maybe some actual conversions

Author: paleolimbot

r/src/vctr_builder_primitive.h

@@ -80,6 +80,126 @@ class IntBuilder : public VctrBuilder {
  public:
   explicit IntBuilder(SEXP ptype_sexp) : VctrBuilder(VECTOR_TYPE_INT, ptype_sexp) {}
 
+  ArrowErrorCode Init(const ArrowSchema* schema, VctrBuilderOptions options,
+                      ArrowError* error) override {
+    NANOARROW_RETURN_NOT_OK(VctrBuilder::Init(schema, options, error));
+    return NANOARROW_OK;
+  }
+
+  ArrowErrorCode Reserve(R_xlen_t n, ArrowError* error) override {
+    NANOARROW_RETURN_NOT_OK(VctrBuilder::Reserve(n, error));
+    value_ = PROTECT(Rf_allocVector(INTSXP, n));
+    SetValue(value_);
+    UNPROTECT(1);
+    return NANOARROW_OK;
+  }
+
+  ArrowErrorCode PushNext(const ArrowArray* array, ArrowError* error) override {
+    int* result = INTEGER(value_);
+    int64_t n_bad_values = 0;
+
+    // True for all the types supported here
+    const uint8_t* is_valid = array_view_.buffer_views[0].data.as_uint8;
+    int64_t raw_src_offset = array_view_.array->offset;
+    R_xlen_t length = array->length;
+
+    // Fill the buffer
+    switch (array_view_.storage_type) {
+      case NANOARROW_TYPE_NA:
+        for (R_xlen_t i = 0; i < length; i++) {
+          result[value_size_ + i] = NA_INTEGER;
+        }
+        break;
+      case NANOARROW_TYPE_INT32:
+        memcpy(result + value_size_,
+               array_view_.buffer_views[1].data.as_int32 + raw_src_offset,
+               length * sizeof(int32_t));
+
+        // Set any nulls to NA_INTEGER
+        if (is_valid != NULL && array_view_.array->null_count != 0) {
+          for (R_xlen_t i = 0; i < length; i++) {
+            if (!ArrowBitGet(is_valid, raw_src_offset + i)) {
+              result[value_size_ + i] = NA_INTEGER;
+            }
+          }
+        }
+        break;
+      case NANOARROW_TYPE_BOOL:
+        ArrowBitsUnpackInt32(array_view_.buffer_views[1].data.as_uint8 + raw_src_offset,
+                             raw_src_offset, length, result + value_size_);
+
+        // Set any nulls to NA_LOGICAL
+        if (is_valid != NULL && array_view_.array->null_count != 0) {
+          for (R_xlen_t i = 0; i < length; i++) {
+            if (!ArrowBitGet(is_valid, raw_src_offset + i)) {
+              result[value_size_ + i] = NA_LOGICAL;
+            }
+          }
+        }
+        break;
+      case NANOARROW_TYPE_INT8:
+      case NANOARROW_TYPE_UINT8:
+      case NANOARROW_TYPE_INT16:
+      case NANOARROW_TYPE_UINT16:
+        // No need to bounds check for these types
+        for (R_xlen_t i = 0; i < length; i++) {
+          result[value_size_ + i] = (int32_t)ArrowArrayViewGetIntUnsafe(&array_view_, i);
+        }
+
+        // Set any nulls to NA_INTEGER
+        if (is_valid != NULL && array_view_.array->null_count != 0) {
+          for (R_xlen_t i = 0; i < length; i++) {
+            if (!ArrowBitGet(is_valid, raw_src_offset + i)) {
+              result[value_size_ + i] = NA_INTEGER;
+            }
+          }
+        }
+        break;
+      case NANOARROW_TYPE_UINT32:
+      case NANOARROW_TYPE_INT64:
+      case NANOARROW_TYPE_UINT64:
+      case NANOARROW_TYPE_FLOAT:
+      case NANOARROW_TYPE_DOUBLE:
+        // Loop + bounds check. Because we don't know what memory might be
+        // in a null slot, we have to check nulls if there are any.
+        if (is_valid != NULL && array_view_.array->null_count != 0) {
+          for (R_xlen_t i = 0; i < length; i++) {
+            if (ArrowBitGet(is_valid, raw_src_offset + i)) {
+              int64_t value = ArrowArrayViewGetIntUnsafe(&array_view_, i);
+              if (value > INT_MAX || value <= NA_INTEGER) {
+                result[value_size_ + i] = NA_INTEGER;
+                n_bad_values++;
+              } else {
+                result[value_size_ + i] = (int32_t)value;
+              }
+            } else {
+              result[value_size_ + i] = NA_INTEGER;
+            }
+          }
+        } else {
+          for (R_xlen_t i = 0; i < length; i++) {
+            int64_t value = ArrowArrayViewGetIntUnsafe(&array_view_, i);
+            if (value > INT_MAX || value <= NA_INTEGER) {
+              result[value_size_ + i] = NA_INTEGER;
+              n_bad_values++;
+            } else {
+              result[value_size_ + i] = (int32_t)value;
+            }
+          }
+        }
+        break;
+
+      default:
+        return EINVAL;
+    }
+
+    if (n_bad_values > 0) {
+      warn_lossy_conversion(n_bad_values, "outside integer range set to NA");
+    }
+
+    return NANOARROW_OK;
+  }
+
   SEXP GetPtype() override { return Rf_allocVector(INTSXP, 0); }
 };