vertices_builder.h

/*
 * 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 <any>
#include <memory>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>
 
#include "graphar/arrow/chunk_writer.h"
#include "graphar/graph_info.h"
#include "graphar/result.h"
 
// forward declaration
namespace arrow {
class Array;
class Table;
}  // namespace arrow
 
namespace graphar::builder {
 
class Vertex {
 public:
  Vertex() : empty_(true) {}
 
  explicit Vertex(IdType id) : id_(id), empty_(false) {}
 
  inline IdType GetId() const noexcept { return id_; }
 
  inline void SetId(IdType id) { id_ = id; }
 
  inline bool Empty() const noexcept { return empty_; }
 
  // TODO(@acezen): Enable the property to be a vector(list).
  inline void AddProperty(const std::string& name, const std::any& val) {
    empty_ = false;
    properties_[name] = val;
  }
 
  inline const std::any& GetProperty(const std::string& property) const {
    return properties_.at(property);
  }
 
  inline const std::unordered_map<std::string, std::any>& GetProperties()
      const {
    return properties_;
  }
 
  inline bool ContainProperty(const std::string& property) {
    return (properties_.find(property) != properties_.end());
  }
 
 private:
  IdType id_;
  bool empty_;
  std::unordered_map<std::string, std::any> properties_;
};
 
class VerticesBuilder {
 public:
  explicit VerticesBuilder(
      const std::shared_ptr<VertexInfo>& vertex_info, const std::string& prefix,
      IdType start_vertex_index = 0,
      const ValidateLevel& validate_level = ValidateLevel::no_validate)
      : vertex_info_(std::move(vertex_info)),
        prefix_(prefix),
        start_vertex_index_(start_vertex_index),
        validate_level_(validate_level) {
    if (validate_level_ == ValidateLevel::default_validate) {
      throw std::runtime_error(
          "default_validate is not allowed to be set as the global validate "
          "level for VerticesBuilder");
    }
    vertices_.clear();
    num_vertices_ = 0;
    is_saved_ = false;
  }
 
  inline void Clear() {
    vertices_.clear();
    num_vertices_ = 0;
    is_saved_ = false;
  }
 
  inline void SetValidateLevel(const ValidateLevel& validate_level) {
    if (validate_level == ValidateLevel::default_validate) {
      return;
    }
    validate_level_ = validate_level;
  }
 
  inline ValidateLevel GetValidateLevel() const { return validate_level_; }
 
  Status AddVertex(
      Vertex& v, IdType index = -1,  // NOLINT
      ValidateLevel validate_level = ValidateLevel::default_validate) {
    // validate
    GAR_RETURN_NOT_OK(validate(v, index, validate_level));
    // add a vertex
    if (index == -1) {
      v.SetId(vertices_.size());
      vertices_.push_back(v);
    } else {
      v.SetId(index);
      if (index >= static_cast<IdType>(vertices_.size()))
        vertices_.resize(index + 1);
      vertices_[index] = v;
    }
    num_vertices_++;
    return Status::OK();
  }
 
  IdType GetNum() const { return num_vertices_; }
 
  Status Dump() {
    // construct the writer
    VertexPropertyWriter writer(vertex_info_, prefix_, validate_level_);
    IdType start_chunk_index =
        start_vertex_index_ / vertex_info_->GetChunkSize();
    // convert to table
    GAR_ASSIGN_OR_RAISE(auto input_table, convertToTable());
    // write table
    GAR_RETURN_NOT_OK(writer.WriteTable(input_table, start_chunk_index));
    GAR_RETURN_NOT_OK(
        writer.WriteVerticesNum(num_vertices_ + start_vertex_index_));
    is_saved_ = true;
    vertices_.clear();
    return Status::OK();
  }
 
  static Result<std::shared_ptr<VerticesBuilder>> Make(
      const std::shared_ptr<VertexInfo>& vertex_info, const std::string& prefix,
      IdType start_vertex_index = 0,
      const ValidateLevel& validate_level = ValidateLevel::no_validate) {
    return std::make_shared<VerticesBuilder>(
        vertex_info, prefix, start_vertex_index, validate_level);
  }
 
  static Result<std::shared_ptr<VerticesBuilder>> Make(
      const std::shared_ptr<GraphInfo>& graph_info, const std::string& label,
      IdType start_vertex_index = 0,
      const ValidateLevel& validate_level = ValidateLevel::no_validate) {
    const auto vertex_info = graph_info->GetVertexInfo(label);
    if (!vertex_info) {
      return Status::KeyError("The vertex type ", label,
                              " doesn't exist in graph ", graph_info->GetName(),
                              ".");
    }
    return Make(vertex_info, graph_info->GetPrefix(), start_vertex_index,
                validate_level);
  }
 
 private:
  Status validate(const Vertex& v, IdType index,
                  ValidateLevel validate_level) const;
 
  Status appendToArray(const std::shared_ptr<DataType>& type,
                       const std::string& property_name,
                       std::shared_ptr<arrow::Array>& array);  // NOLINT
 
  template <Type type>
  Status tryToAppend(const std::string& property_name,
                     std::shared_ptr<arrow::Array>& array);  // NOLINT
 
  Result<std::shared_ptr<arrow::Table>> convertToTable();
 
 private:
  std::shared_ptr<VertexInfo> vertex_info_;
  std::string prefix_;
  std::vector<Vertex> vertices_;
  IdType start_vertex_index_;
  IdType num_vertices_;
  bool is_saved_;
  ValidateLevel validate_level_;
};
 
}  // namespace graphar::builder