Method remove

Fleece/Support/ConcurrentMap.cc:221–254

    bool ConcurrentMap::remove(slice key, hash_t hash) {
        assert_precondition(key);
        int i = indexOfHash(hash);
        while (true) {
        retry:
            Entry current = _entries[i];
            switch (current.keyOffset) {
                case kEmptyKeyOffset:
                    // Not found.
                    return false;
                case kDeletedKeyOffset:
                    break;
                default:
                    if (auto keyPtr = offsetToKey(current.keyOffset); equalKeys(keyPtr, key)) {
                        // Found it -- now replace with a tombstone. Leave the value alone in case
                        // a concurrent torn read sees the prior offset + new value.
                        Entry tombstone = {kDeletedKeyOffset, current.value};
                        if (_usuallyFalse(!_entries[i].compareAndSwap(current, tombstone))) {
                            // I was beaten to it; retry (at the same index,
                            // in case CAS was a false negative)
                            goto retry;
                        }
                        // Success!
                        --_count;
                        // Freeing the key string will only do anything if it was the latest key
                        // to be added, but it's worth a try.
                        (void)freeKey(keyPtr);
                        return true;
                    }
                    break;
            }
            i = wrap(i + 1);
        }
    }


    const char* ConcurrentMap::allocKey(slice key) {