blob: 8a7909e3938a9a7c09f10e0d9fa70bbb4634140d (
plain) (
tree)
|
|
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.
// http://code.google.com/p/protobuf/
//
// Licensed 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.Text;
using System;
using System.Collections.Generic;
using System.Collections;
namespace Google.ProtocolBuffers {
/// <summary>
/// Immutable array of bytes.
/// TODO(jonskeet): Implement the common collection interfaces?
/// </summary>
public sealed class ByteString : IEnumerable<byte>, IEquatable<ByteString> {
private static readonly ByteString empty = new ByteString(new byte[0]);
private byte[] bytes;
/// <summary>
/// Constructs a new ByteString from the given byte array. The array is
/// *not* copied, and must not be modified after this constructor is called.
/// </summary>
private ByteString(byte[] bytes) {
this.bytes = bytes;
}
/// <summary>
/// Returns an empty ByteString.
/// </summary>
public static ByteString Empty {
get { return empty; }
}
/// <summary>
/// Returns the length of this ByteString in bytes.
/// </summary>
public int Length {
get { return bytes.Length; }
}
public bool IsEmpty {
get { return Length == 0; }
}
public byte[] ToByteArray() {
return (byte[])bytes.Clone();
}
/// <summary>
/// Constructs a ByteString from the given array. The contents
/// are copied, so further modifications to the array will not
/// be reflected in the returned ByteString.
/// </summary>
public static ByteString CopyFrom(byte[] bytes) {
return new ByteString((byte[]) bytes.Clone());
}
/// <summary>
/// Constructs a ByteString from a portion of a byte array.
/// </summary>
public static ByteString CopyFrom(byte[] bytes, int offset, int count) {
byte[] portion = new byte[count];
Array.Copy(bytes, offset, portion, 0, count);
return new ByteString(portion);
}
/// <summary>
/// Creates a new ByteString by encoding the specified text with
/// the given encoding.
/// </summary>
public static ByteString CopyFrom(string text, Encoding encoding) {
return new ByteString(encoding.GetBytes(text));
}
/// <summary>
/// Creates a new ByteString by encoding the specified text in UTF-8.
/// </summary>
public static ByteString CopyFromUtf8(string text) {
return CopyFrom(text, Encoding.UTF8);
}
/// <summary>
/// Retuns the byte at the given index.
/// </summary>
public byte this[int index] {
get { return bytes[index]; }
}
public string ToString(Encoding encoding) {
return encoding.GetString(bytes);
}
public string ToStringUtf8() {
return ToString(Encoding.UTF8);
}
public IEnumerator<byte> GetEnumerator() {
return ((IEnumerable<byte>) bytes).GetEnumerator();
}
IEnumerator IEnumerable.GetEnumerator() {
return GetEnumerator();
}
/// <summary>
/// Creates a CodedInputStream from this ByteString's data.
/// </summary>
public CodedInputStream CreateCodedInput() {
// We trust CodedInputStream not to reveal the provided byte array or modify it
return CodedInputStream.CreateInstance(bytes);
}
// TODO(jonskeet): CopyTo, Equals, GetHashCode if they turn out to be required
public override bool Equals(object obj) {
ByteString other = obj as ByteString;
if (obj == null) {
return false;
}
return Equals(other);
}
public override int GetHashCode() {
int ret = 23;
foreach (byte b in bytes) {
ret = (ret << 8) | b;
}
return ret;
}
public bool Equals(ByteString other) {
if (other.bytes.Length != bytes.Length) {
return false;
}
for (int i = 0; i < bytes.Length; i++) {
if (other.bytes[i] != bytes[i]) {
return false;
}
}
return true;
}
/// <summary>
/// Builder for ByteStrings which allows them to be created without extra
/// copying being involved. This has to be a nested type in order to have access
/// to the private ByteString constructor.
/// </summary>
internal class CodedBuilder {
private readonly CodedOutputStream output;
private readonly byte[] buffer;
internal CodedBuilder(int size) {
buffer = new byte[size];
output = CodedOutputStream.CreateInstance(buffer);
}
public ByteString Build() {
output.CheckNoSpaceLeft();
// We can be confident that the CodedOutputStream will not modify the
// underlying bytes anymore because it already wrote all of them. So,
// no need to make a copy.
return new ByteString(buffer);
}
public CodedOutputStream CodedOutput {
get {
return output;
}
}
}
}
}
|