DefaultJsonNameTable
The default JSON name table implementation.
using System;
using System.Runtime.CompilerServices;
using System.Threading;
namespace Newtonsoft.Json
{
[System.Runtime.CompilerServices.NullableContext(1)]
[System.Runtime.CompilerServices.Nullable(0)]
public class DefaultJsonNameTable : JsonNameTable
{
[System.Runtime.CompilerServices.Nullable(0)]
private class Entry
{
internal readonly string Value;
internal readonly int HashCode;
internal Entry Next;
internal Entry(string value, int hashCode, Entry next)
{
Value = value;
HashCode = hashCode;
Next = next;
}
}
private static readonly int HashCodeRandomizer;
private int _count;
private Entry[] _entries;
private int _mask = 31;
static DefaultJsonNameTable()
{
HashCodeRandomizer = Environment.TickCount;
}
public DefaultJsonNameTable()
{
_entries = new Entry[_mask + 1];
}
[return: System.Runtime.CompilerServices.Nullable(2)]
public override string Get(char[] key, int start, int length)
{
if (length == 0)
return string.Empty;
int num = length + HashCodeRandomizer;
num += ((num << 7) ^ key[start]);
int num2 = start + length;
for (int i = start + 1; i < num2; i++) {
num += ((num << 7) ^ key[i]);
}
num -= num >> 17;
num -= num >> 11;
num -= num >> 5;
int num3 = Volatile.Read(ref _mask);
int num4 = num & num3;
for (Entry entry = _entries[num4]; entry != null; entry = entry.Next) {
if (entry.HashCode == num && TextEquals(entry.Value, key, start, length))
return entry.Value;
}
return null;
}
public string Add(string key)
{
if (key == null)
throw new ArgumentNullException("key");
int length = key.Length;
if (length == 0)
return string.Empty;
int num = length + HashCodeRandomizer;
for (int i = 0; i < key.Length; i++) {
num += ((num << 7) ^ key[i]);
}
num -= num >> 17;
num -= num >> 11;
num -= num >> 5;
for (Entry entry = _entries[num & _mask]; entry != null; entry = entry.Next) {
if (entry.HashCode == num && entry.Value.Equals(key, StringComparison.Ordinal))
return entry.Value;
}
return AddEntry(key, num);
}
private string AddEntry(string str, int hashCode)
{
int num = hashCode & _mask;
Entry entry = new Entry(str, hashCode, _entries[num]);
_entries[num] = entry;
if (_count++ == _mask)
Grow();
return entry.Value;
}
private void Grow()
{
Entry[] entries = _entries;
int num = _mask * 2 + 1;
Entry[] array = new Entry[num + 1];
for (int i = 0; i < entries.Length; i++) {
Entry next;
for (Entry entry = entries[i]; entry != null; entry = next) {
int num2 = entry.HashCode & num;
next = entry.Next;
entry.Next = array[num2];
array[num2] = entry;
}
}
_entries = array;
Volatile.Write(ref _mask, num);
}
private static bool TextEquals(string str1, char[] str2, int str2Start, int str2Length)
{
if (str1.Length != str2Length)
return false;
for (int i = 0; i < str1.Length; i++) {
if (str1[i] != str2[str2Start + i])
return false;
}
return true;
}
}
}