1 /*
2 * psql - the PostgreSQL interactive terminal
3 *
4 * Copyright (c) 2000-2021, PostgreSQL Global Development Group
5 *
6 * src/bin/psql/large_obj.c
7 */
8 #include "postgres_fe.h"
9
10 #include "common.h"
11 #include "common/logging.h"
12 #include "fe_utils/cancel.h"
13 #include "large_obj.h"
14 #include "settings.h"
15
16 static void print_lo_result(const char *fmt,...) pg_attribute_printf(1, 2);
17
18 static void
print_lo_result(const char * fmt,...)19 print_lo_result(const char *fmt,...)
20 {
21 va_list ap;
22
23 if (!pset.quiet)
24 {
25 if (pset.popt.topt.format == PRINT_HTML)
26 fputs("<p>", pset.queryFout);
27
28 va_start(ap, fmt);
29 vfprintf(pset.queryFout, fmt, ap);
30 va_end(ap);
31
32 if (pset.popt.topt.format == PRINT_HTML)
33 fputs("</p>\n", pset.queryFout);
34 else
35 fputs("\n", pset.queryFout);
36 }
37
38 if (pset.logfile)
39 {
40 va_start(ap, fmt);
41 vfprintf(pset.logfile, fmt, ap);
42 va_end(ap);
43 fputs("\n", pset.logfile);
44 }
45 }
46
47
48 /*
49 * Prepare to do a large-object operation. We *must* be inside a transaction
50 * block for all these operations, so start one if needed.
51 *
52 * Returns true if okay, false if failed. *own_transaction is set to indicate
53 * if we started our own transaction or not.
54 */
55 static bool
start_lo_xact(const char * operation,bool * own_transaction)56 start_lo_xact(const char *operation, bool *own_transaction)
57 {
58 PGTransactionStatusType tstatus;
59 PGresult *res;
60
61 *own_transaction = false;
62
63 if (!pset.db)
64 {
65 pg_log_error("%s: not connected to a database", operation);
66 return false;
67 }
68
69 tstatus = PQtransactionStatus(pset.db);
70
71 switch (tstatus)
72 {
73 case PQTRANS_IDLE:
74 /* need to start our own xact */
75 if (!(res = PSQLexec("BEGIN")))
76 return false;
77 PQclear(res);
78 *own_transaction = true;
79 break;
80 case PQTRANS_INTRANS:
81 /* use the existing xact */
82 break;
83 case PQTRANS_INERROR:
84 pg_log_error("%s: current transaction is aborted", operation);
85 return false;
86 default:
87 pg_log_error("%s: unknown transaction status", operation);
88 return false;
89 }
90
91 return true;
92 }
93
94 /*
95 * Clean up after a successful LO operation
96 */
97 static bool
finish_lo_xact(const char * operation,bool own_transaction)98 finish_lo_xact(const char *operation, bool own_transaction)
99 {
100 PGresult *res;
101
102 if (own_transaction && pset.autocommit)
103 {
104 /* close out our own xact */
105 if (!(res = PSQLexec("COMMIT")))
106 {
107 res = PSQLexec("ROLLBACK");
108 PQclear(res);
109 return false;
110 }
111 PQclear(res);
112 }
113
114 return true;
115 }
116
117 /*
118 * Clean up after a failed LO operation
119 */
120 static bool
fail_lo_xact(const char * operation,bool own_transaction)121 fail_lo_xact(const char *operation, bool own_transaction)
122 {
123 PGresult *res;
124
125 if (own_transaction && pset.autocommit)
126 {
127 /* close out our own xact */
128 res = PSQLexec("ROLLBACK");
129 PQclear(res);
130 }
131
132 return false; /* always */
133 }
134
135
136 /*
137 * do_lo_export()
138 *
139 * Write a large object to a file
140 */
141 bool
do_lo_export(const char * loid_arg,const char * filename_arg)142 do_lo_export(const char *loid_arg, const char *filename_arg)
143 {
144 int status;
145 bool own_transaction;
146
147 if (!start_lo_xact("\\lo_export", &own_transaction))
148 return false;
149
150 SetCancelConn(NULL);
151 status = lo_export(pset.db, atooid(loid_arg), filename_arg);
152 ResetCancelConn();
153
154 /* of course this status is documented nowhere :( */
155 if (status != 1)
156 {
157 pg_log_info("%s", PQerrorMessage(pset.db));
158 return fail_lo_xact("\\lo_export", own_transaction);
159 }
160
161 if (!finish_lo_xact("\\lo_export", own_transaction))
162 return false;
163
164 print_lo_result("lo_export");
165
166 return true;
167 }
168
169
170 /*
171 * do_lo_import()
172 *
173 * Copy large object from file to database
174 */
175 bool
do_lo_import(const char * filename_arg,const char * comment_arg)176 do_lo_import(const char *filename_arg, const char *comment_arg)
177 {
178 PGresult *res;
179 Oid loid;
180 char oidbuf[32];
181 bool own_transaction;
182
183 if (!start_lo_xact("\\lo_import", &own_transaction))
184 return false;
185
186 SetCancelConn(NULL);
187 loid = lo_import(pset.db, filename_arg);
188 ResetCancelConn();
189
190 if (loid == InvalidOid)
191 {
192 pg_log_info("%s", PQerrorMessage(pset.db));
193 return fail_lo_xact("\\lo_import", own_transaction);
194 }
195
196 /* insert description if given */
197 if (comment_arg)
198 {
199 char *cmdbuf;
200 char *bufptr;
201 size_t slen = strlen(comment_arg);
202
203 cmdbuf = pg_malloc_extended(slen * 2 + 256, MCXT_ALLOC_NO_OOM);
204 if (!cmdbuf)
205 return fail_lo_xact("\\lo_import", own_transaction);
206 sprintf(cmdbuf, "COMMENT ON LARGE OBJECT %u IS '", loid);
207 bufptr = cmdbuf + strlen(cmdbuf);
208 bufptr += PQescapeStringConn(pset.db, bufptr, comment_arg, slen, NULL);
209 strcpy(bufptr, "'");
210
211 if (!(res = PSQLexec(cmdbuf)))
212 {
213 free(cmdbuf);
214 return fail_lo_xact("\\lo_import", own_transaction);
215 }
216
217 PQclear(res);
218 free(cmdbuf);
219 }
220
221 if (!finish_lo_xact("\\lo_import", own_transaction))
222 return false;
223
224 print_lo_result("lo_import %u", loid);
225
226 sprintf(oidbuf, "%u", loid);
227 SetVariable(pset.vars, "LASTOID", oidbuf);
228
229 return true;
230 }
231
232
233 /*
234 * do_lo_unlink()
235 *
236 * removes a large object out of the database
237 */
238 bool
do_lo_unlink(const char * loid_arg)239 do_lo_unlink(const char *loid_arg)
240 {
241 int status;
242 Oid loid = atooid(loid_arg);
243 bool own_transaction;
244
245 if (!start_lo_xact("\\lo_unlink", &own_transaction))
246 return false;
247
248 SetCancelConn(NULL);
249 status = lo_unlink(pset.db, loid);
250 ResetCancelConn();
251
252 if (status == -1)
253 {
254 pg_log_info("%s", PQerrorMessage(pset.db));
255 return fail_lo_xact("\\lo_unlink", own_transaction);
256 }
257
258 if (!finish_lo_xact("\\lo_unlink", own_transaction))
259 return false;
260
261 print_lo_result("lo_unlink %u", loid);
262
263 return true;
264 }
265
266
267
268 /*
269 * do_lo_list()
270 *
271 * Show all large objects in database with comments
272 */
273 bool
do_lo_list(void)274 do_lo_list(void)
275 {
276 PGresult *res;
277 char buf[1024];
278 printQueryOpt myopt = pset.popt;
279
280 if (pset.sversion >= 90000)
281 {
282 snprintf(buf, sizeof(buf),
283 "SELECT oid as \"%s\",\n"
284 " pg_catalog.pg_get_userbyid(lomowner) as \"%s\",\n"
285 " pg_catalog.obj_description(oid, 'pg_largeobject') as \"%s\"\n"
286 " FROM pg_catalog.pg_largeobject_metadata "
287 " ORDER BY oid",
288 gettext_noop("ID"),
289 gettext_noop("Owner"),
290 gettext_noop("Description"));
291 }
292 else
293 {
294 snprintf(buf, sizeof(buf),
295 "SELECT loid as \"%s\",\n"
296 " pg_catalog.obj_description(loid, 'pg_largeobject') as \"%s\"\n"
297 "FROM (SELECT DISTINCT loid FROM pg_catalog.pg_largeobject) x\n"
298 "ORDER BY 1",
299 gettext_noop("ID"),
300 gettext_noop("Description"));
301 }
302
303 res = PSQLexec(buf);
304 if (!res)
305 return false;
306
307 myopt.topt.tuples_only = false;
308 myopt.nullPrint = NULL;
309 myopt.title = _("Large objects");
310 myopt.translate_header = true;
311
312 printQuery(res, &myopt, pset.queryFout, false, pset.logfile);
313
314 PQclear(res);
315 return true;
316 }
317