Working read test with new ArrayView struct members

src/nanoarrow/common/array.c

@@ -645,6 +645,10 @@ void ArrowArrayViewReset(struct ArrowArrayView* array_view) {
  ArrowFree(array_view->union_type_id_map);
  }
 
+ if (array_view->variadic_buffer_views != NULL) {
+ ArrowFree(array_view->variadic_buffer_views);
+ }
+
  ArrowArrayViewInitFromType(array_view, NANOARROW_TYPE_UNINITIALIZED);
 }
 
@@ -704,16 +708,13 @@ static int ArrowArrayViewSetArrayInternal(struct ArrowArrayView* array_view,
  array_view->offset = array->offset;
  array_view->length = array->length;
  array_view->null_count = array->null_count;
-
- const bool fixed_nbuffers = (array_view->storage_type == NANOARROW_TYPE_STRING_VIEW ||
- array_view->storage_type == NANOARROW_TYPE_BINARY_VIEW)
- ? 0
- : 1;
+ array_view->variadic_buffer_sizes = NULL;
+ array_view->variadic_buffer_views = NULL;
+ array_view->n_variadic_buffers = 0;
 
  int64_t buffers_required = 0;
  for (int i = 0; i < NANOARROW_MAX_FIXED_BUFFERS; i++) {
- if (array_view->layout.buffer_type[i] == NANOARROW_BUFFER_TYPE_NONE &&
- fixed_nbuffers) {
+ if (array_view->layout.buffer_type[i] == NANOARROW_BUFFER_TYPE_NONE) {
  break;
  }
 
@@ -730,7 +731,41 @@ static int ArrowArrayViewSetArrayInternal(struct ArrowArrayView* array_view,
  }
  }
 
- if (buffers_required != array->n_buffers && fixed_nbuffers) {
+ if (array_view->storage_type == NANOARROW_TYPE_STRING_VIEW ||
+ array_view->storage_type == NANOARROW_TYPE_BINARY_VIEW) {
+ const int64_t n_buffers = array->n_buffers;
+ const int64_t n_fixed_buffers = 2;
+
+ int64_t n_variadic_buffers = n_buffers - n_fixed_buffers - 1;
+ // Theoretically if the variadic buffers are not used the above subtraction
+ // could yield a negative number
+ n_variadic_buffers = (n_variadic_buffers < 0) ? 0 : n_variadic_buffers;
+
+ array_view->n_variadic_buffers = n_variadic_buffers;
+ // TODO: check malloc failures
+ array_view->variadic_buffer_views =
+ ArrowMalloc(sizeof(struct ArrowBufferView) * n_variadic_buffers);
+
+ for (int64_t i = 0; i < n_variadic_buffers; ++i) {
+ ++buffers_required;
+ array_view->variadic_buffer_views[i].data.data =
+ array->buffers[i + n_fixed_buffers];
+
+ // TODO: why do we need this?
+ // If non-null, set buffer size to unknown.
+ if (array->buffers[i + n_fixed_buffers] == NULL) {
+ array_view->variadic_buffer_views[i].size_bytes = 0;
+ } else {
+ array_view->variadic_buffer_views[i].size_bytes = -1;
+ }
+ }
+
+ // final buffer
+ ++buffers_required;
+ array_view->variadic_buffer_sizes = (int64_t*)array->buffers[n_buffers - 1];
+ }
+
+ if (buffers_required != array->n_buffers) {
  ArrowErrorSet(error,
  "Expected array with %" PRId64 " buffer(s) but found %" PRId64
  " buffer(s)",

src/nanoarrow/common/inline_array.h

@@ -1000,8 +1000,9 @@ static inline struct ArrowStringView ArrowArrayViewGetStringUnsafe(
  view.data = value_view.as_char + idx +
  sizeof(((union ArrowBinaryViewType*)0)->inlined.size);
  } else {
- const int32_t buf_index = bvt.ref.buffer_index + 2;
- view.data = array_view->buffer_views[buf_index].data.as_char + bvt.ref.offset;
+ const int32_t buf_index = bvt.ref.buffer_index;
+ view.data =
+ array_view->variadic_buffer_views[buf_index].data.as_char + bvt.ref.offset;
  }
  break;
  }
@@ -1051,8 +1052,8 @@ static inline struct ArrowBufferView ArrowArrayViewGetBytesUnsafe(
  view.data.as_uint8 = value_view.as_uint8 + idx +
  sizeof(((union ArrowBinaryViewType*)0)->inlined.size);
  } else {
- const int32_t buf_index = bvt.ref.buffer_index + 2;
- view.data = array_view->buffer_views[buf_index].data;
+ const int32_t buf_index = bvt.ref.buffer_index;
+ view.data = array_view->variadic_buffer_views[buf_index].data;
  }
  break;
  }

src/nanoarrow/common/inline_types.h

@@ -815,6 +815,15 @@ struct ArrowArrayView {
  /// type_id == union_type_id_map[128 + child_index]. This value may be
  /// NULL in the case where child_id == type_id.
  int8_t* union_type_id_map;
+
+ /// \brief Number of variadic buffers
+ int64_t n_variadic_buffers;
+
+ /// \brief Size of each variadic buffer
+ int64_t* variadic_buffer_sizes;
+
+ /// \brief Variadic buffer contents
+ struct ArrowBufferView* variadic_buffer_views;
 };
 
 // Used as the private data member for ArrowArrays allocated here and accessed

src/nanoarrow/testing/testing.cc

@@ -1940,6 +1940,7 @@ ArrowErrorCode SetArrayColumnBuffers(const json& value, ArrowArrayView* array_vi
  }
  break;
  }
+ case NANOARROW_BUFFER_TYPE_DATA_VIEW: // TODO: doesn't seem right?
  case NANOARROW_BUFFER_TYPE_NONE:
  break;
  }