Example usage for org.apache.hadoop.io SortedMapWritable clear

Introduction

In this page you can find the example usage for org.apache.hadoop.io SortedMapWritable clear.

Prototype

@Override
    public void clear() 

Source Link

Usage

From source file:Assignment4_P4_MemoryConscious.MovingRatingMemConscious_Combiner.java

public void reduce(IntWritable key, Iterable<SortedMapWritable> values, Context context)
        throws IOException, InterruptedException {

    // loop through each hashmap for this movie id
    for (SortedMapWritable val : values) {
        // inside each hashmap, loop for every entry
        for (Map.Entry<WritableComparable, Writable> entry : val.entrySet()) {
            // check if current entry's key is already present in new hashmap
            if (result.containsKey(entry.getKey())) {
                //if yes, extract current value from result hashmap for this key
                LongWritable existingValue = (LongWritable) result.get(entry.getKey());

                // increment existing value by 1
                existingValue.set(existingValue.get() + 1);

                // update result hashmap with new value
                result.put(entry.getKey(), existingValue);
            } else {
                //if not, create new entry with init value 1
                result.put(entry.getKey(), new LongWritable(1));
            }//from w  w  w.j a  v  a2  s  . c o m
        }

        val.clear();
    }

    context.write(key, result);
}

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