Add fast paths for Data initialization for common sequences (#1051)
diff --git a/Foundation/Data.swift b/Foundation/Data.swift
index fd5b4a4..8701d8d 100644
--- a/Foundation/Data.swift
+++ b/Foundation/Data.swift
@@ -1082,6 +1082,43 @@
}
+ // slightly faster paths for common sequences
+
+ public init<S: Sequence>(_ elements: S) where S.Iterator.Element == UInt8 {
+ let underestimatedCount = elements.underestimatedCount
+ self.init(count: underestimatedCount)
+ var idx = 0
+ for byte in elements {
+ if idx < underestimatedCount {
+ self[idx] = byte
+ } else {
+ self.append(byte)
+ }
+ idx += 1
+ }
+ }
+
+ public init(_ bytes: Array<UInt8>) {
+ self.init(bytes: bytes)
+ }
+
+ public init(_ bytes: ArraySlice<UInt8>) {
+ self.init(bytes: bytes)
+ }
+
+ public init(_ buffer: UnsafeBufferPointer<UInt8>) {
+ self.init(buffer: buffer)
+ }
+
+ public init(_ buffer: UnsafeMutableBufferPointer<UInt8>) {
+ self.init(buffer: buffer)
+ }
+
+ public init(_ data: Data) {
+ _sliceRange = 0..<data.count
+ _backing = data._backing.mutableCopy(data._sliceRange)
+ }
+
@_versioned
internal init(backing: _DataStorage, range: Range<Index>) {
_backing = backing
