From 7300e5c4bd6632a5d9a1458a5003d93caeccc8d7 Mon Sep 17 00:00:00 2001
From: Richard Berger <richard.berger@temple.edu>
Date: Thu, 15 Apr 2021 18:33:21 -0400
Subject: [PATCH] Use C++ for AtomVec::Method

---
 src/atom_vec.cpp | 142 ++++++++++++++++++-----------------------------
 src/atom_vec.h   |  22 ++++----
 2 files changed, 66 insertions(+), 98 deletions(-)

diff --git a/src/atom_vec.cpp b/src/atom_vec.cpp
index 7d7cfa4878..78903d6a7f 100644
--- a/src/atom_vec.cpp
+++ b/src/atom_vec.cpp
@@ -71,21 +71,6 @@ AtomVec::AtomVec(LAMMPS *lmp) : Pointers(lmp)
   default_create = "id type mask image x v";
   default_data_atom = "";
   default_data_vel = "";
-
-  // initializations
-
-  init_method(&mgrow);
-  init_method(&mcopy);
-  init_method(&mcomm);
-  init_method(&mcomm_vel);
-  init_method(&mreverse);
-  init_method(&mborder);
-  init_method(&mborder_vel);
-  init_method(&mexchange);
-  init_method(&mrestart);
-  init_method(&mcreate);
-  init_method(&mdata_atom);
-  init_method(&mdata_vel);
 }
 
 /* ---------------------------------------------------------------------- */
@@ -129,19 +114,6 @@ AtomVec::~AtomVec()
     }
   }
 
-  destroy_method(&mgrow);
-  destroy_method(&mcopy);
-  destroy_method(&mcomm);
-  destroy_method(&mcomm_vel);
-  destroy_method(&mreverse);
-  destroy_method(&mborder);
-  destroy_method(&mborder_vel);
-  destroy_method(&mexchange);
-  destroy_method(&mrestart);
-  destroy_method(&mcreate);
-  destroy_method(&mdata_atom);
-  destroy_method(&mdata_vel);
-
   delete [] threads;
 }
 
@@ -2395,18 +2367,18 @@ void AtomVec::setup_fields()
 
   // populate field-based data struct for each method to use
 
-  create_method(ngrow,&mgrow);
-  create_method(ncopy,&mcopy);
-  create_method(ncomm,&mcomm);
-  create_method(ncomm_vel,&mcomm_vel);
-  create_method(nreverse,&mreverse);
-  create_method(nborder,&mborder);
-  create_method(nborder_vel,&mborder_vel);
-  create_method(nexchange,&mexchange);
-  create_method(nrestart,&mrestart);
-  create_method(ncreate,&mcreate);
-  create_method(ndata_atom,&mdata_atom);
-  create_method(ndata_vel,&mdata_vel);
+  init_method(ngrow,&mgrow);
+  init_method(ncopy,&mcopy);
+  init_method(ncomm,&mcomm);
+  init_method(ncomm_vel,&mcomm_vel);
+  init_method(nreverse,&mreverse);
+  init_method(nborder,&mborder);
+  init_method(nborder_vel,&mborder_vel);
+  init_method(nexchange,&mexchange);
+  init_method(nrestart,&mrestart);
+  init_method(ncreate,&mcreate);
+  init_method(ndata_atom,&mdata_atom);
+  init_method(ndata_vel,&mdata_vel);
 
   // create threads data struct for grow and memory_usage to use
 
@@ -2480,7 +2452,6 @@ void AtomVec::setup_fields()
 int AtomVec::process_fields(char *str, const char *default_str, Method *method)
 {
   if (str == nullptr) {
-    method->index = nullptr;
     return 0;
   }
 
@@ -2496,17 +2467,19 @@ int AtomVec::process_fields(char *str, const char *default_str, Method *method)
   Atom::PerAtom *peratom = atom->peratom;
   int nperatom = atom->nperatom;
 
-  int *index;
+  // allocate memory in method
+  method->resize(nfield);
+
+  int *index = method->index;
   int match;
 
-  if (nfield) index = new int[nfield];
   for (int i = 0; i < nfield; i++) {
-    const char * field = words[i].c_str();
+    const std::string & field = words[i];
 
     // find field in master Atom::peratom list
 
     for (match = 0; match < nperatom; match++)
-      if (strcmp(field, peratom[match].name) == 0) break;
+      if (field == peratom[match].name) break;
     if (match == nperatom)
       error->all(FLERR,fmt::format("Peratom field {} not recognized", field));
     index[i] = match;
@@ -2520,38 +2493,19 @@ int AtomVec::process_fields(char *str, const char *default_str, Method *method)
     // error if field is in default str
 
     for (match = 0; match < ndef; match++)
-      if (strcmp(field, def_words[match].c_str()) == 0)
+      if (field == def_words[match])
         error->all(FLERR,fmt::format("Peratom field {} is a default", field));
   }
 
-  if (nfield) method->index = index;
-  else method->index = nullptr;
   return nfield;
 }
 
 /* ----------------------------------------------------------------------
-   create a method data structs for processing fields
+   init method data structs for processing fields
 ------------------------------------------------------------------------- */
 
-void AtomVec::create_method(int nfield, Method *method)
+void AtomVec::init_method(int nfield, Method *method)
 {
-  if (nfield > 0) {
-    method->pdata = new void*[nfield];
-    method->datatype = new int[nfield];
-    method->cols = new int[nfield];
-    method->maxcols = new int*[nfield];
-    method->collength = new int[nfield];
-    method->plength = new void*[nfield];
-  } else {
-    method->pdata = nullptr;
-    method->datatype = nullptr;
-    method->cols = nullptr;
-    method->maxcols = nullptr;
-    method->collength = nullptr;
-    method->plength = nullptr;
-    return;
-  }
-
   for (int i = 0; i < nfield; i++) {
     Atom::PerAtom *field = &atom->peratom[method->index[i]];
     method->pdata[i] = (void *) field->address;
@@ -2566,31 +2520,43 @@ void AtomVec::create_method(int nfield, Method *method)
 }
 
 /* ----------------------------------------------------------------------
-   free memory in a method data structs
+   Method class members
 ------------------------------------------------------------------------- */
 
-void AtomVec::init_method(Method *method)
+AtomVec::Method::~Method()
 {
-  method->pdata = nullptr;
-  method->datatype = nullptr;
-  method->cols = nullptr;
-  method->maxcols = nullptr;
-  method->collength = nullptr;
-  method->plength = nullptr;
-  method->index = nullptr;
+  delete [] pdata;
+  delete [] datatype;
+  delete [] cols;
+  delete [] maxcols;
+  delete [] collength;
+  delete [] plength;
+  delete [] index;
 }
 
-/* ----------------------------------------------------------------------
-   free memory in a method data structs
-------------------------------------------------------------------------- */
+void AtomVec::Method::resize(int nfield) {
+  delete [] pdata;
+  delete [] datatype;
+  delete [] cols;
+  delete [] maxcols;
+  delete [] collength;
+  delete [] plength;
+  delete [] index;
+  pdata = nullptr;
+  datatype = nullptr;
+  cols = nullptr;
+  maxcols = nullptr;
+  collength = nullptr;
+  plength = nullptr;
+  index = nullptr;
 
-void AtomVec::destroy_method(Method *method)
-{
-  delete [] method->pdata;
-  delete [] method->datatype;
-  delete [] method->cols;
-  delete [] method->maxcols;
-  delete [] method->collength;
-  delete [] method->plength;
-  delete [] method->index;
+  if (nfield > 0) {
+    pdata = new void*[nfield];
+    datatype = new int[nfield];
+    cols = new int[nfield];
+    maxcols = new int*[nfield];
+    collength = new int[nfield];
+    plength = new void*[nfield];
+    index = new int[nfield];
+  }
 }
diff --git a/src/atom_vec.h b/src/atom_vec.h
index 8e670304ed..d1915ba508 100644
--- a/src/atom_vec.h
+++ b/src/atom_vec.h
@@ -191,13 +191,17 @@ class AtomVec : protected Pointers {
   const char *default_create,*default_data_atom,*default_data_vel;
 
   struct Method {
-    void **pdata;
-    int *datatype;
-    int *cols;
-    int **maxcols;
-    int *collength;
-    void **plength;
-    int *index;
+    void **pdata = nullptr;
+    int *datatype = nullptr;
+    int *cols = nullptr;
+    int **maxcols = nullptr;
+    int *collength = nullptr;
+    void **plength = nullptr;
+    int *index = nullptr;
+
+    Method() = default;
+    ~Method();
+    void resize(int nfield);
   };
 
   Method mgrow,mcopy;
@@ -219,9 +223,7 @@ class AtomVec : protected Pointers {
   int grow_nmax_bonus(int);
   void setup_fields();
   int process_fields(char *, const char *, Method *);
-  void create_method(int, Method *);
-  void init_method(Method *);
-  void destroy_method(Method *);
+  void init_method(int, Method *);
 };
 
 }