1 files changed, 104 insertions, 0 deletions
diff --git a/src/bin/pg_rewind/filemap.h b/src/bin/pg_rewind/filemap.h
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+++ b/src/bin/pg_rewind/filemap.h
@@ -0,0 +1,104 @@
+/*-------------------------------------------------------------------------
+ *
+ * filemap.h
+ *
+ * Copyright (c) 2013-2020, PostgreSQL Global Development Group
+ *-------------------------------------------------------------------------
+ */
+#ifndef FILEMAP_H
+#define FILEMAP_H
+
+#include "datapagemap.h"
+#include "storage/block.h"
+#include "storage/relfilenode.h"
+
+/*
+ * For every file found in the local or remote system, we have a file entry
+ * which says what we are going to do with the file. For relation files,
+ * there is also a page map, marking pages in the file that were changed
+ * locally.
+ *
+ * The enum values are sorted in the order we want actions to be processed.
+ */
+typedef enum
+{
+	FILE_ACTION_CREATE,			/* create local directory or symbolic link */
+	FILE_ACTION_COPY,			/* copy whole file, overwriting if exists */
+	FILE_ACTION_COPY_TAIL,		/* copy tail from 'oldsize' to 'newsize' */
+	FILE_ACTION_NONE,			/* no action (we might still copy modified
+								 * blocks based on the parsed WAL) */
+	FILE_ACTION_TRUNCATE,		/* truncate local file to 'newsize' bytes */
+	FILE_ACTION_REMOVE			/* remove local file / directory / symlink */
+} file_action_t;
+
+typedef enum
+{
+	FILE_TYPE_REGULAR,
+	FILE_TYPE_DIRECTORY,
+	FILE_TYPE_SYMLINK
+} file_type_t;
+
+typedef struct file_entry_t
+{
+	char	   *path;
+	file_type_t type;
+
+	file_action_t action;
+
+	/* for a regular file */
+	size_t		oldsize;
+	size_t		newsize;
+	bool		isrelfile;		/* is it a relation data file? */
+
+	datapagemap_t pagemap;
+
+	/* for a symlink */
+	char	   *link_target;
+
+	struct file_entry_t *next;
+} file_entry_t;
+
+typedef struct filemap_t
+{
+	/*
+	 * New entries are accumulated to a linked list, in process_source_file
+	 * and process_target_file.
+	 */
+	file_entry_t *first;
+	file_entry_t *last;
+	int			nlist;			/* number of entries currently in list */
+
+	/*
+	 * After processing all the remote files, the entries in the linked list
+	 * are moved to this array. After processing local files, too, all the
+	 * local entries are added to the array by filemap_finalize, and sorted in
+	 * the final order. After filemap_finalize, all the entries are in the
+	 * array, and the linked list is empty.
+	 */
+	file_entry_t **array;
+	int			narray;			/* current length of array */
+
+	/*
+	 * Summary information. total_size is the total size of the source
+	 * cluster, and fetch_size is the number of bytes that needs to be copied.
+	 */
+	uint64		total_size;
+	uint64		fetch_size;
+} filemap_t;
+
+extern filemap_t *filemap;
+
+extern void filemap_create(void);
+extern void calculate_totals(void);
+extern void print_filemap(void);
+
+/* Functions for populating the filemap */
+extern void process_source_file(const char *path, file_type_t type,
+								size_t newsize, const char *link_target);
+extern void process_target_file(const char *path, file_type_t type,
+								size_t newsize, const char *link_target);
+extern void process_block_change(ForkNumber forknum, RelFileNode rnode,
+								 BlockNumber blkno);
+extern void filemap_finalize(void);
+
+#endif							/* FILEMAP_H */