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/*
*
* Copyright 2015, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#import "GRXForwardingWriter.h"
@interface GRXForwardingWriter () <GRXWriteable>
@end
@implementation GRXForwardingWriter {
GRXWriter *_writer;
id<GRXWriteable> _writeable;
}
- (instancetype)init {
return [self initWithWriter:nil];
}
// Designated initializer
- (instancetype)initWithWriter:(GRXWriter *)writer {
if (!writer) {
return nil;
}
if (writer.state != GRXWriterStateNotStarted) {
[NSException raise:NSInvalidArgumentException
format:@"The writer argument must not have already started."];
}
if ((self = [super init])) {
_writer = writer;
}
return self;
}
// This is used to send a completion or an error to the writeable. It nillifies
// our reference to it in order to guarantee no more messages are sent to it,
// and to release it.
- (void)finishOutputWithError:(NSError *)errorOrNil {
id<GRXWriteable> writeable = _writeable;
_writeable = nil;
[writeable writesFinishedWithError:errorOrNil];
}
// This is used to stop the input writer. It nillifies our reference to it
// to release it.
- (void)finishInput {
GRXWriter *writer = _writer;
_writer = nil;
writer.state = GRXWriterStateFinished;
}
#pragma mark GRXWriteable implementation
- (void)writeValue:(id)value {
[_writeable writeValue:value];
}
- (void)writesFinishedWithError:(NSError *)errorOrNil {
_writer = nil;
[self finishOutputWithError:errorOrNil];
}
#pragma mark GRXWriter implementation
- (GRXWriterState)state {
return _writer ? _writer.state : GRXWriterStateFinished;
}
- (void)setState:(GRXWriterState)state {
if (state == GRXWriterStateFinished) {
_writeable = nil;
[self finishInput];
} else {
_writer.state = state;
}
}
- (void)startWithWriteable:(id<GRXWriteable>)writeable {
_writeable = writeable;
[_writer startWithWriteable:self];
}
- (void)finishWithError:(NSError *)errorOrNil {
[self finishOutputWithError:errorOrNil];
[self finishInput];
}
@end
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