Merge pull request #2358 from tallakahath/master

Support for multiple paths in OPENMM_PLUGIN_DIR

olla/include/openmm/Platform.h

@@ -213,12 +213,17 @@ public:
      */
     static void loadPluginLibrary(const std::string& file);
     /**
-     * Load multiple dynamic libraries (DLLs) which contain OpenMM plugins from a single directory.
-     * This method loops over every file contained in the specified directory and calls loadPluginLibrary()
+     * Load multiple dynamic libraries (DLLs) which contain OpenMM plugins from one or more directories.
+     * Multiple fully-qualified paths can be joined together with ':' on unix-like systems
+     * (or ';' on windows-like systems); each will be searched for plugins, in-order. For example,
+     * '/foo/plugins:/bar/plugins' will search both `/foo/plugins` and `/bar/plugins`. If an
+     * identically-named plugin is encountered twice it will be loaded at both points; be careful!!!
+     *
+     * This method loops over every file contained in the specified directories and calls loadPluginLibrary()
      * for each one.  If an error occurs while trying to load a particular file, that file is simply
      * ignored. You can retrieve a list of all such errors by calling getPluginLoadFailures().
      *
-     * @param directory    the path to the directory containing libraries to load
+     * @param directory    a ':' (unix) or ';' (windows) deliminated list of paths containing libraries to load
      * @return the names of all files which were successfully loaded as libraries
      */
     static std::vector<std::string> loadPluginsFromDirectory(const std::string& directory);

olla/src/Platform.cpp

@@ -37,7 +37,6 @@
 #include "openmm/internal/ContextImpl.h"
 #ifdef WIN32
 #include <windows.h>
-#include <sstream>
 #else
 #ifndef __PNACL__
     #include <dlfcn.h>
@@ -45,6 +44,7 @@
 #include <dirent.h>
 #include <cstdlib>
 #endif
+#include <sstream>
 #include <set>
 #include <algorithm>
 
@@ -261,31 +261,42 @@ void Platform::loadPluginLibrary(const string& file) {
 vector<string> Platform::loadPluginsFromDirectory(const string& directory) {
     vector<string> files;
     char dirSeparator;
+    char pathSeparator;
+    stringstream sdirectory(directory);
 #ifdef WIN32
     dirSeparator = '\\';
+    pathSeparator = ';';
     WIN32_FIND_DATA fileInfo;
-    string filePattern(directory + dirSeparator + "*.dll");
+
+    for (string path; std::getline(sdirectory, path, pathSeparator);) {
+        string filePattern(path + dirSeparator + "*.dll");
         HANDLE findHandle = FindFirstFile(filePattern.c_str(), &fileInfo);
         if (findHandle != INVALID_HANDLE_VALUE) {
             do {
                 if (fileInfo.cFileName[0] != '.')
-                files.push_back(string(fileInfo.cFileName));
+                    files.push_back(path+dirSeparator+string(fileInfo.cFileName));
             } while (FindNextFile(findHandle, &fileInfo));
             FindClose(findHandle);
         }
+    }
     vector<HMODULE> plugins;
 #else
-    dirSeparator = '/';
     DIR* dir;
+    dirSeparator = '/';
+    pathSeparator = ':';
     struct dirent *entry;
-    dir = opendir(directory.c_str());
+
+    for (string path; std::getline(sdirectory, path, pathSeparator);) {
+        dir = opendir(path.c_str());
         if (dir != NULL) {
             while ((entry = readdir(dir)) != NULL) {
                 if (entry->d_name[0] != '.')
-                files.push_back(string(entry->d_name));
+                    files.push_back(path+dirSeparator+string(entry->d_name));
             }
             closedir(dir);
         }
+    }
+
     vector<void*> plugins;
 #endif
     vector<string> loadedLibraries;
@@ -294,7 +305,7 @@ vector<string> Platform::loadPluginsFromDirectory(const string& directory) {
 
     for (unsigned int i = 0; i < files.size(); ++i) {
         try {
-            plugins.push_back(loadOneLibrary(directory+dirSeparator+files[i]));
+            plugins.push_back(loadOneLibrary(files[i]));
             loadedLibraries.push_back(files[i]);
         } catch (OpenMMException& ex) {
 	    pluginLoadFailures.push_back(ex.what());