Move common potentials opening code to utils

src/force.cpp

@@ -1037,102 +1037,18 @@ tagint Force::tnumeric(const char *file, int line, char *str)
 
 FILE *Force::open_potential(const char *name)
 {
-  FILE *fp;
+  std::string filepath = utils::get_potential_file_path(name);
+  std::string date;
 
-  if (name == NULL) return NULL;
+  if(!filepath.empty()) {
+    date = utils::get_potential_date(filepath, "potential");
 
-  // attempt to open file directly
-  // if successful, return ptr
-
-  fp = fopen(name,"r");
-  if (fp) {
-    if (comm->me == 0) potential_date(fp,name);
-    rewind(fp);
-    return fp;
-  }
-
-  // try the environment variable directory
-
-  const char *path = getenv("LAMMPS_POTENTIALS");
-  if (path == NULL) return NULL;
-
-  const char *pot = potential_name(name);
-  if (pot == NULL) return NULL;
-
-  size_t len1 = strlen(path);
-  size_t len2 = strlen(pot);
-  char *newpath = new char[len1+len2+2];
-
-  strcpy(newpath,path);
-#if defined(_WIN32)
-  newpath[len1] = '\\';
-  newpath[len1+1] = 0;
-#else
-  newpath[len1] = '/';
-  newpath[len1+1] = 0;
-#endif
-  strcat(newpath,pot);
-
-  fp = fopen(newpath,"r");
-  if (fp) {
-    if (comm->me == 0) potential_date(fp,name);
-    rewind(fp);
-  }
-
-  delete [] newpath;
-  return fp;
-}
-
-/* ----------------------------------------------------------------------
-   strip off leading part of path, return just the filename
-------------------------------------------------------------------------- */
-
-const char *Force::potential_name(const char *path)
-{
-  const char *pot;
-
-  if (path == NULL) return NULL;
-
-#if defined(_WIN32)
-  // skip over the disk drive part of windows pathnames
-  if (isalpha(path[0]) && path[1] == ':')
-    path += 2;
-#endif
-
-  for (pot = path; *path != '\0'; ++path) {
-#if defined(_WIN32)
-    if ((*path == '\\') || (*path == '/')) pot = path + 1;
-#else
-    if (*path == '/') pot = path + 1;
-#endif
-  }
-
-  return pot;
-}
-
-/* ----------------------------------------------------------------------
-   read first line of potential file
-   if has DATE field, print following word
-------------------------------------------------------------------------- */
-
-void Force::potential_date(FILE *fp, const char *name)
-{
-  char line[MAXLINE];
-  char *ptr = fgets(line,MAXLINE,fp);
-  if (ptr == NULL) return;
-
-  char *word;
-  word = strtok(line," \t\n\r\f");
-  while (word) {
-    if (strcmp(word,"DATE:") == 0) {
-      word = strtok(NULL," \t\n\r\f");
-      if (word == NULL) return;
-      utils::logmesg(lmp,fmt::format("Reading potential "
-                     "file {} with DATE: {}",name,word));
-      return;
+    if(!date.empty()) {
+      utils::logmesg(lmp, fmt::format("Reading potential file {} with DATE: {}", name, date));
     }
-    word = strtok(NULL," \t\n\r\f");
+    return fopen(filepath.c_str(), "r");
   }
+  return nullptr;
 }
 
 /* ----------------------------------------------------------------------

src/force.h

@@ -136,8 +136,6 @@ class Force : protected Pointers {
   tagint tnumeric(const char *, int, char *);
 
   FILE *open_potential(const char *);
-  const char *potential_name(const char *);
-  void potential_date(FILE *, const char *);
 
   bigint memory_usage();
 

src/potential_file_reader.cpp

@@ -142,66 +142,17 @@ std::string PotentialFileReader::next_string() {
   return "";
 }
 
-/* ----------------------------------------------------------------------
-   open a potential file as specified by name
-   if fails, search in dir specified by env variable LAMMPS_POTENTIALS
-------------------------------------------------------------------------- */
-
 TextFileReader * PotentialFileReader::open_potential(const std::string& path) {
-  // attempt to open file directly
-  // if successful, return filename
-  std::string filepath = path;
-  std::string filename = utils::path_basename(path);
+  std::string filepath = utils::get_potential_file_path(path);
   std::string date;
 
-  if(utils::file_is_readable(filepath)) {
-    date = get_potential_date(filepath);
-  } else {
-    // try the environment variable directory
-    const char *path = getenv("LAMMPS_POTENTIALS");
+  if(!filepath.empty()) {
+    date = utils::get_potential_date(filepath, filetype);
 
-    if (path != nullptr){
-      std::string pot = utils::path_basename(filepath);
-      filepath = utils::path_join(path, pot);
-
-      if (utils::file_is_readable(filepath)) {
-        date = get_potential_date(filepath);
-      } else {
-        return nullptr;
-      }
-    } else {
-      return nullptr;
+    if(!date.empty()) {
+      utils::logmesg(lmp, fmt::format("Reading potential file {} with DATE: {}", filename, date));
     }
+    return new TextFileReader(filepath, filetype);
   }
-
-  if(!date.empty()) {
-    utils::logmesg(lmp, fmt::format("Reading potential file {} with DATE: {}", filename, date));
-  }
-
-  return new TextFileReader(filepath, filetype);
-}
-
-/* ----------------------------------------------------------------------
-   read first line of potential file
-   if has DATE field, print following word
-------------------------------------------------------------------------- */
-
-std::string PotentialFileReader::get_potential_date(const std::string & path) {
-  TextFileReader reader(path, filetype);
-  reader.ignore_comments = false;
-  char * line = nullptr;
-
-  while (line = reader.next_line()) {
-    ValueTokenizer values(line);
-    while (values.has_next()) {
-      std::string word = values.next_string();
-      if (word == "DATE:") {
-        if (values.has_next()) {
-          std::string date = values.next_string();
-          return date;
-        }
-      }
-    }
-  }
-  return "";
+  return nullptr;
 }

src/potential_file_reader.h

@@ -33,7 +33,6 @@ namespace LAMMPS_NS
     std::string filetype;
 
     TextFileReader * open_potential(const std::string& path);
-    std::string get_potential_date(const std::string & path);
 
   public:
     PotentialFileReader(class LAMMPS *lmp, const std::string &filename, const std::string &potential_name);

src/utils.cpp

@@ -17,6 +17,7 @@
 #include "lammps.h"
 #include "error.h"
 #include "tokenizer.h"
+#include "text_file_reader.h"
 #include "fmt/format.h"
 
 #if defined(__linux__)
@@ -450,6 +451,59 @@ bool utils::file_is_readable(const std::string & path) {
   return false;
 }
 
+/* ----------------------------------------------------------------------
+   try to find potential file as specified by name
+   search current directory and the LAMMPS_POTENTIALS directory if
+   specified
+------------------------------------------------------------------------- */
+
+std::string utils::get_potential_file_path(const std::string& path) {
+  std::string filepath = path;
+  std::string filename = utils::path_basename(path);
+
+  if(utils::file_is_readable(filepath)) {
+    return filepath;
+  } else {
+    // try the environment variable directory
+    const char *path = getenv("LAMMPS_POTENTIALS");
+
+    if (path != nullptr){
+      std::string pot = utils::path_basename(filepath);
+      filepath = utils::path_join(path, pot);
+
+      if (utils::file_is_readable(filepath)) {
+        return filepath;
+      }
+    }
+  }
+  return "";
+}
+
+/* ----------------------------------------------------------------------
+   read first line of potential file
+   if has DATE field, print following word
+------------------------------------------------------------------------- */
+
+std::string utils::get_potential_date(const std::string & path, const std::string & potential_name) {
+  TextFileReader reader(path, potential_name);
+  reader.ignore_comments = false;
+  char * line = nullptr;
+
+  while (line = reader.next_line()) {
+    ValueTokenizer values(line);
+    while (values.has_next()) {
+      std::string word = values.next_string();
+      if (word == "DATE:") {
+        if (values.has_next()) {
+          std::string date = values.next_string();
+          return date;
+        }
+      }
+    }
+  }
+  return "";
+}
+
 /* ------------------------------------------------------------------ */
 
 extern "C" {

src/utils.h

@@ -193,6 +193,22 @@ namespace LAMMPS_NS {
      * \return true if file exists and is readable
      */
     bool file_is_readable(const std::string & path);
+
+    /**
+     * \brief Determine full path of potential file
+     *        If file is not found in current directory, search LAMMPS_POTENTIALS folder
+     * \param path file path
+     * \return full path to potential file
+     */
+    std::string get_potential_file_path(const std::string& path);
+
+    /**
+     * \brief Read potential file and return DATE field if it is present
+     * \param path file path
+     * \param potential_name name of potential that is being read
+     * \return DATE field if present
+     */
+    std::string get_potential_date(const std::string & path, const std::string & potential_name);
   }
 }