internal long BinarySearchUnchecked(int index, int length, T value, KeyComparer <T> comparer)
{
int lo = index;
int hi = index + length - 1;
while (lo <= hi)
{
int i = lo + ((hi - lo) >> 1);
int order = comparer.Compare(this[i], value);
if (order == 0)
{
return(i);
}
if (order < 0)
{
lo = i + 1;
}
else
{
hi = i - 1;
}
}
return(~lo);
}
public static int BinarySearch <T, TVec>(ref TVec vec, int start, int length, T value, KeyComparer <T> comparer = default)
where TVec : IVector <T>
{
Debug.Assert(unchecked ((uint)start + (uint)length) <= vec.Length);
unchecked
{
int lo = start;
int hi = start + length - 1;
while (lo <= hi)
{
int i = (int)(((uint)hi + (uint)lo) >> 1);
int c = comparer.Compare(value, vec.DangerousGet(i));
if (c == 0)
{
return(i);
}
else if (c > 0)
{
lo = i + 1;
}
else
{
hi = i - 1;
}
}
return(~lo);
}
}
public static int BinarySearch <T>(this Span <T> span, int index, int length, T value, KeyComparer <T> comparer)
{
if ((uint)(index) + (uint)length > (uint)span.Length)
{
throw new ArgumentException("Index + Length fall outside the span boundary.");
}
if (comparer == null)
{
comparer = KeyComparer <T> .Default;
}
int lo = index;
int hi = index + length - 1;
while (lo <= hi)
{
int i = lo + ((hi - lo) >> 1);
int order = comparer.Compare(span[i], value);
if (order == 0)
{
return(i);
}
if (order < 0)
{
lo = i + 1;
}
else
{
hi = i - 1;
}
}
return(~lo);
}
/// <summary>
/// Construct a tree from given storage, using the specified comparer of key
/// </summary>
/// <param name="keySerializer">Tool to serialize node keys.</param>
/// <param name="valueSerializer">Tool to serialize node values<param>
/// <param name="recordStorage">Underlying tool for storage.</param>
/// <param name="keyComparer">Key comparer.</param>
public TreeDiskNodeManager(ISerializer <K> keySerializer
, ISerializer <V> valueSerializer
, IRecordStorage recordStorage
, IComparer <K> keyComparer)
{
if (recordStorage == null)
{
throw new ArgumentNullException("nodeStorge");
}
this.recordStorage = recordStorage;
this.serializer = new TreeDiskNodeSerializer <K, V> (this, keySerializer, valueSerializer);
this.KeyComparer = keyComparer;
this.EntryComparer = Comparer <Tuple <K, V> > .Create((a, b) => {
return(KeyComparer.Compare(a.Item1, b.Item1));
});
// The first record of nodeStorage stores id of root node,
// if this record do not exist at the time this index instanitate,
// then attempt to create it
var firstBlockData = recordStorage.Find(1u);
if (firstBlockData != null)
{
this.rootNode = Find(BufferHelper.ReadBufferUInt32(firstBlockData, 0));
}
else
{
this.rootNode = CreateFirstRoot();
}
}
private (bool isInvalid, int expand) IsInvalidWidth(ref TCursor lagged, ref TCursor current)
{
var diff = default(SubtractOp <TKey>).Apply(current.CurrentKey, lagged.CurrentKey);
var cmp = _cmp.Compare(diff, _width);
if (cmp > 0)
{
// Diff is too big, should shrink if invalid
return(_lookup != Lookup.GE && _lookup != Lookup.GT, -1);
}
if (cmp < 0)
{
// Diff is too small, should expand if invalid
return(_lookup != Lookup.LE && _lookup != Lookup.LT, 1);
}
// cmp == 0
if (_lookup == Lookup.LT)
{
// need to shrink, equal is not valid
return(true, -1);
}
if (_lookup == Lookup.GT)
{
// need to expand, equal is not valid
return(true, 1);
}
return(false, 0);
}
public override int Compare(TObject x, TObject y)
{
var xValue = KeySelector(x);
var yValue = KeySelector(y);
return(KeyComparer.Compare(xValue, yValue));
}
internal static int BinarySearchHybrid <T>(ref T searchSpace, int offset, int length, T value, KeyComparer <T> comparer = default)
{
unchecked
{
int c;
int lo = offset;
int hi = offset + length - 1;
while (hi - lo > 7)
{
int i = (int)(((uint)hi + (uint)lo) >> 1);
c = comparer.Compare(value, UnsafeEx.ReadUnaligned(ref Unsafe.Add(ref searchSpace, i)));
if (c > 0)
{
lo = i + 1;
}
else
{
if (c == 0)
{
goto RETURN;
}
hi = i - 1;
}
}
while ((c = comparer.Compare(value, UnsafeEx.ReadUnaligned(ref Unsafe.Add(ref searchSpace, lo)))) > 0 &&
++lo <= hi)
{
}
RETURN:
var ceq1 = -UnsafeEx.Ceq(c, 0);
return((ceq1 & lo) | (~ceq1 & ~lo));
}
}
private bool TryAddSorted(TKey key, TValue value)
{
if (keys.Count > 0)
{
var lastKey = keys.Last();
if (KeyComparer.Compare(key, lastKey) <= 0)
{
return(false);
}
}
keys.Add(key);
values.Add(value);
return(true);
}
private object FindKey(IDictionary <object, object> dictionary, object key)
{
var tempContext = new ComparisonContext();
foreach (var key2 in dictionary.Keys)
{
if (KeyComparer.Compare(tempContext, key, key2) == ComparisonResult.Pass)
{
return(key2);
}
}
return(null);
}
private Node FindNodeRecursive(TKey key, Node node, ref Node resultNodeParent)
{
if (node == null)
{
return(null);
}
var cmpResult = KeyComparer.Compare(key, node.Key);
if (cmpResult == 0)
{
return(node);
}
resultNodeParent = node; // Set parent, we continue searching
return(FindNodeRecursive(key, cmpResult < 0 ? node.Left : node.Right, ref resultNodeParent));
}
private Node InsertNewNode(TKey key, TValue value, Node parentNode)
{
var node = new Node(key, value, parentNode);
if (KeyComparer.Compare(key, parentNode.Key) < 0)
{
parentNode.Left = node;
}
else
{
parentNode.Right = node;
}
Splay(node);
Count++;
return(node);
}
public void Can_Compare_Only_Keys_With_Given_Comparer()
{
var a = new KeyValuePair <int, int>(100, 200);
var b = new KeyValuePair <int, int>(300, 400);
var comparerResult = 123;
var comparer = A.Fake <IComparer <int> >();
A.CallTo(() => comparer.Compare(a.Key, b.Key))
.Returns(comparerResult);
var sut = new KeyComparer <int, int>(comparer);
var result = sut.Compare(a, b);
Assert.That(result, Is.EqualTo(comparerResult));
}
public static IEnumerable <T> GetValuesOfKey <T>(List <KeyValuePair <String, T> > keyValuePairs,
string word)
{
var target = new KeyValuePair <String, T>(word, default(T));
var comparer = new KeyComparer <T>();
int endIndex = keyValuePairs.BinarySearch(target, comparer);
if (endIndex > -1 && endIndex < keyValuePairs.Count)
{
int startInex;
for (startInex = endIndex; startInex > 0 && comparer.Compare(keyValuePairs.ElementAt(startInex - 1),
target) == 0; startInex--)
{
;
}
return(keyValuePairs.GetRange(startInex, endIndex - startInex + 1).Select(p => p.Value));
}
return(Enumerable.Empty <T>());
}
internal static int BinarySearchClassic <T>(ref T searchSpace, int offset, int length, T value, KeyComparer <T> comparer = default)
{
unchecked
{
int lo = offset;
int hi = offset + length - 1;
// If length == 0, hi == -1, and loop will not be entered
while (lo <= hi)
{
// PERF: `lo` or `hi` will never be negative inside the loop,
// so computing median using uints is safe since we know
// `length <= int.MaxValue`, and indices are >= 0
// and thus cannot overflow an uint.
// Saves one subtraction per loop compared to
// `int i = lo + ((hi - lo) >> 1);`
int i = (int)(((uint)hi + (uint)lo) >> 1);
int c = comparer.Compare(value, UnsafeEx.ReadUnaligned(ref Unsafe.Add(ref searchSpace, i)));
if (c == 0)
{
return(i);
}
if (c > 0)
{
lo = i + 1;
}
else
{
hi = i - 1;
}
}
// If none found, then a negative number that is the bitwise complement
// of the index of the next element that is larger than or, if there is
// no larger element, the bitwise complement of `length`, which
// is `lo` at this point.
return(~lo);
}
}
private static TV Find <TK, TV>(KeyComparer <TK> comparer, TK k, MapTree <TK, TV> m)
{
while (true)
{
if (m == null)
{
throw new KeyNotFoundException();
}
var c = comparer.Compare(k, m.Key);
// Common for MapOne and MapNode
if (c == 0)
{
// do not return from loop.
// Even thought https://github.com/dotnet/coreclr/issues/9692
// closed/fixed in 2017 in this case it's very visible
break;
}
// This is pure isinst without casting.
// Then using Unsafe for cast without a local var.
m = m as MapTreeNode <TK, TV>;
if (m != null)
{
if (c < 0)
{
m = Unsafe.As <MapTreeNode <TK, TV> >(m).Left;
}
else
{
m = Unsafe.As <MapTreeNode <TK, TV> >(m).Right;
}
}
// m == null for MapOne case after `as` and we go to KeyNotFoundException
}
return(m.Value);
}
internal bool TryFindBlockAtFromSource([NotNullWhen(true)] out DataBlock?db,
DataBlockSource <TKey> ds,
TKey key,
Lookup sourceDirection)
{
if (!ds.TryFindAt(key, sourceDirection, out var kvp))
{
db = null;
return(false);
}
if (AdditionalCorrectnessChecks.Enabled)
{
if (kvp.Value.RowCount <= 0 ||
_comparer.Compare(kvp.Key, kvp.Value.DangerousRowKey <TKey>(index: 0)) != 0)
{
ThrowBadBlockFromSource();
}
}
db = kvp.Value;
return(true);
}
public int Compare(KeyValuePair <TKey, TValue> x, KeyValuePair <TKey, TValue> y)
{
return(KeyComparer.Compare(x.Key, y.Key).IfEqual(0, ValueComparer.Compare(x.Value, y.Value)));
}
internal static int InterpolationSearchGeneric <T>(ref T searchSpace, int offset, int length, T value, KeyComparer <T> comparer = default)
{
// Try interpolation only for big-enough lengths and do minimal job,
// just find the range with exponential search with minimal branches
// and switch to binary search.
unchecked
{
int i;
int lo = offset;
int hi = offset + length - 1;
if (hi - lo > 16)
{
var vlo = UnsafeEx.ReadUnaligned(ref searchSpace);
var vhi = UnsafeEx.ReadUnaligned(ref Unsafe.Add(ref searchSpace, hi));
int range = hi - lo;
long vRange = comparer.Diff(vhi, vlo);
// (hi - lo) <= int32.MaxValue
// vlo could be zero while value could easily be close to int64.MaxValue (nanos in unix time, we are now between 60 and 61 bit at 60.4)
// convert to double here to avoid overflow and for much faster calculations
// (only 4 cycles vs 25 cycles https://lemire.me/blog/2017/11/16/fast-exact-integer-divisions-using-floating-point-operations/)
double nominator = (hi - lo) * (double)comparer.Diff(value, vlo);
i = (int)(nominator / vRange);
if ((uint)i > range)
{
i = i < 0 ? 0 : range;
}
// make i relative to vecStart
i += lo;
int c = comparer.Compare(value, UnsafeEx.ReadUnaligned(ref Unsafe.Add(ref searchSpace, i)));
if (c == 0)
{
goto FOUND;
}
var step = 1;
if (c > 0)
{
while (true)
{
i += step;
if (i > hi)
{
break;
}
c = comparer.Compare(value, UnsafeEx.ReadUnaligned(ref Unsafe.Add(ref searchSpace, i)));
if (c <= 0)
{
if (c == 0)
{
goto FOUND;
}
hi = i - 1;
break;
}
step <<= 1;
}
lo = i - step + 1;
}
else
{
while (true)
{
i -= step;
if (i < lo)
{
break;
}
c = comparer.Compare(value, UnsafeEx.ReadUnaligned(ref Unsafe.Add(ref searchSpace, i)));
if (c >= 0)
{
if (c == 0)
{
goto FOUND;
}
lo = i + 1;
break;
}
step <<= 1;
}
hi = i + step - 1;
}
}
return(BinarySearch(ref searchSpace, lo, 1 + hi - lo, value));
FOUND:
return(i);
}
}
