start geom utiles

cpp/src/parquet/geometry_util.h

@@ -0,0 +1,81 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#pragma once
+
+#include <limits>
+#include <string>
+
+#include "arrow/util/logging.h"
+#include "arrow/util/ubsan.h"
+
+namespace parquet {
+
+namespace geometry {
+
+constexpr double kInf = std::numeric_limits<double>::infinity();
+
+struct BoundingBox {
+  BoundingBox(): min{kInf, kInf, kInf, kInf}, max{-kInf, -kInf, -kInf, -kInf} {}
+  double min[4];
+  double max[4];
+};
+
+class WKBCoordSeq {
+public:
+  size_t Init(const uint8_t* data, size_t data_size) {
+    if (data_size < sizeof(uint32_t)) {
+        // error
+    }
+
+    // Read uint32_t size_coords
+    memcpy(&num_coords_, data, sizeof(uint32_t));
+
+    size_t data_size_required = sizeof(uint32_t) + (num_coords_ * num_dims_ * sizeof(double));
+
+    if (data_size_required > data_size) {
+        // error
+    }
+
+    data_ = data;
+    coord_data_size_ = data_size_required - sizeof(uint32_t);
+    return data_size_required;
+  }
+
+  void UpdateBox(BoundingBox* box) {
+    size_t coord_size_bytes = num_dims_ * sizeof(double);
+    double coord[4];
+    for (size_t offset = 0; offset < coord_data_size_; offset += coord_size_bytes) {
+      memcpy(coord, data_ + offset, coord_size_bytes);
+      for (uint32_t i = 0; i < num_dims_; i++) {
+        box->max[i] = std::max(box->max[i], coord[i]);
+      }
+    }
+  }
+
+ private:
+  const uint8_t* data_;
+  size_t coord_data_size_;
+  uint32_t num_coords_;
+  uint32_t num_dims_;
+};
+
+
+
+}  // namespace geometry
+
+}  // namespace parquet