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Diffstat (limited to 'csharp/src/Google.Protobuf/Reflection/CustomOptions.cs')
| -rw-r--r-- | csharp/src/Google.Protobuf/Reflection/CustomOptions.cs | 390 |
1 files changed, 390 insertions, 0 deletions
diff --git a/csharp/src/Google.Protobuf/Reflection/CustomOptions.cs b/csharp/src/Google.Protobuf/Reflection/CustomOptions.cs new file mode 100644 index 00000000..88b3ec00 --- /dev/null +++ b/csharp/src/Google.Protobuf/Reflection/CustomOptions.cs @@ -0,0 +1,390 @@ +#region Copyright notice and license +// Protocol Buffers - Google's data interchange format +// Copyright 2017 Google Inc. All rights reserved. +// https://developers.google.com/protocol-buffers/ +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +#endregion + +using System; +using System.Collections.Generic; + +namespace Google.Protobuf.Reflection +{ + /// <summary> + /// Container for a set of custom options specified within a message, field etc. + /// </summary> + /// <remarks> + /// <para> + /// This type is publicly immutable, but internally mutable. It is only populated + /// by the descriptor parsing code - by the time any user code is able to see an instance, + /// it will be fully initialized. + /// </para> + /// <para> + /// If an option is requested using the incorrect method, an answer may still be returned: all + /// of the numeric types are represented internally using 64-bit integers, for example. It is up to + /// the caller to ensure that they make the appropriate method call for the option they're interested in. + /// Note that enum options are simply stored as integers, so the value should be fetched using + /// <see cref="TryGetInt32(int, out int)"/> and then cast appropriately. + /// </para> + /// <para> + /// Repeated options are currently not supported. Asking for a single value of an option + /// which was actually repeated will return the last value, except for message types where + /// all the set values are merged together. + /// </para> + /// </remarks> + public sealed class CustomOptions + { + /// <summary> + /// Singleton for all descriptors with an empty set of options. + /// </summary> + internal static readonly CustomOptions Empty = new CustomOptions(); + + /// <summary> + /// A sequence of values per field. This needs to be per field rather than per tag to allow correct deserialization + /// of repeated fields which could be "int, ByteString, int" - unlikely as that is. The fact that values are boxed + /// is unfortunate; we might be able to use a struct instead, and we could combine uint and ulong values. + /// </summary> + private readonly Dictionary<int, List<FieldValue>> valuesByField = new Dictionary<int, List<FieldValue>>(); + + private CustomOptions() { } + + /// <summary> + /// Retrieves a Boolean value for the specified option field. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetBool(int field, out bool value) + { + ulong? tmp = GetLastNumericValue(field); + value = tmp == 1UL; + return tmp != null; + } + + /// <summary> + /// Retrieves a signed 32-bit integer value for the specified option field. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetInt32(int field, out int value) + { + ulong? tmp = GetLastNumericValue(field); + value = (int) tmp.GetValueOrDefault(); + return tmp != null; + } + + /// <summary> + /// Retrieves a signed 64-bit integer value for the specified option field. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetInt64(int field, out long value) + { + ulong? tmp = GetLastNumericValue(field); + value = (long) tmp.GetValueOrDefault(); + return tmp != null; + } + + /// <summary> + /// Retrieves an unsigned 32-bit integer value for the specified option field, + /// assuming a fixed-length representation. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetFixed32(int field, out uint value) => TryGetUInt32(field, out value); + + /// <summary> + /// Retrieves an unsigned 64-bit integer value for the specified option field, + /// assuming a fixed-length representation. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetFixed64(int field, out ulong value) => TryGetUInt64(field, out value); + + /// <summary> + /// Retrieves a signed 32-bit integer value for the specified option field, + /// assuming a fixed-length representation. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetSFixed32(int field, out int value) => TryGetInt32(field, out value); + + /// <summary> + /// Retrieves a signed 64-bit integer value for the specified option field, + /// assuming a fixed-length representation. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetSFixed64(int field, out long value) => TryGetInt64(field, out value); + + /// <summary> + /// Retrieves a signed 32-bit integer value for the specified option field, + /// assuming a zigzag encoding. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetSInt32(int field, out int value) + { + ulong? tmp = GetLastNumericValue(field); + value = CodedInputStream.DecodeZigZag32((uint) tmp.GetValueOrDefault()); + return tmp != null; + } + + /// <summary> + /// Retrieves a signed 64-bit integer value for the specified option field, + /// assuming a zigzag encoding. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetSInt64(int field, out long value) + { + ulong? tmp = GetLastNumericValue(field); + value = CodedInputStream.DecodeZigZag64(tmp.GetValueOrDefault()); + return tmp != null; + } + + /// <summary> + /// Retrieves an unsigned 32-bit integer value for the specified option field. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetUInt32(int field, out uint value) + { + ulong? tmp = GetLastNumericValue(field); + value = (uint) tmp.GetValueOrDefault(); + return tmp != null; + } + + /// <summary> + /// Retrieves an unsigned 64-bit integer value for the specified option field. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetUInt64(int field, out ulong value) + { + ulong? tmp = GetLastNumericValue(field); + value = tmp.GetValueOrDefault(); + return tmp != null; + } + + /// <summary> + /// Retrieves a 32-bit floating point value for the specified option field. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetFloat(int field, out float value) + { + ulong? tmp = GetLastNumericValue(field); + int int32 = (int) tmp.GetValueOrDefault(); + byte[] bytes = BitConverter.GetBytes(int32); + value = BitConverter.ToSingle(bytes, 0); + return tmp != null; + } + + /// <summary> + /// Retrieves a 64-bit floating point value for the specified option field. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetDouble(int field, out double value) + { + ulong? tmp = GetLastNumericValue(field); + value = BitConverter.Int64BitsToDouble((long) tmp.GetValueOrDefault()); + return tmp != null; + } + + /// <summary> + /// Retrieves a string value for the specified option field. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetString(int field, out string value) + { + ByteString bytes = GetLastByteStringValue(field); + value = bytes?.ToStringUtf8(); + return bytes != null; + } + + /// <summary> + /// Retrieves a bytes value for the specified option field. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetBytes(int field, out ByteString value) + { + ByteString bytes = GetLastByteStringValue(field); + value = bytes; + return bytes != null; + } + + /// <summary> + /// Retrieves a message value for the specified option field. + /// </summary> + /// <param name="field">The field to fetch the value for.</param> + /// <param name="value">The output variable to populate.</param> + /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns> + public bool TryGetMessage<T>(int field, out T value) where T : class, IMessage, new() + { + value = null; + List<FieldValue> values; + if (!valuesByField.TryGetValue(field, out values)) + { + return false; + } + foreach (FieldValue fieldValue in values) + { + if (fieldValue.ByteString != null) + { + if (value == null) + { + value = new T(); + } + value.MergeFrom(fieldValue.ByteString); + } + } + return value != null; + } + + private ulong? GetLastNumericValue(int field) + { + List<FieldValue> values; + if (!valuesByField.TryGetValue(field, out values)) + { + return null; + } + for (int i = values.Count - 1; i >= 0; i--) + { + // A non-bytestring value is a numeric value + if (values[i].ByteString == null) + { + return values[i].Number; + } + } + return null; + } + + private ByteString GetLastByteStringValue(int field) + { + List<FieldValue> values; + if (!valuesByField.TryGetValue(field, out values)) + { + return null; + } + for (int i = values.Count - 1; i >= 0; i--) + { + if (values[i].ByteString != null) + { + return values[i].ByteString; + } + } + return null; + } + + /// <summary> + /// Reads an unknown field, either parsing it and storing it or skipping it. + /// </summary> + /// <remarks> + /// If the current set of options is empty and we manage to read a field, a new set of options + /// will be created and returned. Otherwise, the return value is <c>this</c>. This allows + /// us to start with a singleton empty set of options and just create new ones where necessary. + /// </remarks> + /// <param name="input">Input stream to read from. </param> + /// <returns>The resulting set of custom options, either <c>this</c> or a new set.</returns> + internal CustomOptions ReadOrSkipUnknownField(CodedInputStream input) + { + var tag = input.LastTag; + var field = WireFormat.GetTagFieldNumber(tag); + switch (WireFormat.GetTagWireType(tag)) + { + case WireFormat.WireType.LengthDelimited: + return AddValue(field, new FieldValue(input.ReadBytes())); + case WireFormat.WireType.Fixed32: + return AddValue(field, new FieldValue(input.ReadFixed32())); + case WireFormat.WireType.Fixed64: + return AddValue(field, new FieldValue(input.ReadFixed64())); + case WireFormat.WireType.Varint: + return AddValue(field, new FieldValue(input.ReadRawVarint64())); + // For StartGroup, EndGroup or any wire format we don't understand, + // just use the normal behavior (call SkipLastField). + default: + input.SkipLastField(); + return this; + } + } + + private CustomOptions AddValue(int field, FieldValue value) + { + var ret = valuesByField.Count == 0 ? new CustomOptions() : this; + List<FieldValue> valuesForField; + if (!ret.valuesByField.TryGetValue(field, out valuesForField)) + { + // Expect almost all + valuesForField = new List<FieldValue>(1); + ret.valuesByField[field] = valuesForField; + } + valuesForField.Add(value); + return ret; + } + + /// <summary> + /// All field values can be stored as a byte string or a 64-bit integer. + /// This struct avoids unnecessary boxing. + /// </summary> + private struct FieldValue + { + internal ulong Number { get; } + internal ByteString ByteString { get; } + + internal FieldValue(ulong number) + { + Number = number; + ByteString = null; + } + + internal FieldValue(ByteString byteString) + { + Number = 0; + ByteString = byteString; + } + } + } +} |