Add speed for alpha numeric sorting

This commit is contained in:
Bond_009 2020-03-05 00:57:24 +01:00
parent ada3f96668
commit be1d4b32c6

View File

@ -1,94 +1,132 @@
#nullable enable
using System;
using System.Collections.Generic;
using System.Text;
using MediaBrowser.Controller.Sorting;
namespace MediaBrowser.Controller.Sorting
{
public class AlphanumComparator : IComparer<string>
public class AlphanumComparator : IComparer<string?>
{
public static int CompareValues(string s1, string s2)
public static int CompareValues(string? s1, string? s2)
{
if (s1 == null || s2 == null)
if (s1 == null && s2 == null)
{
return 0;
}
int thisMarker = 0, thisNumericChunk = 0;
int thatMarker = 0, thatNumericChunk = 0;
while ((thisMarker < s1.Length) || (thatMarker < s2.Length))
else if (s1 == null)
{
if (thisMarker >= s1.Length)
{
return -1;
}
else if (thatMarker >= s2.Length)
{
return 1;
}
char thisCh = s1[thisMarker];
char thatCh = s2[thatMarker];
return -1;
}
else if (s2 == null)
{
return 1;
}
var thisChunk = new StringBuilder();
var thatChunk = new StringBuilder();
bool thisNumeric = char.IsDigit(thisCh), thatNumeric = char.IsDigit(thatCh);
int len1 = s1.Length;
int len2 = s2.Length;
while (thisMarker < s1.Length && char.IsDigit(thisCh) == thisNumeric)
// Early return for empty strings
if (len1 == 0 && len2 == 0)
{
return 0;
}
else if (len1 == 0)
{
return -1;
}
else if (len2 == 0)
{
return 1;
}
int pos1 = 0;
int pos2 = 0;
do
{
int start1 = pos1;
int start2 = pos2;
bool isNum1 = char.IsDigit(s1[pos1++]);
bool isNum2 = char.IsDigit(s2[pos2++]);
while (pos1 < len1 && char.IsDigit(s1[pos1]) == isNum1)
{
thisChunk.Append(thisCh);
thisMarker++;
if (thisMarker < s1.Length)
{
thisCh = s1[thisMarker];
}
pos1++;
}
while (thatMarker < s2.Length && char.IsDigit(thatCh) == thatNumeric)
while (pos2 < len2 && char.IsDigit(s2[pos2]) == isNum2)
{
thatChunk.Append(thatCh);
thatMarker++;
if (thatMarker < s2.Length)
{
thatCh = s2[thatMarker];
}
pos2++;
}
var span1 = s1.AsSpan(start1, pos1 - start1);
var span2 = s2.AsSpan(start2, pos2 - start2);
// If both chunks contain numeric characters, sort them numerically
if (thisNumeric && thatNumeric)
if (isNum1 && isNum2)
{
if (!int.TryParse(thisChunk.ToString(), out thisNumericChunk)
|| !int.TryParse(thatChunk.ToString(), out thatNumericChunk))
{
return 0;
}
if (thisNumericChunk < thatNumericChunk)
// Trim leading zeros so we can compare the length
// of the strings to find the largest number
span1 = span1.TrimStart('0');
span2 = span2.TrimStart('0');
var span1Len = span1.Length;
var span2Len = span2.Length;
if (span1Len < span2Len)
{
return -1;
}
else if (span1Len > span2Len)
{
return 1;
}
else if (span1Len >= 20) // Number is probably too big for a ulong
{
// Trim all the first digits that are the same
int i = 0;
while (i < span1Len && span1[i] == span2[i])
{
i++;
}
if (thisNumericChunk > thatNumericChunk)
// If there are no more digits it's the same number
if (i == span1Len)
{
continue;
}
// Only need to compare the most significant digit
span1 = span1.Slice(i, 1);
span2 = span2.Slice(i, 1);
}
if (!ulong.TryParse(span1, out var num1)
|| !ulong.TryParse(span2, out var num2))
{
return 0;
}
else if (num1 < num2)
{
return -1;
}
else if (num1 > num2)
{
return 1;
}
}
else
{
int result = thisChunk.ToString().CompareTo(thatChunk.ToString());
int result = span1.CompareTo(span2, StringComparison.InvariantCulture);
if (result != 0)
{
return result;
}
}
} while (pos1 < len1 && pos2 < len2);
}
return 0;
return len1 - len2;
}
/// <inheritdoc />
public int Compare(string x, string y)
{
return CompareValues(x, y);