Converting an UnsafePointer with length to a Swift Array type
You can simply initialize a Swift Array
from an UnsafeBufferPointer
:
func convert(length: Int, data: UnsafePointer<Int8>) -> [Int8] {
let buffer = UnsafeBufferPointer(start: data, count: length);
return Array(buffer)
}
This creates an array of the needed size and copies the data.
Or as a generic function:
func convert<T>(count: Int, data: UnsafePointer<T>) -> [T] {
let buffer = UnsafeBufferPointer(start: data, count: count);
return Array(buffer)
}
where length
is the number of items that the pointer points to.
If you have a UInt8
pointer but want to create an [T]
array from
the pointed-to data, then this is a possible solution:
// Swift 2:
func convert<T>(length: Int, data: UnsafePointer<UInt8>, _: T.Type) -> [T] {
let buffer = UnsafeBufferPointer<T>(start: UnsafePointer(data), count: length/strideof(T));
return Array(buffer)
}
// Swift 3:
func convert<T>(length: Int, data: UnsafePointer<UInt8>, _: T.Type) -> [T] {
let numItems = length/MemoryLayout<T>.stride
let buffer = data.withMemoryRebound(to: T.self, capacity: numItems) {
UnsafeBufferPointer(start: $0, count: numItems)
}
return Array(buffer)
}
where length
now is the number of bytes. Example:
let arr = convert(12, data: ptr, Float.self)
would create an array of 3 Float
s from the 12 bytes pointed to by ptr
.
extension NSData {
public func convertToBytes() -> [UInt8] {
let count = self.length / sizeof(UInt8)
var bytesArray = [UInt8](count: count, repeatedValue: 0)
self.getBytes(&bytesArray, length:count * sizeof(UInt8))
return bytesArray
}
}
You can convert row data to byts (Uint8)
Copy Extension and use it..