| // 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. |
| |
| using System; |
| using System.Collections.Generic; |
| using System.Linq; |
| |
| namespace Apache.Arrow |
| { |
| public partial class Schema |
| { |
| public IReadOnlyDictionary<string, Field> Fields |
| { |
| get => _fieldsDictionary; |
| } |
| |
| private readonly Dictionary<string, Field> _fieldsDictionary; |
| |
| public IReadOnlyDictionary<string, string> Metadata { get; } |
| |
| public bool HasMetadata => |
| Metadata != null && Metadata.Count > 0; |
| |
| private readonly IList<Field> _fields; |
| |
| public Schema( |
| IEnumerable<Field> fields, |
| IEnumerable<KeyValuePair<string, string>> metadata) |
| { |
| if (fields == null) |
| { |
| throw new ArgumentNullException(nameof(fields)); |
| } |
| |
| _fields = fields.ToList(); |
| |
| _fieldsDictionary = fields.ToDictionary( |
| field => field.Name, field => field, |
| StringComparer.OrdinalIgnoreCase); |
| |
| Metadata = metadata?.ToDictionary(kv => kv.Key, kv => kv.Value); |
| } |
| |
| public Field GetFieldByIndex(int i) |
| { |
| return _fields[i]; |
| } |
| |
| public Field GetFieldByName(string name) => |
| Fields.TryGetValue(name, out var field) ? field : null; |
| |
| public int GetFieldIndex(string name, StringComparer comparer = default) |
| { |
| if (comparer == null) |
| comparer = StringComparer.CurrentCulture; |
| |
| return _fields.IndexOf( |
| _fields.Single(x => comparer.Compare(x.Name, name) == 0)); |
| } |
| |
| public Schema RemoveField(int fieldIndex) |
| { |
| if (fieldIndex < 0 || fieldIndex >= _fields.Count) |
| { |
| throw new ArgumentException("Invalid fieldIndex", nameof(fieldIndex)); |
| } |
| |
| IList<Field> fields = Utility.DeleteListElement(_fields, fieldIndex); |
| |
| return new Schema(fields, Metadata); |
| } |
| |
| public Schema InsertField(int fieldIndex, Field newField) |
| { |
| newField = newField ?? throw new ArgumentNullException(nameof(newField)); |
| if (fieldIndex < 0 || fieldIndex > _fields.Count) |
| { |
| throw new ArgumentException(nameof(fieldIndex), $"Invalid fieldIndex {fieldIndex} passed in to Schema.AddField"); |
| } |
| |
| IList<Field> fields = Utility.AddListElement(_fields, fieldIndex, newField); |
| |
| return new Schema(fields, Metadata); |
| } |
| |
| public Schema SetField(int fieldIndex, Field newField) |
| { |
| if (fieldIndex <0 || fieldIndex >= Fields.Count) |
| { |
| throw new ArgumentException($"Invalid fieldIndex {fieldIndex} passed in to Schema.SetColumn"); |
| } |
| |
| IList<Field> fields = Utility.SetListElement(_fields, fieldIndex, newField); |
| |
| return new Schema(fields, Metadata); |
| } |
| } |
| } |