Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * basebackup_sink.h
4 : * API for filtering or sending to a final destination the archives
5 : * produced by the base backup process
6 : *
7 : * Taking a base backup produces one archive per tablespace directory,
8 : * plus a backup manifest unless that feature has been disabled. The
9 : * goal of the backup process is to put those archives and that manifest
10 : * someplace, possibly after postprocessing them in some way. A 'bbsink'
11 : * is an object to which those archives, and the manifest if present,
12 : * can be sent.
13 : *
14 : * In practice, there will be a chain of 'bbsink' objects rather than
15 : * just one, with callbacks being forwarded from one to the next,
16 : * possibly with modification. Each object is responsible for a
17 : * single task e.g. command progress reporting, throttling, or
18 : * communication with the client.
19 : *
20 : * Portions Copyright (c) 2010-2026, PostgreSQL Global Development Group
21 : *
22 : * src/include/backup/basebackup_sink.h
23 : *
24 : *-------------------------------------------------------------------------
25 : */
26 : #ifndef BASEBACKUP_SINK_H
27 : #define BASEBACKUP_SINK_H
28 :
29 : #include "access/xlogdefs.h"
30 : #include "common/compression.h"
31 : #include "nodes/pg_list.h"
32 :
33 : /* Forward declarations. */
34 : struct bbsink;
35 : struct bbsink_ops;
36 : typedef struct bbsink bbsink;
37 : typedef struct bbsink_ops bbsink_ops;
38 :
39 : /*
40 : * Overall backup state shared by all bbsink objects for a backup.
41 : *
42 : * Before calling bbstate_begin_backup, caller must initiate a bbsink_state
43 : * object which will last for the lifetime of the backup, and must thereafter
44 : * update it as required before each new call to a bbsink method. The bbsink
45 : * will retain a pointer to the state object and will consult it to understand
46 : * the progress of the backup.
47 : *
48 : * 'tablespaces' is a list of tablespaceinfo objects. It must be set before
49 : * calling bbstate_begin_backup() and must not be modified thereafter.
50 : *
51 : * 'tablespace_num' is the index of the current tablespace within the list
52 : * stored in 'tablespaces'.
53 : *
54 : * 'bytes_done' is the number of bytes of archive data generated so far. This
55 : * is counted before any server-side compression.
56 : *
57 : * 'bytes_total' is the total number of bytes of archive data estimated to be
58 : * generated, if we have estimated this. The estimate is for data before any
59 : * server-side compression.
60 : *
61 : * 'bytes_total_is_valid' is true if and only if a proper estimate has been
62 : * stored into 'bytes_total'.
63 : *
64 : * 'startptr' and 'starttli' identify the point in the WAL stream at which
65 : * the backup began. They must be set before calling bbstate_begin_backup()
66 : * and must not be modified thereafter.
67 : */
68 : typedef struct bbsink_state
69 : {
70 : List *tablespaces;
71 : int tablespace_num;
72 : uint64 bytes_done;
73 : uint64 bytes_total;
74 : bool bytes_total_is_valid;
75 : XLogRecPtr startptr;
76 : TimeLineID starttli;
77 : } bbsink_state;
78 :
79 : /*
80 : * Common data for any type of basebackup sink.
81 : *
82 : * 'bbs_ops' is the relevant callback table.
83 : *
84 : * 'bbs_buffer' is the buffer into which data destined for the bbsink
85 : * should be stored. It must be a multiple of BLCKSZ.
86 : *
87 : * 'bbs_buffer_length' is the allocated length of the buffer.
88 : *
89 : * 'bbs_next' is a pointer to another bbsink to which this bbsink is
90 : * forwarding some or all operations.
91 : *
92 : * 'bbs_state' is a pointer to the bbsink_state object for this backup.
93 : * Every bbsink associated with this backup should point to the same
94 : * underlying state object.
95 : *
96 : * In general it is expected that the values of these fields are set when
97 : * a bbsink is created and that they do not change thereafter. It's OK
98 : * to modify the data to which bbs_buffer or bbs_state point, but no changes
99 : * should be made to the contents of this struct.
100 : */
101 : struct bbsink
102 : {
103 : const bbsink_ops *bbs_ops;
104 : char *bbs_buffer;
105 : size_t bbs_buffer_length;
106 : bbsink *bbs_next;
107 : bbsink_state *bbs_state;
108 : };
109 :
110 : /*
111 : * Callbacks for a base backup sink.
112 : *
113 : * All of these callbacks are required. If a particular callback just needs to
114 : * forward the call to sink->bbs_next, use bbsink_forward_<callback_name> as
115 : * the callback.
116 : *
117 : * Callers should always invoke these callbacks via the bbsink_* inline
118 : * functions rather than calling them directly.
119 : */
120 : struct bbsink_ops
121 : {
122 : /*
123 : * This callback is invoked just once, at the very start of the backup. It
124 : * must set bbs_buffer to point to a chunk of storage where at least
125 : * bbs_buffer_length bytes of data can be written.
126 : */
127 : void (*begin_backup) (bbsink *sink);
128 :
129 : /*
130 : * For each archive transmitted to a bbsink, there will be one call to the
131 : * begin_archive() callback, some number of calls to the
132 : * archive_contents() callback, and then one call to the end_archive()
133 : * callback.
134 : *
135 : * Before invoking the archive_contents() callback, the caller should copy
136 : * a number of bytes equal to what will be passed as len into bbs_buffer,
137 : * but not more than bbs_buffer_length.
138 : *
139 : * It's generally good if the buffer is as full as possible before the
140 : * archive_contents() callback is invoked, but it's not worth expending
141 : * extra cycles to make sure it's absolutely 100% full.
142 : */
143 : void (*begin_archive) (bbsink *sink, const char *archive_name);
144 : void (*archive_contents) (bbsink *sink, size_t len);
145 : void (*end_archive) (bbsink *sink);
146 :
147 : /*
148 : * If a backup manifest is to be transmitted to a bbsink, there will be
149 : * one call to the begin_manifest() callback, some number of calls to the
150 : * manifest_contents() callback, and then one call to the end_manifest()
151 : * callback. These calls will occur after all archives are transmitted.
152 : *
153 : * The rules for invoking the manifest_contents() callback are the same as
154 : * for the archive_contents() callback above.
155 : */
156 : void (*begin_manifest) (bbsink *sink);
157 : void (*manifest_contents) (bbsink *sink, size_t len);
158 : void (*end_manifest) (bbsink *sink);
159 :
160 : /*
161 : * This callback is invoked just once, after all archives and the manifest
162 : * have been sent.
163 : */
164 : void (*end_backup) (bbsink *sink, XLogRecPtr endptr, TimeLineID endtli);
165 :
166 : /*
167 : * If a backup is aborted by an error, this callback is invoked before the
168 : * bbsink object is destroyed, so that it can release any resources that
169 : * would not be released automatically. If no error occurs, this callback
170 : * is invoked after the end_backup callback.
171 : */
172 : void (*cleanup) (bbsink *sink);
173 : };
174 :
175 : /* Begin a backup. */
176 : static inline void
177 403 : bbsink_begin_backup(bbsink *sink, bbsink_state *state, int buffer_length)
178 : {
179 : Assert(sink != NULL);
180 :
181 : Assert(buffer_length > 0);
182 :
183 403 : sink->bbs_state = state;
184 403 : sink->bbs_buffer_length = buffer_length;
185 403 : sink->bbs_ops->begin_backup(sink);
186 :
187 : Assert(sink->bbs_buffer != NULL);
188 : Assert((sink->bbs_buffer_length % BLCKSZ) == 0);
189 403 : }
190 :
191 : /* Begin an archive. */
192 : static inline void
193 486 : bbsink_begin_archive(bbsink *sink, const char *archive_name)
194 : {
195 : Assert(sink != NULL);
196 :
197 486 : sink->bbs_ops->begin_archive(sink, archive_name);
198 486 : }
199 :
200 : /* Process some of the contents of an archive. */
201 : static inline void
202 888726 : bbsink_archive_contents(bbsink *sink, size_t len)
203 : {
204 : Assert(sink != NULL);
205 :
206 : /*
207 : * The caller should make a reasonable attempt to fill the buffer before
208 : * calling this function, so it shouldn't be completely empty. Nor should
209 : * it be filled beyond capacity.
210 : */
211 : Assert(len > 0 && len <= sink->bbs_buffer_length);
212 :
213 888726 : sink->bbs_ops->archive_contents(sink, len);
214 888724 : }
215 :
216 : /* Finish an archive. */
217 : static inline void
218 472 : bbsink_end_archive(bbsink *sink)
219 : {
220 : Assert(sink != NULL);
221 :
222 472 : sink->bbs_ops->end_archive(sink);
223 472 : }
224 :
225 : /* Begin the backup manifest. */
226 : static inline void
227 387 : bbsink_begin_manifest(bbsink *sink)
228 : {
229 : Assert(sink != NULL);
230 :
231 387 : sink->bbs_ops->begin_manifest(sink);
232 387 : }
233 :
234 : /* Process some of the manifest contents. */
235 : static inline void
236 1991 : bbsink_manifest_contents(bbsink *sink, size_t len)
237 : {
238 : Assert(sink != NULL);
239 :
240 : /* See comments in bbsink_archive_contents. */
241 : Assert(len > 0 && len <= sink->bbs_buffer_length);
242 :
243 1991 : sink->bbs_ops->manifest_contents(sink, len);
244 1991 : }
245 :
246 : /* Finish the backup manifest. */
247 : static inline void
248 387 : bbsink_end_manifest(bbsink *sink)
249 : {
250 : Assert(sink != NULL);
251 :
252 387 : sink->bbs_ops->end_manifest(sink);
253 387 : }
254 :
255 : /* Finish a backup. */
256 : static inline void
257 389 : bbsink_end_backup(bbsink *sink, XLogRecPtr endptr, TimeLineID endtli)
258 : {
259 : Assert(sink != NULL);
260 : Assert(sink->bbs_state->tablespace_num == list_length(sink->bbs_state->tablespaces));
261 :
262 389 : sink->bbs_ops->end_backup(sink, endptr, endtli);
263 389 : }
264 :
265 : /* Release resources before destruction. */
266 : static inline void
267 386 : bbsink_cleanup(bbsink *sink)
268 : {
269 : Assert(sink != NULL);
270 :
271 386 : sink->bbs_ops->cleanup(sink);
272 386 : }
273 :
274 : /* Forwarding callbacks. Use these to pass operations through to next sink. */
275 : extern void bbsink_forward_begin_backup(bbsink *sink);
276 : extern void bbsink_forward_begin_archive(bbsink *sink,
277 : const char *archive_name);
278 : extern void bbsink_forward_archive_contents(bbsink *sink, size_t len);
279 : extern void bbsink_forward_end_archive(bbsink *sink);
280 : extern void bbsink_forward_begin_manifest(bbsink *sink);
281 : extern void bbsink_forward_manifest_contents(bbsink *sink, size_t len);
282 : extern void bbsink_forward_end_manifest(bbsink *sink);
283 : extern void bbsink_forward_end_backup(bbsink *sink, XLogRecPtr endptr,
284 : TimeLineID endtli);
285 : extern void bbsink_forward_cleanup(bbsink *sink);
286 :
287 : /* Constructors for various types of sinks. */
288 : extern bbsink *bbsink_copystream_new(bool send_to_client);
289 : extern bbsink *bbsink_gzip_new(bbsink *next, pg_compress_specification *);
290 : extern bbsink *bbsink_lz4_new(bbsink *next, pg_compress_specification *);
291 : extern bbsink *bbsink_zstd_new(bbsink *next, pg_compress_specification *);
292 : extern bbsink *bbsink_progress_new(bbsink *next, bool estimate_backup_size,
293 : bool incremental);
294 : extern bbsink *bbsink_server_new(bbsink *next, char *pathname);
295 : extern bbsink *bbsink_throttle_new(bbsink *next, uint32 maxrate);
296 :
297 : /* Extra interface functions for progress reporting. */
298 : extern void basebackup_progress_wait_checkpoint(void);
299 : extern void basebackup_progress_estimate_backup_size(void);
300 : extern void basebackup_progress_wait_wal_archive(bbsink_state *);
301 : extern void basebackup_progress_transfer_wal(void);
302 :
303 : #endif
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