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|
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System.Diagnostics;
using System.Globalization;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using Internal.Runtime.CompilerServices;
#if BIT64
using nuint = System.UInt64;
#else
using nuint = System.UInt32;
#endif
namespace System
{
public partial class String
{
//
//Native Static Methods
//
private static unsafe int FastCompareStringHelper(uint* strAChars, int countA, uint* strBChars, int countB)
{
int count = (countA < countB) ? countA : countB;
#if BIT64
long diff = (long)((byte*)strAChars - (byte*)strBChars);
#else
int diff = (int)((byte*)strAChars - (byte*)strBChars);
#endif
#if BIT64
int alignmentA = (int)((long)strAChars) & (sizeof(IntPtr) - 1);
int alignmentB = (int)((long)strBChars) & (sizeof(IntPtr) - 1);
if (alignmentA == alignmentB)
{
if ((alignmentA == 2 || alignmentA == 6) && (count >= 1))
{
char* ptr2 = (char*)strBChars;
if ((*((char*)((byte*)ptr2 + diff)) - *ptr2) != 0)
return ((int)*((char*)((byte*)ptr2 + diff)) - (int)*ptr2);
strBChars = (uint*)(++ptr2);
count -= 1;
alignmentA = (alignmentA == 2 ? 4 : 0);
}
if ((alignmentA == 4) && (count >= 2))
{
uint* ptr2 = (uint*)strBChars;
if ((*((uint*)((byte*)ptr2 + diff)) - *ptr2) != 0)
{
char* chkptr1 = (char*)((byte*)strBChars + diff);
char* chkptr2 = (char*)strBChars;
if (*chkptr1 != *chkptr2)
return ((int)*chkptr1 - (int)*chkptr2);
return ((int)*(chkptr1 + 1) - (int)*(chkptr2 + 1));
}
strBChars = ++ptr2;
count -= 2;
alignmentA = 0;
}
if ((alignmentA == 0))
{
while (count >= 4)
{
long* ptr2 = (long*)strBChars;
if ((*((long*)((byte*)ptr2 + diff)) - *ptr2) != 0)
{
if ((*((uint*)((byte*)ptr2 + diff)) - *(uint*)ptr2) != 0)
{
char* chkptr1 = (char*)((byte*)strBChars + diff);
char* chkptr2 = (char*)strBChars;
if (*chkptr1 != *chkptr2)
return ((int)*chkptr1 - (int)*chkptr2);
return ((int)*(chkptr1 + 1) - (int)*(chkptr2 + 1));
}
else
{
char* chkptr1 = (char*)((uint*)((byte*)strBChars + diff) + 1);
char* chkptr2 = (char*)((uint*)strBChars + 1);
if (*chkptr1 != *chkptr2)
return ((int)*chkptr1 - (int)*chkptr2);
return ((int)*(chkptr1 + 1) - (int)*(chkptr2 + 1));
}
}
strBChars = (uint*)(++ptr2);
count -= 4;
}
}
{
char* ptr2 = (char*)strBChars;
while ((count -= 1) >= 0)
{
if ((*((char*)((byte*)ptr2 + diff)) - *ptr2) != 0)
return ((int)*((char*)((byte*)ptr2 + diff)) - (int)*ptr2);
++ptr2;
}
}
}
else
#endif // BIT64
{
#if BIT64
if (Math.Abs(alignmentA - alignmentB) == 4)
{
if ((alignmentA == 2) || (alignmentB == 2))
{
char* ptr2 = (char*)strBChars;
if ((*((char*)((byte*)ptr2 + diff)) - *ptr2) != 0)
return ((int)*((char*)((byte*)ptr2 + diff)) - (int)*ptr2);
strBChars = (uint*)(++ptr2);
count -= 1;
}
}
#endif // BIT64
// Loop comparing a DWORD at a time.
// Reads are potentially unaligned
while ((count -= 2) >= 0)
{
if ((*((uint*)((byte*)strBChars + diff)) - *strBChars) != 0)
{
char* ptr1 = (char*)((byte*)strBChars + diff);
char* ptr2 = (char*)strBChars;
if (*ptr1 != *ptr2)
return ((int)*ptr1 - (int)*ptr2);
return ((int)*(ptr1 + 1) - (int)*(ptr2 + 1));
}
++strBChars;
}
int c;
if (count == -1)
if ((c = *((char*)((byte*)strBChars + diff)) - *((char*)strBChars)) != 0)
return c;
}
return countA - countB;
}
//
//
// NATIVE INSTANCE METHODS
//
//
//
// Search/Query methods
//
//
// Common worker for the various Equality methods. The caller must have already ensured that
// both strings are non-null and that their lengths are equal. Ther caller should also have
// done the Object.ReferenceEquals() fastpath check as we won't repeat it here.
//
private static unsafe bool EqualsHelper(String strA, String strB)
{
Debug.Assert(strA != null);
Debug.Assert(strB != null);
Debug.Assert(strA.Length == strB.Length);
int length = strA.Length;
fixed (char* ap = &strA._firstChar) fixed (char* bp = &strB._firstChar)
{
char* a = ap;
char* b = bp;
#if BIT64
// Single int read aligns pointers for the following long reads
// PERF: No length check needed as there is always an int32 worth of string allocated
// This read can also include the null terminator which both strings will have
if (*(int*)a != *(int*)b) return false;
length -= 2; a += 2; b += 2;
// for 64-bit platforms we unroll by 12 and
// check 3 qword at a time. This is less code
// than the 32 bit case and is a shorter path length
while (length >= 12)
{
if (*(long*)a != *(long*)b) goto ReturnFalse;
if (*(long*)(a + 4) != *(long*)(b + 4)) goto ReturnFalse;
if (*(long*)(a + 8) != *(long*)(b + 8)) goto ReturnFalse;
length -= 12; a += 12; b += 12;
}
#else
while (length >= 10)
{
if (*(int*)a != *(int*)b) goto ReturnFalse;
if (*(int*)(a + 2) != *(int*)(b + 2)) goto ReturnFalse;
if (*(int*)(a + 4) != *(int*)(b + 4)) goto ReturnFalse;
if (*(int*)(a + 6) != *(int*)(b + 6)) goto ReturnFalse;
if (*(int*)(a + 8) != *(int*)(b + 8)) goto ReturnFalse;
length -= 10; a += 10; b += 10;
}
#endif
// This depends on the fact that the String objects are
// always zero terminated and that the terminating zero is not included
// in the length. For odd string sizes, the last compare will include
// the zero terminator.
while (length > 0)
{
if (*(int*)a != *(int*)b) goto ReturnFalse;
length -= 2; a += 2; b += 2;
}
return true;
ReturnFalse:
return false;
}
}
private static unsafe bool StartsWithOrdinalHelper(String str, String startsWith)
{
Debug.Assert(str != null);
Debug.Assert(startsWith != null);
Debug.Assert(str.Length >= startsWith.Length);
int length = startsWith.Length;
fixed (char* ap = &str._firstChar) fixed (char* bp = &startsWith._firstChar)
{
char* a = ap;
char* b = bp;
#if BIT64
// Single int read aligns pointers for the following long reads
// No length check needed as this method is called when length >= 2
Debug.Assert(length >= 2);
if (*(int*)a != *(int*)b) goto ReturnFalse;
length -= 2; a += 2; b += 2;
while (length >= 12)
{
if (*(long*)a != *(long*)b) goto ReturnFalse;
if (*(long*)(a + 4) != *(long*)(b + 4)) goto ReturnFalse;
if (*(long*)(a + 8) != *(long*)(b + 8)) goto ReturnFalse;
length -= 12; a += 12; b += 12;
}
#else
while (length >= 10)
{
if (*(int*)a != *(int*)b) goto ReturnFalse;
if (*(int*)(a + 2) != *(int*)(b + 2)) goto ReturnFalse;
if (*(int*)(a + 4) != *(int*)(b + 4)) goto ReturnFalse;
if (*(int*)(a + 6) != *(int*)(b + 6)) goto ReturnFalse;
if (*(int*)(a + 8) != *(int*)(b + 8)) goto ReturnFalse;
length -= 10; a += 10; b += 10;
}
#endif
while (length >= 2)
{
if (*(int*)a != *(int*)b) goto ReturnFalse;
length -= 2; a += 2; b += 2;
}
// PERF: This depends on the fact that the String objects are always zero terminated
// and that the terminating zero is not included in the length. For even string sizes
// this compare can include the zero terminator. Bitwise OR avoids a branch.
return length == 0 | *a == *b;
ReturnFalse:
return false;
}
}
private static unsafe int CompareOrdinalHelper(String strA, String strB)
{
Debug.Assert(strA != null);
Debug.Assert(strB != null);
// NOTE: This may be subject to change if eliminating the check
// in the callers makes them small enough to be inlined
Debug.Assert(strA._firstChar == strB._firstChar,
"For performance reasons, callers of this method should " +
"check/short-circuit beforehand if the first char is the same.");
int length = Math.Min(strA.Length, strB.Length);
fixed (char* ap = &strA._firstChar) fixed (char* bp = &strB._firstChar)
{
char* a = ap;
char* b = bp;
// Check if the second chars are different here
// The reason we check if _firstChar is different is because
// it's the most common case and allows us to avoid a method call
// to here.
// The reason we check if the second char is different is because
// if the first two chars the same we can increment by 4 bytes,
// leaving us word-aligned on both 32-bit (12 bytes into the string)
// and 64-bit (16 bytes) platforms.
// For empty strings, the second char will be null due to padding.
// The start of the string is the EE type pointer + string length,
// which takes up 8 bytes on 32-bit, 12 on x64. For empty strings,
// the null terminator immediately follows, leaving us with an object
// 10/14 bytes in size. Since everything needs to be a multiple
// of 4/8, this will get padded and zeroed out.
// For one-char strings the second char will be the null terminator.
// NOTE: If in the future there is a way to read the second char
// without pinning the string (e.g. System.Runtime.CompilerServices.Unsafe
// is exposed to mscorlib, or a future version of C# allows inline IL),
// then do that and short-circuit before the fixed.
if (*(a + 1) != *(b + 1)) goto DiffOffset1;
// Since we know that the first two chars are the same,
// we can increment by 2 here and skip 4 bytes.
// This leaves us 8-byte aligned, which results
// on better perf for 64-bit platforms.
length -= 2; a += 2; b += 2;
// unroll the loop
#if BIT64
while (length >= 12)
{
if (*(long*)a != *(long*)b) goto DiffOffset0;
if (*(long*)(a + 4) != *(long*)(b + 4)) goto DiffOffset4;
if (*(long*)(a + 8) != *(long*)(b + 8)) goto DiffOffset8;
length -= 12; a += 12; b += 12;
}
#else // BIT64
while (length >= 10)
{
if (*(int*)a != *(int*)b) goto DiffOffset0;
if (*(int*)(a + 2) != *(int*)(b + 2)) goto DiffOffset2;
if (*(int*)(a + 4) != *(int*)(b + 4)) goto DiffOffset4;
if (*(int*)(a + 6) != *(int*)(b + 6)) goto DiffOffset6;
if (*(int*)(a + 8) != *(int*)(b + 8)) goto DiffOffset8;
length -= 10; a += 10; b += 10;
}
#endif // BIT64
// Fallback loop:
// go back to slower code path and do comparison on 4 bytes at a time.
// This depends on the fact that the String objects are
// always zero terminated and that the terminating zero is not included
// in the length. For odd string sizes, the last compare will include
// the zero terminator.
while (length > 0)
{
if (*(int*)a != *(int*)b) goto DiffNextInt;
length -= 2;
a += 2;
b += 2;
}
// At this point, we have compared all the characters in at least one string.
// The longer string will be larger.
return strA.Length - strB.Length;
#if BIT64
DiffOffset8: a += 4; b += 4;
DiffOffset4: a += 4; b += 4;
#else // BIT64
// Use jumps instead of falling through, since
// otherwise going to DiffOffset8 will involve
// 8 add instructions before getting to DiffNextInt
DiffOffset8: a += 8; b += 8; goto DiffOffset0;
DiffOffset6: a += 6; b += 6; goto DiffOffset0;
DiffOffset4: a += 2; b += 2;
DiffOffset2: a += 2; b += 2;
#endif // BIT64
DiffOffset0:
// If we reached here, we already see a difference in the unrolled loop above
#if BIT64
if (*(int*)a == *(int*)b)
{
a += 2; b += 2;
}
#endif // BIT64
DiffNextInt:
if (*a != *b) return *a - *b;
DiffOffset1:
Debug.Assert(*(a + 1) != *(b + 1), "This char must be different if we reach here!");
return *(a + 1) - *(b + 1);
}
}
internal static unsafe int CompareOrdinalHelper(string strA, int indexA, int countA, string strB, int indexB, int countB)
{
// Argument validation should be handled by callers.
Debug.Assert(strA != null && strB != null);
Debug.Assert(indexA >= 0 && indexB >= 0);
Debug.Assert(countA >= 0 && countB >= 0);
Debug.Assert(countA <= strA.Length - indexA);
Debug.Assert(countB <= strB.Length - indexB);
// Set up the loop variables.
fixed (char* pStrA = &strA._firstChar, pStrB = &strB._firstChar)
{
char* strAChars = pStrA + indexA;
char* strBChars = pStrB + indexB;
return FastCompareStringHelper((uint*)strAChars, countA, (uint*)strBChars, countB);
}
}
public static int Compare(String strA, String strB)
{
return Compare(strA, strB, StringComparison.CurrentCulture);
}
public static int Compare(String strA, String strB, bool ignoreCase)
{
var comparisonType = ignoreCase ? StringComparison.CurrentCultureIgnoreCase : StringComparison.CurrentCulture;
return Compare(strA, strB, comparisonType);
}
// Provides a more flexible function for string comparision. See StringComparison
// for meaning of different comparisonType.
public static int Compare(String strA, String strB, StringComparison comparisonType)
{
if (object.ReferenceEquals(strA, strB))
{
StringSpanHelpers.CheckStringComparison(comparisonType);
return 0;
}
// They can't both be null at this point.
if (strA == null)
{
StringSpanHelpers.CheckStringComparison(comparisonType);
return -1;
}
if (strB == null)
{
StringSpanHelpers.CheckStringComparison(comparisonType);
return 1;
}
switch (comparisonType)
{
case StringComparison.CurrentCulture:
return CultureInfo.CurrentCulture.CompareInfo.Compare(strA, 0, strA.Length, strB, 0, strB.Length, CompareOptions.None);
case StringComparison.CurrentCultureIgnoreCase:
return CultureInfo.CurrentCulture.CompareInfo.Compare(strA, 0, strA.Length, strB, 0, strB.Length, CompareOptions.IgnoreCase);
case StringComparison.Ordinal:
// Most common case: first character is different.
// Returns false for empty strings.
if (strA._firstChar != strB._firstChar)
{
return strA._firstChar - strB._firstChar;
}
return CompareOrdinalHelper(strA, strB);
case StringComparison.OrdinalIgnoreCase:
return CompareInfo.CompareOrdinalIgnoreCase(strA, 0, strA.Length, strB, 0, strB.Length);
case StringComparison.InvariantCulture:
return CompareInfo.Invariant.Compare(strA, strB, CompareOptions.None);
case StringComparison.InvariantCultureIgnoreCase:
return CompareInfo.Invariant.Compare(strA, strB, CompareOptions.IgnoreCase);
default:
throw new ArgumentException(SR.NotSupported_StringComparison, nameof(comparisonType));
}
}
// Provides a culture-correct string comparison. strA is compared to strB
// to determine whether it is lexicographically less, equal, or greater, and then a
// negative integer, 0, or a positive integer is returned; respectively.
//
public static int Compare(String strA, String strB, CultureInfo culture, CompareOptions options)
{
if (culture == null)
{
throw new ArgumentNullException(nameof(culture));
}
return culture.CompareInfo.Compare(strA, strB, options);
}
// Provides a culture-correct string comparison. strA is compared to strB
// to determine whether it is lexicographically less, equal, or greater, and then a
// negative integer, 0, or a positive integer is returned; respectively.
// The case-sensitive option is set by ignoreCase, and the culture is set
// by culture
//
public static int Compare(String strA, String strB, bool ignoreCase, CultureInfo culture)
{
CompareOptions options = ignoreCase ? CompareOptions.IgnoreCase : CompareOptions.None;
return Compare(strA, strB, culture, options);
}
// Determines whether two string regions match. The substring of strA beginning
// at indexA of length length is compared with the substring of strB
// beginning at indexB of the same length.
//
public static int Compare(String strA, int indexA, String strB, int indexB, int length)
{
// NOTE: It's important we call the boolean overload, and not the StringComparison
// one. The two have some subtly different behavior (see notes in the former).
return Compare(strA, indexA, strB, indexB, length, ignoreCase: false);
}
// Determines whether two string regions match. The substring of strA beginning
// at indexA of length count is compared with the substring of strB
// beginning at indexB of the same length. Case sensitivity is determined by the ignoreCase boolean.
//
public static int Compare(String strA, int indexA, String strB, int indexB, int length, bool ignoreCase)
{
// Ideally we would just forward to the string.Compare overload that takes
// a StringComparison parameter, and just pass in CurrentCulture/CurrentCultureIgnoreCase.
// That function will return early if an optimization can be applied, e.g. if
// (object)strA == strB && indexA == indexB then it will return 0 straightaway.
// There are a couple of subtle behavior differences that prevent us from doing so
// however:
// - string.Compare(null, -1, null, -1, -1, StringComparison.CurrentCulture) works
// since that method also returns early for nulls before validation. It shouldn't
// for this overload.
// - Since we originally forwarded to FormatProvider for all of the argument
// validation logic, the ArgumentOutOfRangeExceptions thrown will contain different
// parameter names.
// Therefore, we have to duplicate some of the logic here.
int lengthA = length;
int lengthB = length;
if (strA != null)
{
lengthA = Math.Min(lengthA, strA.Length - indexA);
}
if (strB != null)
{
lengthB = Math.Min(lengthB, strB.Length - indexB);
}
CompareOptions options = ignoreCase ? CompareOptions.IgnoreCase : CompareOptions.None;
return CultureInfo.CurrentCulture.CompareInfo.Compare(strA, indexA, lengthA, strB, indexB, lengthB, options);
}
// Determines whether two string regions match. The substring of strA beginning
// at indexA of length length is compared with the substring of strB
// beginning at indexB of the same length. Case sensitivity is determined by the ignoreCase boolean,
// and the culture is set by culture.
//
public static int Compare(String strA, int indexA, String strB, int indexB, int length, bool ignoreCase, CultureInfo culture)
{
CompareOptions options = ignoreCase ? CompareOptions.IgnoreCase : CompareOptions.None;
return Compare(strA, indexA, strB, indexB, length, culture, options);
}
// Determines whether two string regions match. The substring of strA beginning
// at indexA of length length is compared with the substring of strB
// beginning at indexB of the same length.
//
public static int Compare(String strA, int indexA, String strB, int indexB, int length, CultureInfo culture, CompareOptions options)
{
if (culture == null)
{
throw new ArgumentNullException(nameof(culture));
}
int lengthA = length;
int lengthB = length;
if (strA != null)
{
lengthA = Math.Min(lengthA, strA.Length - indexA);
}
if (strB != null)
{
lengthB = Math.Min(lengthB, strB.Length - indexB);
}
return culture.CompareInfo.Compare(strA, indexA, lengthA, strB, indexB, lengthB, options);
}
public static int Compare(String strA, int indexA, String strB, int indexB, int length, StringComparison comparisonType)
{
StringSpanHelpers.CheckStringComparison(comparisonType);
if (strA == null || strB == null)
{
if (object.ReferenceEquals(strA, strB))
{
// They're both null
return 0;
}
return strA == null ? -1 : 1;
}
// @TODO: Spec#: Figure out what to do here with the return statement above.
if (length < 0)
{
throw new ArgumentOutOfRangeException(nameof(length), SR.ArgumentOutOfRange_NegativeLength);
}
if (indexA < 0 || indexB < 0)
{
string paramName = indexA < 0 ? nameof(indexA) : nameof(indexB);
throw new ArgumentOutOfRangeException(paramName, SR.ArgumentOutOfRange_Index);
}
if (strA.Length - indexA < 0 || strB.Length - indexB < 0)
{
string paramName = strA.Length - indexA < 0 ? nameof(indexA) : nameof(indexB);
throw new ArgumentOutOfRangeException(paramName, SR.ArgumentOutOfRange_Index);
}
if (length == 0 || (object.ReferenceEquals(strA, strB) && indexA == indexB))
{
return 0;
}
int lengthA = Math.Min(length, strA.Length - indexA);
int lengthB = Math.Min(length, strB.Length - indexB);
switch (comparisonType)
{
case StringComparison.CurrentCulture:
return CultureInfo.CurrentCulture.CompareInfo.Compare(strA, indexA, lengthA, strB, indexB, lengthB, CompareOptions.None);
case StringComparison.CurrentCultureIgnoreCase:
return CultureInfo.CurrentCulture.CompareInfo.Compare(strA, indexA, lengthA, strB, indexB, lengthB, CompareOptions.IgnoreCase);
case StringComparison.Ordinal:
return CompareOrdinalHelper(strA, indexA, lengthA, strB, indexB, lengthB);
case StringComparison.OrdinalIgnoreCase:
return CompareInfo.CompareOrdinalIgnoreCase(strA, indexA, lengthA, strB, indexB, lengthB);
case StringComparison.InvariantCulture:
return CompareInfo.Invariant.Compare(strA, indexA, lengthA, strB, indexB, lengthB, CompareOptions.None);
case StringComparison.InvariantCultureIgnoreCase:
return CompareInfo.Invariant.Compare(strA, indexA, lengthA, strB, indexB, lengthB, CompareOptions.IgnoreCase);
default:
throw new ArgumentException(SR.NotSupported_StringComparison, nameof(comparisonType));
}
}
// Compares strA and strB using an ordinal (code-point) comparison.
//
public static int CompareOrdinal(String strA, String strB)
{
if (object.ReferenceEquals(strA, strB))
{
return 0;
}
// They can't both be null at this point.
if (strA == null)
{
return -1;
}
if (strB == null)
{
return 1;
}
// Most common case, first character is different.
// This will return false for empty strings.
if (strA._firstChar != strB._firstChar)
{
return strA._firstChar - strB._firstChar;
}
return CompareOrdinalHelper(strA, strB);
}
// TODO https://github.com/dotnet/corefx/issues/21395: Expose this publicly?
internal static int CompareOrdinal(ReadOnlySpan<char> strA, ReadOnlySpan<char> strB)
{
// TODO: Add a vectorized code path, similar to SequenceEqual
// https://github.com/dotnet/corefx/blob/master/src/System.Memory/src/System/SpanHelpers.byte.cs#L900
int minLength = Math.Min(strA.Length, strB.Length);
ref char first = ref MemoryMarshal.GetReference(strA);
ref char second = ref MemoryMarshal.GetReference(strB);
int i = 0;
if (minLength >= sizeof(nuint) / sizeof(char))
{
while (i < minLength - sizeof(nuint) / sizeof(char))
{
if (Unsafe.ReadUnaligned<nuint>(ref Unsafe.As<char, byte>(ref Unsafe.Add(ref first, i))) !=
Unsafe.ReadUnaligned<nuint>(ref Unsafe.As<char, byte>(ref Unsafe.Add(ref second, i))))
{
break;
}
i += sizeof(nuint) / sizeof(char);
}
}
while (i < minLength)
{
char a = Unsafe.Add(ref first, i);
char b = Unsafe.Add(ref second, i);
if (a != b)
{
return a - b;
}
i++;
}
return strA.Length - strB.Length;
}
public static int CompareOrdinal(String strA, int indexA, String strB, int indexB, int length)
{
if (strA == null || strB == null)
{
if (object.ReferenceEquals(strA, strB))
{
// They're both null
return 0;
}
return strA == null ? -1 : 1;
}
// COMPAT: Checking for nulls should become before the arguments are validated,
// but other optimizations which allow us to return early should come after.
if (length < 0)
{
throw new ArgumentOutOfRangeException(nameof(length), SR.ArgumentOutOfRange_NegativeCount);
}
if (indexA < 0 || indexB < 0)
{
string paramName = indexA < 0 ? nameof(indexA) : nameof(indexB);
throw new ArgumentOutOfRangeException(paramName, SR.ArgumentOutOfRange_Index);
}
int lengthA = Math.Min(length, strA.Length - indexA);
int lengthB = Math.Min(length, strB.Length - indexB);
if (lengthA < 0 || lengthB < 0)
{
string paramName = lengthA < 0 ? nameof(indexA) : nameof(indexB);
throw new ArgumentOutOfRangeException(paramName, SR.ArgumentOutOfRange_Index);
}
if (length == 0 || (object.ReferenceEquals(strA, strB) && indexA == indexB))
{
return 0;
}
return CompareOrdinalHelper(strA, indexA, lengthA, strB, indexB, lengthB);
}
// Compares this String to another String (cast as object), returning an integer that
// indicates the relationship. This method returns a value less than 0 if this is less than value, 0
// if this is equal to value, or a value greater than 0 if this is greater than value.
//
public int CompareTo(Object value)
{
if (value == null)
{
return 1;
}
string other = value as string;
if (other == null)
{
throw new ArgumentException(SR.Arg_MustBeString);
}
return CompareTo(other); // will call the string-based overload
}
// Determines the sorting relation of StrB to the current instance.
//
public int CompareTo(String strB)
{
return string.Compare(this, strB, StringComparison.CurrentCulture);
}
// Determines whether a specified string is a suffix of the the current instance.
//
// The case-sensitive and culture-sensitive option is set by options,
// and the default culture is used.
//
public Boolean EndsWith(String value)
{
return EndsWith(value, StringComparison.CurrentCulture);
}
public Boolean EndsWith(String value, StringComparison comparisonType)
{
if ((Object)value == null)
{
throw new ArgumentNullException(nameof(value));
}
if ((Object)this == (Object)value)
{
StringSpanHelpers.CheckStringComparison(comparisonType);
return true;
}
if (value.Length == 0)
{
StringSpanHelpers.CheckStringComparison(comparisonType);
return true;
}
switch (comparisonType)
{
case StringComparison.CurrentCulture:
return CultureInfo.CurrentCulture.CompareInfo.IsSuffix(this, value, CompareOptions.None);
case StringComparison.CurrentCultureIgnoreCase:
return CultureInfo.CurrentCulture.CompareInfo.IsSuffix(this, value, CompareOptions.IgnoreCase);
case StringComparison.Ordinal:
return this.Length < value.Length ? false : (CompareOrdinalHelper(this, this.Length - value.Length, value.Length, value, 0, value.Length) == 0);
case StringComparison.OrdinalIgnoreCase:
return this.Length < value.Length ? false : (CompareInfo.CompareOrdinalIgnoreCase(this, this.Length - value.Length, value.Length, value, 0, value.Length) == 0);
case StringComparison.InvariantCulture:
return CompareInfo.Invariant.IsSuffix(this, value, CompareOptions.None);
case StringComparison.InvariantCultureIgnoreCase:
return CompareInfo.Invariant.IsSuffix(this, value, CompareOptions.IgnoreCase);
default:
throw new ArgumentException(SR.NotSupported_StringComparison, nameof(comparisonType));
}
}
public Boolean EndsWith(String value, Boolean ignoreCase, CultureInfo culture)
{
if (null == value)
{
throw new ArgumentNullException(nameof(value));
}
if ((object)this == (object)value)
{
return true;
}
CultureInfo referenceCulture;
if (culture == null)
referenceCulture = CultureInfo.CurrentCulture;
else
referenceCulture = culture;
return referenceCulture.CompareInfo.IsSuffix(this, value, ignoreCase ? CompareOptions.IgnoreCase : CompareOptions.None);
}
public bool EndsWith(char value)
{
int thisLen = Length;
return thisLen != 0 && this[thisLen - 1] == value;
}
// Determines whether two strings match.
public override bool Equals(Object obj)
{
if (Object.ReferenceEquals(this, obj))
return true;
String str = obj as String;
if (str == null)
return false;
if (this.Length != str.Length)
return false;
return EqualsHelper(this, str);
}
// Determines whether two strings match.
public bool Equals(String value)
{
if (Object.ReferenceEquals(this, value))
return true;
// NOTE: No need to worry about casting to object here.
// If either side of an == comparison between strings
// is null, Roslyn generates a simple ceq instruction
// instead of calling string.op_Equality.
if (value == null)
return false;
if (this.Length != value.Length)
return false;
return EqualsHelper(this, value);
}
public bool Equals(String value, StringComparison comparisonType)
{
if ((Object)this == (Object)value)
{
StringSpanHelpers.CheckStringComparison(comparisonType);
return true;
}
if ((Object)value == null)
{
StringSpanHelpers.CheckStringComparison(comparisonType);
return false;
}
switch (comparisonType)
{
case StringComparison.CurrentCulture:
return (CultureInfo.CurrentCulture.CompareInfo.Compare(this, 0, this.Length, value, 0, value.Length, CompareOptions.None) == 0);
case StringComparison.CurrentCultureIgnoreCase:
return (CultureInfo.CurrentCulture.CompareInfo.Compare(this, 0, this.Length, value, 0, value.Length, CompareOptions.IgnoreCase) == 0);
case StringComparison.Ordinal:
if (this.Length != value.Length)
return false;
return EqualsHelper(this, value);
case StringComparison.OrdinalIgnoreCase:
if (this.Length != value.Length)
return false;
else
{
return CompareInfo.CompareOrdinalIgnoreCase(this, 0, this.Length, value, 0, value.Length) == 0;
}
case StringComparison.InvariantCulture:
return (CompareInfo.Invariant.Compare(this, value, CompareOptions.None) == 0);
case StringComparison.InvariantCultureIgnoreCase:
return (CompareInfo.Invariant.Compare(this, value, CompareOptions.IgnoreCase) == 0);
default:
throw new ArgumentException(SR.NotSupported_StringComparison, nameof(comparisonType));
}
}
// Determines whether two Strings match.
public static bool Equals(String a, String b)
{
if ((Object)a == (Object)b)
{
return true;
}
if ((Object)a == null || (Object)b == null || a.Length != b.Length)
{
return false;
}
return EqualsHelper(a, b);
}
public static bool Equals(String a, String b, StringComparison comparisonType)
{
if ((Object)a == (Object)b)
{
StringSpanHelpers.CheckStringComparison(comparisonType);
return true;
}
if ((Object)a == null || (Object)b == null)
{
StringSpanHelpers.CheckStringComparison(comparisonType);
return false;
}
switch (comparisonType)
{
case StringComparison.CurrentCulture:
return (CultureInfo.CurrentCulture.CompareInfo.Compare(a, 0, a.Length, b, 0, b.Length, CompareOptions.None) == 0);
case StringComparison.CurrentCultureIgnoreCase:
return (CultureInfo.CurrentCulture.CompareInfo.Compare(a, 0, a.Length, b, 0, b.Length, CompareOptions.IgnoreCase) == 0);
case StringComparison.Ordinal:
if (a.Length != b.Length)
return false;
return EqualsHelper(a, b);
case StringComparison.OrdinalIgnoreCase:
if (a.Length != b.Length)
return false;
else
{
return CompareInfo.CompareOrdinalIgnoreCase(a, 0, a.Length, b, 0, b.Length) == 0;
}
case StringComparison.InvariantCulture:
return (CompareInfo.Invariant.Compare(a, b, CompareOptions.None) == 0);
case StringComparison.InvariantCultureIgnoreCase:
return (CompareInfo.Invariant.Compare(a, b, CompareOptions.IgnoreCase) == 0);
default:
throw new ArgumentException(SR.NotSupported_StringComparison, nameof(comparisonType));
}
}
public static bool operator ==(String a, String b)
{
if (Object.ReferenceEquals(a, b))
return true;
if (a == null || b == null || a.Length != b.Length)
return false;
return EqualsHelper(a, b);
}
public static bool operator !=(String a, String b)
{
if (Object.ReferenceEquals(a, b))
return false;
if (a == null || b == null || a.Length != b.Length)
return true;
return !EqualsHelper(a, b);
}
// Gets a hash code for this string. If strings A and B are such that A.Equals(B), then
// they will return the same hash code.
public override int GetHashCode()
{
return Marvin.ComputeHash32(ref Unsafe.As<char, byte>(ref _firstChar), _stringLength * 2, Marvin.DefaultSeed);
}
// Gets a hash code for this string and this comparison. If strings A and B and comparison C are such
// that String.Equals(A, B, C), then they will return the same hash code with this comparison C.
public int GetHashCode(StringComparison comparisonType) => StringComparer.FromComparison(comparisonType).GetHashCode(this);
// Use this if and only if you need the hashcode to not change across app domains (e.g. you have an app domain agile
// hash table).
internal int GetLegacyNonRandomizedHashCode()
{
unsafe
{
fixed (char* src = &_firstChar)
{
Debug.Assert(src[this.Length] == '\0', "src[this.Length] == '\\0'");
Debug.Assert(((int)src) % 4 == 0, "Managed string should start at 4 bytes boundary");
#if BIT64
int hash1 = 5381;
#else // !BIT64 (32)
int hash1 = (5381<<16) + 5381;
#endif
int hash2 = hash1;
#if BIT64
int c;
char* s = src;
while ((c = s[0]) != 0)
{
hash1 = ((hash1 << 5) + hash1) ^ c;
c = s[1];
if (c == 0)
break;
hash2 = ((hash2 << 5) + hash2) ^ c;
s += 2;
}
#else // !BIT64 (32)
// 32 bit machines.
int* pint = (int *)src;
int len = this.Length;
while (len > 2)
{
hash1 = ((hash1 << 5) + hash1 + (hash1 >> 27)) ^ pint[0];
hash2 = ((hash2 << 5) + hash2 + (hash2 >> 27)) ^ pint[1];
pint += 2;
len -= 4;
}
if (len > 0)
{
hash1 = ((hash1 << 5) + hash1 + (hash1 >> 27)) ^ pint[0];
}
#endif
return hash1 + (hash2 * 1566083941);
}
}
}
// Determines whether a specified string is a prefix of the current instance
//
public Boolean StartsWith(String value)
{
if ((Object)value == null)
{
throw new ArgumentNullException(nameof(value));
}
return StartsWith(value, StringComparison.CurrentCulture);
}
public Boolean StartsWith(String value, StringComparison comparisonType)
{
if ((Object)value == null)
{
throw new ArgumentNullException(nameof(value));
}
if ((Object)this == (Object)value)
{
StringSpanHelpers.CheckStringComparison(comparisonType);
return true;
}
if (value.Length == 0)
{
StringSpanHelpers.CheckStringComparison(comparisonType);
return true;
}
switch (comparisonType)
{
case StringComparison.CurrentCulture:
return CultureInfo.CurrentCulture.CompareInfo.IsPrefix(this, value, CompareOptions.None);
case StringComparison.CurrentCultureIgnoreCase:
return CultureInfo.CurrentCulture.CompareInfo.IsPrefix(this, value, CompareOptions.IgnoreCase);
case StringComparison.Ordinal:
if (this.Length < value.Length || _firstChar != value._firstChar)
{
return false;
}
return (value.Length == 1) ?
true : // First char is the same and thats all there is to compare
StartsWithOrdinalHelper(this, value);
case StringComparison.OrdinalIgnoreCase:
if (this.Length < value.Length)
{
return false;
}
return CompareInfo.CompareOrdinalIgnoreCase(this, 0, value.Length, value, 0, value.Length) == 0;
case StringComparison.InvariantCulture:
return CompareInfo.Invariant.IsPrefix(this, value, CompareOptions.None);
case StringComparison.InvariantCultureIgnoreCase:
return CompareInfo.Invariant.IsPrefix(this, value, CompareOptions.IgnoreCase);
default:
throw new ArgumentException(SR.NotSupported_StringComparison, nameof(comparisonType));
}
}
public Boolean StartsWith(String value, Boolean ignoreCase, CultureInfo culture)
{
if (null == value)
{
throw new ArgumentNullException(nameof(value));
}
if ((object)this == (object)value)
{
return true;
}
CultureInfo referenceCulture;
if (culture == null)
referenceCulture = CultureInfo.CurrentCulture;
else
referenceCulture = culture;
return referenceCulture.CompareInfo.IsPrefix(this, value, ignoreCase ? CompareOptions.IgnoreCase : CompareOptions.None);
}
public bool StartsWith(char value) => Length != 0 && _firstChar == value;
}
}
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