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view libraries/mondelefant/mondelefant_native.c @ 424:553a1a9dbc4c

Fixed bug which was introduced during code-cleanup of <db_handle>:quote_string(...) function
author jbe
date Tue Jan 12 19:30:59 2016 +0100 (2016-01-12)
parents e64ef2b681d2
children 1dbbe4c62f08
line source
1 #include <lua.h>
2 #include <lauxlib.h>
3 #include <libpq-fe.h>
4 #include <postgres.h>
5 #include <catalog/pg_type.h>
6 #include <stdint.h>
7 #include <time.h>
9 // NOTE: Comments with format "// <number>" denote the Lua stack position
11 // prefix for all Lua registry entries of this library:
12 #define MONDELEFANT_REGKEY "mondelefant_"
14 // registry key of module "mondelefant_native":
15 #define MONDELEFANT_MODULE_REGKEY (MONDELEFANT_REGKEY "module")
16 // registry key of meta-table for database connections:
17 #define MONDELEFANT_CONN_MT_REGKEY (MONDELEFANT_REGKEY "connection")
18 // registry key of meta-table for database result lists and objects:
19 #define MONDELEFANT_RESULT_MT_REGKEY (MONDELEFANT_REGKEY "result")
20 // registry key of meta-table for database error objects:
21 #define MONDELEFANT_ERROROBJECT_MT_REGKEY (MONDELEFANT_REGKEY "errorobject")
22 // registry key of meta-table for models (named classes here):
23 #define MONDELEFANT_CLASS_MT_REGKEY (MONDELEFANT_REGKEY "class")
24 // registry key of default prototype for models/classes:
25 #define MONDELEFANT_CLASS_PROTO_REGKEY (MONDELEFANT_REGKEY "class_proto")
26 // registry key of meta-table for column proxy:
27 #define MONDELEFANT_COLUMNS_MT_REGKEY (MONDELEFANT_REGKEY "columns")
28 // table (lightuserdata) key to store result object in column proxy:
29 // (address of struct used as unique reference)
30 #define MONDELEFANT_COLUMNS_RESULT_LUKEY ((void *)&mondelefant_columns_result_lukey_dummy)
32 // dummy variable for MONDELEFANT_COLUMNS_RESULT_LUKEY reference:
33 char mondelefant_columns_result_lukey_dummy;
35 // C-structure for database connection userdata:
36 typedef struct {
37 PGconn *pgconn;
38 int server_encoding;
39 void *todo_PQfreemem;
40 PGresult *todo_PQclear;
41 } mondelefant_conn_t;
42 #define MONDELEFANT_SERVER_ENCODING_ASCII 0
43 #define MONDELEFANT_SERVER_ENCODING_UTF8 1
45 // transform codepoint-position to byte-position for a given UTF-8 string:
46 static size_t utf8_position_to_byte(const char *str, size_t utf8pos) {
47 size_t bytepos;
48 for (bytepos = 0; utf8pos > 0; bytepos++) {
49 uint8_t c;
50 c = ((const uint8_t *)str)[bytepos];
51 if (!c) break;
52 if (c <= 0x7f || c >= 0xc0) utf8pos--;
53 }
54 return bytepos;
55 }
57 // PostgreSQL's OID for binary data type (bytea):
58 #define MONDELEFANT_POSTGRESQL_BINARY_OID ((Oid)17)
60 // mapping a PostgreSQL type given by its OID to a string identifier:
61 static const char *mondelefant_oid_to_typestr(Oid oid) {
62 switch (oid) {
63 case 16: return "bool";
64 case 17: return "bytea";
65 case 18: return "char";
66 case 19: return "name";
67 case 20: return "int8";
68 case 21: return "int2";
69 case 23: return "int4";
70 case 25: return "text";
71 case 26: return "oid";
72 case 27: return "tid";
73 case 28: return "xid";
74 case 29: return "cid";
75 case 114: return "json";
76 case 600: return "point";
77 case 601: return "lseg";
78 case 602: return "path";
79 case 603: return "box";
80 case 604: return "polygon";
81 case 628: return "line";
82 case 700: return "float4";
83 case 701: return "float8";
84 case 705: return "unknown";
85 case 718: return "circle";
86 case 790: return "money";
87 case 829: return "macaddr";
88 case 869: return "inet";
89 case 650: return "cidr";
90 case 1042: return "bpchar";
91 case 1043: return "varchar";
92 case 1082: return "date";
93 case 1083: return "time";
94 case 1114: return "timestamp";
95 case 1184: return "timestamptz";
96 case 1186: return "interval";
97 case 1266: return "timetz";
98 case 1560: return "bit";
99 case 1562: return "varbit";
100 case 1700: return "numeric";
101 case 3802: return "jsonb";
102 default: return NULL;
103 }
104 }
106 // This library maps PostgreSQL's error codes to CamelCase string
107 // identifiers, which consist of CamelCase identifiers and are seperated
108 // by dots (".") (no leading or trailing dots).
109 // There are additional error identifiers which do not have a corresponding
110 // PostgreSQL error associated with it.
112 // matching start of local variable 'pgcode' against string 'incode',
113 // returning string 'outcode' on match:
114 #define mondelefant_errcode_item(incode, outcode) \
115 if (!strncmp(pgcode, (incode), strlen(incode))) return outcode; else
117 // additional error identifiers without corresponding PostgreSQL error:
118 #define MONDELEFANT_ERRCODE_UNKNOWN "unknown"
119 #define MONDELEFANT_ERRCODE_CONNECTION "ConnectionException"
120 #define MONDELEFANT_ERRCODE_RESULTCOUNT_LOW "WrongResultSetCount.ResultSetMissing"
121 #define MONDELEFANT_ERRCODE_RESULTCOUNT_HIGH "WrongResultSetCount.TooManyResults"
122 #define MONDELEFANT_ERRCODE_QUERY1_NO_ROWS "NoData.OneRowExpected"
123 #define MONDELEFANT_ERRCODE_QUERY1_MULTIPLE_ROWS "CardinalityViolation.OneRowExpected"
125 // mapping PostgreSQL error code to error code as returned by this library:
126 static const char *mondelefant_translate_errcode(const char *pgcode) {
127 if (!pgcode) abort(); // should not happen
128 mondelefant_errcode_item("02", "NoData")
129 mondelefant_errcode_item("03", "SqlStatementNotYetComplete")
130 mondelefant_errcode_item("08", "ConnectionException")
131 mondelefant_errcode_item("09", "TriggeredActionException")
132 mondelefant_errcode_item("0A", "FeatureNotSupported")
133 mondelefant_errcode_item("0B", "InvalidTransactionInitiation")
134 mondelefant_errcode_item("0F", "LocatorException")
135 mondelefant_errcode_item("0L", "InvalidGrantor")
136 mondelefant_errcode_item("0P", "InvalidRoleSpecification")
137 mondelefant_errcode_item("21", "CardinalityViolation")
138 mondelefant_errcode_item("22", "DataException")
139 mondelefant_errcode_item("23001", "IntegrityConstraintViolation.RestrictViolation")
140 mondelefant_errcode_item("23502", "IntegrityConstraintViolation.NotNullViolation")
141 mondelefant_errcode_item("23503", "IntegrityConstraintViolation.ForeignKeyViolation")
142 mondelefant_errcode_item("23505", "IntegrityConstraintViolation.UniqueViolation")
143 mondelefant_errcode_item("23514", "IntegrityConstraintViolation.CheckViolation")
144 mondelefant_errcode_item("23", "IntegrityConstraintViolation")
145 mondelefant_errcode_item("24", "InvalidCursorState")
146 mondelefant_errcode_item("25", "InvalidTransactionState")
147 mondelefant_errcode_item("26", "InvalidSqlStatementName")
148 mondelefant_errcode_item("27", "TriggeredDataChangeViolation")
149 mondelefant_errcode_item("28", "InvalidAuthorizationSpecification")
150 mondelefant_errcode_item("2B", "DependentPrivilegeDescriptorsStillExist")
151 mondelefant_errcode_item("2D", "InvalidTransactionTermination")
152 mondelefant_errcode_item("2F", "SqlRoutineException")
153 mondelefant_errcode_item("34", "InvalidCursorName")
154 mondelefant_errcode_item("38", "ExternalRoutineException")
155 mondelefant_errcode_item("39", "ExternalRoutineInvocationException")
156 mondelefant_errcode_item("3B", "SavepointException")
157 mondelefant_errcode_item("3D", "InvalidCatalogName")
158 mondelefant_errcode_item("3F", "InvalidSchemaName")
159 mondelefant_errcode_item("40", "TransactionRollback")
160 mondelefant_errcode_item("42", "SyntaxErrorOrAccessRuleViolation")
161 mondelefant_errcode_item("44", "WithCheckOptionViolation")
162 mondelefant_errcode_item("53", "InsufficientResources")
163 mondelefant_errcode_item("54", "ProgramLimitExceeded")
164 mondelefant_errcode_item("55", "ObjectNotInPrerequisiteState")
165 mondelefant_errcode_item("57", "OperatorIntervention")
166 mondelefant_errcode_item("58", "SystemError")
167 mondelefant_errcode_item("F0", "ConfigurationFileError")
168 mondelefant_errcode_item("P0", "PlpgsqlError")
169 mondelefant_errcode_item("XX", "InternalError")
170 return "unknown";
171 }
173 // C-function, checking if a given error code (as defined by this library)
174 // is belonging to a certain class of errors (strings are equal or error
175 // code begins with error class followed by a dot):
176 static int mondelefant_check_error_class(
177 const char *errcode, const char *errclass
178 ) {
179 size_t i = 0;
180 while (1) {
181 if (errclass[i] == 0) {
182 if (errcode[i] == 0 || errcode[i] == '.') return 1;
183 else return 0;
184 }
185 if (errcode[i] != errclass[i]) return 0;
186 i++;
187 }
188 }
190 // pushing first line of a string on Lua's stack (without trailing CR/LF):
191 static void mondelefant_push_first_line(lua_State *L, const char *str) {
192 size_t i = 0;
193 if (!str) abort(); // should not happen
194 while (1) {
195 char c = str[i];
196 if (c == '\n' || c == '\r' || c == 0) {
197 lua_pushlstring(L, str, i);
198 return;
199 }
200 i++;
201 }
202 }
204 // "connect" function of library, which establishes a database connection
205 // and returns a database connection handle:
206 static int mondelefant_connect(lua_State *L) {
207 const char *conninfo; // string for PQconnectdb function
208 mondelefant_conn_t *conn; // C-structure for userdata
209 // check if string is given as first argument:
210 if (lua_type(L, 1) != LUA_TSTRING) {
211 // expect a table as first argument if no string is given:
212 luaL_checktype(L, 1, LUA_TTABLE);
213 // extract conninfo string for PQconnectdb if possible:
214 lua_getfield(L, 1, "conninfo");
215 if (!lua_isnil(L, -1)) {
216 // if yes, use that value but check its type:
217 luaL_argcheck(L, lua_type(L, -1) == LUA_TSTRING, 1, "\"conninfo\" value is not a string");
218 } else {
219 // otherwise assemble conninfo string from the named options:
220 luaL_Buffer buf;
221 int need_seperator = 0;
222 const char *value;
223 size_t value_len;
224 size_t value_pos;
225 lua_settop(L, 1);
226 lua_pushnil(L); // slot for key at stack position 2
227 lua_pushnil(L); // slot for value at stack position 3
228 luaL_buffinit(L, &buf);
229 while (lua_pushvalue(L, 2), lua_next(L, 1)) {
230 luaL_argcheck(L, lua_isstring(L, -2), 1, "key in table is not a string");
231 value = luaL_tolstring(L, -1, &value_len);
232 lua_replace(L, 3);
233 lua_pop(L, 1);
234 lua_replace(L, 2);
235 if (need_seperator) luaL_addchar(&buf, ' ');
236 // NOTE: numbers will be converted to strings automatically here,
237 // but perhaps this will change in future versions of lua
238 lua_pushvalue(L, 2);
239 luaL_addvalue(&buf);
240 luaL_addchar(&buf, '=');
241 luaL_addchar(&buf, '\'');
242 value_pos = 0;
243 do {
244 char c;
245 c = value[value_pos++];
246 if (c == '\'') luaL_addchar(&buf, '\\');
247 luaL_addchar(&buf, c);
248 } while (value_pos < value_len);
249 luaL_addchar(&buf, '\'');
250 need_seperator = 1;
251 }
252 luaL_pushresult(&buf);
253 }
254 // ensure that string is on stack position 1:
255 lua_replace(L, 1);
256 }
257 // use conninfo string on stack position 1:
258 conninfo = lua_tostring(L, 1);
259 // create (zero'ed) userdata on stack position 2:
260 lua_settop(L, 1);
261 conn = memset(lua_newuserdata(L, sizeof(*conn)), 0, sizeof(*conn)); // 2
262 // call PQconnectdb function of libpq:
263 conn->pgconn = PQconnectdb(conninfo);
264 // try emergency garbage collection on first failure:
265 if (!conn->pgconn) {
266 lua_gc(L, LUA_GCCOLLECT, 0);
267 conn->pgconn = PQconnectdb(conninfo);
268 // throw error in case of (unexpected) error of PQconnectdb call:
269 if (!conn->pgconn) return luaL_error(L,
270 "Error in libpq while creating 'PGconn' structure."
271 );
272 }
273 // set metatable for userdata (ensure PQfinish on unexpected error below):
274 luaL_setmetatable(L, MONDELEFANT_CONN_MT_REGKEY);
275 // check result of PQconnectdb call:
276 if (PQstatus(conn->pgconn) != CONNECTION_OK) {
277 lua_pushnil(L); // 3
278 mondelefant_push_first_line(L, PQerrorMessage(conn->pgconn)); // 4
279 lua_newtable(L); // 5
280 luaL_setmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY);
281 lua_pushliteral(L, MONDELEFANT_ERRCODE_CONNECTION);
282 lua_setfield(L, 5, "code");
283 lua_pushvalue(L, 4);
284 lua_setfield(L, 5, "message");
285 // manual PQfinish (do not wait until garbage collection):
286 PQfinish(conn->pgconn);
287 conn->pgconn = NULL;
288 return 3;
289 }
290 // set 'server_encoding' in C-struct of userdata:
291 {
292 const char *charset;
293 charset = PQparameterStatus(conn->pgconn, "server_encoding");
294 if (charset && !strcmp(charset, "UTF8")) {
295 conn->server_encoding = MONDELEFANT_SERVER_ENCODING_UTF8;
296 } else {
297 conn->server_encoding = MONDELEFANT_SERVER_ENCODING_ASCII;
298 }
299 }
300 // create and associate userdata table:
301 lua_newtable(L);
302 lua_setuservalue(L, 2);
303 // store key "fd" with file descriptor of connection:
304 lua_pushinteger(L, PQsocket(conn->pgconn));
305 lua_setfield(L, 2, "fd");
306 // store key "engine" with value "postgresql" as connection specific data:
307 lua_pushliteral(L, "postgresql");
308 lua_setfield(L, 2, "engine");
309 // return userdata:
310 return 1;
311 }
313 // returns pointer to libpq handle 'pgconn' of userdata at given index
314 // (or throws error, if database connection has been closed):
315 static mondelefant_conn_t *mondelefant_get_conn(lua_State *L, int index) {
316 mondelefant_conn_t *conn;
317 conn = luaL_checkudata(L, index, MONDELEFANT_CONN_MT_REGKEY);
318 if (!conn->pgconn) {
319 luaL_error(L, "PostgreSQL connection has been closed.");
320 return NULL;
321 }
322 return conn;
323 }
325 // meta-method "__index" of database handles (userdata):
326 static int mondelefant_conn_index(lua_State *L) {
327 // try table for connection specific data:
328 lua_settop(L, 2);
329 lua_getuservalue(L, 1); // 3
330 lua_pushvalue(L, 2); // 4
331 lua_gettable(L, 3); // 4
332 if (!lua_isnil(L, 4)) return 1;
333 // try to use prototype stored in connection specific data:
334 lua_settop(L, 3);
335 lua_getfield(L, 3, "prototype"); // 4
336 if (lua_toboolean(L, 4)) {
337 lua_pushvalue(L, 2); // 5
338 lua_gettable(L, 4); // 5
339 if (!lua_isnil(L, 5)) return 1;
340 }
341 // try to use "postgresql_connection_prototype" of library:
342 lua_settop(L, 2);
343 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY); // 3
344 lua_getfield(L, 3, "postgresql_connection_prototype"); // 4
345 if (lua_toboolean(L, 4)) {
346 lua_pushvalue(L, 2); // 5
347 lua_gettable(L, 4); // 5
348 if (!lua_isnil(L, 5)) return 1;
349 }
350 // try to use "connection_prototype" of library:
351 lua_settop(L, 3);
352 lua_getfield(L, 3, "connection_prototype"); // 4
353 if (lua_toboolean(L, 4)) {
354 lua_pushvalue(L, 2); // 5
355 lua_gettable(L, 4); // 5
356 if (!lua_isnil(L, 5)) return 1;
357 }
358 // give up and return nothing:
359 return 0;
360 }
362 // meta-method "__newindex" of database handles (userdata):
363 static int mondelefant_conn_newindex(lua_State *L) {
364 // store key-value pair in table for connection specific data:
365 lua_settop(L, 3);
366 lua_getuservalue(L, 1); // 4
367 lua_pushvalue(L, 2);
368 lua_pushvalue(L, 3);
369 lua_settable(L, 4);
370 // return nothing:
371 return 0;
372 }
374 // meta-method "__gc" of database handles:
375 static int mondelefant_conn_free(lua_State *L) {
376 mondelefant_conn_t *conn;
377 conn = luaL_checkudata(L, 1, MONDELEFANT_CONN_MT_REGKEY);
378 if (conn->todo_PQfreemem) {
379 PQfreemem(conn->todo_PQfreemem);
380 conn->todo_PQfreemem = NULL;
381 }
382 if (conn->todo_PQclear) {
383 PQclear(conn->todo_PQclear);
384 conn->todo_PQclear = NULL;
385 }
386 if (conn->pgconn) {
387 PQfinish(conn->pgconn);
388 conn->pgconn = NULL;
389 }
390 return 0;
391 }
393 // method "close" of database handles:
394 static int mondelefant_conn_close(lua_State *L) {
395 mondelefant_conn_t *conn;
396 conn = mondelefant_get_conn(L, 1);
397 PQfinish(conn->pgconn);
398 conn->pgconn = NULL;
399 lua_pushnil(L);
400 lua_setfield(L, 1, "fd"); // set "fd" attribute to nil
401 return 0;
402 }
404 // method "is_okay" of database handles:
405 static int mondelefant_conn_is_ok(lua_State *L) {
406 mondelefant_conn_t *conn;
407 conn = mondelefant_get_conn(L, 1);
408 lua_pushboolean(L, PQstatus(conn->pgconn) == CONNECTION_OK);
409 return 1;
410 }
412 // method "get_transaction_status" of database handles:
413 static int mondelefant_conn_get_transaction_status(lua_State *L) {
414 mondelefant_conn_t *conn;
415 conn = mondelefant_get_conn(L, 1);
416 switch (PQtransactionStatus(conn->pgconn)) {
417 case PQTRANS_IDLE:
418 lua_pushliteral(L, "idle");
419 break;
420 case PQTRANS_ACTIVE:
421 lua_pushliteral(L, "active");
422 break;
423 case PQTRANS_INTRANS:
424 lua_pushliteral(L, "intrans");
425 break;
426 case PQTRANS_INERROR:
427 lua_pushliteral(L, "inerror");
428 break;
429 default:
430 lua_pushliteral(L, "unknown");
431 }
432 return 1;
433 }
435 // method "try_wait" of database handles:
436 static int mondelefant_conn_try_wait(lua_State *L) {
437 mondelefant_conn_t *conn;
438 int infinite, nonblock = 0;
439 struct timespec wakeup;
440 int fd;
441 fd_set fds;
442 conn = mondelefant_get_conn(L, 1);
443 infinite = lua_isnoneornil(L, 2);
444 if (!infinite) {
445 lua_Number n;
446 int isnum;
447 n = lua_tonumberx(L, 2, &isnum);
448 if (isnum && n>0 && n<=86400*366) {
449 if (clock_gettime(CLOCK_MONOTONIC, &wakeup)) {
450 return luaL_error(L, "Could not access CLOCK_MONOTONIC");
451 }
452 wakeup.tv_sec += n;
453 wakeup.tv_nsec += 1000000000 * (n - (time_t)n);
454 if (wakeup.tv_nsec >= 1000000000) {
455 wakeup.tv_sec += 1;
456 wakeup.tv_nsec -= 1000000000;
457 }
458 } else if (isnum && n==0) {
459 nonblock = 1;
460 } else {
461 luaL_argcheck(L, 0, 2, "not a valid timeout");
462 }
463 }
464 lua_settop(L, 1);
465 if (!nonblock) {
466 fd = PQsocket(conn->pgconn);
467 FD_ZERO(&fds);
468 FD_SET(fd, &fds);
469 }
470 while (true) {
471 {
472 PGnotify *notify;
473 if (!PQconsumeInput(conn->pgconn)) {
474 lua_newtable(L); // 2
475 luaL_setmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY);
476 lua_pushliteral(L, MONDELEFANT_ERRCODE_CONNECTION);
477 lua_setfield(L, 2, "code");
478 mondelefant_push_first_line(L, PQerrorMessage(conn->pgconn)); // 3
479 lua_setfield(L, 2, "message");
480 return 1;
481 }
482 // avoid cumulating memory leaks in case of previous out-of-memory errors:
483 if (conn->todo_PQfreemem) {
484 PQfreemem(conn->todo_PQfreemem);
485 conn->todo_PQfreemem = NULL;
486 }
487 notify = PQnotifies(conn->pgconn);
488 if (notify) {
489 // ensure call of PQfreemem in case of out-of-memory errors:
490 conn->todo_PQfreemem = notify;
491 // do Lua operations:
492 lua_pushnil(L);
493 lua_pushstring(L, notify->relname);
494 lua_pushstring(L, notify->extra);
495 lua_pushinteger(L, notify->be_pid);
496 // free memory allocated by PQnotifies:
497 PQfreemem(notify);
498 // avoid double call of PQfreemem later:
499 conn->todo_PQfreemem = NULL;
500 return 4;
501 }
502 }
503 if (infinite) {
504 select(fd+1, &fds, NULL, NULL, NULL);
505 } else if (nonblock) {
506 break;
507 } else {
508 struct timespec tp;
509 struct timeval timeout = { 0, };
510 if (clock_gettime(CLOCK_MONOTONIC, &tp)) {
511 return luaL_error(L, "Could not access CLOCK_MONOTONIC");
512 }
513 tp.tv_sec = wakeup.tv_sec - tp.tv_sec;
514 tp.tv_nsec = wakeup.tv_nsec - tp.tv_nsec;
515 if (tp.tv_nsec < 0) {
516 tp.tv_sec -= 1;
517 tp.tv_nsec += 1000000000;
518 }
519 timeout.tv_sec = tp.tv_sec;
520 timeout.tv_usec = (tp.tv_nsec + 500) / 1000;
521 if (
522 timeout.tv_sec < 0 ||
523 (timeout.tv_sec == 0 && timeout.tv_usec == 0)
524 ) break;
525 select(fd+1, &fds, NULL, NULL, &timeout);
526 }
527 }
528 lua_pushnil(L);
529 lua_pushnil(L);
530 return 2;
531 }
533 // method "create_list" of database handles:
534 static int mondelefant_conn_create_list(lua_State *L) {
535 // ensure that first argument is a database connection:
536 luaL_checkudata(L, 1, MONDELEFANT_CONN_MT_REGKEY);
537 // if no second argument is given, use an empty table:
538 if (lua_isnoneornil(L, 2)) {
539 lua_settop(L, 1);
540 lua_newtable(L); // 2
541 } else {
542 luaL_checktype(L, 2, LUA_TTABLE);
543 lua_settop(L, 2);
544 }
545 // set meta-table for database result lists/objects:
546 luaL_setmetatable(L, MONDELEFANT_RESULT_MT_REGKEY);
547 // set "_connection" attribute to self:
548 lua_pushvalue(L, 1); // 3
549 lua_setfield(L, 2, "_connection");
550 // set "_type" attribute to string "list":
551 lua_pushliteral(L, "list"); // 3
552 lua_setfield(L, 2, "_type");
553 // return created database result list:
554 return 1;
555 }
557 // method "create_object" of database handles:
558 static int mondelefant_conn_create_object(lua_State *L) {
559 // ensure that first argument is a database connection:
560 luaL_checkudata(L, 1, MONDELEFANT_CONN_MT_REGKEY);
561 // if no second argument is given, use an empty table:
562 if (lua_isnoneornil(L, 2)) {
563 lua_settop(L, 1);
564 lua_newtable(L); // 2
565 } else {
566 luaL_checktype(L, 2, LUA_TTABLE);
567 lua_settop(L, 2);
568 }
569 // set meta-table for database result lists/objects:
570 luaL_setmetatable(L, MONDELEFANT_RESULT_MT_REGKEY);
571 // set "_connection" attribute to self:
572 lua_pushvalue(L, 1); // 3
573 lua_setfield(L, 2, "_connection");
574 // set "_type" attribute to string "object":
575 lua_pushliteral(L, "object"); // 3
576 lua_setfield(L, 2, "_type"); // "object" or "list"
577 // create empty tables for "_data", "_dirty" and "_ref" attributes:
578 lua_newtable(L); // 3
579 lua_setfield(L, 2, "_data");
580 lua_newtable(L); // 3
581 lua_setfield(L, 2, "_dirty");
582 lua_newtable(L); // 3
583 lua_setfield(L, 2, "_ref"); // nil=no info, false=nil, else table
584 // create column proxy (field "_col" in result object):
585 lua_newtable(L); // 3
586 luaL_setmetatable(L, MONDELEFANT_COLUMNS_MT_REGKEY);
587 lua_pushvalue(L, 2); // 4
588 lua_rawsetp(L, 3, MONDELEFANT_COLUMNS_RESULT_LUKEY);
589 lua_setfield(L, 2, "_col");
590 // return created database result object (from stack position 2):
591 return 1;
592 }
594 // method "quote_string" of database handles:
595 static int mondelefant_conn_quote_string(lua_State *L) {
596 mondelefant_conn_t *conn;
597 const char *input;
598 size_t input_len;
599 luaL_Buffer buf;
600 char *output;
601 size_t output_len;
602 // get database connection object:
603 conn = mondelefant_get_conn(L, 1);
604 // get second argument, which must be a string:
605 input = luaL_checklstring(L, 2, &input_len);
606 // throw error, if string is too long:
607 if (input_len > (SIZE_MAX / sizeof(char) - 3) / 2) {
608 return luaL_error(L, "String to be escaped is too long.");
609 }
610 // allocate memory for quoted string:
611 output = luaL_buffinitsize(L, &buf, (2 * input_len + 3) * sizeof(char));
612 // do escaping by calling PQescapeStringConn and enclosing result with
613 // single quotes:
614 output[0] = '\'';
615 output_len = PQescapeStringConn(
616 conn->pgconn, output + 1, input, input_len, NULL
617 );
618 output[output_len + 1] = '\'';
619 output[output_len + 2] = 0;
620 // create Lua string:
621 luaL_addsize(&buf, output_len + 2);
622 luaL_pushresult(&buf);
623 // return Lua string:
624 return 1;
625 }
627 // method "quote_binary" of database handles:
628 static int mondelefant_conn_quote_binary(lua_State *L) {
629 mondelefant_conn_t *conn;
630 const char *input;
631 size_t input_len;
632 char *output;
633 size_t output_len;
634 luaL_Buffer buf;
635 // get database connection object:
636 conn = mondelefant_get_conn(L, 1);
637 // get second argument, which must be a string:
638 input = luaL_checklstring(L, 2, &input_len);
639 // avoid cumulating memory leaks in case of previous out-of-memory errors:
640 if (conn->todo_PQfreemem) {
641 PQfreemem(conn->todo_PQfreemem);
642 conn->todo_PQfreemem = NULL;
643 }
644 // call PQescapeByteaConn, which allocates memory itself:
645 output = (char *)PQescapeByteaConn(
646 conn->pgconn, (const unsigned char *)input, input_len, &output_len
647 );
648 if (!output) {
649 lua_gc(L, LUA_GCCOLLECT, 0);
650 output = (char *)PQescapeByteaConn(
651 conn->pgconn, (const unsigned char *)input, input_len, &output_len
652 );
653 if (!output) {
654 return luaL_error(L, "Could not allocate memory for binary quoting.");
655 }
656 }
657 // ensure call of PQfreemem in case of out-of-memory errors:
658 conn->todo_PQfreemem = output;
659 // create Lua string enclosed by single quotes:
660 luaL_buffinit(L, &buf);
661 luaL_addchar(&buf, '\'');
662 luaL_addlstring(&buf, output, output_len - 1);
663 luaL_addchar(&buf, '\'');
664 luaL_pushresult(&buf);
665 // free memory allocated by PQescapeByteaConn:
666 PQfreemem(output);
667 // avoid double call of PQfreemem later:
668 conn->todo_PQfreemem = NULL;
669 // return Lua string:
670 return 1;
671 }
673 // method "assemble_command" of database handles:
674 static int mondelefant_conn_assemble_command(lua_State *L) {
675 mondelefant_conn_t *conn;
676 int paramidx = 2;
677 const char *template;
678 size_t template_pos = 0;
679 luaL_Buffer buf;
680 // get database connection object:
681 conn = mondelefant_get_conn(L, 1);
682 // if second argument is a string, return this string:
683 if (lua_type(L, 2) == LUA_TSTRING) {
684 lua_settop(L, 2);
685 return 1;
686 }
687 // if second argument has __tostring meta-method,
688 // then use this method and return its result:
689 if (luaL_callmeta(L, 2, "__tostring")) return 1;
690 // otherwise, require that second argument is a table:
691 luaL_checktype(L, 2, LUA_TTABLE);
692 // set stack top:
693 lua_settop(L, 2);
694 // get first element of table, which must be a string:
695 lua_rawgeti(L, 2, 1); // 3
696 luaL_argcheck(L,
697 lua_isstring(L, 3),
698 2,
699 "First entry of SQL command structure is not a string."
700 );
701 template = lua_tostring(L, 3);
702 // get value of "input_converter" attribute of database connection:
703 lua_pushliteral(L, "input_converter"); // 4
704 lua_gettable(L, 1); // input_converter at stack position 4
705 // reserve space on Lua stack:
706 lua_pushnil(L); // free space at stack position 5
707 lua_pushnil(L); // free space at stack position 6
708 // initialize Lua buffer for result string:
709 luaL_buffinit(L, &buf);
710 // fill buffer in loop:
711 while (1) {
712 // variable declaration:
713 char c;
714 // get next character:
715 c = template[template_pos++];
716 // break, when character is NULL byte:
717 if (!c) break;
718 // question-mark and dollar-sign are special characters:
719 if (c == '?' || c == '$') { // special character found
720 // check, if same character follows:
721 if (template[template_pos] == c) { // special character is escaped
722 // consume two characters of input and add one character to buffer:
723 template_pos++;
724 luaL_addchar(&buf, c);
725 } else { // special character is not escaped
726 luaL_Buffer keybuf;
727 int subcmd;
728 // set 'subcmd' = true, if special character was a dollar-sign,
729 // set 'subcmd' = false, if special character was a question-mark:
730 subcmd = (c == '$');
731 // read any number of alpha numeric chars or underscores
732 // and store them on Lua stack:
733 luaL_buffinit(L, &keybuf);
734 while (1) {
735 c = template[template_pos];
736 if (
737 (c < 'A' || c > 'Z') &&
738 (c < 'a' || c > 'z') &&
739 (c < '0' || c > '9') &&
740 (c != '_')
741 ) break;
742 luaL_addchar(&keybuf, c);
743 template_pos++;
744 }
745 luaL_pushresult(&keybuf);
746 // check, if any characters matched:
747 if (lua_rawlen(L, -1)) {
748 // if any alpha numeric chars or underscores were found,
749 // push them on stack as a Lua string and use them to lookup
750 // value from second argument:
751 lua_pushvalue(L, -1); // save key on stack
752 lua_gettable(L, 2); // fetch value (raw-value)
753 } else {
754 // otherwise push nil and use numeric lookup based on 'paramidx':
755 lua_pop(L, 1);
756 lua_pushnil(L); // put nil on key position
757 lua_rawgeti(L, 2, paramidx++); // fetch value (raw-value)
758 }
759 // Lua stack contains: ..., <buffer>, key, raw-value
760 // branch according to type of special character ("?" or "$"):
761 if (subcmd) { // dollar-sign
762 size_t i;
763 size_t count;
764 // store fetched value (which is supposed to be sub-structure)
765 // on Lua stack position 5 and drop key:
766 lua_replace(L, 5);
767 lua_pop(L, 1);
768 // Lua stack contains: ..., <buffer>
769 // check, if fetched value is really a sub-structure:
770 luaL_argcheck(L,
771 !lua_isnil(L, 5),
772 2,
773 "SQL sub-structure not found."
774 );
775 luaL_argcheck(L,
776 lua_type(L, 5) == LUA_TTABLE,
777 2,
778 "SQL sub-structure must be a table."
779 );
780 // Lua stack contains: ..., <buffer>
781 // get value of "sep" attribute of sub-structure,
782 // and place it on Lua stack position 6:
783 lua_getfield(L, 5, "sep");
784 lua_replace(L, 6);
785 // if seperator is nil, then use ", " as default,
786 // if seperator is neither nil nor a string, then throw error:
787 if (lua_isnil(L, 6)) {
788 lua_pushstring(L, ", ");
789 lua_replace(L, 6);
790 } else {
791 luaL_argcheck(L,
792 lua_isstring(L, 6),
793 2,
794 "Seperator of SQL sub-structure has to be a string."
795 );
796 }
797 // iterate over items of sub-structure:
798 count = lua_rawlen(L, 5);
799 for (i = 0; i < count; i++) {
800 // add seperator, unless this is the first run:
801 if (i) {
802 lua_pushvalue(L, 6);
803 luaL_addvalue(&buf);
804 }
805 // recursivly apply assemble function and add results to buffer:
806 lua_pushcfunction(L, mondelefant_conn_assemble_command);
807 lua_pushvalue(L, 1);
808 lua_rawgeti(L, 5, i+1);
809 lua_call(L, 2, 1);
810 luaL_addvalue(&buf);
811 }
812 } else { // question-mark
813 if (lua_toboolean(L, 4)) {
814 // call input_converter with connection handle, raw-value and
815 // an info-table which contains a "field_name" entry with the
816 // used key:
817 lua_pushvalue(L, 4);
818 lua_pushvalue(L, 1);
819 lua_pushvalue(L, -3);
820 lua_newtable(L);
821 lua_pushvalue(L, -6);
822 lua_setfield(L, -2, "field_name");
823 lua_call(L, 3, 1);
824 // Lua stack contains: ..., <buffer>, key, raw-value, final-value
825 // remove key and raw-value:
826 lua_remove(L, -2);
827 lua_remove(L, -2);
828 // Lua stack contains: ..., <buffer>, final-value
829 // throw error, if final-value is not a string:
830 if (!lua_isstring(L, -1)) {
831 return luaL_error(L, "input_converter returned non-string.");
832 }
833 } else {
834 // remove key from stack:
835 lua_remove(L, -2);
836 // Lua stack contains: ..., <buffer>, raw-value
837 // branch according to type of value:
838 // NOTE: Lua automatically converts numbers to strings
839 if (lua_isnil(L, -1)) { // value is nil
840 // push string "NULL" to stack:
841 lua_pushliteral(L, "NULL");
842 } else if (lua_type(L, -1) == LUA_TBOOLEAN) { // value is boolean
843 // push strings "TRUE" or "FALSE" to stack:
844 lua_pushstring(L, lua_toboolean(L, -1) ? "TRUE" : "FALSE");
845 } else if (lua_isstring(L, -1)) { // value is string or number
846 // push output of "quote_string" method of database connection
847 // to stack:
848 lua_tostring(L, -1);
849 lua_pushcfunction(L, mondelefant_conn_quote_string);
850 lua_pushvalue(L, 1);
851 lua_pushvalue(L, -3);
852 lua_call(L, 2, 1);
853 } else { // value is of other type
854 // throw error:
855 return luaL_error(L,
856 "Unable to convert SQL value due to unknown type "
857 "or missing input_converter."
858 );
859 }
860 // Lua stack contains: ..., <buffer>, raw-value, final-value
861 // remove raw-value:
862 lua_remove(L, -2);
863 // Lua stack contains: ..., <buffer>, final-value
864 }
865 // append final-value to buffer:
866 luaL_addvalue(&buf);
867 }
868 }
869 } else { // character is not special
870 // just copy character:
871 luaL_addchar(&buf, c);
872 }
873 }
874 // return string in buffer:
875 luaL_pushresult(&buf);
876 return 1;
877 }
879 // max number of SQL statements executed by one "query" method call:
880 #define MONDELEFANT_MAX_COMMAND_COUNT 64
881 // max number of columns in a database result:
882 #define MONDELEFANT_MAX_COLUMN_COUNT 1024
883 // enum values for 'modes' array in C-function below:
884 #define MONDELEFANT_QUERY_MODE_LIST 1
885 #define MONDELEFANT_QUERY_MODE_OBJECT 2
886 #define MONDELEFANT_QUERY_MODE_OPT_OBJECT 3
888 // method "try_query" of database handles:
889 static int mondelefant_conn_try_query(lua_State *L) {
890 mondelefant_conn_t *conn;
891 int command_count;
892 int command_idx;
893 int modes[MONDELEFANT_MAX_COMMAND_COUNT];
894 luaL_Buffer buf;
895 int sent_success;
896 PGresult *res;
897 int rows, cols, row, col;
898 // get database connection object:
899 conn = mondelefant_get_conn(L, 1);
900 // calculate number of commands (2 arguments for one command):
901 command_count = lua_gettop(L) / 2;
902 // push nil on stack, which is needed, if last mode was ommitted:
903 lua_pushnil(L);
904 // throw error, if number of commands is too high:
905 if (command_count > MONDELEFANT_MAX_COMMAND_COUNT) {
906 return luaL_error(L, "Exceeded maximum command count in one query.");
907 }
908 // create SQL string, store query modes and push SQL string on stack:
909 luaL_buffinit(L, &buf);
910 for (command_idx = 0; command_idx < command_count; command_idx++) {
911 int mode;
912 int mode_idx; // stack index of mode string
913 if (command_idx) luaL_addchar(&buf, ' ');
914 lua_pushcfunction(L, mondelefant_conn_assemble_command);
915 lua_pushvalue(L, 1);
916 lua_pushvalue(L, 2 + 2 * command_idx);
917 lua_call(L, 2, 1);
918 luaL_addvalue(&buf);
919 luaL_addchar(&buf, ';');
920 mode_idx = 3 + 2 * command_idx;
921 if (lua_isnil(L, mode_idx)) {
922 mode = MONDELEFANT_QUERY_MODE_LIST;
923 } else {
924 const char *modestr;
925 modestr = luaL_checkstring(L, mode_idx);
926 if (!strcmp(modestr, "list")) {
927 mode = MONDELEFANT_QUERY_MODE_LIST;
928 } else if (!strcmp(modestr, "object")) {
929 mode = MONDELEFANT_QUERY_MODE_OBJECT;
930 } else if (!strcmp(modestr, "opt_object")) {
931 mode = MONDELEFANT_QUERY_MODE_OPT_OBJECT;
932 } else {
933 return luaL_argerror(L, mode_idx, "unknown query mode");
934 }
935 }
936 modes[command_idx] = mode;
937 }
938 luaL_pushresult(&buf); // stack position unknown
939 lua_replace(L, 2); // SQL command string to stack position 2
940 // call sql_tracer, if set:
941 lua_settop(L, 2);
942 lua_getfield(L, 1, "sql_tracer"); // tracer at stack position 3
943 if (lua_toboolean(L, 3)) {
944 lua_pushvalue(L, 1); // 4
945 lua_pushvalue(L, 2); // 5
946 lua_call(L, 2, 1); // trace callback at stack position 3
947 }
948 // NOTE: If no tracer was found, then nil or false is stored at stack
949 // position 3.
950 // call PQsendQuery function and store result in 'sent_success' variable:
951 sent_success = PQsendQuery(conn->pgconn, lua_tostring(L, 2));
952 // create preliminary result table:
953 lua_newtable(L); // results in table at stack position 4
954 // iterate over results using function PQgetResult to fill result table:
955 for (command_idx = 0; ; command_idx++) {
956 int mode;
957 char binary[MONDELEFANT_MAX_COLUMN_COUNT];
958 ExecStatusType pgstatus;
959 // fetch mode which was given for the command:
960 mode = modes[command_idx];
961 // if PQsendQuery call was successful, then fetch result data:
962 if (sent_success) {
963 // avoid cumulating memory leaks in case of previous out-of-memory errors:
964 if (conn->todo_PQclear) {
965 PQclear(conn->todo_PQclear);
966 conn->todo_PQclear = NULL;
967 }
968 // NOTE: PQgetResult called one extra time. Break only, if all
969 // queries have been processed and PQgetResult returned NULL.
970 res = PQgetResult(conn->pgconn);
971 if (command_idx >= command_count && !res) break;
972 if (res) {
973 pgstatus = PQresultStatus(res);
974 rows = PQntuples(res);
975 cols = PQnfields(res);
976 // ensure call of PQclear in case of Lua errors:
977 conn->todo_PQclear = res;
978 }
979 }
980 // handle errors:
981 if (
982 !sent_success || command_idx >= command_count || !res ||
983 (pgstatus != PGRES_TUPLES_OK && pgstatus != PGRES_COMMAND_OK) ||
984 (rows < 1 && mode == MONDELEFANT_QUERY_MODE_OBJECT) ||
985 (rows > 1 && mode != MONDELEFANT_QUERY_MODE_LIST)
986 ) {
987 const char *command;
988 command = lua_tostring(L, 2);
989 lua_newtable(L); // 5
990 luaL_setmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY);
991 lua_pushvalue(L, 1);
992 lua_setfield(L, 5, "connection");
993 lua_pushvalue(L, 2);
994 lua_setfield(L, 5, "sql_command");
995 if (!sent_success) {
996 lua_pushliteral(L, MONDELEFANT_ERRCODE_CONNECTION);
997 lua_setfield(L, 5, "code");
998 mondelefant_push_first_line(L, PQerrorMessage(conn->pgconn));
999 lua_setfield(L, 5, "message");
1000 } else {
1001 lua_pushinteger(L, command_idx + 1);
1002 lua_setfield(L, 5, "command_number");
1003 if (!res) {
1004 lua_pushliteral(L, MONDELEFANT_ERRCODE_RESULTCOUNT_LOW);
1005 lua_setfield(L, 5, "code");
1006 lua_pushliteral(L, "Received too few database result sets.");
1007 lua_setfield(L, 5, "message");
1008 } else if (command_idx >= command_count) {
1009 lua_pushliteral(L, MONDELEFANT_ERRCODE_RESULTCOUNT_HIGH);
1010 lua_setfield(L, 5, "code");
1011 lua_pushliteral(L, "Received too many database result sets.");
1012 lua_setfield(L, 5, "message");
1013 } else if (
1014 pgstatus != PGRES_TUPLES_OK && pgstatus != PGRES_COMMAND_OK
1015 ) {
1016 const char *sqlstate;
1017 const char *errmsg;
1018 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SEVERITY));
1019 lua_setfield(L, 5, "pg_severity");
1020 sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
1021 if (sqlstate) {
1022 lua_pushstring(L, sqlstate);
1023 lua_setfield(L, 5, "pg_sqlstate");
1024 lua_pushstring(L, mondelefant_translate_errcode(sqlstate));
1025 lua_setfield(L, 5, "code");
1026 } else {
1027 lua_pushliteral(L, MONDELEFANT_ERRCODE_UNKNOWN);
1028 lua_setfield(L, 5, "code");
1030 errmsg = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY);
1031 if (errmsg) {
1032 mondelefant_push_first_line(L, errmsg);
1033 lua_setfield(L, 5, "message");
1034 lua_pushstring(L, errmsg);
1035 lua_setfield(L, 5, "pg_message_primary");
1036 } else {
1037 lua_pushliteral(L,
1038 "Error while fetching result, but no error message given."
1039 );
1040 lua_setfield(L, 5, "message");
1042 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL));
1043 lua_setfield(L, 5, "pg_message_detail");
1044 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_MESSAGE_HINT));
1045 lua_setfield(L, 5, "pg_message_hint");
1046 // NOTE: "position" and "pg_internal_position" are recalculated to
1047 // byte offsets, as Lua 5.2 is not Unicode aware.
1049 char *tmp;
1050 tmp = PQresultErrorField(res, PG_DIAG_STATEMENT_POSITION);
1051 if (tmp) {
1052 int pos;
1053 pos = atoi(tmp) - 1;
1054 if (conn->server_encoding == MONDELEFANT_SERVER_ENCODING_UTF8) {
1055 pos = utf8_position_to_byte(command, pos);
1057 lua_pushinteger(L, pos + 1);
1058 lua_setfield(L, 5, "position");
1062 const char *internal_query;
1063 internal_query = PQresultErrorField(res, PG_DIAG_INTERNAL_QUERY);
1064 lua_pushstring(L, internal_query);
1065 lua_setfield(L, 5, "pg_internal_query");
1066 char *tmp;
1067 tmp = PQresultErrorField(res, PG_DIAG_INTERNAL_POSITION);
1068 if (tmp) {
1069 int pos;
1070 pos = atoi(tmp) - 1;
1071 if (conn->server_encoding == MONDELEFANT_SERVER_ENCODING_UTF8) {
1072 pos = utf8_position_to_byte(internal_query, pos);
1074 lua_pushinteger(L, pos + 1);
1075 lua_setfield(L, 5, "pg_internal_position");
1078 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_CONTEXT));
1079 lua_setfield(L, 5, "pg_context");
1080 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_FILE));
1081 lua_setfield(L, 5, "pg_source_file");
1082 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_LINE));
1083 lua_setfield(L, 5, "pg_source_line");
1084 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_FUNCTION));
1085 lua_setfield(L, 5, "pg_source_function");
1086 } else if (rows < 1 && mode == MONDELEFANT_QUERY_MODE_OBJECT) {
1087 lua_pushliteral(L, MONDELEFANT_ERRCODE_QUERY1_NO_ROWS);
1088 lua_setfield(L, 5, "code");
1089 lua_pushliteral(L, "Expected one row, but got empty set.");
1090 lua_setfield(L, 5, "message");
1091 } else if (rows > 1 && mode != MONDELEFANT_QUERY_MODE_LIST) {
1092 lua_pushliteral(L, MONDELEFANT_ERRCODE_QUERY1_MULTIPLE_ROWS);
1093 lua_setfield(L, 5, "code");
1094 lua_pushliteral(L, "Got more than one result row.");
1095 lua_setfield(L, 5, "message");
1096 } else {
1097 // should not happen
1098 abort();
1100 if (res) {
1101 PQclear(res);
1102 while ((res = PQgetResult(conn->pgconn))) PQclear(res);
1103 // avoid double call of PQclear later:
1104 conn->todo_PQclear = NULL;
1107 if (lua_toboolean(L, 3)) {
1108 lua_pushvalue(L, 3);
1109 lua_pushvalue(L, 5);
1110 lua_call(L, 1, 0);
1112 return 1;
1114 // call "create_list" or "create_object" method of database handle,
1115 // result will be at stack position 5:
1116 if (modes[command_idx] == MONDELEFANT_QUERY_MODE_LIST) {
1117 lua_pushcfunction(L, mondelefant_conn_create_list); // 5
1118 lua_pushvalue(L, 1); // 6
1119 lua_call(L, 1, 1); // 5
1120 } else {
1121 lua_pushcfunction(L, mondelefant_conn_create_object); // 5
1122 lua_pushvalue(L, 1); // 6
1123 lua_call(L, 1, 1); // 5
1125 // set "_column_info":
1126 lua_newtable(L); // 6
1127 for (col = 0; col < cols; col++) {
1128 lua_newtable(L); // 7
1129 lua_pushstring(L, PQfname(res, col)); // 8
1130 lua_pushvalue(L, 8); // 9
1131 lua_pushvalue(L, 7); // 10
1132 lua_rawset(L, 6);
1133 lua_setfield(L, 7, "field_name");
1134 // _column_info entry (for current column) on stack position 7
1136 Oid tmp;
1137 tmp = PQftable(res, col);
1138 if (tmp == InvalidOid) lua_pushnil(L);
1139 else lua_pushinteger(L, tmp);
1140 lua_setfield(L, 7, "table_oid");
1143 int tmp;
1144 tmp = PQftablecol(res, col);
1145 if (tmp == 0) lua_pushnil(L);
1146 else lua_pushinteger(L, tmp);
1147 lua_setfield(L, 7, "table_column_number");
1150 Oid tmp;
1151 tmp = PQftype(res, col);
1152 binary[col] = (tmp == MONDELEFANT_POSTGRESQL_BINARY_OID);
1153 lua_pushinteger(L, tmp);
1154 lua_setfield(L, 7, "type_oid");
1155 lua_pushstring(L, mondelefant_oid_to_typestr(tmp));
1156 lua_setfield(L, 7, "type");
1159 int tmp;
1160 tmp = PQfmod(res, col);
1161 if (tmp == -1) lua_pushnil(L);
1162 else lua_pushinteger(L, tmp);
1163 lua_setfield(L, 7, "type_modifier");
1165 lua_rawseti(L, 6, col+1);
1167 lua_setfield(L, 5, "_column_info");
1168 // set "_rows_affected":
1170 char *tmp;
1171 tmp = PQcmdTuples(res);
1172 if (tmp[0]) {
1173 lua_pushinteger(L, atoi(tmp));
1174 lua_setfield(L, 5, "_rows_affected");
1177 // set "_oid":
1179 Oid tmp;
1180 tmp = PQoidValue(res);
1181 if (tmp != InvalidOid) {
1182 lua_pushinteger(L, tmp);
1183 lua_setfield(L, 5, "_oid");
1186 // copy data as strings or nil, while performing binary unescaping
1187 // automatically:
1188 if (modes[command_idx] == MONDELEFANT_QUERY_MODE_LIST) {
1189 for (row = 0; row < rows; row++) {
1190 lua_pushcfunction(L, mondelefant_conn_create_object); // 6
1191 lua_pushvalue(L, 1); // 7
1192 lua_call(L, 1, 1); // 6
1193 for (col = 0; col < cols; col++) {
1194 if (PQgetisnull(res, row, col)) {
1195 lua_pushnil(L);
1196 } else if (binary[col]) {
1197 size_t binlen;
1198 char *binval;
1199 // avoid cumulating memory leaks in case of previous out-of-memory errors:
1200 if (conn->todo_PQfreemem) {
1201 PQfreemem(conn->todo_PQfreemem);
1202 conn->todo_PQfreemem = NULL;
1204 // Unescape binary data:
1205 binval = (char *)PQunescapeBytea(
1206 (unsigned char *)PQgetvalue(res, row, col), &binlen
1207 );
1208 if (!binval) {
1209 return luaL_error(L,
1210 "Could not allocate memory for binary unescaping."
1211 );
1213 // ensure call of PQfreemem in case of out-of-memory error:
1214 conn->todo_PQfreemem = binval;
1215 // create Lua string:
1216 lua_pushlstring(L, binval, binlen);
1217 // free memory allocated by PQunescapeBytea:
1218 PQfreemem(binval);
1219 // avoid double call of PQfreemem later:
1220 conn->todo_PQfreemem = NULL;
1221 } else {
1222 lua_pushstring(L, PQgetvalue(res, row, col));
1224 lua_rawseti(L, 6, col+1);
1226 lua_rawseti(L, 5, row+1);
1228 } else if (rows == 1) {
1229 for (col = 0; col < cols; col++) {
1230 if (PQgetisnull(res, 0, col)) {
1231 lua_pushnil(L);
1232 } else if (binary[col]) {
1233 size_t binlen;
1234 char *binval;
1235 // avoid cumulating memory leaks in case of previous out-of-memory errors:
1236 if (conn->todo_PQfreemem) {
1237 PQfreemem(conn->todo_PQfreemem);
1238 conn->todo_PQfreemem = NULL;
1240 // Unescape binary data:
1241 binval = (char *)PQunescapeBytea(
1242 (unsigned char *)PQgetvalue(res, 0, col), &binlen
1243 );
1244 if (!binval) {
1245 return luaL_error(L,
1246 "Could not allocate memory for binary unescaping."
1247 );
1249 // ensure call of PQfreemem in case of out-of-memory error:
1250 conn->todo_PQfreemem = binval;
1251 // create Lua string:
1252 lua_pushlstring(L, binval, binlen);
1253 // free memory allocated by PQunescapeBytea:
1254 PQfreemem(binval);
1255 // avoid double call of PQfreemem later:
1256 conn->todo_PQfreemem = NULL;
1257 } else {
1258 lua_pushstring(L, PQgetvalue(res, 0, col));
1260 lua_rawseti(L, 5, col+1);
1262 } else {
1263 // no row in optrow mode
1264 lua_pop(L, 1);
1265 lua_pushnil(L);
1267 // save result in result list:
1268 lua_rawseti(L, 4, command_idx+1);
1269 // extra assertion:
1270 if (lua_gettop(L) != 4) abort(); // should not happen
1271 // free memory acquired by libpq:
1272 PQclear(res);
1273 // avoid double call of PQclear later:
1274 conn->todo_PQclear = NULL;
1276 // trace callback at stack position 3
1277 // result at stack position 4 (top of stack)
1278 // if a trace callback is existent, then call:
1279 if (lua_toboolean(L, 3)) {
1280 lua_pushvalue(L, 3);
1281 lua_call(L, 0, 0);
1283 // put result at stack position 3:
1284 lua_replace(L, 3);
1285 // get output converter to stack position 4:
1286 lua_getfield(L, 1, "output_converter");
1287 // get mutability state saver to stack position 5:
1288 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY);
1289 lua_getfield(L, -1, "save_mutability_state");
1290 lua_replace(L, -2);
1291 // apply output converters and fill "_data" table according to column names:
1292 for (command_idx = 0; command_idx < command_count; command_idx++) {
1293 int mode;
1294 mode = modes[command_idx];
1295 lua_rawgeti(L, 3, command_idx+1); // raw result at stack position 6
1296 if (lua_toboolean(L, 6)) {
1297 lua_getfield(L, 6, "_column_info"); // column_info list at position 7
1298 cols = lua_rawlen(L, 7);
1299 if (mode == MONDELEFANT_QUERY_MODE_LIST) {
1300 rows = lua_rawlen(L, 6);
1301 for (row = 0; row < rows; row++) {
1302 lua_rawgeti(L, 6, row+1); // row at stack position 8
1303 lua_getfield(L, 8, "_data"); // _data table at stack position 9
1304 lua_getfield(L, 8, "_dirty"); // _dirty table at stack position 10
1305 for (col = 0; col < cols; col++) {
1306 lua_rawgeti(L, 7, col+1); // this column info at position 11
1307 lua_getfield(L, 11, "field_name"); // 12
1308 if (lua_toboolean(L, 4)) {
1309 lua_pushvalue(L, 4); // output-converter
1310 lua_pushvalue(L, 1); // connection
1311 lua_rawgeti(L, 8, col+1); // raw-value
1312 lua_pushvalue(L, 11); // this column info
1313 lua_call(L, 3, 1); // converted value at position 13
1314 } else {
1315 lua_rawgeti(L, 8, col+1); // raw-value at position 13
1317 if (lua_toboolean(L, 5)) { // handle mutable values?
1318 lua_pushvalue(L, 12); // copy of field name
1319 lua_pushvalue(L, 5); // mutability state saver function
1320 lua_pushvalue(L, 13); // copy of value
1321 lua_call(L, 1, 1); // calculated mutability state of value
1322 lua_rawset(L, 10); // store mutability state in _dirty table
1324 lua_pushvalue(L, 13); // 14
1325 lua_rawseti(L, 8, col+1);
1326 lua_rawset(L, 9);
1327 lua_settop(L, 10);
1329 lua_settop(L, 7);
1331 } else {
1332 lua_getfield(L, 6, "_data"); // _data table at stack position 8
1333 lua_getfield(L, 6, "_dirty"); // _dirty table at stack position 9
1334 for (col = 0; col < cols; col++) {
1335 lua_rawgeti(L, 7, col+1); // this column info at position 10
1336 lua_getfield(L, 10, "field_name"); // 11
1337 if (lua_toboolean(L, 4)) {
1338 lua_pushvalue(L, 4); // output-converter
1339 lua_pushvalue(L, 1); // connection
1340 lua_rawgeti(L, 6, col+1); // raw-value
1341 lua_pushvalue(L, 10); // this column info
1342 lua_call(L, 3, 1); // converted value at position 12
1343 } else {
1344 lua_rawgeti(L, 6, col+1); // raw-value at position 12
1346 if (lua_toboolean(L, 5)) { // handle mutable values?
1347 lua_pushvalue(L, 11); // copy of field name
1348 lua_pushvalue(L, 5); // mutability state saver function
1349 lua_pushvalue(L, 12); // copy of value
1350 lua_call(L, 1, 1); // calculated mutability state of value
1351 lua_rawset(L, 9); // store mutability state in _dirty table
1353 lua_pushvalue(L, 12); // 13
1354 lua_rawseti(L, 6, col+1);
1355 lua_rawset(L, 8);
1356 lua_settop(L, 9);
1360 lua_settop(L, 5);
1362 // return nil as first result value, followed by result lists/objects:
1363 lua_settop(L, 3);
1364 lua_pushnil(L);
1365 for (command_idx = 0; command_idx < command_count; command_idx++) {
1366 lua_rawgeti(L, 3, command_idx+1);
1368 return command_count+1;
1371 // method "is_kind_of" of error objects:
1372 static int mondelefant_errorobject_is_kind_of(lua_State *L) {
1373 const char *errclass;
1374 luaL_checktype(L, 1, LUA_TTABLE);
1375 errclass = luaL_checkstring(L, 2);
1376 lua_settop(L, 2);
1377 lua_getfield(L, 1, "code"); // 3
1378 luaL_argcheck(L,
1379 lua_type(L, 3) == LUA_TSTRING,
1380 1,
1381 "field 'code' of error object is not a string"
1382 );
1383 lua_pushboolean(L,
1384 mondelefant_check_error_class(lua_tostring(L, 3), errclass)
1385 );
1386 return 1;
1389 // method "wait" of database handles:
1390 static int mondelefant_conn_wait(lua_State *L) {
1391 int argc;
1392 // count number of arguments:
1393 argc = lua_gettop(L);
1394 // insert "try_wait" function/method at stack position 1:
1395 lua_pushcfunction(L, mondelefant_conn_try_wait);
1396 lua_insert(L, 1);
1397 // call "try_wait" method:
1398 lua_call(L, argc, LUA_MULTRET); // results (with error) starting at index 1
1399 // check, if error occurred:
1400 if (lua_toboolean(L, 1)) {
1401 // raise error
1402 lua_settop(L, 1);
1403 return lua_error(L);
1404 } else {
1405 // return everything but nil error object:
1406 return lua_gettop(L) - 1;
1410 // method "query" of database handles:
1411 static int mondelefant_conn_query(lua_State *L) {
1412 int argc;
1413 // count number of arguments:
1414 argc = lua_gettop(L);
1415 // insert "try_query" function/method at stack position 1:
1416 lua_pushcfunction(L, mondelefant_conn_try_query);
1417 lua_insert(L, 1);
1418 // call "try_query" method:
1419 lua_call(L, argc, LUA_MULTRET); // results (with error) starting at index 1
1420 // check, if error occurred:
1421 if (lua_toboolean(L, 1)) {
1422 // raise error
1423 lua_settop(L, 1);
1424 return lua_error(L);
1425 } else {
1426 // return everything but nil error object:
1427 return lua_gettop(L) - 1;
1431 // library function "set_class":
1432 static int mondelefant_set_class(lua_State *L) {
1433 // ensure that first argument is a database result list/object:
1434 lua_settop(L, 2);
1435 lua_getmetatable(L, 1); // 3
1436 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_RESULT_MT_REGKEY); // 4
1437 luaL_argcheck(L, lua_compare(L, 3, 4, LUA_OPEQ), 1, "not a database result");
1438 // ensure that second argument is a database class (model):
1439 lua_settop(L, 2);
1440 lua_getmetatable(L, 2); // 3
1441 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_MT_REGKEY); // 4
1442 luaL_argcheck(L, lua_compare(L, 3, 4, LUA_OPEQ), 2, "not a database class");
1443 // set attribute "_class" of result list/object to given class:
1444 lua_settop(L, 2);
1445 lua_pushvalue(L, 2); // 3
1446 lua_setfield(L, 1, "_class");
1447 // test, if database result is a list (and not a single object):
1448 lua_getfield(L, 1, "_type"); // 3
1449 lua_pushliteral(L, "list"); // 4
1450 if (lua_rawequal(L, 3, 4)) {
1451 int i;
1452 // set attribute "_class" of all elements to given class:
1453 for (i=0; i < lua_rawlen(L, 1); i++) {
1454 lua_settop(L, 2);
1455 lua_rawgeti(L, 1, i+1); // 3
1456 lua_pushvalue(L, 2); // 4
1457 lua_setfield(L, 3, "_class");
1460 // return first argument:
1461 lua_settop(L, 1);
1462 return 1;
1465 // library function "new_class":
1466 static int mondelefant_new_class(lua_State *L) {
1467 // if no argument is given, use an empty table:
1468 if (lua_isnoneornil(L, 1)) {
1469 lua_settop(L, 0);
1470 lua_newtable(L); // 1
1471 } else {
1472 luaL_checktype(L, 1, LUA_TTABLE);
1473 lua_settop(L, 1);
1475 // set meta-table for database classes (models):
1476 luaL_setmetatable(L, MONDELEFANT_CLASS_MT_REGKEY);
1477 // check, if "prototype" attribute is not set:
1478 lua_pushliteral(L, "prototype"); // 2
1479 lua_rawget(L, 1); // 2
1480 if (!lua_toboolean(L, 2)) {
1481 // set "prototype" attribute to default prototype:
1482 lua_pushliteral(L, "prototype"); // 3
1483 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 4
1484 lua_rawset(L, 1);
1486 // set "object" attribute to empty table, unless it is already set:
1487 lua_settop(L, 1);
1488 lua_pushliteral(L, "object"); // 2
1489 lua_rawget(L, 1); // 2
1490 if (!lua_toboolean(L, 2)) {
1491 lua_pushliteral(L, "object"); // 3
1492 lua_newtable(L); // 4
1493 lua_rawset(L, 1);
1495 // set "object_get" attribute to empty table, unless it is already set:
1496 lua_settop(L, 1);
1497 lua_pushliteral(L, "object_get"); // 2
1498 lua_rawget(L, 1); // 2
1499 if (!lua_toboolean(L, 2)) {
1500 lua_pushliteral(L, "object_get"); // 3
1501 lua_newtable(L); // 4
1502 lua_rawset(L, 1);
1504 // set "object_set" attribute to empty table, unless it is already set:
1505 lua_settop(L, 1);
1506 lua_pushliteral(L, "object_set"); // 2
1507 lua_rawget(L, 1); // 2
1508 if (!lua_toboolean(L, 2)) {
1509 lua_pushliteral(L, "object_set"); // 3
1510 lua_newtable(L); // 4
1511 lua_rawset(L, 1);
1513 // set "list" attribute to empty table, unless it is already set:
1514 lua_settop(L, 1);
1515 lua_pushliteral(L, "list"); // 2
1516 lua_rawget(L, 1); // 2
1517 if (!lua_toboolean(L, 2)) {
1518 lua_pushliteral(L, "list"); // 3
1519 lua_newtable(L); // 4
1520 lua_rawset(L, 1);
1522 // set "references" attribute to empty table, unless it is already set:
1523 lua_settop(L, 1);
1524 lua_pushliteral(L, "references"); // 2
1525 lua_rawget(L, 1); // 2
1526 if (!lua_toboolean(L, 2)) {
1527 lua_pushliteral(L, "references"); // 3
1528 lua_newtable(L); // 4
1529 lua_rawset(L, 1);
1531 // set "foreign_keys" attribute to empty table, unless it is already set:
1532 lua_settop(L, 1);
1533 lua_pushliteral(L, "foreign_keys"); // 2
1534 lua_rawget(L, 1); // 2
1535 if (!lua_toboolean(L, 2)) {
1536 lua_pushliteral(L, "foreign_keys"); // 3
1537 lua_newtable(L); // 4
1538 lua_rawset(L, 1);
1540 // return table:
1541 lua_settop(L, 1);
1542 return 1;
1545 // method "get_reference" of classes (models):
1546 static int mondelefant_class_get_reference(lua_State *L) {
1547 lua_settop(L, 2);
1548 while (lua_toboolean(L, 1)) {
1549 // get "references" table:
1550 lua_getfield(L, 1, "references"); // 3
1551 // perform lookup:
1552 lua_pushvalue(L, 2); // 4
1553 lua_gettable(L, 3); // 4
1554 // return result, if lookup was successful:
1555 if (!lua_isnil(L, 4)) return 1;
1556 // replace current table by its prototype:
1557 lua_settop(L, 2);
1558 lua_pushliteral(L, "prototype"); // 3
1559 lua_rawget(L, 1); // 3
1560 lua_replace(L, 1);
1562 // return nothing:
1563 return 0;
1566 // method "iterate_over_references" of classes (models):
1567 static int mondelefant_class_iterate_over_references(lua_State *L) {
1568 return luaL_error(L, "Reference iterator not implemented yet."); // TODO
1571 // method "get_foreign_key_reference_name" of classes (models):
1572 static int mondelefant_class_get_foreign_key_reference_name(lua_State *L) {
1573 lua_settop(L, 2);
1574 while (lua_toboolean(L, 1)) {
1575 // get "foreign_keys" table:
1576 lua_getfield(L, 1, "foreign_keys"); // 3
1577 // perform lookup:
1578 lua_pushvalue(L, 2); // 4
1579 lua_gettable(L, 3); // 4
1580 // return result, if lookup was successful:
1581 if (!lua_isnil(L, 4)) return 1;
1582 // replace current table by its prototype:
1583 lua_settop(L, 2);
1584 lua_pushliteral(L, "prototype"); // 3
1585 lua_rawget(L, 1); // 3
1586 lua_replace(L, 1);
1588 // return nothing:
1589 return 0;
1592 // meta-method "__index" of database result lists and objects:
1593 static int mondelefant_result_index(lua_State *L) {
1594 const char *result_type;
1595 // only lookup, when key is a string not beginning with an underscore:
1596 if (lua_type(L, 2) != LUA_TSTRING || lua_tostring(L, 2)[0] == '_') {
1597 return 0;
1599 // value of "_class" attribute or default class on stack position 3:
1600 lua_settop(L, 2);
1601 lua_getfield(L, 1, "_class"); // 3
1602 if (!lua_toboolean(L, 3)) {
1603 lua_settop(L, 2);
1604 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 3
1606 // get value of "_type" attribute:
1607 lua_getfield(L, 1, "_type"); // 4
1608 result_type = lua_tostring(L, 4);
1609 // different lookup for lists and objects:
1610 if (result_type && !strcmp(result_type, "object")) { // object
1611 lua_settop(L, 3);
1612 // try inherited attributes, methods or getter functions:
1613 lua_pushvalue(L, 3); // 4
1614 while (lua_toboolean(L, 4)) {
1615 lua_getfield(L, 4, "object"); // 5
1616 lua_pushvalue(L, 2); // 6
1617 lua_gettable(L, 5); // 6
1618 if (!lua_isnil(L, 6)) return 1;
1619 lua_settop(L, 4);
1620 lua_getfield(L, 4, "object_get"); // 5
1621 lua_pushvalue(L, 2); // 6
1622 lua_gettable(L, 5); // 6
1623 if (lua_toboolean(L, 6)) {
1624 lua_pushvalue(L, 1); // 7
1625 lua_call(L, 1, 1); // 6
1626 return 1;
1628 lua_settop(L, 4);
1629 lua_pushliteral(L, "prototype"); // 5
1630 lua_rawget(L, 4); // 5
1631 lua_replace(L, 4);
1633 lua_settop(L, 3);
1634 // try primary keys of referenced objects:
1635 lua_pushcfunction(L,
1636 mondelefant_class_get_foreign_key_reference_name
1637 ); // 4
1638 lua_pushvalue(L, 3); // 5
1639 lua_pushvalue(L, 2); // 6
1640 lua_call(L, 2, 1); // 4
1641 if (!lua_isnil(L, 4)) {
1642 // reference name at stack position 4
1643 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1644 lua_pushvalue(L, 3); // 6
1645 lua_pushvalue(L, 4); // 7
1646 lua_call(L, 2, 1); // reference info at stack position 5
1647 lua_getfield(L, 1, "_ref"); // 6
1648 lua_getfield(L, 5, "ref"); // 7
1649 lua_gettable(L, 6); // 7
1650 if (!lua_isnil(L, 7)) {
1651 if (lua_toboolean(L, 7)) {
1652 lua_getfield(L, 5, "that_key"); // 8
1653 if (lua_isnil(L, 8)) {
1654 return luaL_error(L, "Missing 'that_key' entry in model reference.");
1656 lua_gettable(L, 7); // 8
1657 } else {
1658 lua_pushnil(L);
1660 return 1;
1663 lua_settop(L, 3);
1664 lua_getfield(L, 1, "_data"); // _data table on stack position 4
1665 // try cached referenced object (or cached NULL reference):
1666 lua_getfield(L, 1, "_ref"); // 5
1667 lua_pushvalue(L, 2); // 6
1668 lua_gettable(L, 5); // 6
1669 if (lua_isboolean(L, 6) && !lua_toboolean(L, 6)) {
1670 lua_pushnil(L);
1671 return 1;
1672 } else if (!lua_isnil(L, 6)) {
1673 return 1;
1675 lua_settop(L, 4);
1676 // try to load a referenced object:
1677 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1678 lua_pushvalue(L, 3); // 6
1679 lua_pushvalue(L, 2); // 7
1680 lua_call(L, 2, 1); // 5
1681 if (!lua_isnil(L, 5)) {
1682 lua_settop(L, 2);
1683 lua_getfield(L, 1, "load"); // 3
1684 lua_pushvalue(L, 1); // 4 (self)
1685 lua_pushvalue(L, 2); // 5
1686 lua_call(L, 2, 0);
1687 lua_settop(L, 2);
1688 lua_getfield(L, 1, "_ref"); // 3
1689 lua_pushvalue(L, 2); // 4
1690 lua_gettable(L, 3); // 4
1691 if (lua_isboolean(L, 4) && !lua_toboolean(L, 4)) lua_pushnil(L); // TODO: use special object instead of false
1692 return 1;
1694 lua_settop(L, 4);
1695 // check if proxy access to document in special column is enabled:
1696 lua_getfield(L, 3, "document_column"); // 5
1697 if (lua_toboolean(L, 5)) {
1698 // if yes, then proxy access:
1699 lua_gettable(L, 4); // 5
1700 if (!lua_isnil(L, 5)) {
1701 lua_pushvalue(L, 2); // 6
1702 lua_gettable(L, 5); // 6
1704 } else {
1705 // else use _data table:
1706 lua_pushvalue(L, 2); // 6
1707 lua_gettable(L, 4); // 6
1709 return 1; // return element at stack position 5 or 6
1710 } else if (result_type && !strcmp(result_type, "list")) { // list
1711 lua_settop(L, 3);
1712 // try inherited list attributes or methods:
1713 while (lua_toboolean(L, 3)) {
1714 lua_getfield(L, 3, "list"); // 4
1715 lua_pushvalue(L, 2); // 5
1716 lua_gettable(L, 4); // 5
1717 if (!lua_isnil(L, 5)) return 1;
1718 lua_settop(L, 3);
1719 lua_pushliteral(L, "prototype"); // 4
1720 lua_rawget(L, 3); // 4
1721 lua_replace(L, 3);
1724 // return nothing:
1725 return 0;
1728 // meta-method "__newindex" of database result lists and objects:
1729 static int mondelefant_result_newindex(lua_State *L) {
1730 const char *result_type;
1731 // perform rawset, unless key is a string not starting with underscore:
1732 lua_settop(L, 3);
1733 if (lua_type(L, 2) != LUA_TSTRING || lua_tostring(L, 2)[0] == '_') {
1734 lua_rawset(L, 1);
1735 return 1;
1737 // value of "_class" attribute or default class on stack position 4:
1738 lua_settop(L, 3);
1739 lua_getfield(L, 1, "_class"); // 4
1740 if (!lua_toboolean(L, 4)) {
1741 lua_settop(L, 3);
1742 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 4
1744 // get value of "_type" attribute:
1745 lua_getfield(L, 1, "_type"); // 5
1746 result_type = lua_tostring(L, 5);
1747 // distinguish between lists and objects:
1748 if (result_type && !strcmp(result_type, "object")) { // objects
1749 lua_settop(L, 4);
1750 // try object setter functions:
1751 lua_pushvalue(L, 4); // 5
1752 while (lua_toboolean(L, 5)) {
1753 lua_getfield(L, 5, "object_set"); // 6
1754 lua_pushvalue(L, 2); // 7
1755 lua_gettable(L, 6); // 7
1756 if (lua_toboolean(L, 7)) {
1757 lua_pushvalue(L, 1); // 8
1758 lua_pushvalue(L, 3); // 9
1759 lua_call(L, 2, 0);
1760 return 0;
1762 lua_settop(L, 5);
1763 lua_pushliteral(L, "prototype"); // 6
1764 lua_rawget(L, 5); // 6
1765 lua_replace(L, 5);
1767 lua_settop(L, 4);
1768 lua_getfield(L, 1, "_data"); // _data table on stack position 5
1769 // check, if a object reference is changed:
1770 lua_pushcfunction(L, mondelefant_class_get_reference); // 6
1771 lua_pushvalue(L, 4); // 7
1772 lua_pushvalue(L, 2); // 8
1773 lua_call(L, 2, 1); // 6
1774 if (!lua_isnil(L, 6)) {
1775 // store object in _ref table (use false for nil): // TODO: use special object instead of false
1776 lua_getfield(L, 1, "_ref"); // 7
1777 lua_pushvalue(L, 2); // 8
1778 if (lua_isnil(L, 3)) lua_pushboolean(L, 0); // 9
1779 else lua_pushvalue(L, 3); // 9
1780 lua_settable(L, 7);
1781 lua_settop(L, 6);
1782 // delete referencing key from _data table:
1783 lua_getfield(L, 6, "this_key"); // 7
1784 if (lua_isnil(L, 7)) {
1785 return luaL_error(L, "Missing 'this_key' entry in model reference.");
1787 lua_pushvalue(L, 7); // 8
1788 lua_pushnil(L); // 9
1789 lua_settable(L, 5);
1790 lua_getfield(L, 1, "_dirty"); // 8
1791 lua_pushvalue(L, 7); // 9
1792 lua_pushboolean(L, 1); // 10
1793 lua_settable(L, 8);
1794 return 0;
1796 lua_settop(L, 5);
1797 // check proxy access to document in special column:
1798 lua_getfield(L, 4, "document_column"); // 6
1799 if (lua_toboolean(L, 6)) {
1800 lua_gettable(L, 5); // 6
1801 if (lua_isnil(L, 6)) {
1802 return luaL_error(L, "Cannot write to document column: document is nil");
1804 lua_pushvalue(L, 2); // 7
1805 lua_pushvalue(L, 3); // 8
1806 lua_settable(L, 6);
1807 return 0;
1809 lua_settop(L, 5);
1810 // store value in data field info:
1811 lua_pushvalue(L, 2); // 6
1812 lua_pushvalue(L, 3); // 7
1813 lua_settable(L, 5);
1814 lua_settop(L, 4);
1815 // mark field as dirty (needs to be UPDATEd on save):
1816 lua_getfield(L, 1, "_dirty"); // 5
1817 lua_pushvalue(L, 2); // 6
1818 lua_pushboolean(L, 1); // 7
1819 lua_settable(L, 5);
1820 lua_settop(L, 4);
1821 // reset reference cache, if neccessary:
1822 lua_pushcfunction(L,
1823 mondelefant_class_get_foreign_key_reference_name
1824 ); // 5
1825 lua_pushvalue(L, 4); // 6
1826 lua_pushvalue(L, 2); // 7
1827 lua_call(L, 2, 1); // 5
1828 if (!lua_isnil(L, 5)) {
1829 lua_getfield(L, 1, "_ref"); // 6
1830 lua_pushvalue(L, 5); // 7
1831 lua_pushnil(L); // 8
1832 lua_settable(L, 6);
1834 return 0;
1835 } else { // non-objects (i.e. lists)
1836 // perform rawset:
1837 lua_settop(L, 3);
1838 lua_rawset(L, 1);
1839 return 0;
1843 // meta-method "__index" of column proxy:
1844 static int mondelefant_columns_index(lua_State *L) {
1845 luaL_checktype(L, 1, LUA_TTABLE);
1846 lua_settop(L, 2);
1847 lua_rawgetp(L, 1, MONDELEFANT_COLUMNS_RESULT_LUKEY); // 3
1848 lua_getfield(L, 3, "_data"); // 4
1849 lua_pushvalue(L, 2); // 5
1850 lua_gettable(L, 4); // 5
1851 return 1;
1854 // meta-method "__newindex" of column proxy:
1855 static int mondelefant_columns_newindex(lua_State *L) {
1856 luaL_checktype(L, 1, LUA_TTABLE);
1857 lua_settop(L, 3);
1858 lua_rawgetp(L, 1, MONDELEFANT_COLUMNS_RESULT_LUKEY); // 4
1859 lua_getfield(L, 4, "_data"); // 5
1860 lua_getfield(L, 4, "_dirty"); // 6
1861 lua_pushvalue(L, 2);
1862 lua_pushvalue(L, 3);
1863 lua_settable(L, 5);
1864 lua_pushvalue(L, 2);
1865 lua_pushboolean(L, 1);
1866 lua_settable(L, 6);
1867 return 0;
1870 // meta-method "__index" of classes (models):
1871 static int mondelefant_class_index(lua_State *L) {
1872 // perform lookup in prototype:
1873 lua_settop(L, 2);
1874 lua_pushliteral(L, "prototype"); // 3
1875 lua_rawget(L, 1); // 3
1876 lua_pushvalue(L, 2); // 4
1877 lua_gettable(L, 3); // 4
1878 return 1;
1881 // registration information for functions of library:
1882 static const struct luaL_Reg mondelefant_module_functions[] = {
1883 {"connect", mondelefant_connect},
1884 {"set_class", mondelefant_set_class},
1885 {"new_class", mondelefant_new_class},
1886 {NULL, NULL}
1887 };
1889 // registration information for meta-methods of database connections:
1890 static const struct luaL_Reg mondelefant_conn_mt_functions[] = {
1891 {"__gc", mondelefant_conn_free},
1892 {"__index", mondelefant_conn_index},
1893 {"__newindex", mondelefant_conn_newindex},
1894 {NULL, NULL}
1895 };
1897 // registration information for methods of database connections:
1898 static const struct luaL_Reg mondelefant_conn_methods[] = {
1899 {"close", mondelefant_conn_close},
1900 {"is_ok", mondelefant_conn_is_ok},
1901 {"get_transaction_status", mondelefant_conn_get_transaction_status},
1902 {"try_wait", mondelefant_conn_try_wait},
1903 {"wait", mondelefant_conn_wait},
1904 {"create_list", mondelefant_conn_create_list},
1905 {"create_object", mondelefant_conn_create_object},
1906 {"quote_string", mondelefant_conn_quote_string},
1907 {"quote_binary", mondelefant_conn_quote_binary},
1908 {"assemble_command", mondelefant_conn_assemble_command},
1909 {"try_query", mondelefant_conn_try_query},
1910 {"query", mondelefant_conn_query},
1911 {NULL, NULL}
1912 };
1914 // registration information for meta-methods of error objects:
1915 static const struct luaL_Reg mondelefant_errorobject_mt_functions[] = {
1916 {NULL, NULL}
1917 };
1919 // registration information for methods of error objects:
1920 static const struct luaL_Reg mondelefant_errorobject_methods[] = {
1921 {"escalate", lua_error},
1922 {"is_kind_of", mondelefant_errorobject_is_kind_of},
1923 {NULL, NULL}
1924 };
1926 // registration information for meta-methods of database result lists/objects:
1927 static const struct luaL_Reg mondelefant_result_mt_functions[] = {
1928 {"__index", mondelefant_result_index},
1929 {"__newindex", mondelefant_result_newindex},
1930 {NULL, NULL}
1931 };
1933 // registration information for meta-methods of classes (models):
1934 static const struct luaL_Reg mondelefant_class_mt_functions[] = {
1935 {"__index", mondelefant_class_index},
1936 {NULL, NULL}
1937 };
1939 // registration information for methods of classes (models):
1940 static const struct luaL_Reg mondelefant_class_methods[] = {
1941 {"get_reference", mondelefant_class_get_reference},
1942 {"iterate_over_references", mondelefant_class_iterate_over_references},
1943 {"get_foreign_key_reference_name",
1944 mondelefant_class_get_foreign_key_reference_name},
1945 {NULL, NULL}
1946 };
1948 // registration information for methods of database result objects (not lists!):
1949 static const struct luaL_Reg mondelefant_object_methods[] = {
1950 {NULL, NULL}
1951 };
1953 // registration information for methods of database result lists (not single objects!):
1954 static const struct luaL_Reg mondelefant_list_methods[] = {
1955 {NULL, NULL}
1956 };
1958 // registration information for meta-methods of column proxy:
1959 static const struct luaL_Reg mondelefant_columns_mt_functions[] = {
1960 {"__index", mondelefant_columns_index},
1961 {"__newindex", mondelefant_columns_newindex},
1962 {NULL, NULL}
1963 };
1965 // luaopen function to initialize/register library:
1966 int luaopen_mondelefant_native(lua_State *L) {
1967 lua_settop(L, 0);
1969 lua_newtable(L); // meta-table for columns proxy
1970 luaL_setfuncs(L, mondelefant_columns_mt_functions, 0);
1971 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_COLUMNS_MT_REGKEY);
1973 lua_newtable(L); // module at stack position 1
1974 luaL_setfuncs(L, mondelefant_module_functions, 0);
1976 lua_pushvalue(L, 1); // 2
1977 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY);
1979 lua_newtable(L); // 2
1980 // NOTE: only PostgreSQL is supported yet:
1981 luaL_setfuncs(L, mondelefant_conn_methods, 0);
1982 lua_setfield(L, 1, "postgresql_connection_prototype");
1983 lua_newtable(L); // 2
1984 lua_setfield(L, 1, "connection_prototype");
1986 luaL_newmetatable(L, MONDELEFANT_CONN_MT_REGKEY); // 2
1987 luaL_setfuncs(L, mondelefant_conn_mt_functions, 0);
1988 lua_settop(L, 1);
1989 luaL_newmetatable(L, MONDELEFANT_RESULT_MT_REGKEY); // 2
1990 luaL_setfuncs(L, mondelefant_result_mt_functions, 0);
1991 lua_setfield(L, 1, "result_metatable");
1992 luaL_newmetatable(L, MONDELEFANT_CLASS_MT_REGKEY); // 2
1993 luaL_setfuncs(L, mondelefant_class_mt_functions, 0);
1994 lua_setfield(L, 1, "class_metatable");
1996 lua_newtable(L); // 2
1997 luaL_setfuncs(L, mondelefant_class_methods, 0);
1998 lua_newtable(L); // 3
1999 luaL_setfuncs(L, mondelefant_object_methods, 0);
2000 lua_setfield(L, 2, "object");
2001 lua_newtable(L); // 3
2002 lua_setfield(L, 2, "object_get");
2003 lua_newtable(L); // 3
2004 lua_setfield(L, 2, "object_set");
2005 lua_newtable(L); // 3
2006 luaL_setfuncs(L, mondelefant_list_methods, 0);
2007 lua_setfield(L, 2, "list");
2008 lua_newtable(L); // 3
2009 lua_setfield(L, 2, "references");
2010 lua_newtable(L); // 3
2011 lua_setfield(L, 2, "foreign_keys");
2012 lua_pushvalue(L, 2); // 3
2013 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY);
2014 lua_setfield(L, 1, "class_prototype");
2016 luaL_newmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY); // 2
2017 luaL_setfuncs(L, mondelefant_errorobject_mt_functions, 0);
2018 lua_newtable(L); // 3
2019 luaL_setfuncs(L, mondelefant_errorobject_methods, 0);
2020 lua_setfield(L, 2, "__index");
2021 lua_setfield(L, 1, "errorobject_metatable");
2023 return 1;

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