cog/Audio/Chain/ChunkList.m

//
//  ChunkList.m
//  CogAudio Framework
//
//  Created by Christopher Snowhill on 2/5/22.
//

#import "ChunkList.h"

@implementation ChunkList

@synthesize listDuration;
@synthesize maxDuration;

- (id) initWithMaximumDuration:(double)duration {
    self = [super init];
    
    if (self) {
        chunkList = [[NSMutableArray alloc] init];
        listDuration = 0.0;
        maxDuration = duration;
        
        inAdder = NO;
        inRemover = NO;
        stopping = NO;
    }
    
    return self;
}

- (void) dealloc {
    stopping = YES;
    while (inAdder || inRemover) {
        usleep(500);
    }
}

- (void) reset {
    @synchronized (chunkList) {
        [chunkList removeAllObjects];
        listDuration = 0.0;
    }
}

- (BOOL) isEmpty {
    @synchronized (chunkList) {
        return [chunkList count] == 0;
    }
}

- (BOOL) isFull {
    return listDuration >= maxDuration;
}

- (void) addChunk:(AudioChunk *)chunk {
    if (stopping) return;
    
    inAdder = YES;
    
    const double chunkDuration = [chunk duration];
    
    @synchronized(chunkList) {
        [chunkList addObject:chunk];
        listDuration += chunkDuration;
    }
    
    inAdder = NO;
}

- (AudioChunk *) removeSamples:(size_t)maxFrameCount {
    if (stopping) {
        return [[AudioChunk alloc] init];
    }
    
    @synchronized (chunkList) {
        inRemover = YES;
        if (![chunkList count])
            return [[AudioChunk alloc] init];
        AudioChunk * chunk = [chunkList objectAtIndex:0];
        if ([chunk frameCount] <= maxFrameCount) {
            [chunkList removeObjectAtIndex:0];
            listDuration -= [chunk duration];
            inRemover = NO;
            return chunk;
        }
        NSData * removedData = [chunk removeSamples:maxFrameCount];
        AudioChunk * ret = [[AudioChunk alloc] init];
        [ret setFormat:[chunk format]];
        [ret assignSamples:[removedData bytes] frameCount:maxFrameCount];
        listDuration -= [ret duration];
        inRemover = NO;
        return ret;
    }
}

@end