public <E> List<E> selectList(String statement, Object parameter, RowBounds rowBounds) {
  try {
   MappedStatement ms = configuration.getMappedStatement(statement);
   return executor.query(ms, wrapCollection(parameter), rowBounds, Executor.NO_RESULT_HANDLER);
  } catch (Exception e) {
   throw ExceptionFactory.wrapException("Error querying database. Cause: " + e, e);
  } finally {
   ErrorContext.instance().reset();
  }
}

 public <E> List<E> query(MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler) throws SQLException {
   BoundSql boundSql = ms.getBoundSql(parameter);
   CacheKey key = createCacheKey(ms, parameter, rowBounds, boundSql);
   return query(ms, parameter, rowBounds, resultHandler, key, boundSql);
 }

public <E> List<E> query(MappedStatement ms, Object parameterObject, RowBounds rowBounds, ResultHandler resultHandler, CacheKey key, BoundSql boundSql)
   throws SQLException {
  Cache cache = ms.getCache();
  if (cache != null) {
   flushCacheIfRequired(ms);
   if (ms.isUseCache() && resultHandler == null) {
    ensureNoOutParams(ms, parameterObject, boundSql);
    @SuppressWarnings("unchecked")
    List<E> list = (List<E>) tcm.getObject(cache, key);
    if (list == null) {
     list = delegate.<E> query(ms, parameterObject, rowBounds, resultHandler, key, boundSql);
     tcm.putObject(cache, key, list); // issue #578 and #116
    }
    return list;
   }
  }
  return delegate.<E> query(ms, parameterObject, rowBounds, resultHandler, key, boundSql);
}

public <E> List<E> query(MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler, CacheKey key, BoundSql boundSql) throws SQLException {
  ErrorContext.instance().resource(ms.getResource()).activity("executing a query").object(ms.getId());
  if (closed) {
   throw new ExecutorException("Executor was closed.");
  }
  if (queryStack == 0 && ms.isFlushCacheRequired()) {
   clearLocalCache();
  }
  List<E> list;
  try {
   queryStack++;
   list = resultHandler == null ? (List<E>) localCache.getObject(key) : null;
   if (list != null) {
    handleLocallyCachedOutputParameters(ms, key, parameter, boundSql);
   } else {
    list = queryFromDatabase(ms, parameter, rowBounds, resultHandler, key, boundSql);
   }
  } finally {
   queryStack--;
  }
  ...
}

public int update(MappedStatement ms, Object parameter) throws SQLException {
  ErrorContext.instance().resource(ms.getResource()).activity("executing an update").object(ms.getId());
  if (closed) {
   throw new ExecutorException("Executor was closed.");
  }
  clearLocalCache();
  return doUpdate(ms, parameter);
}

public class CacheKey implements Cloneable, Serializable {

 private static final long serialVersionUID = 1146682552656046210L;

 public static final CacheKey NULL_CACHE_KEY = new NullCacheKey();

 private static final int DEFAULT_MULTIPLYER = 37;
 private static final int DEFAULT_HASHCODE = 17;

 private int multiplier;
 private int hashcode;
 private long checksum;
 private int count;
 private List<Object> updateList;
 ...
}

public boolean equals(Object object) {
  if (this == object) {
   return true;
  }
  if (!(object instanceof CacheKey)) {
   return false;
  }

  final CacheKey cacheKey = (CacheKey) object;

  if (hashcode != cacheKey.hashcode) {
   return false;
  }
  if (checksum != cacheKey.checksum) {
   return false;
  }
  if (count != cacheKey.count) {
   return false;
  }

  for (int i = 0; i < updateList.size(); i++) {
   Object thisObject = updateList.get(i);
   Object thatObject = cacheKey.updateList.get(i);
   if (thisObject == null) {
    if (thatObject != null) {
     return false;
    }
   } else {
    if (!thisObject.equals(thatObject)) {
     return false;
    }
   }
  }
  return true;
}

private void doUpdate(Object object) {
  int baseHashCode = object == null ? 1 : object.hashCode();

  count++;
  checksum += baseHashCode;
  baseHashCode *= count;

  hashcode = multiplier * hashcode + baseHashCode;

  updateList.add(object);
}

public void update(Object object) {
  if (object != null && object.getClass().isArray()) {
   int length = Array.getLength(object);
   for (int i = 0; i < length; i++) {
    Object element = Array.get(object, i);
    doUpdate(element);
   }
  } else {
   doUpdate(object);
  }
}

...
CacheKey cacheKey = new CacheKey();
cacheKey.update(ms.getId());
cacheKey.update(rowBounds.getOffset());
cacheKey.update(rowBounds.getLimit());
cacheKey.update(boundSql.getSql());
...

public <E> List<E> selectList(String statement, Object parameter, RowBounds rowBounds) {
  try {
   MappedStatement ms = configuration.getMappedStatement(statement);
   return executor.query(ms, wrapCollection(parameter), rowBounds, Executor.NO_RESULT_HANDLER);
  } catch (Exception e) {
   throw ExceptionFactory.wrapException("Error querying database. Cause: " + e, e);
  } finally {
   ErrorContext.instance().reset();
  }
}

 public <E> List<E> query(MappedStatement ms, Object parameterObject, RowBounds rowBounds, ResultHandler resultHandler) throws SQLException {
   BoundSql boundSql = ms.getBoundSql(parameterObject);
   CacheKey key = createCacheKey(ms, parameterObject, rowBounds, boundSql);
   return query(ms, parameterObject, rowBounds, resultHandler, key, boundSql);
 }

public <E> List<E> query(MappedStatement ms, Object parameterObject, RowBounds rowBounds, ResultHandler resultHandler, CacheKey key, BoundSql boundSql)
   throws SQLException {
  Cache cache = ms.getCache();
  if (cache != null) {
   flushCacheIfRequired(ms);
   if (ms.isUseCache() && resultHandler == null) {
    ensureNoOutParams(ms, parameterObject, boundSql);
    @SuppressWarnings("unchecked")
    List<E> list = (List<E>) tcm.getObject(cache, key);
    if (list == null) {
     list = delegate.<E> query(ms, parameterObject, rowBounds, resultHandler, key, boundSql);
     tcm.putObject(cache, key, list); // issue #578 and #116
    }
    return list;
   }
  }
  return delegate.<E> query(ms, parameterObject, rowBounds, resultHandler, key, boundSql);
}

protected final Map<String, MappedStatement> mappedStatements = new StrictMap<MappedStatement>("Mapped Statements collection");

private void cacheElement(XNode context) throws Exception {
  if (context != null) {
   String type = context.getStringAttribute("type", "PERPETUAL");
   Class<? extends Cache> typeClass = typeAliasRegistry.resolveAlias(type);
   String eviction = context.getStringAttribute("eviction", "LRU");
   Class<? extends Cache> evictionClass = typeAliasRegistry.resolveAlias(eviction);
   Long flushInterval = context.getLongAttribute("flushInterval");
   Integer size = context.getIntAttribute("size");
   boolean readWrite = !context.getBooleanAttribute("readOnly", false);
   boolean blocking = context.getBooleanAttribute("blocking", false);
   Properties props = context.getChildrenAsProperties();
   builderAssistant.useNewCache(typeClass, evictionClass, flushInterval, size, readWrite, blocking, props);
  }
}

public Cache useNewCache(Class<? extends Cache> typeClass,
   Class<? extends Cache> evictionClass,
   Long flushInterval,
   Integer size,
   boolean readWrite,
   boolean blocking,
   Properties props) {
  Cache cache = new CacheBuilder(currentNamespace)
    .implementation(valueOrDefault(typeClass, PerpetualCache.class))
    .addDecorator(valueOrDefault(evictionClass, LruCache.class))
    .clearInterval(flushInterval)
    .size(size)
    .readWrite(readWrite)
    .blocking(blocking)
    .properties(props)
    .build();
  configuration.addCache(cache);
  currentCache = cache;
  return cache;
}

public Cache build() {
  setDefaultImplementations();
  Cache cache = newBaseCacheInstance(implementation, id);
  setCacheProperties(cache);
  // issue #352, do not apply decorators to custom caches
  if (PerpetualCache.class.equals(cache.getClass())) {
   for (Class<? extends Cache> decorator : decorators) {
    cache = newCacheDecoratorInstance(decorator, cache);
    setCacheProperties(cache);
   }
   cache = setStandardDecorators(cache);
  } else if (!LoggingCache.class.isAssignableFrom(cache.getClass())) {
   cache = new LoggingCache(cache);
  }
  return cache;
}

private Cache setStandardDecorators(Cache cache) {
  try {
   MetaObject metaCache = SystemMetaObject.forObject(cache);
   if (size != null && metaCache.hasSetter("size")) {
    metaCache.setValue("size", size);
   }
   if (clearInterval != null) {
    cache = new ScheduledCache(cache);
    ((ScheduledCache) cache).setClearInterval(clearInterval);
   }
   if (readWrite) {
    cache = new SerializedCache(cache);
   }
   cache = new LoggingCache(cache);
   cache = new SynchronizedCache(cache);
   if (blocking) {
    cache = new BlockingCache(cache);
   }
   return cache;
  } catch (Exception e) {
   throw new CacheException("Error building standard cache decorators. Cause: " + e, e);
  }
}