ImageClient1-original/CFNetworkLoader.m

/*
 
File: CFNetworkLoader.m
 
Abstract: CFNetwork ImageClient Sample
 
Version: 1.0
 
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MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
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Copyright (c) 2005 Apple Computer, Inc., All Rights Reserved
 
*/ 
 
#import "CFNetworkLoader.h"
#import "ImageClient.h"
#import "NSURLLoader.h"
 
#define BUFSIZE 4096
 
@implementation CFNetworkLoader
 
- (id)initWithImageClient:(ImageClient *)imgClient {
    if (self = [super init]) {
        imageClient = imgClient; // No retain because the ImageClient instance is retaining us
    }
    return self;
}
 
- (void)dealloc {
    if (request) CFRelease(request);
    if (readStream) {
        CFReadStreamClose(readStream);
        CFRelease(readStream);
    }
    if (data) CFRelease(data);
    [super dealloc];
}
 
- (void)loadURL:(NSURL *)url {
    // set the request for the new transaction
    if (request) CFRelease(request);
    request = CFHTTPMessageCreateRequest(NULL, CFSTR("GET"), (CFURLRef)url, kCFHTTPVersion1_1);
    
    // Start the load
    [self loadRequest];
}
 
- (void)loadRequest {
    // Cancel any load currently in progress
    [self cancelLoad];
 
    // Start a fresh data to hold the downloaded image
    data = CFDataCreateMutable(NULL, 0);
    
    readStream = CFReadStreamCreateForHTTPRequest(NULL, request);
    
    if (CFReadStreamOpen(readStream)) {
        BOOL done = NO;
        do {
            UInt8 buf[BUFSIZE];
            int bytesRead = CFReadStreamRead(readStream, buf, BUFSIZE);
            if (bytesRead > 0) {
                CFDataAppendBytes(data, buf, bytesRead);
            } else if (bytesRead == 0) {
                // All done
                [imageClient setImageData:(NSData *)data];
                done = YES;
            } else {
                // Error occurred
                [imageClient errorOccurredLoadingImage];
                done = YES;
            }
        } while (!done);
    } else {
        [imageClient errorOccurredLoadingImage];
    }
 
    // Clean up
    CFReadStreamClose(readStream);
    CFRelease(readStream);
    readStream = nil;
 
    CFRelease(data);
    data = NULL;
}
 
- (void)cancelLoad {
    // Synchronous; nothing to do.
}
 
 
@end