span

Author: rok

cpp/src/arrow/extension/tensor_internal.cc

@@ -27,7 +27,7 @@
 
 namespace arrow::internal {
 
-bool IsPermutationTrivial(const std::vector<int64_t>& permutation) {
+bool IsPermutationTrivial(util::span<const int64_t> permutation) {
   for (size_t i = 1; i < permutation.size(); ++i) {
     if (permutation[i - 1] + 1 != permutation[i]) {
       return false;
@@ -36,7 +36,7 @@ bool IsPermutationTrivial(const std::vector<int64_t>& permutation) {
   return true;
 }
 
-Status IsPermutationValid(const std::vector<int64_t>& permutation) {
+Status IsPermutationValid(util::span<const int64_t> permutation) {
   const auto size = static_cast<int64_t>(permutation.size());
   std::vector<uint8_t> dim_seen(size, 0);
 
@@ -53,8 +53,8 @@ Status IsPermutationValid(const std::vector<int64_t>& permutation) {
 }
 
 Result<std::vector<int64_t>> ComputeStrides(const std::shared_ptr<DataType>& value_type,
-                                            const std::vector<int64_t>& shape,
-                                            const std::vector<int64_t>& permutation) {
+                                            util::span<const int64_t> shape,
+                                            util::span<const int64_t> permutation) {
   const auto ndim = shape.size();
   const int byte_width = value_type->byte_width();
 
@@ -64,11 +64,11 @@ Result<std::vector<int64_t>> ComputeStrides(const std::shared_ptr<DataType>& val
     perm.resize(ndim);
     std::iota(perm.begin(), perm.end(), 0);
   } else {
-    perm = permutation;
+    perm.assign(permutation.begin(), permutation.end());
   }
 
   int64_t remaining = 0;
-  if (!shape.empty() && shape.front() > 0) {
+  if (!shape.empty() && shape[0] > 0) {
     remaining = byte_width;
     for (auto i : perm) {
       if (i > 0) {

cpp/src/arrow/extension/tensor_internal.h

@@ -21,18 +21,19 @@
 #include <vector>
 
 #include "arrow/array/array_nested.h"
+#include "arrow/util/span.h"
 
 namespace arrow::internal {
 
 ARROW_EXPORT
-bool IsPermutationTrivial(const std::vector<int64_t>& permutation);
+bool IsPermutationTrivial(util::span<const int64_t> permutation);
 
 ARROW_EXPORT
-Status IsPermutationValid(const std::vector<int64_t>& permutation);
+Status IsPermutationValid(util::span<const int64_t> permutation);
 
 ARROW_EXPORT
 Result<std::vector<int64_t>> ComputeStrides(const std::shared_ptr<DataType>& value_type,
-                                            const std::vector<int64_t>& shape,
-                                            const std::vector<int64_t>& permutation);
+                                            util::span<const int64_t> shape,
+                                            util::span<const int64_t> permutation);
 
 }  // namespace arrow::internal