k-9/src/com/android/email/preferences/Editor.java

package com.android.email.preferences;

import android.util.Log;
import com.android.email.Email;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

public class Editor implements android.content.SharedPreferences.Editor
{
    private Storage storage;
    private HashMap<String, String> changes = new HashMap<String, String>();
    private ArrayList<String> removals = new ArrayList<String>();
    private boolean removeAll = false;

    Map<String, String> snapshot = new HashMap<String, String>();


    protected Editor(Storage storage)
    {
        this.storage = storage;
        snapshot.putAll(storage.getAll());
    }

    public void copy(android.content.SharedPreferences input)
    {
        Map<String, ?> oldVals = input.getAll();
        for (Entry<String, ?> entry : oldVals.entrySet())
        {
            String key = entry.getKey();
            Object value = entry.getValue();
            if (key != null && value != null)
            {
                if (Email.DEBUG)
                {
                    Log.d(Email.LOG_TAG, "Copying key '" + key + "', value '" + value + "'");
                }
                changes.put(key, "" + value);
            }
            else
            {
                if (Email.DEBUG)
                {
                    Log.d(Email.LOG_TAG, "Skipping copying key '" + key + "', value '" + value + "'");
                }
            }
        }
    }

    //@Override
    public android.content.SharedPreferences.Editor clear()
    {
        removeAll = true;
        return this;
    }

    /* This method is poorly defined.  It should throw an Exception on failure */
    //@Override
    public boolean commit()
    {
        try
        {
            commitChanges();
            return true;
        }
        catch (Exception e)
        {
            Log.e(Email.LOG_TAG, "Failed to save preferences", e);
            return false;
        }
    }

    public void commitChanges() throws Exception
    {
        long startTime = System.currentTimeMillis();
        Log.i(Email.LOG_TAG, "Committing preference changes");
        Runnable committer = new Runnable()
        {
            public void run()
            {
                if (removeAll)
                {
                    storage.removeAll();
                }
                for (String removeKey : removals)
                {
                    storage.remove(removeKey);
                }
                for (Entry<String, String> entry : changes.entrySet())
                {
                    String key = entry.getKey();
                    String newValue = entry.getValue();
                    String oldValue = snapshot.get(key);
                    if (removeAll || removals.contains(key) || newValue.equals(oldValue) != true)
                    {
                        storage.put(key, newValue);
                    }
                }
            }
        };
        storage.doInTransaction(committer);
        long endTime = System.currentTimeMillis();
        Log.i(Email.LOG_TAG, "Preferences commit took " + (endTime - startTime) + "ms");

    }

    //@Override
    public android.content.SharedPreferences.Editor putBoolean(String key,
            boolean value)
    {
        changes.put(key, "" + value);
        return this;
    }

    //@Override
    public android.content.SharedPreferences.Editor putFloat(String key,
            float value)
    {
        changes.put(key, "" + value);
        return this;
    }

    //@Override
    public android.content.SharedPreferences.Editor putInt(String key, int value)
    {
        changes.put(key, "" + value);
        return this;
    }

    //@Override
    public android.content.SharedPreferences.Editor putLong(String key, long value)
    {
        changes.put(key, "" + value);
        return this;
    }

    //@Override
    public android.content.SharedPreferences.Editor putString(String key,
            String value)
    {
        if (value == null)
        {
            remove(key);
        }
        else
        {
            changes.put(key, value);
        }
        return this;
    }

    //@Override
    public android.content.SharedPreferences.Editor remove(String key)
    {
        removals.add(key);
        return this;
    }

}