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//
// ASIInputStream.m
// asi-http-request
//
// Created by Ben Copsey on 10/08/2009.
// Copyright 2009 All-Seeing Interactive. All rights reserved.
//
#import "ASIInputStream.h"
#import "ASIHTTPRequest.h"
// Used to ensure only one request can read data at once
static NSLock *readLock = nil;
@implementation ASIInputStream
+ (void)initialize
{
if (self == [ASIInputStream class]) {
readLock = [[NSLock alloc] init];
}
}
+ (id)inputStreamWithFileAtPath:(NSString *)path
{
ASIInputStream *stream = [[[self alloc] init] autorelease];
[stream setStream:[NSInputStream inputStreamWithFileAtPath:path]];
return stream;
}
+ (id)inputStreamWithData:(NSData *)data
{
ASIInputStream *stream = [[[self alloc] init] autorelease];
[stream setStream:[NSInputStream inputStreamWithData:data]];
return stream;
}
- (void)dealloc
{
[stream release];
[super dealloc];
}
// Ok, so this works, but I don't really understand why.
// Ideally, we'd just return the stream's hasBytesAvailable, but CFNetwork seems to want to monopolise our run loop until (presumably) its buffer is full, which will cause timeouts if we're throttling the bandwidth
// We return NO when we shouldn't be uploading any more data because our bandwidth limit has run out (for now)
// The call to maxUploadReadLength will recognise that we've run out of our allotted bandwidth limit, and sleep this thread for the rest of the measurement period
// This method will be called again, but we'll almost certainly return YES the next time around, because we'll have more limit to use up
// The NO returns seem to snap CFNetwork out of its reverie, and return control to the main loop in loadRequest, so that we can manage timeouts and progress delegate updates
- (BOOL)hasBytesAvailable
{
if ([ASIHTTPRequest isBandwidthThrottled]) {
[readLock lock];
if ([ASIHTTPRequest maxUploadReadLength] == 0) {
[readLock unlock];
return NO;
}
[readLock unlock];
}
return [[self stream] hasBytesAvailable];
}
// Called when CFNetwork wants to read more of our request body
// When throttling is on, we ask ASIHTTPRequest for the maximum amount of data we can read
- (NSInteger)read:(uint8_t *)buffer maxLength:(NSUInteger)len
{
[readLock lock];
unsigned long toRead = len;
if ([ASIHTTPRequest isBandwidthThrottled]) {
toRead = [ASIHTTPRequest maxUploadReadLength];
if (toRead > len) {
toRead = len;
// Hopefully this won't happen because hasBytesAvailable will have returned NO, but just in case - we need to read at least 1 byte, or bad things might happen
} else if (toRead == 0) {
toRead = 1;
}
//NSLog(@"Throttled read %u",toRead);
} else {
//NSLog(@"Unthrottled read %u",toRead);
}
[ASIHTTPRequest incrementBandwidthUsedInLastSecond:toRead];
[readLock unlock];
return [[self stream] read:buffer maxLength:toRead];
}
// If we get asked to perform a method we don't have (which is almost all of them), we'll just forward the message to our stream
- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector
{
return [[self stream] methodSignatureForSelector:aSelector];
}
- (void)forwardInvocation:(NSInvocation *)anInvocation
{
[anInvocation invokeWithTarget:[self stream]];
}
@synthesize stream;
@end