package com.ctc.wstx.dtd;

import com.ctc.wstx.util.PrefixedName;

PrefixedNameSet implementation suitable for storing small set of PrefixedName
values (generally 8 or less). Uses linear search, and is thus the
most compact presentation for a set

Notes about usage:

 
All Strings contained in PrefixedName instances are assumed interned, so that equality comparison can be done (both for values stored and keys used) 
 
It is assumed that sets are never empty, ie. always contain at
   least one entry.
  
 
It is assumed that caller has ensured that there are no duplicates
   in the set -- this data structure does no further validation.
  

/**
 * PrefixedNameSet implementation suitable for storing small set of PrefixedName
 * values (generally 8 or less). Uses linear search, and is thus the
 * most compact presentation for a set
 *<p>
 * Notes about usage:
 * <ul>
 *  <li>All Strings contained in {@link PrefixedName} instances are assumed
 *   interned, so that equality comparison can be done (both for values
 *   stored and keys used)
 *   </li>
 *  <li>It is assumed that sets are never empty, ie. always contain at
 *    least one entry.
 *   </li>
 *  <li>It is assumed that caller has ensured that there are no duplicates
 *    in the set -- this data structure does no further validation.
 *   </li>
 * </ul>
 */
public final class SmallPrefixedNameSet
    extends PrefixedNameSet
{
    final boolean mNsAware;

    final String[] mStrings;

    public SmallPrefixedNameSet(boolean nsAware, PrefixedName[] names)
    {
        mNsAware = nsAware;
        int len = names.length;
        if (len == 0) { // sanity check
            throw new IllegalStateException("Trying to construct empty PrefixedNameSet");
        }
        mStrings = new String[nsAware ? (len+len) : len];
        for (int out = 0, in = 0; in < len; ++in) {
            PrefixedName nk = names[in];
            if (nsAware) {
                mStrings[out++] = nk.getPrefix();
            }
            mStrings[out++] = nk.getLocalName();
        }
    }

    @Override
    public boolean hasMultiple() {
        return mStrings.length > 1;
    }

    
Returns:
True if the set contains specified name; false if not./**
     * @return True if the set contains specified name; false if not.
     */
    @Override
    public boolean contains(PrefixedName name)
    {
        int len = mStrings.length;
        String ln = name.getLocalName();
        String[] strs = mStrings;

        if (mNsAware) {
            String prefix = name.getPrefix();
            if (strs[1] == ln && strs[0] == prefix) {
                return true;
            }
            for (int i = 2; i < len; i += 2) {
                if (strs[i+1] == ln && strs[i] == prefix) {
                    return true;
                }
            }
        } else {
            if (strs[0] == ln) {
                return true;
            }
            for (int i = 1; i < len; ++i) {
                if (strs[i] == ln) {
                    return true;
                }
            }
        }

        return false;
    }

    @Override
    public void appendNames(StringBuilder sb, String sep)
    {
        for (int i = 0; i < mStrings.length; ) {
            if (i > 0) {
                sb.append(sep);
            }
            if (mNsAware) {
                String prefix = mStrings[i++];
                if (prefix != null) {
                    sb.append(prefix);
                    sb.append(':');
                }
            }
            sb.append(mStrings[i++]);
        }
    }
}