RFR 8005704: Update ConcurrentHashMap to v8 (original) (raw)

Martin Buchholz martinrb at google.com
Tue May 28 20:03:01 UTC 2013

A long-returning size method seems like a framework-level decision. We could add a default method to Collection.java and Map.java

default long mappingCount() { return size(); }

I'm not sure mappingCount is the best name, but all names will be confusing. Using the name "length()" at least has an onomatopoeic mnemonic advantage - it suggests that it might return a long.

/**
 * Returns the number of mappings. This method should be used
 * instead of {@link #size} because a ConcurrentHashMap may
 * contain more mappings than can be represented as an int. The
 * value returned is an estimate; the actual count may differ if
 * there are concurrent insertions or removals.
 *
 * @return the number of mappings
 */
public long mappingCount() {
    long n = sumCount();
    return (n < 0L) ? 0L : n; // ignore transient negative values
}

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