PostgreSQL Source Code  git master
large_obj.c
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1 /*
2  * psql - the PostgreSQL interactive terminal
3  *
4  * Copyright (c) 2000-2019, PostgreSQL Global Development Group
5  *
6  * src/bin/psql/large_obj.c
7  */
8 #include "postgres_fe.h"
9 #include "large_obj.h"
10 
11 #include "settings.h"
12 #include "common.h"
13 
14 #include "common/logging.h"
15 
16 static void print_lo_result(const char *fmt,...) pg_attribute_printf(1, 2);
17 
18 static void
19 print_lo_result(const char *fmt,...)
20 {
21  va_list ap;
22 
23  if (!pset.quiet)
24  {
26  fputs("<p>", pset.queryFout);
27 
28  va_start(ap, fmt);
29  vfprintf(pset.queryFout, fmt, ap);
30  va_end(ap);
31 
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
56 start_lo_xact(const char *operation, bool *own_transaction)
57 {
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
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
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
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();
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  {
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
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();
187  loid = lo_import(pset.db, filename_arg);
188  ResetCancelConn();
189 
190  if (loid == InvalidOid)
191  {
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
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();
249  status = lo_unlink(pset.db, loid);
250  ResetCancelConn();
251 
252  if (status == -1)
253  {
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
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 }
bool do_lo_export(const char *loid_arg, const char *filename_arg)
Definition: large_obj.c:142
PGconn * db
Definition: settings.h:83
char * PQerrorMessage(const PGconn *conn)
Definition: fe-connect.c:6619
char * nullPrint
Definition: print.h:168
PsqlSettings pset
Definition: startup.c:35
#define pg_log_error(...)
Definition: logging.h:79
int lo_unlink(PGconn *conn, Oid lobjId)
Definition: fe-lobj.c:628
static bool finish_lo_xact(const char *operation, bool own_transaction)
Definition: large_obj.c:98
bool do_lo_unlink(const char *loid_arg)
Definition: large_obj.c:239
enum printFormat format
Definition: print.h:99
printTableOpt topt
Definition: print.h:167
#define gettext_noop(x)
Definition: c.h:1117
FILE * queryFout
Definition: settings.h:85
#define MCXT_ALLOC_NO_OOM
Definition: fe_memutils.h:18
bool autocommit
Definition: settings.h:125
unsigned int Oid
Definition: postgres_ext.h:31
#define pg_attribute_printf(f, a)
Definition: c.h:132
#define sprintf
Definition: port.h:194
bool tuples_only
Definition: print.h:108
int lo_export(PGconn *conn, Oid lobjId, const char *filename)
Definition: fe-lobj.c:784
static char * buf
Definition: pg_test_fsync.c:68
static bool fail_lo_xact(const char *operation, bool own_transaction)
Definition: large_obj.c:121
size_t PQescapeStringConn(PGconn *conn, char *to, const char *from, size_t length, int *error)
Definition: fe-exec.c:3411
void * pg_malloc_extended(size_t size, int flags)
Definition: fe_memutils.c:59
void SetCancelConn(void)
Definition: common.c:439
bool translate_header
Definition: print.h:171
bool do_lo_import(const char *filename_arg, const char *comment_arg)
Definition: large_obj.c:176
#define atooid(x)
Definition: postgres_ext.h:42
static void print_lo_result(const char *fmt,...) pg_attribute_printf(1
Definition: large_obj.c:19
PGTransactionStatusType PQtransactionStatus(const PGconn *conn)
Definition: fe-connect.c:6574
FILE * logfile
Definition: settings.h:116
#define InvalidOid
Definition: postgres_ext.h:36
void PQclear(PGresult *res)
Definition: fe-exec.c:695
#define free(a)
Definition: header.h:65
PGTransactionStatusType
Definition: libpq-fe.h:103
char * title
Definition: print.h:169
bool SetVariable(VariableSpace space, const char *name, const char *value)
Definition: variables.c:213
static bool start_lo_xact(const char *operation, bool *own_transaction)
Definition: large_obj.c:56
printQueryOpt popt
Definition: settings.h:92
void printQuery(const PGresult *result, const printQueryOpt *opt, FILE *fout, bool is_pager, FILE *flog)
Definition: print.c:3436
bool do_lo_list(void)
Definition: large_obj.c:274
#define vfprintf
Definition: port.h:195
static void static void status(const char *fmt,...) pg_attribute_printf(1
Definition: pg_regress.c:227
#define snprintf
Definition: port.h:192
void ResetCancelConn(void)
Definition: common.c:469
#define _(x)
Definition: elog.c:84
Oid lo_import(PGconn *conn, const char *filename)
Definition: fe-lobj.c:668
#define pg_log_info(...)
Definition: logging.h:87
PGresult * PSQLexec(const char *query)
Definition: common.c:683
VariableSpace vars
Definition: settings.h:118