4 files changed, 460 insertions, 0 deletions
diff --git a/src/include/backup/backup_manifest.h b/src/include/backup/backup_manifest.h
new file mode 100644
index 0000000..d41b439
--- /dev/null
+++ b/src/include/backup/backup_manifest.h
@@ -0,0 +1,54 @@
+/*-------------------------------------------------------------------------
+ *
+ * backup_manifest.h
+ *	  Routines for generating a backup manifest.
+ *
+ * Portions Copyright (c) 2010-2023, PostgreSQL Global Development Group
+ *
+ * src/include/backup/backup_manifest.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef BACKUP_MANIFEST_H
+#define BACKUP_MANIFEST_H
+
+#include "backup/basebackup_sink.h"
+#include "common/checksum_helper.h"
+#include "pgtime.h"
+#include "storage/buffile.h"
+
+typedef enum manifest_option
+{
+	MANIFEST_OPTION_YES,
+	MANIFEST_OPTION_NO,
+	MANIFEST_OPTION_FORCE_ENCODE
+} backup_manifest_option;
+
+typedef struct backup_manifest_info
+{
+	BufFile    *buffile;
+	pg_checksum_type checksum_type;
+	pg_cryptohash_ctx *manifest_ctx;
+	uint64		manifest_size;
+	bool		force_encode;
+	bool		first_file;
+	bool		still_checksumming;
+} backup_manifest_info;
+
+extern void InitializeBackupManifest(backup_manifest_info *manifest,
+									 backup_manifest_option want_manifest,
+									 pg_checksum_type manifest_checksum_type);
+extern void AddFileToBackupManifest(backup_manifest_info *manifest,
+									const char *spcoid,
+									const char *pathname, size_t size,
+									pg_time_t mtime,
+									pg_checksum_context *checksum_ctx);
+extern void AddWALInfoToBackupManifest(backup_manifest_info *manifest,
+									   XLogRecPtr startptr,
+									   TimeLineID starttli, XLogRecPtr endptr,
+									   TimeLineID endtli);
+
+extern void SendBackupManifest(backup_manifest_info *manifest, bbsink *sink);
+extern void FreeBackupManifest(backup_manifest_info *manifest);
+
+#endif
diff --git a/src/include/backup/basebackup.h b/src/include/backup/basebackup.h
new file mode 100644
index 0000000..3e68abc
--- /dev/null
+++ b/src/include/backup/basebackup.h
@@ -0,0 +1,39 @@
+/*-------------------------------------------------------------------------
+ *
+ * basebackup.h
+ *	  Exports from replication/basebackup.c.
+ *
+ * Portions Copyright (c) 2010-2023, PostgreSQL Global Development Group
+ *
+ * src/include/backup/basebackup.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef _BASEBACKUP_H
+#define _BASEBACKUP_H
+
+#include "nodes/replnodes.h"
+
+/*
+ * Minimum and maximum values of MAX_RATE option in BASE_BACKUP command.
+ */
+#define MAX_RATE_LOWER	32
+#define MAX_RATE_UPPER	1048576
+
+/*
+ * Information about a tablespace
+ *
+ * In some usages, "path" can be NULL to denote the PGDATA directory itself.
+ */
+typedef struct
+{
+	char	   *oid;			/* tablespace's OID, as a decimal string */
+	char	   *path;			/* full path to tablespace's directory */
+	char	   *rpath;			/* relative path if it's within PGDATA, else
+								 * NULL */
+	int64		size;			/* total size as sent; -1 if not known */
+} tablespaceinfo;
+
+extern void SendBaseBackup(BaseBackupCmd *cmd);
+
+#endif							/* _BASEBACKUP_H */
diff --git a/src/include/backup/basebackup_sink.h b/src/include/backup/basebackup_sink.h
new file mode 100644
index 0000000..224732e
--- /dev/null
+++ b/src/include/backup/basebackup_sink.h
@@ -0,0 +1,301 @@
+/*-------------------------------------------------------------------------
+ *
+ * basebackup_sink.h
+ *	  API for filtering or sending to a final destination the archives
+ *	  produced by the base backup process
+ *
+ * Taking a base backup produces one archive per tablespace directory,
+ * plus a backup manifest unless that feature has been disabled. The
+ * goal of the backup process is to put those archives and that manifest
+ * someplace, possibly after postprocessing them in some way. A 'bbsink'
+ * is an object to which those archives, and the manifest if present,
+ * can be sent.
+ *
+ * In practice, there will be a chain of 'bbsink' objects rather than
+ * just one, with callbacks being forwarded from one to the next,
+ * possibly with modification. Each object is responsible for a
+ * single task e.g. command progress reporting, throttling, or
+ * communication with the client.
+ *
+ * Portions Copyright (c) 2010-2023, PostgreSQL Global Development Group
+ *
+ * src/include/backup/basebackup_sink.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef BASEBACKUP_SINK_H
+#define BASEBACKUP_SINK_H
+
+#include "access/xlogdefs.h"
+#include "common/compression.h"
+#include "nodes/pg_list.h"
+
+/* Forward declarations. */
+struct bbsink;
+struct bbsink_ops;
+typedef struct bbsink bbsink;
+typedef struct bbsink_ops bbsink_ops;
+
+/*
+ * Overall backup state shared by all bbsink objects for a backup.
+ *
+ * Before calling bbstate_begin_backup, caller must initiate a bbsink_state
+ * object which will last for the lifetime of the backup, and must thereafter
+ * update it as required before each new call to a bbsink method. The bbsink
+ * will retain a pointer to the state object and will consult it to understand
+ * the progress of the backup.
+ *
+ * 'tablespaces' is a list of tablespaceinfo objects. It must be set before
+ * calling bbstate_begin_backup() and must not be modified thereafter.
+ *
+ * 'tablespace_num' is the index of the current tablespace within the list
+ * stored in 'tablespaces'.
+ *
+ * 'bytes_done' is the number of bytes read so far from $PGDATA.
+ *
+ * 'bytes_total' is the total number of bytes estimated to be present in
+ * $PGDATA, if we have estimated this.
+ *
+ * 'bytes_total_is_valid' is true if and only if a proper estimate has been
+ * stored into 'bytes_total'.
+ *
+ * 'startptr' and 'starttli' identify the point in the WAL stream at which
+ * the backup began. They must be set before calling bbstate_begin_backup()
+ * and must not be modified thereafter.
+ */
+typedef struct bbsink_state
+{
+	List	   *tablespaces;
+	int			tablespace_num;
+	uint64		bytes_done;
+	uint64		bytes_total;
+	bool		bytes_total_is_valid;
+	XLogRecPtr	startptr;
+	TimeLineID	starttli;
+} bbsink_state;
+
+/*
+ * Common data for any type of basebackup sink.
+ *
+ * 'bbs_ops' is the relevant callback table.
+ *
+ * 'bbs_buffer' is the buffer into which data destined for the bbsink
+ * should be stored. It must be a multiple of BLCKSZ.
+ *
+ * 'bbs_buffer_length' is the allocated length of the buffer.
+ *
+ * 'bbs_next' is a pointer to another bbsink to which this bbsink is
+ * forwarding some or all operations.
+ *
+ * 'bbs_state' is a pointer to the bbsink_state object for this backup.
+ * Every bbsink associated with this backup should point to the same
+ * underlying state object.
+ *
+ * In general it is expected that the values of these fields are set when
+ * a bbsink is created and that they do not change thereafter. It's OK
+ * to modify the data to which bbs_buffer or bbs_state point, but no changes
+ * should be made to the contents of this struct.
+ */
+struct bbsink
+{
+	const bbsink_ops *bbs_ops;
+	char	   *bbs_buffer;
+	size_t		bbs_buffer_length;
+	bbsink	   *bbs_next;
+	bbsink_state *bbs_state;
+};
+
+/*
+ * Callbacks for a base backup sink.
+ *
+ * All of these callbacks are required. If a particular callback just needs to
+ * forward the call to sink->bbs_next, use bbsink_forward_<callback_name> as
+ * the callback.
+ *
+ * Callers should always invoke these callbacks via the bbsink_* inline
+ * functions rather than calling them directly.
+ */
+struct bbsink_ops
+{
+	/*
+	 * This callback is invoked just once, at the very start of the backup. It
+	 * must set bbs_buffer to point to a chunk of storage where at least
+	 * bbs_buffer_length bytes of data can be written.
+	 */
+	void		(*begin_backup) (bbsink *sink);
+
+	/*
+	 * For each archive transmitted to a bbsink, there will be one call to the
+	 * begin_archive() callback, some number of calls to the
+	 * archive_contents() callback, and then one call to the end_archive()
+	 * callback.
+	 *
+	 * Before invoking the archive_contents() callback, the caller should copy
+	 * a number of bytes equal to what will be passed as len into bbs_buffer,
+	 * but not more than bbs_buffer_length.
+	 *
+	 * It's generally good if the buffer is as full as possible before the
+	 * archive_contents() callback is invoked, but it's not worth expending
+	 * extra cycles to make sure it's absolutely 100% full.
+	 */
+	void		(*begin_archive) (bbsink *sink, const char *archive_name);
+	void		(*archive_contents) (bbsink *sink, size_t len);
+	void		(*end_archive) (bbsink *sink);
+
+	/*
+	 * If a backup manifest is to be transmitted to a bbsink, there will be
+	 * one call to the begin_manifest() callback, some number of calls to the
+	 * manifest_contents() callback, and then one call to the end_manifest()
+	 * callback. These calls will occur after all archives are transmitted.
+	 *
+	 * The rules for invoking the manifest_contents() callback are the same as
+	 * for the archive_contents() callback above.
+	 */
+	void		(*begin_manifest) (bbsink *sink);
+	void		(*manifest_contents) (bbsink *sink, size_t len);
+	void		(*end_manifest) (bbsink *sink);
+
+	/*
+	 * This callback is invoked just once, after all archives and the manifest
+	 * have been sent.
+	 */
+	void		(*end_backup) (bbsink *sink, XLogRecPtr endptr, TimeLineID endtli);
+
+	/*
+	 * If a backup is aborted by an error, this callback is invoked before the
+	 * bbsink object is destroyed, so that it can release any resources that
+	 * would not be released automatically. If no error occurs, this callback
+	 * is invoked after the end_backup callback.
+	 */
+	void		(*cleanup) (bbsink *sink);
+};
+
+/* Begin a backup. */
+static inline void
+bbsink_begin_backup(bbsink *sink, bbsink_state *state, int buffer_length)
+{
+	Assert(sink != NULL);
+
+	Assert(buffer_length > 0);
+
+	sink->bbs_state = state;
+	sink->bbs_buffer_length = buffer_length;
+	sink->bbs_ops->begin_backup(sink);
+
+	Assert(sink->bbs_buffer != NULL);
+	Assert((sink->bbs_buffer_length % BLCKSZ) == 0);
+}
+
+/* Begin an archive. */
+static inline void
+bbsink_begin_archive(bbsink *sink, const char *archive_name)
+{
+	Assert(sink != NULL);
+
+	sink->bbs_ops->begin_archive(sink, archive_name);
+}
+
+/* Process some of the contents of an archive. */
+static inline void
+bbsink_archive_contents(bbsink *sink, size_t len)
+{
+	Assert(sink != NULL);
+
+	/*
+	 * The caller should make a reasonable attempt to fill the buffer before
+	 * calling this function, so it shouldn't be completely empty. Nor should
+	 * it be filled beyond capacity.
+	 */
+	Assert(len > 0 && len <= sink->bbs_buffer_length);
+
+	sink->bbs_ops->archive_contents(sink, len);
+}
+
+/* Finish an archive. */
+static inline void
+bbsink_end_archive(bbsink *sink)
+{
+	Assert(sink != NULL);
+
+	sink->bbs_ops->end_archive(sink);
+}
+
+/* Begin the backup manifest. */
+static inline void
+bbsink_begin_manifest(bbsink *sink)
+{
+	Assert(sink != NULL);
+
+	sink->bbs_ops->begin_manifest(sink);
+}
+
+/* Process some of the manifest contents. */
+static inline void
+bbsink_manifest_contents(bbsink *sink, size_t len)
+{
+	Assert(sink != NULL);
+
+	/* See comments in bbsink_archive_contents. */
+	Assert(len > 0 && len <= sink->bbs_buffer_length);
+
+	sink->bbs_ops->manifest_contents(sink, len);
+}
+
+/* Finish the backup manifest. */
+static inline void
+bbsink_end_manifest(bbsink *sink)
+{
+	Assert(sink != NULL);
+
+	sink->bbs_ops->end_manifest(sink);
+}
+
+/* Finish a backup. */
+static inline void
+bbsink_end_backup(bbsink *sink, XLogRecPtr endptr, TimeLineID endtli)
+{
+	Assert(sink != NULL);
+	Assert(sink->bbs_state->tablespace_num == list_length(sink->bbs_state->tablespaces));
+
+	sink->bbs_ops->end_backup(sink, endptr, endtli);
+}
+
+/* Release resources before destruction. */
+static inline void
+bbsink_cleanup(bbsink *sink)
+{
+	Assert(sink != NULL);
+
+	sink->bbs_ops->cleanup(sink);
+}
+
+/* Forwarding callbacks. Use these to pass operations through to next sink. */
+extern void bbsink_forward_begin_backup(bbsink *sink);
+extern void bbsink_forward_begin_archive(bbsink *sink,
+										 const char *archive_name);
+extern void bbsink_forward_archive_contents(bbsink *sink, size_t len);
+extern void bbsink_forward_end_archive(bbsink *sink);
+extern void bbsink_forward_begin_manifest(bbsink *sink);
+extern void bbsink_forward_manifest_contents(bbsink *sink, size_t len);
+extern void bbsink_forward_end_manifest(bbsink *sink);
+extern void bbsink_forward_end_backup(bbsink *sink, XLogRecPtr endptr,
+									  TimeLineID endtli);
+extern void bbsink_forward_cleanup(bbsink *sink);
+
+/* Constructors for various types of sinks. */
+extern bbsink *bbsink_copystream_new(bool send_to_client);
+extern bbsink *bbsink_gzip_new(bbsink *next, pg_compress_specification *);
+extern bbsink *bbsink_lz4_new(bbsink *next, pg_compress_specification *);
+extern bbsink *bbsink_zstd_new(bbsink *next, pg_compress_specification *);
+extern bbsink *bbsink_progress_new(bbsink *next, bool estimate_backup_size);
+extern bbsink *bbsink_server_new(bbsink *next, char *pathname);
+extern bbsink *bbsink_throttle_new(bbsink *next, uint32 maxrate);
+
+/* Extra interface functions for progress reporting. */
+extern void basebackup_progress_wait_checkpoint(void);
+extern void basebackup_progress_estimate_backup_size(void);
+extern void basebackup_progress_wait_wal_archive(bbsink_state *);
+extern void basebackup_progress_transfer_wal(void);
+extern void basebackup_progress_done(void);
+
+#endif
diff --git a/src/include/backup/basebackup_target.h b/src/include/backup/basebackup_target.h
new file mode 100644
index 0000000..250572f
--- /dev/null
+++ b/src/include/backup/basebackup_target.h
@@ -0,0 +1,66 @@
+/*-------------------------------------------------------------------------
+ *
+ * basebackup_target.h
+ *	  Extensibility framework for adding base backup targets.
+ *
+ * Portions Copyright (c) 2010-2023, PostgreSQL Global Development Group
+ *
+ * src/include/backup/basebackup_target.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef BASEBACKUP_TARGET_H
+#define BASEBACKUP_TARGET_H
+
+#include "backup/basebackup_sink.h"
+
+struct BaseBackupTargetHandle;
+typedef struct BaseBackupTargetHandle BaseBackupTargetHandle;
+
+/*
+ * Extensions can call this function to create new backup targets.
+ *
+ * 'name' is the name of the new target.
+ *
+ * 'check_detail' is a function that accepts a target name and target detail
+ * and either throws an error (if the target detail is not valid or some other
+ * problem, such as a permissions issue, is detected) or returns a pointer to
+ * the data that will be needed to create a bbsink implementing that target.
+ * The second argument will be NULL if the TARGET_DETAIL option to the
+ * BASE_BACKUP command was not specified.
+ *
+ * 'get_sink' is a function that creates the bbsink. The first argument
+ * is the successor sink; the sink created by this function should always
+ * forward to this sink. The second argument is the pointer returned by a
+ * previous call to the 'check_detail' function.
+ *
+ * In practice, a user will type something like "pg_basebackup --target foo:bar
+ * -Xfetch". That will cause the server to look for a backup target named
+ * "foo". If one is found, the check_detail callback will be invoked for the
+ * string "bar", and whatever that callback returns will be passed as the
+ * second argument to the get_sink callback.
+ */
+extern void BaseBackupAddTarget(char *name,
+								void *(*check_detail) (char *, char *),
+								bbsink *(*get_sink) (bbsink *, void *));
+
+/*
+ * These functions are used by the core code to access base backup targets
+ * added via BaseBackupAddTarget(). The core code will pass the TARGET and
+ * TARGET_DETAIL strings obtained from the user to BaseBackupGetTargetHandle,
+ * which will either throw an error (if the TARGET is not recognized or the
+ * check_detail hook for that TARGET doesn't like the TARGET_DETAIL) or
+ * return a BaseBackupTargetHandle object that can later be passed to
+ * BaseBackupGetSink.
+ *
+ * BaseBackupGetSink constructs a bbsink implementing the desired target
+ * using the BaseBackupTargetHandle and the successor bbsink. It does this
+ * by arranging to call the get_sink() callback provided by the extension
+ * that implements the base backup target.
+ */
+extern BaseBackupTargetHandle *BaseBackupGetTargetHandle(char *target,
+														 char *target_detail);
+extern bbsink *BaseBackupGetSink(BaseBackupTargetHandle *handle,
+								 bbsink *next_sink);
+
+#endif