vendor/subversion/subversion-1.10.0

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diff --git a/subversion/libsvn_fs_x/batch_fsync.h b/subversion/libsvn_fs_x/batch_fsync.h
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+/* batch_fsync.h --- efficiently fsync multiple targets
+ *
+ * ====================================================================
+ *    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.
+ * ====================================================================
+ */
+
+#ifndef SVN_LIBSVN_FS_X__BATCH_FSYNC_H
+#define SVN_LIBSVN_FS_X__BATCH_FSYNC_H
+
+#include "svn_error.h"
+
+/* Infrastructure for efficiently calling fsync on files and directories.
+ *
+ * The idea is to have a container of open file handles (including
+ * directory handles on POSIX), at most one per file.  During the course
+ * of an FS operation that needs to be fsync'ed, all touched files and
+ * folders accumulate in the container.
+ *
+ * At the end of the FS operation, all file changes will be written the
+ * physical disk, once per file and folder.  Afterwards, all handles will
+ * be closed and the container is ready for reuse.
+ *
+ * To minimize the delay caused by the batch flush, run all fsync calls
+ * concurrently - if the OS supports multi-threading.
+ */
+
+/* Opaque container type.
+ */
+typedef struct svn_fs_x__batch_fsync_t svn_fs_x__batch_fsync_t;
+
+/* Initialize the concurrent fsync infrastructure.  Clean it up when
+ * OWNING_POOL gets cleared.
+ *
+ * This function must be called before using any of the other functions in
+ * in this module.  It should only be called once.
+ */
+svn_error_t *
+svn_fs_x__batch_fsync_init(apr_pool_t *owning_pool);
+
+/* Set *RESULT_P to a new batch fsync structure, allocated in RESULT_POOL.
+ * If FLUSH_TO_DISK is not set, the resulting struct will not actually use
+ * fsync. */
+svn_error_t *
+svn_fs_x__batch_fsync_create(svn_fs_x__batch_fsync_t **result_p,
+                             svn_boolean_t flush_to_disk,
+                             apr_pool_t *result_pool);
+
+/* Open the file at FILENAME for read and write access.  Return it in *FILE
+ * and schedule it for fsync in BATCH.  If BATCH already contains an open
+ * file for FILENAME, return that instead creating a new instance.
+ *
+ * Use SCRATCH_POOL for temporaries. */
+svn_error_t *
+svn_fs_x__batch_fsync_open_file(apr_file_t **file,
+                                svn_fs_x__batch_fsync_t *batch,
+                                const char *filename,
+                                apr_pool_t *scratch_pool);
+
+/* Inform the BATCH that a file or directory has been created at PATH.
+ * "Created" means either newly created to renamed to PATH - even if another
+ * item with the same name existed before.  Depending on the OS, the correct
+ * path will scheduled for fsync.
+ *
+ * Use SCRATCH_POOL for temporaries. */
+svn_error_t *
+svn_fs_x__batch_fsync_new_path(svn_fs_x__batch_fsync_t *batch,
+                               const char *path,
+                               apr_pool_t *scratch_pool);
+
+/* For all files and directories in BATCH, flush all changes to disk and
+ * close the file handles.  Use SCRATCH_POOL for temporaries. */
+svn_error_t *
+svn_fs_x__batch_fsync_run(svn_fs_x__batch_fsync_t *batch,
+                          apr_pool_t *scratch_pool);
+
+#endif