blob: e7365d3097c516b4afbdcf4ed40427f387708681 [file] [log] [blame]
/*
*
* Copyright 2015 gRPC authors.
*
* Licensed 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 "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