/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

parcel Lucy;

/** In-memory FileHandle.
 *
 * RAM-based implementation of FileHandle, to be used in conjunction with
 * RAMFolder.
 */
class Lucy::Store::RAMFileHandle cnick RAMFH
    inherits Lucy::Store::FileHandle {

    RAMFile *ram_file;
    int64_t  len;

    inert incremented nullable RAMFileHandle*
    open(const CharBuf *path = NULL, uint32_t flags, RAMFile *file = NULL);

    /**
     * Return a new RAMFileHandle, or set Err_error and return NULL on
     * failure.
     *
     * @param path Filepath.
     * @param flags FileHandle flags.
     * @param file An existing RAMFile; if not supplied, the FH_CREATE flag
     * must be passed or an error will occur.
     */
    inert nullable RAMFileHandle*
    do_open(RAMFileHandle *self, const CharBuf *path = NULL, uint32_t flags,
            RAMFile *file = NULL);

    /** Access the backing RAMFile.
     */
    RAMFile*
    Get_File(RAMFileHandle *self);

    bool_t
    Grow(RAMFileHandle *self, int64_t len);

    public void
    Destroy(RAMFileHandle *self);

    bool_t
    Window(RAMFileHandle *self, FileWindow *window, int64_t offset, int64_t len);

    bool_t
    Release_Window(RAMFileHandle *self, FileWindow *window);

    bool_t
    Read(RAMFileHandle *self, char *dest, int64_t offset, size_t len);

    bool_t
    Write(RAMFileHandle *self, const void *data, size_t len);

    int64_t
    Length(RAMFileHandle *self);

    bool_t
    Close(RAMFileHandle *self);
}