ObjectiveCMIS/Utils/CMISHttpDownloadRequest.m

/*
  Licensed to the Apache Software Foundation (ASF) under one
  or more contributor license agreements.  See the NOTICE file
  distributed with this work for additional information
  regarding copyright ownership.  The ASF licenses this file
  to you under the Apache License, Version 2.0 (the
  "License"); you may not use this file except in compliance
  with the License.  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing,
  software distributed under the License is distributed on an
  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  KIND, either express or implied.  See the License for the
  specific language governing permissions and limitations
  under the License.
 */

#import "CMISHttpDownloadRequest.h"
#import "CMISErrors.h"
#import "CMISLog.h"

@interface CMISHttpDownloadRequest ()

@property (nonatomic, copy) void (^progressBlock)(unsigned long long bytesDownloaded, unsigned long long bytesTotal);
@property (nonatomic, assign) unsigned long long bytesDownloaded;
@property (nonatomic, assign) BOOL cancelled;

- (id)initWithHttpMethod:(CMISHttpRequestMethod)httpRequestMethod
         completionBlock:(void (^)(CMISHttpResponse *httpResponse, NSError *error))completionBlock
           progressBlock:(void (^)(unsigned long long bytesDownloaded, unsigned long long bytesTotal))progressBlock;

@end


@implementation CMISHttpDownloadRequest

+ (id)startRequest:(NSMutableURLRequest *)urlRequest
        httpMethod:(CMISHttpRequestMethod)httpRequestMethod
      outputStream:(NSOutputStream*)outputStream
     bytesExpected:(unsigned long long)bytesExpected
authenticationProvider:(id<CMISAuthenticationProvider>) authenticationProvider
   completionBlock:(void (^)(CMISHttpResponse *httpResponse, NSError *error))completionBlock
     progressBlock:(void (^)(unsigned long long bytesDownloaded, unsigned long long bytesTotal))progressBlock
{
    return [CMISHttpDownloadRequest startRequest:urlRequest
                               httpMethod:httpRequestMethod
                             outputStream:outputStream
                            bytesExpected:bytesExpected
                   authenticationProvider:authenticationProvider
                          completionBlock:completionBlock
                            progressBlock:progressBlock];
}

+ (id)startRequest:(NSMutableURLRequest *)urlRequest
                              httpMethod:(CMISHttpRequestMethod)httpRequestMethod
                            outputStream:(NSOutputStream*)outputStream
                           bytesExpected:(unsigned long long)bytesExpected
                                  offset:(NSDecimalNumber*)offset
                                  length:(NSDecimalNumber*)length
                  authenticationProvider:(id<CMISAuthenticationProvider>) authenticationProvider
                         completionBlock:(void (^)(CMISHttpResponse *httpResponse, NSError *error))completionBlock
                           progressBlock:(void (^)(unsigned long long bytesDownloaded, unsigned long long bytesTotal))progressBlock
{
    CMISHttpDownloadRequest *httpRequest = [[self alloc] initWithHttpMethod:httpRequestMethod
                                                            completionBlock:completionBlock
                                                              progressBlock:progressBlock];
    httpRequest.outputStream = outputStream;
    httpRequest.bytesExpected = bytesExpected;
    httpRequest.authenticationProvider = authenticationProvider;
    
    //range
    if ((offset != nil) || (length != nil)) {
        if (offset == nil) {
            offset = [NSDecimalNumber zero];
        }
        
        NSMutableString *range = [NSMutableString stringWithFormat:@"bytes=%@-",[offset stringValue]];
        
        if ((length != nil) && ([length longLongValue] >= 1)) {
            [range appendFormat:@"%llu", [offset unsignedLongLongValue] + [length unsignedLongLongValue] - 1];
        }
        
        httpRequest.additionalHeaders = [NSDictionary dictionaryWithObject:range forKey:@"Range"];
    }

    if (![httpRequest startRequest:urlRequest]) {
        httpRequest = nil;
    };
    
    return httpRequest;
}


- (id)initWithHttpMethod:(CMISHttpRequestMethod)httpRequestMethod
         completionBlock:(void (^)(CMISHttpResponse *httpResponse, NSError *error))completionBlock
           progressBlock:(void (^)(unsigned long long bytesDownloaded, unsigned long long bytesTotal))progressBlock
{
    self = [super initWithHttpMethod:httpRequestMethod
                     completionBlock:completionBlock];
    if (self) {
        _progressBlock = progressBlock;
    }
    return self;
}


- (void)cancel
{
    [self.outputStream close];
    
    self.progressBlock = nil;
    
    [super cancel];
}


- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    [super connection:connection didReceiveResponse:response];
    
    // update statistics
    if (self.bytesExpected == 0 && response.expectedContentLength != NSURLResponseUnknownLength) {
        self.bytesExpected = response.expectedContentLength;
    }
    self.bytesDownloaded = 0;

    // set up output stream if available
    if (self.outputStream) { // otherwise store data in memory in self.data
        // create file for downloaded content
        BOOL isStreamReady = self.outputStream.streamStatus == NSStreamStatusOpen;
        if (!isStreamReady) {
            [self.outputStream open];
            isStreamReady = self.outputStream.streamStatus == NSStreamStatusOpen;
        }
    
        if (!isStreamReady) {
            [connection cancel];
            
            if (self.completionBlock)
            {
                NSError *cmisError = [CMISErrors createCMISErrorWithCode:kCMISErrorCodeStorage
                                                     detailedDescription:@"Could not open output stream"];
                self.completionBlock(nil, cmisError);
            }
        }
    }
}


- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    if (self.outputStream == nil) { // if there is no outputStream then store data in memory in self.data
        [super connection:connection didReceiveData:data];
    } else {
        const uint8_t *bytes = data.bytes;
        NSUInteger length = data.length;
        NSUInteger offset = 0;
        do {
            NSUInteger written = [self.outputStream write:&bytes[offset] maxLength:length - offset];
            if (written <= 0) {
                CMISLogError(@"Error while writing downloaded data to file");
                [connection cancel];
                return;
            } else {
                offset += written;
            }
        } while (offset < length);
    }
    
    // update statistics
    self.bytesDownloaded += data.length;
    // pass progress to progressBlock
    if (self.progressBlock) {
        self.progressBlock(self.bytesDownloaded, self.bytesExpected);
    }
    
}


- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    [self.outputStream close];

    self.progressBlock = nil;

    [super connection:connection didFailWithError:error];
}


- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    [self.outputStream close];

    self.progressBlock = nil;

    [super connectionDidFinishLoading:connection];
}

@end