1 /* batch_fsync.h --- efficiently fsync multiple targets 2 * 3 * ==================================================================== 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, 15 * software distributed under the License is distributed on an 16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 17 * KIND, either express or implied. See the License for the 18 * specific language governing permissions and limitations 19 * under the License. 20 * ==================================================================== 21 */ 22 23 #ifndef SVN_LIBSVN_FS_X__BATCH_FSYNC_H 24 #define SVN_LIBSVN_FS_X__BATCH_FSYNC_H 25 26 #include "svn_error.h" 27 28 /* Infrastructure for efficiently calling fsync on files and directories. 29 * 30 * The idea is to have a container of open file handles (including 31 * directory handles on POSIX), at most one per file. During the course 32 * of an FS operation that needs to be fsync'ed, all touched files and 33 * folders accumulate in the container. 34 * 35 * At the end of the FS operation, all file changes will be written the 36 * physical disk, once per file and folder. Afterwards, all handles will 37 * be closed and the container is ready for reuse. 38 * 39 * To minimize the delay caused by the batch flush, run all fsync calls 40 * concurrently - if the OS supports multi-threading. 41 */ 42 43 /* Opaque container type. 44 */ 45 typedef struct svn_fs_x__batch_fsync_t svn_fs_x__batch_fsync_t; 46 47 /* Initialize the concurrent fsync infrastructure. Clean it up when 48 * OWNING_POOL gets cleared. 49 * 50 * This function must be called before using any of the other functions in 51 * in this module. It should only be called once. 52 */ 53 svn_error_t * 54 svn_fs_x__batch_fsync_init(apr_pool_t *owning_pool); 55 56 /* Set *RESULT_P to a new batch fsync structure, allocated in RESULT_POOL. 57 * If FLUSH_TO_DISK is not set, the resulting struct will not actually use 58 * fsync. */ 59 svn_error_t * 60 svn_fs_x__batch_fsync_create(svn_fs_x__batch_fsync_t **result_p, 61 svn_boolean_t flush_to_disk, 62 apr_pool_t *result_pool); 63 64 /* Open the file at FILENAME for read and write access. Return it in *FILE 65 * and schedule it for fsync in BATCH. If BATCH already contains an open 66 * file for FILENAME, return that instead creating a new instance. 67 * 68 * Use SCRATCH_POOL for temporaries. */ 69 svn_error_t * 70 svn_fs_x__batch_fsync_open_file(apr_file_t **file, 71 svn_fs_x__batch_fsync_t *batch, 72 const char *filename, 73 apr_pool_t *scratch_pool); 74 75 /* Inform the BATCH that a file or directory has been created at PATH. 76 * "Created" means either newly created to renamed to PATH - even if another 77 * item with the same name existed before. Depending on the OS, the correct 78 * path will scheduled for fsync. 79 * 80 * Use SCRATCH_POOL for temporaries. */ 81 svn_error_t * 82 svn_fs_x__batch_fsync_new_path(svn_fs_x__batch_fsync_t *batch, 83 const char *path, 84 apr_pool_t *scratch_pool); 85 86 /* For all files and directories in BATCH, flush all changes to disk and 87 * close the file handles. Use SCRATCH_POOL for temporaries. */ 88 svn_error_t * 89 svn_fs_x__batch_fsync_run(svn_fs_x__batch_fsync_t *batch, 90 apr_pool_t *scratch_pool); 91 92 #endif 93