#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
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// 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;
}
}
}
}
