// Download.swift
//
// Copyright (c) 2014–2016 Alamofire Software Foundation (http://alamofire.org/)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
import Foundation
extension Manager {
private enum Downloadable {
case Request(NSURLRequest)
case ResumeData(NSData)
}
private func download(downloadable: Downloadable, destination: Request.DownloadFileDestination) -> Request {
var downloadTask: NSURLSessionDownloadTask!
switch downloadable {
case .Request(let request):
dispatch_sync(queue) {
downloadTask = self.session.downloadTaskWithRequest(request)
}
case .ResumeData(let resumeData):
dispatch_sync(queue) {
downloadTask = self.session.downloadTaskWithResumeData(resumeData)
}
}
let request = Request(session: session, task: downloadTask)
if let downloadDelegate = request.delegate as? Request.DownloadTaskDelegate {
downloadDelegate.downloadTaskDidFinishDownloadingToURL = { session, downloadTask, URL in
return destination(URL, downloadTask.response as! NSHTTPURLResponse)
}
}
delegate[request.delegate.task] = request.delegate
if startRequestsImmediately {
request.resume()
}
return request
}
// MARK: Request
/**
Creates a download request for the specified method, URL string, parameters, parameter encoding, headers
and destination.
If `startRequestsImmediately` is `true`, the request will have `resume()` called before being returned.
- parameter method: The HTTP method.
- parameter URLString: The URL string.
- parameter parameters: The parameters. `nil` by default.
- parameter encoding: The parameter encoding. `.URL` by default.
- parameter headers: The HTTP headers. `nil` by default.
- parameter destination: The closure used to determine the destination of the downloaded file.
- returns: The created download request.
*/
public func download(
method: Method,
_ URLString: URLStringConvertible,
parameters: [String: AnyObject]? = nil,
encoding: ParameterEncoding = .URL,
headers: [String: String]? = nil,
destination: Request.DownloadFileDestination)
-> Request
{
let mutableURLRequest = URLRequest(method, URLString, headers: headers)
let encodedURLRequest = encoding.encode(mutableURLRequest, parameters: parameters).0
return download(encodedURLRequest, destination: destination)
}
/**
Creates a request for downloading from the specified URL request.
If `startRequestsImmediately` is `true`, the request will have `resume()` called before being returned.
- parameter URLRequest: The URL request
- parameter destination: The closure used to determine the destination of the downloaded file.
- returns: The created download request.
*/
public func download(URLRequest: URLRequestConvertible, destination: Request.DownloadFileDestination) -> Request {
return download(.Request(URLRequest.URLRequest), destination: destination)
}
// MARK: Resume Data
/**
Creates a request for downloading from the resume data produced from a previous request cancellation.
If `startRequestsImmediately` is `true`, the request will have `resume()` called before being returned.
- parameter resumeData: The resume data. This is an opaque data blob produced by `NSURLSessionDownloadTask`
when a task is cancelled. See `NSURLSession -downloadTaskWithResumeData:` for
additional information.
- parameter destination: The closure used to determine the destination of the downloaded file.
- returns: The created download request.
*/
public func download(resumeData: NSData, destination: Request.DownloadFileDestination) -> Request {
return download(.ResumeData(resumeData), destination: destination)
}
}
// MARK: -
extension Request {
/**
A closure executed once a request has successfully completed in order to determine where to move the temporary
file written to during the download process. The closure takes two arguments: the temporary file URL and the URL
response, and returns a single argument: the file URL where the temporary file should be moved.
*/
public typealias DownloadFileDestination = (NSURL, NSHTTPURLResponse) -> NSURL
/**
Creates a download file destination closure which uses the default file manager to move the temporary file to a
file URL in the first available directory with the specified search path directory and search path domain mask.
- parameter directory: The search path directory. `.DocumentDirectory` by default.
- parameter domain: The search path domain mask. `.UserDomainMask` by default.
- returns: A download file destination closure.
*/
public class func suggestedDownloadDestination(
directory directory: NSSearchPathDirectory = .DocumentDirectory,
domain: NSSearchPathDomainMask = .UserDomainMask)
-> DownloadFileDestination
{
return { temporaryURL, response -> NSURL in
let directoryURLs = NSFileManager.defaultManager().URLsForDirectory(directory, inDomains: domain)
if !directoryURLs.isEmpty {
return directoryURLs[0].URLByAppendingPathComponent(response.suggestedFilename!)
}
return temporaryURL
}
}
/// The resume data of the underlying download task if available after a failure.
public var resumeData: NSData? {
var data: NSData?
if let delegate = delegate as? DownloadTaskDelegate {
data = delegate.resumeData
}
return data
}
// MARK: - DownloadTaskDelegate
class DownloadTaskDelegate: TaskDelegate, NSURLSessionDownloadDelegate {
var downloadTask: NSURLSessionDownloadTask? { return task as? NSURLSessionDownloadTask }
var downloadProgress: ((Int64, Int64, Int64) -> Void)?
var resumeData: NSData?
override var data: NSData? { return resumeData }
// MARK: - NSURLSessionDownloadDelegate
// MARK: Override Closures
var downloadTaskDidFinishDownloadingToURL: ((NSURLSession, NSURLSessionDownloadTask, NSURL) -> NSURL)?
var downloadTaskDidWriteData: ((NSURLSession, NSURLSessionDownloadTask, Int64, Int64, Int64) -> Void)?
var downloadTaskDidResumeAtOffset: ((NSURLSession, NSURLSessionDownloadTask, Int64, Int64) -> Void)?
// MARK: Delegate Methods
func URLSession(
session: NSURLSession,
downloadTask: NSURLSessionDownloadTask,
didFinishDownloadingToURL location: NSURL)
{
if let downloadTaskDidFinishDownloadingToURL = downloadTaskDidFinishDownloadingToURL {
do {
let destination = downloadTaskDidFinishDownloadingToURL(session, downloadTask, location)
try NSFileManager.defaultManager().moveItemAtURL(location, toURL: destination)
} catch {
self.error = error as NSError
}
}
}
func URLSession(
session: NSURLSession,
downloadTask: NSURLSessionDownloadTask,
didWriteData bytesWritten: Int64,
totalBytesWritten: Int64,
totalBytesExpectedToWrite: Int64)
{
if initialResponseTime == nil { initialResponseTime = CFAbsoluteTimeGetCurrent() }
if let downloadTaskDidWriteData = downloadTaskDidWriteData {
downloadTaskDidWriteData(
session,
downloadTask,
bytesWritten,
totalBytesWritten,
totalBytesExpectedToWrite
)
} else {
progress.totalUnitCount = totalBytesExpectedToWrite
progress.completedUnitCount = totalBytesWritten
downloadProgress?(bytesWritten, totalBytesWritten, totalBytesExpectedToWrite)
}
}
func URLSession(
session: NSURLSession,
downloadTask: NSURLSessionDownloadTask,
didResumeAtOffset fileOffset: Int64,
expectedTotalBytes: Int64)
{
if let downloadTaskDidResumeAtOffset = downloadTaskDidResumeAtOffset {
downloadTaskDidResumeAtOffset(session, downloadTask, fileOffset, expectedTotalBytes)
} else {
progress.totalUnitCount = expectedTotalBytes
progress.completedUnitCount = fileOffset
}
}
}
}