Don't use non-API functions SETLENGTH and SET_TRUELENGTH

src/column.cpp

@@ -4,6 +4,7 @@
 #include "column.h"
 #include "string_utils.h"
 #include "iconv.h"
+#include "column_utils.h"
 
 #include <Rcpp.h>
 using namespace Rcpp;
@@ -101,47 +102,28 @@ void ColumnInteger::setValue(int i, const char* x_start, const char* x_end) {
 }
 
 void ColumnCharacter::resize(int n) {
-  if (n == n_)
-    return;
-
-  if (n > 0 && n < n_) {
-    SETLENGTH(values_, n);
-    SET_TRUELENGTH(values_, n);
-  } else {
-    values_ = Rf_lengthgets(values_, n);
-  }
+  if (n == n_) return;
+  values_ = resize_character_vector(values_, n_, n);
   n_ = n;
-
 }
 
-void ColumnDouble::resize(int n) {
-  if (n == n_)
-    return;
 
-  if (n > 0 && n < n_) {
-    SETLENGTH(values_, n);
-    SET_TRUELENGTH(values_, n);
-  } else {
-    values_ = Rf_lengthgets(values_, n);
-  }
+void ColumnDouble::resize(int n) {
+  if (n == n_) return;
+  values_ = resize_numeric_vector(values_, n_, n);
   n_ = n;
   valuepointer = REAL(values_);
 }
 
-void ColumnInteger::resize(int n) {
-  if (n == n_)
-    return;
 
-  if (n > 0 && n < n_) {
-    SETLENGTH(values_, n);
-    SET_TRUELENGTH(values_, n);
-  } else {
-    values_ = Rf_lengthgets(values_, n);
-  }
+void ColumnInteger::resize(int n) {
+  if (n == n_) return;
+  values_ = resize_integer_vector(values_, n_, n);
   n_ = n;
   valuepointer = INTEGER(values_);
 }
 
+
 std::vector<ColumnPtr> createAllColumns(CharacterVector types, Rcpp::List var_opts, Iconv* pEncoder_) {
   int num_cols = static_cast<int>(types.size());
   std::vector<ColumnPtr> out;

src/column_utils.h

@@ -0,0 +1,56 @@
+#ifndef VECTOR_UTILS_H
+#define VECTOR_UTILS_H
+
+#include <Rinternals.h>
+#include <algorithm>
+#include <cstring>  // for memcpy
+
+inline SEXP resize_numeric_vector(SEXP original, int old_size, int new_size) {
+  SEXP new_vec = PROTECT(Rf_allocVector(REALSXP, new_size));
+  double* new_data = REAL(new_vec);
+
+  std::fill_n(new_data, new_size, NA_REAL);
+
+  if (original != R_NilValue && old_size > 0) {
+    int copy_len = std::min(old_size, new_size);
+    memcpy(new_data, REAL(original), copy_len * sizeof(double));
+  }
+
+  UNPROTECT(1);
+  return new_vec;
+}
+
+inline SEXP resize_integer_vector(SEXP original, int old_size, int new_size) {
+  SEXP new_vec = PROTECT(Rf_allocVector(INTSXP, new_size));
+  int* new_data = INTEGER(new_vec);
+
+  std::fill_n(new_data, new_size, NA_INTEGER);
+
+  if (original != R_NilValue && old_size > 0) {
+    int copy_len = std::min(old_size, new_size);
+    memcpy(new_data, INTEGER(original), copy_len * sizeof(int));
+  }
+
+  UNPROTECT(1);
+  return new_vec;
+}
+
+inline SEXP resize_character_vector(SEXP original, int old_size, int new_size) {
+  SEXP new_vec = PROTECT(Rf_allocVector(STRSXP, new_size));
+
+  for (int i = 0; i < new_size; ++i) {
+    SET_STRING_ELT(new_vec, i, NA_STRING);
+  }
+
+  if (original != R_NilValue && old_size > 0) {
+    int copy_len = std::min(old_size, new_size);
+    for (int i = 0; i < copy_len; ++i) {
+      SET_STRING_ELT(new_vec, i, STRING_ELT(original, i));
+    }
+  }
+
+  UNPROTECT(1);
+  return new_vec;
+}
+
+#endif // VECTOR_UTILS_H