882,27 @@ bool cmFileInstaller::InstallFile(const char* fromFile, const char* toFile,
     return this->InstallSymlink(fromFile, toFile, always);
     }
 
+  // Determine whether we will copy the file.
+  bool copy = true;
+  if(!always)
+    {
+    // If both files exist and "fromFile" is not newer than "toFile"
+    // do not copy.
+    int timeResult;
+    if(this->FileTimes.FileTimeCompare(fromFile, toFile, &timeResult) &&
+       timeResult <= 0)
+      {
+      copy = false;
+      }
+    }
+
   // Inform the user about this file installation.
-  std::string message = "Installing ";
+  std::string message = (copy? "Installing: " : "Up-to-date: ");
   message += toFile;
   this->Makefile->DisplayStatus(message.c_str(), -1);
 
   // Copy the file.
-  if(!cmSystemTools::CopyAFile(fromFile, toFile, always))
+  if(copy && !cmSystemTools::CopyAFile(fromFile, toFile, true))
     {
     cmOStringStream e;
     e << "INSTALL cannot copy file \"" << fromFile
@@ -893,6 +914,12 @@ bool cmFileInstaller::InstallFile(const char* fromFile, const char* toFile,
   // Add the file to the manifest.
   this->ManifestAppend(toFile);
 
+  // Set the file modification time of the destination file.
+  if(copy && !always)
+    {
+    cmSystemTools::CopyFileTime(fromFile, toFile);
+    }
+
   // Set permissions of the destination file.
   mode_t permissions = (match_properties.Permissions?
                         match_properties.Permissions : this->FilePermissions);
@@ -934,7 +961,7 @@ bool cmFileInstaller::InstallDirectory(const char* source,
     }
 
   // Inform the user about this directory installation.
-  std::string message = "Installing ";
+  std::string message = "Installing: ";
   message += destination;
   this->Makefile->DisplayStatus(message.c_str(), -1);