| /** |
| * 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 Avro.IO; |
| |
| namespace Avro.Generic |
| { |
| public interface DatumReader<T> |
| { |
| Schema ReaderSchema { get; } |
| Schema WriterSchema { get; } |
| |
| /// <summary> |
| /// Read a datum. Traverse the schema, depth-first, reading all leaf values |
| /// in the schema into a datum that is returned. If the provided datum is |
| /// non-null it may be reused and returned. |
| /// </summary> |
| T Read(T reuse, Decoder decoder); |
| } |
| |
| ///// <summary> |
| ///// Deserialize Avro-encoded data into a .net data structure. |
| ///// </summary> |
| //public class DatumReader |
| //{ |
| // public Schema WriterSchema { get; private set; } |
| // public Schema ReaderSchema { get; private set; } |
| |
| // /// <summary> |
| // /// As defined in the Avro specification, we call the schema encoded |
| // /// in the data the "writer's schema", and the schema expected by the |
| // /// reader the "reader's schema". |
| // /// </summary> |
| // /// <param name="writerSchema"></param> |
| // /// <param name="readerSchema"></param> |
| // public DatumReader(Schema writerSchema, Schema readerSchema) |
| // { |
| // if (null == writerSchema) throw new ArgumentNullException("writerSchema", "writerSchema cannot be null."); |
| // if (null == readerSchema) throw new ArgumentNullException("readerSchema", "readerSchema cannot be null."); |
| |
| // this.WriterSchema = writerSchema; |
| // this.ReaderSchema = readerSchema; |
| // } |
| |
| |
| // static bool checkProps(Schema a, Schema b, params string[] props) |
| // { |
| // foreach (string prop in props) |
| // { |
| // if (!string.Equals(a[prop], b[prop])) |
| // return false; |
| // } |
| |
| // return true; |
| // } |
| // //static bool CheckProps(Schema schema_one, Schema schema_two, IEnumerable<string> props) |
| // //{ |
| |
| // //} |
| |
| // static bool matchSchemas(Schema writers_schema, Schema readers_schema) |
| // { |
| // string w_type = writers_schema.Type, r_type = readers_schema.Type; |
| |
| // if (string.Equals(Schema.UNION, w_type) || string.Equals(Schema.UNION, r_type)) |
| // return true; |
| // else if (PrimitiveSchema.PrimitiveKeyLookup.ContainsKey(w_type) && PrimitiveSchema.PrimitiveKeyLookup.ContainsKey(r_type) && w_type == r_type) |
| // return true; |
| // else if (w_type == Schema.RECORD && r_type == Schema.RECORD && DatumReader.checkProps(writers_schema, readers_schema, "fullname")) |
| // return true; |
| // else if (w_type == "error" && r_type == "error" && DatumReader.checkProps(writers_schema, readers_schema, "fullname")) |
| // return true; |
| // else if (w_type == "request" && r_type == "request") |
| // return true; |
| // else if (w_type == Schema.FIXED && r_type == Schema.FIXED && DatumReader.checkProps(writers_schema, readers_schema, "fullname", "size")) |
| // return true; |
| // else if (w_type == Schema.ENUM && r_type == Schema.ENUM && DatumReader.checkProps(writers_schema, readers_schema, "fullname")) |
| // return true; |
| // //else if (w_type == Schema.MAP && r_type == Schema.MAP && DatumReader.CheckProps(writers_schema.values, readers_schema.values, "type")) |
| // // return true; |
| // //else if (w_type == Schema.ARRAY && r_type == Schema.ARRAY && DatumReader.check_props(writers_schema.items, readers_schema.items, "type")) |
| // // return true; |
| // else if (w_type == Schema.INT && Util.checkIsValue(r_type, Schema.LONG, Schema.FLOAT, Schema.DOUBLE)) |
| // return true; |
| // else if (w_type == Schema.LONG && Util.checkIsValue(r_type, Schema.FLOAT, Schema.DOUBLE)) |
| // return true; |
| // else if (w_type == Schema.FLOAT && r_type == Schema.DOUBLE) |
| // return true; |
| |
| // if (Util.checkIsValue(w_type, Schema.MAP, Schema.ARRAY)) |
| // throw new NotImplementedException(w_type); |
| |
| // return false; |
| // } |
| |
| // public object Read(BinaryDecoder decoder) |
| // { |
| // if (null == this.ReaderSchema) |
| // this.ReaderSchema = this.WriterSchema; |
| |
| // return ReadData(this.WriterSchema, this.ReaderSchema, decoder); |
| |
| // } |
| |
| // private object ReadData(Schema writers_schema, Schema readers_schema, BinaryDecoder decoder) |
| // { |
| // if (!matchSchemas(writers_schema, readers_schema)) |
| // throw new SchemaResolutionException("Schemas do not match.", writers_schema, readers_schema); |
| |
| // if (writers_schema.Type != Schema.UNION && readers_schema.Type == Schema.UNION) |
| // { |
| // foreach (Schema s in ((UnionSchema)readers_schema).Schemas) |
| // { |
| // if (DatumReader.matchSchemas(writers_schema, s)) |
| // { |
| // return ReadData(writers_schema, s, decoder); |
| // } |
| // } |
| |
| // throw new SchemaResolutionException("Schemas do not match.", writers_schema, readers_schema); |
| // } |
| |
| // if (writers_schema.Type == Schema.NULL) |
| // return decoder.ReadNull(); |
| // else if (writers_schema.Type == Schema.BOOLEAN) |
| // return decoder.ReadBool(); |
| // else if (writers_schema.Type == Schema.STRING) |
| // return decoder.ReadUTF8(); |
| // else if (writers_schema.Type == Schema.INT) |
| // return decoder.ReadInt(); |
| // else if (writers_schema.Type == Schema.LONG) |
| // return decoder.ReadLong(); |
| // else if (writers_schema.Type == Schema.FLOAT) |
| // return decoder.ReadFloat(); |
| // else if (writers_schema.Type == Schema.DOUBLE) |
| // return decoder.ReadDouble(); |
| // else if (writers_schema.Type == Schema.BYTES) |
| // return decoder.ReadBytes(); |
| // else if (writers_schema.Type == Schema.FIXED) |
| // return ReadFixed(writers_schema, readers_schema, decoder); |
| // else if (writers_schema.Type == Schema.ENUM) |
| // return ReadEnum(writers_schema, readers_schema, decoder); |
| // else if (writers_schema.Type == Schema.ARRAY) |
| // return ReadArray(writers_schema, readers_schema, decoder); |
| // else if (writers_schema.Type == Schema.MAP) |
| // return ReadMap(writers_schema, readers_schema, decoder); |
| // else if (writers_schema.Type == Schema.UNION) |
| // return ReadUnion(writers_schema, readers_schema, decoder); |
| // else if (Util.checkIsValue(writers_schema.Type, Schema.RECORD, "error", "request")) |
| // return ReadRecord(writers_schema, readers_schema, decoder); |
| // else |
| // throw new AvroException("Cannot Read unknown type type) " + writers_schema.Type); |
| // } |
| |
| // public void SkipData(Schema writers_schema, BinaryDecoder decoder) |
| // { |
| // if (writers_schema.Type == Schema.NULL) |
| // decoder.SkipNull(); |
| // else if (writers_schema.Type == Schema.BOOLEAN) |
| // decoder.SkipBoolean(); |
| // else if (writers_schema.Type == Schema.STRING) |
| // decoder.SkipUTF8(); |
| // else if (writers_schema.Type == Schema.INT) |
| // decoder.SkipInt(); |
| // else if (writers_schema.Type == Schema.LONG) |
| // decoder.SkipLong(); |
| // else if (writers_schema.Type == Schema.FLOAT) |
| // decoder.SkipFloat(); |
| // else if (writers_schema.Type == Schema.DOUBLE) |
| // decoder.SkipDouble(); |
| // else if (writers_schema.Type == Schema.BYTES) |
| // decoder.ReadBytes(); |
| // else if (writers_schema.Type == Schema.FIXED) |
| // SkipFixed(writers_schema as FixedSchema, decoder); |
| // else if (writers_schema.Type == Schema.ENUM) |
| // SkipEnum(writers_schema, decoder); |
| // else if (writers_schema.Type == Schema.ARRAY) |
| // SkipArray(writers_schema as ArraySchema, decoder); |
| // else if (writers_schema.Type == Schema.MAP) |
| // SkipMap(writers_schema as MapSchema, decoder); |
| // else if (writers_schema.Type == Schema.UNION) |
| // SkipUnion(writers_schema as UnionSchema, decoder); |
| // else if (Util.checkIsValue(writers_schema.Type, Schema.RECORD, "error", "request")) |
| // SkipRecord(writers_schema as RecordSchema, decoder); |
| // else |
| // throw new AvroException("Unknown type type: %s" + writers_schema.Type); |
| |
| // } |
| |
| // private void SkipRecord(RecordSchema writers_schema, BinaryDecoder decoder) |
| // { |
| // foreach (Field field in writers_schema.Fields) |
| // SkipData(field.Schema, decoder); |
| // } |
| |
| // private void SkipUnion(UnionSchema writers_schema, BinaryDecoder decoder) |
| // { |
| // int index_of_schema = (int)decoder.ReadLong(); |
| // SkipData(writers_schema.Schemas[index_of_schema], decoder); |
| // } |
| |
| // private void SkipMap(MapSchema writers_schema, BinaryDecoder decoder) |
| // { |
| // long block_count = decoder.ReadLong(); |
| // while (block_count != 0) |
| // { |
| // if (block_count < 0) |
| // { |
| // long block_size = decoder.ReadLong(); |
| // decoder.skip(block_size); |
| // } |
| // else |
| // { |
| // for (int i = 0; i < block_count; i++) |
| // { |
| // decoder.SkipUTF8(); |
| // SkipData(writers_schema.Values, decoder); |
| // block_count = decoder.ReadLong(); |
| // } |
| // } |
| // } |
| // } |
| |
| // private void SkipArray(ArraySchema writers_schema, BinaryDecoder decoder) |
| // { |
| // long block_count = decoder.ReadLong(); |
| // while (block_count != 0) |
| // { |
| // if (block_count < 0) |
| // { |
| // long block_size = decoder.ReadLong(); |
| // decoder.skip(block_size); |
| // } |
| // else |
| // { |
| // for (int i = 0; i < block_count; i++) |
| // { |
| // decoder.SkipUTF8(); |
| // SkipData(writers_schema.Items, decoder); |
| // block_count = decoder.ReadLong(); |
| // } |
| // } |
| // } |
| // } |
| |
| // private void SkipEnum(Schema writers_schema, BinaryDecoder decoder) |
| // { |
| // decoder.SkipInt(); |
| // } |
| |
| // private void SkipFixed(FixedSchema writers_schema, BinaryDecoder decoder) |
| // { |
| // decoder.skip(writers_schema.Size); |
| // } |
| |
| // /// <summary> |
| // /// A record is encoded by encoding the values of its fields |
| // /// in the order that they are declared. In other words, a record |
| // /// is encoded as just the concatenation of the encodings of its fields. |
| // /// Field values are encoded per their schema. |
| |
| // /// Schema Resolution: |
| // /// * the ordering of fields may be different: fields are matched by name. |
| // /// * schemas for fields with the same name in both records are resolved |
| // /// recursively. |
| // /// * if the writer's record contains a field with a name not present in the |
| // /// reader's record, the writer's value for that field is ignored. |
| // /// * if the reader's record schema has a field that contains a default value, |
| // /// and writer's schema does not have a field with the same name, then the |
| // /// reader should use the default value from its field. |
| // /// * if the reader's record schema has a field with no default value, and |
| // /// writer's schema does not have a field with the same name, then the |
| // /// field's value is unset. |
| // /// </summary> |
| // /// <param name="writers_schema"></param> |
| // /// <param name="readers_schema"></param> |
| // /// <param name="decoder"></param> |
| // /// <returns></returns> |
| // private object ReadRecord(Schema writers_schema, Schema readers_schema, BinaryDecoder decoder) |
| // { |
| // throw new NotImplementedException(); |
| // } |
| |
| // private object ReadUnion(Schema writers_schema, Schema readers_schema, BinaryDecoder decoder) |
| // { |
| // throw new NotImplementedException(); |
| // } |
| |
| // private object ReadMap(Schema writers_schema, Schema readers_schema, BinaryDecoder decoder) |
| // { |
| // throw new NotImplementedException(); |
| // } |
| |
| // private object ReadArray(Schema writers_schema, Schema readers_schema, BinaryDecoder decoder) |
| // { |
| // throw new NotImplementedException(); |
| // } |
| |
| // private object ReadEnum(Schema writers_schema, Schema readers_schema, BinaryDecoder decoder) |
| // { |
| // throw new NotImplementedException(); |
| // } |
| |
| // private object ReadFixed(Schema writers_schema, Schema readers_schema, BinaryDecoder decoder) |
| // { |
| // throw new NotImplementedException(); |
| // } |
| //} |
| } |
