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view libraries/mondelefant/mondelefant_native.c @ 562:328f120924a2

Removed if-clause when initializing file descriptor set to avoid compiler warning for mondelefant_conn_try_wait
author jbe
date Fri Feb 05 15:51:39 2021 +0100 (3 months ago)
parents e13a3fa97aad
children
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 199: return "json_array";
77 case 600: return "point";
78 case 601: return "lseg";
79 case 602: return "path";
80 case 603: return "box";
81 case 604: return "polygon";
82 case 628: return "line";
83 case 700: return "float4";
84 case 701: return "float8";
85 case 705: return "unknown";
86 case 718: return "circle";
87 case 790: return "money";
88 case 829: return "macaddr";
89 case 869: return "inet";
90 case 650: return "cidr";
91 case 1000: return "bool_array";
92 case 1001: return "bytea_array";
93 case 1002: return "char_array";
94 case 1005: return "int2_array";
95 case 1007: return "int4_array";
96 case 1009: return "text_array";
97 case 1015: return "varchar_array";
98 case 1016: return "int8_array";
99 case 1021: return "float4_array";
100 case 1022: return "float8_array";
101 case 1042: return "bpchar";
102 case 1043: return "varchar";
103 case 1082: return "date";
104 case 1083: return "time";
105 case 1114: return "timestamp";
106 case 1115: return "timestamp_array";
107 case 1182: return "date_array";
108 case 1183: return "time_array";
109 case 1184: return "timestamptz";
110 case 1185: return "timestamptz_array";
111 case 1186: return "interval";
112 case 1187: return "interval_array";
113 case 1231: return "numeric_array";
114 case 1266: return "timetz";
115 case 1270: return "timetz_array";
116 case 1560: return "bit";
117 case 1561: return "bit_array";
118 case 1562: return "varbit";
119 case 1563: return "varbit_array";
120 case 1700: return "numeric";
121 case 3802: return "jsonb";
122 case 3807: return "jsonb_array";
123 default: return NULL;
124 }
125 }
127 // This library maps PostgreSQL's error codes to CamelCase string
128 // identifiers, which consist of CamelCase identifiers and are seperated
129 // by dots (".") (no leading or trailing dots).
130 // There are additional error identifiers which do not have a corresponding
131 // PostgreSQL error associated with it.
133 // matching start of local variable 'pgcode' against string 'incode',
134 // returning string 'outcode' on match:
135 #define mondelefant_errcode_item(incode, outcode) \
136 if (!strncmp(pgcode, (incode), strlen(incode))) return outcode; else
138 // additional error identifiers without corresponding PostgreSQL error:
139 #define MONDELEFANT_ERRCODE_UNKNOWN "unknown"
140 #define MONDELEFANT_ERRCODE_CONNECTION "ConnectionException"
141 #define MONDELEFANT_ERRCODE_RESULTCOUNT_LOW "WrongResultSetCount.ResultSetMissing"
142 #define MONDELEFANT_ERRCODE_RESULTCOUNT_HIGH "WrongResultSetCount.TooManyResults"
143 #define MONDELEFANT_ERRCODE_QUERY1_NO_ROWS "NoData.OneRowExpected"
144 #define MONDELEFANT_ERRCODE_QUERY1_MULTIPLE_ROWS "CardinalityViolation.OneRowExpected"
146 // mapping PostgreSQL error code to error code as returned by this library:
147 static const char *mondelefant_translate_errcode(const char *pgcode) {
148 if (!pgcode) abort(); // should not happen
149 mondelefant_errcode_item("02", "NoData")
150 mondelefant_errcode_item("03", "SqlStatementNotYetComplete")
151 mondelefant_errcode_item("08", "ConnectionException")
152 mondelefant_errcode_item("09", "TriggeredActionException")
153 mondelefant_errcode_item("0A", "FeatureNotSupported")
154 mondelefant_errcode_item("0B", "InvalidTransactionInitiation")
155 mondelefant_errcode_item("0F", "LocatorException")
156 mondelefant_errcode_item("0L", "InvalidGrantor")
157 mondelefant_errcode_item("0P", "InvalidRoleSpecification")
158 mondelefant_errcode_item("21", "CardinalityViolation")
159 mondelefant_errcode_item("22", "DataException")
160 mondelefant_errcode_item("23001", "IntegrityConstraintViolation.RestrictViolation")
161 mondelefant_errcode_item("23502", "IntegrityConstraintViolation.NotNullViolation")
162 mondelefant_errcode_item("23503", "IntegrityConstraintViolation.ForeignKeyViolation")
163 mondelefant_errcode_item("23505", "IntegrityConstraintViolation.UniqueViolation")
164 mondelefant_errcode_item("23514", "IntegrityConstraintViolation.CheckViolation")
165 mondelefant_errcode_item("23", "IntegrityConstraintViolation")
166 mondelefant_errcode_item("24", "InvalidCursorState")
167 mondelefant_errcode_item("25", "InvalidTransactionState")
168 mondelefant_errcode_item("26", "InvalidSqlStatementName")
169 mondelefant_errcode_item("27", "TriggeredDataChangeViolation")
170 mondelefant_errcode_item("28", "InvalidAuthorizationSpecification")
171 mondelefant_errcode_item("2B", "DependentPrivilegeDescriptorsStillExist")
172 mondelefant_errcode_item("2D", "InvalidTransactionTermination")
173 mondelefant_errcode_item("2F", "SqlRoutineException")
174 mondelefant_errcode_item("34", "InvalidCursorName")
175 mondelefant_errcode_item("38", "ExternalRoutineException")
176 mondelefant_errcode_item("39", "ExternalRoutineInvocationException")
177 mondelefant_errcode_item("3B", "SavepointException")
178 mondelefant_errcode_item("3D", "InvalidCatalogName")
179 mondelefant_errcode_item("3F", "InvalidSchemaName")
180 mondelefant_errcode_item("40", "TransactionRollback")
181 mondelefant_errcode_item("42", "SyntaxErrorOrAccessRuleViolation")
182 mondelefant_errcode_item("44", "WithCheckOptionViolation")
183 mondelefant_errcode_item("53", "InsufficientResources")
184 mondelefant_errcode_item("54", "ProgramLimitExceeded")
185 mondelefant_errcode_item("55", "ObjectNotInPrerequisiteState")
186 mondelefant_errcode_item("57", "OperatorIntervention")
187 mondelefant_errcode_item("58", "SystemError")
188 mondelefant_errcode_item("F0", "ConfigurationFileError")
189 mondelefant_errcode_item("P0", "PlpgsqlError")
190 mondelefant_errcode_item("XX", "InternalError")
191 return "unknown";
192 }
194 // C-function, checking if a given error code (as defined by this library)
195 // is belonging to a certain class of errors (strings are equal or error
196 // code begins with error class followed by a dot):
197 static int mondelefant_check_error_class(
198 const char *errcode, const char *errclass
199 ) {
200 size_t i = 0;
201 while (1) {
202 if (errclass[i] == 0) {
203 if (errcode[i] == 0 || errcode[i] == '.') return 1;
204 else return 0;
205 }
206 if (errcode[i] != errclass[i]) return 0;
207 i++;
208 }
209 }
211 // pushing first line of a string on Lua's stack (without trailing CR/LF):
212 static void mondelefant_push_first_line(lua_State *L, const char *str) {
213 size_t i = 0;
214 if (!str) abort(); // should not happen
215 while (1) {
216 char c = str[i];
217 if (c == '\n' || c == '\r' || c == 0) {
218 lua_pushlstring(L, str, i);
219 return;
220 }
221 i++;
222 }
223 }
225 // "connect" function of library, which establishes a database connection
226 // and returns a database connection handle:
227 static int mondelefant_connect(lua_State *L) {
228 const char *conninfo; // string for PQconnectdb function
229 mondelefant_conn_t *conn; // C-structure for userdata
230 // check if string is given as first argument:
231 if (lua_type(L, 1) != LUA_TSTRING) {
232 // expect a table as first argument if no string is given:
233 luaL_checktype(L, 1, LUA_TTABLE);
234 // extract conninfo string for PQconnectdb if possible:
235 lua_getfield(L, 1, "conninfo");
236 if (!lua_isnil(L, -1)) {
237 // if yes, use that value but check its type:
238 luaL_argcheck(L, lua_type(L, -1) == LUA_TSTRING, 1, "\"conninfo\" value is not a string");
239 } else {
240 // otherwise assemble conninfo string from the named options:
241 luaL_Buffer buf;
242 int need_seperator = 0;
243 const char *value;
244 size_t value_len;
245 size_t value_pos;
246 lua_settop(L, 1);
247 lua_pushnil(L); // slot for key at stack position 2
248 lua_pushnil(L); // slot for value at stack position 3
249 luaL_buffinit(L, &buf);
250 while (lua_pushvalue(L, 2), lua_next(L, 1)) {
251 luaL_argcheck(L, lua_isstring(L, -2), 1, "key in table is not a string");
252 value = luaL_tolstring(L, -1, &value_len);
253 lua_replace(L, 3);
254 lua_pop(L, 1);
255 lua_replace(L, 2);
256 if (need_seperator) luaL_addchar(&buf, ' ');
257 // NOTE: numbers will be converted to strings automatically here,
258 // but perhaps this will change in future versions of lua
259 lua_pushvalue(L, 2);
260 luaL_addvalue(&buf);
261 luaL_addchar(&buf, '=');
262 luaL_addchar(&buf, '\'');
263 value_pos = 0;
264 do {
265 char c;
266 c = value[value_pos++];
267 if (c == '\'') luaL_addchar(&buf, '\\');
268 luaL_addchar(&buf, c);
269 } while (value_pos < value_len);
270 luaL_addchar(&buf, '\'');
271 need_seperator = 1;
272 }
273 luaL_pushresult(&buf);
274 }
275 // ensure that string is on stack position 1:
276 lua_replace(L, 1);
277 }
278 // use conninfo string on stack position 1:
279 conninfo = lua_tostring(L, 1);
280 // create (zero'ed) userdata on stack position 2:
281 lua_settop(L, 1);
282 conn = memset(lua_newuserdata(L, sizeof(*conn)), 0, sizeof(*conn)); // 2
283 // call PQconnectdb function of libpq:
284 conn->pgconn = PQconnectdb(conninfo);
285 // try emergency garbage collection on first failure:
286 if (!conn->pgconn) {
287 lua_gc(L, LUA_GCCOLLECT, 0);
288 conn->pgconn = PQconnectdb(conninfo);
289 // throw error in case of (unexpected) error of PQconnectdb call:
290 if (!conn->pgconn) return luaL_error(L,
291 "Error in libpq while creating 'PGconn' structure."
292 );
293 }
294 // set metatable for userdata (ensure PQfinish on unexpected error below):
295 luaL_setmetatable(L, MONDELEFANT_CONN_MT_REGKEY);
296 // check result of PQconnectdb call:
297 if (PQstatus(conn->pgconn) != CONNECTION_OK) {
298 lua_pushnil(L); // 3
299 mondelefant_push_first_line(L, PQerrorMessage(conn->pgconn)); // 4
300 lua_newtable(L); // 5
301 luaL_setmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY);
302 lua_pushliteral(L, MONDELEFANT_ERRCODE_CONNECTION);
303 lua_setfield(L, 5, "code");
304 lua_pushvalue(L, 4);
305 lua_setfield(L, 5, "message");
306 // manual PQfinish (do not wait until garbage collection):
307 PQfinish(conn->pgconn);
308 conn->pgconn = NULL;
309 return 3;
310 }
311 // set 'server_encoding' in C-struct of userdata:
312 {
313 const char *charset;
314 charset = PQparameterStatus(conn->pgconn, "server_encoding");
315 if (charset && !strcmp(charset, "UTF8")) {
316 conn->server_encoding = MONDELEFANT_SERVER_ENCODING_UTF8;
317 } else {
318 conn->server_encoding = MONDELEFANT_SERVER_ENCODING_ASCII;
319 }
320 }
321 // create and associate userdata table:
322 lua_newtable(L);
323 lua_setuservalue(L, 2);
324 // store key "fd" with file descriptor of connection:
325 lua_pushinteger(L, PQsocket(conn->pgconn));
326 lua_setfield(L, 2, "fd");
327 // store key "engine" with value "postgresql" as connection specific data:
328 lua_pushliteral(L, "postgresql");
329 lua_setfield(L, 2, "engine");
330 // return userdata:
331 return 1;
332 }
334 // returns pointer to libpq handle 'pgconn' of userdata at given index
335 // (or throws error, if database connection has been closed):
336 static mondelefant_conn_t *mondelefant_get_conn(lua_State *L, int index) {
337 mondelefant_conn_t *conn;
338 conn = luaL_checkudata(L, index, MONDELEFANT_CONN_MT_REGKEY);
339 if (!conn->pgconn) {
340 luaL_error(L, "PostgreSQL connection has been closed.");
341 return NULL;
342 }
343 return conn;
344 }
346 // meta-method "__index" of database handles (userdata):
347 static int mondelefant_conn_index(lua_State *L) {
348 // try table for connection specific data:
349 lua_settop(L, 2);
350 lua_getuservalue(L, 1); // 3
351 lua_pushvalue(L, 2); // 4
352 lua_gettable(L, 3); // 4
353 if (!lua_isnil(L, 4)) return 1;
354 // try to use prototype stored in connection specific data:
355 lua_settop(L, 3);
356 lua_getfield(L, 3, "prototype"); // 4
357 if (lua_toboolean(L, 4)) {
358 lua_pushvalue(L, 2); // 5
359 lua_gettable(L, 4); // 5
360 if (!lua_isnil(L, 5)) return 1;
361 }
362 // try to use "postgresql_connection_prototype" of library:
363 lua_settop(L, 2);
364 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY); // 3
365 lua_getfield(L, 3, "postgresql_connection_prototype"); // 4
366 if (lua_toboolean(L, 4)) {
367 lua_pushvalue(L, 2); // 5
368 lua_gettable(L, 4); // 5
369 if (!lua_isnil(L, 5)) return 1;
370 }
371 // try to use "connection_prototype" of library:
372 lua_settop(L, 3);
373 lua_getfield(L, 3, "connection_prototype"); // 4
374 if (lua_toboolean(L, 4)) {
375 lua_pushvalue(L, 2); // 5
376 lua_gettable(L, 4); // 5
377 if (!lua_isnil(L, 5)) return 1;
378 }
379 // give up and return nothing:
380 return 0;
381 }
383 // meta-method "__newindex" of database handles (userdata):
384 static int mondelefant_conn_newindex(lua_State *L) {
385 // store key-value pair in table for connection specific data:
386 lua_settop(L, 3);
387 lua_getuservalue(L, 1); // 4
388 lua_pushvalue(L, 2);
389 lua_pushvalue(L, 3);
390 lua_settable(L, 4);
391 // return nothing:
392 return 0;
393 }
395 // meta-method "__gc" of database handles:
396 static int mondelefant_conn_free(lua_State *L) {
397 mondelefant_conn_t *conn;
398 conn = luaL_checkudata(L, 1, MONDELEFANT_CONN_MT_REGKEY);
399 if (conn->todo_PQfreemem) {
400 PQfreemem(conn->todo_PQfreemem);
401 conn->todo_PQfreemem = NULL;
402 }
403 if (conn->todo_PQclear) {
404 PQclear(conn->todo_PQclear);
405 conn->todo_PQclear = NULL;
406 }
407 if (conn->pgconn) {
408 PQfinish(conn->pgconn);
409 conn->pgconn = NULL;
410 }
411 return 0;
412 }
414 // method "close" of database handles:
415 static int mondelefant_conn_close(lua_State *L) {
416 mondelefant_conn_t *conn;
417 conn = mondelefant_get_conn(L, 1);
418 PQfinish(conn->pgconn);
419 conn->pgconn = NULL;
420 lua_pushnil(L);
421 lua_setfield(L, 1, "fd"); // set "fd" attribute to nil
422 return 0;
423 }
425 // method "is_okay" of database handles:
426 static int mondelefant_conn_is_ok(lua_State *L) {
427 mondelefant_conn_t *conn;
428 conn = mondelefant_get_conn(L, 1);
429 lua_pushboolean(L, PQstatus(conn->pgconn) == CONNECTION_OK);
430 return 1;
431 }
433 // method "get_transaction_status" of database handles:
434 static int mondelefant_conn_get_transaction_status(lua_State *L) {
435 mondelefant_conn_t *conn;
436 conn = mondelefant_get_conn(L, 1);
437 switch (PQtransactionStatus(conn->pgconn)) {
438 case PQTRANS_IDLE:
439 lua_pushliteral(L, "idle");
440 break;
441 case PQTRANS_ACTIVE:
442 lua_pushliteral(L, "active");
443 break;
444 case PQTRANS_INTRANS:
445 lua_pushliteral(L, "intrans");
446 break;
447 case PQTRANS_INERROR:
448 lua_pushliteral(L, "inerror");
449 break;
450 default:
451 lua_pushliteral(L, "unknown");
452 }
453 return 1;
454 }
456 // method "try_wait" of database handles:
457 static int mondelefant_conn_try_wait(lua_State *L) {
458 mondelefant_conn_t *conn;
459 int infinite, nonblock = 0;
460 struct timespec wakeup;
461 int fd;
462 fd_set fds;
463 conn = mondelefant_get_conn(L, 1);
464 infinite = lua_isnoneornil(L, 2);
465 if (!infinite) {
466 lua_Number n;
467 int isnum;
468 n = lua_tonumberx(L, 2, &isnum);
469 if (isnum && n>0 && n<=86400*366) {
470 if (clock_gettime(CLOCK_MONOTONIC, &wakeup)) {
471 return luaL_error(L, "Could not access CLOCK_MONOTONIC");
472 }
473 wakeup.tv_sec += n;
474 wakeup.tv_nsec += 1000000000 * (n - (time_t)n);
475 if (wakeup.tv_nsec >= 1000000000) {
476 wakeup.tv_sec += 1;
477 wakeup.tv_nsec -= 1000000000;
478 }
479 } else if (isnum && n==0) {
480 nonblock = 1;
481 } else {
482 luaL_argcheck(L, 0, 2, "not a valid timeout");
483 }
484 }
485 lua_settop(L, 1);
486 if (!nonblock || 1) { // execute always to avoid compiler warning
487 fd = PQsocket(conn->pgconn);
488 FD_ZERO(&fds);
489 FD_SET(fd, &fds);
490 }
491 while (true) {
492 {
493 PGnotify *notify;
494 if (!PQconsumeInput(conn->pgconn)) {
495 lua_newtable(L); // 2
496 luaL_setmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY);
497 lua_pushliteral(L, MONDELEFANT_ERRCODE_CONNECTION);
498 lua_setfield(L, 2, "code");
499 mondelefant_push_first_line(L, PQerrorMessage(conn->pgconn)); // 3
500 lua_setfield(L, 2, "message");
501 return 1;
502 }
503 // avoid cumulating memory leaks in case of previous out-of-memory errors:
504 if (conn->todo_PQfreemem) {
505 PQfreemem(conn->todo_PQfreemem);
506 conn->todo_PQfreemem = NULL;
507 }
508 notify = PQnotifies(conn->pgconn);
509 if (notify) {
510 // ensure call of PQfreemem in case of out-of-memory errors:
511 conn->todo_PQfreemem = notify;
512 // do Lua operations:
513 lua_pushnil(L);
514 lua_pushstring(L, notify->relname);
515 lua_pushstring(L, notify->extra);
516 lua_pushinteger(L, notify->be_pid);
517 // free memory allocated by PQnotifies:
518 PQfreemem(notify);
519 // avoid double call of PQfreemem later:
520 conn->todo_PQfreemem = NULL;
521 return 4;
522 }
523 }
524 if (infinite) {
525 select(fd+1, &fds, NULL, NULL, NULL);
526 } else if (nonblock) {
527 break;
528 } else {
529 struct timespec tp;
530 struct timeval timeout = { 0, };
531 if (clock_gettime(CLOCK_MONOTONIC, &tp)) {
532 return luaL_error(L, "Could not access CLOCK_MONOTONIC");
533 }
534 tp.tv_sec = wakeup.tv_sec - tp.tv_sec;
535 tp.tv_nsec = wakeup.tv_nsec - tp.tv_nsec;
536 if (tp.tv_nsec < 0) {
537 tp.tv_sec -= 1;
538 tp.tv_nsec += 1000000000;
539 }
540 timeout.tv_sec = tp.tv_sec;
541 timeout.tv_usec = (tp.tv_nsec + 500) / 1000;
542 if (
543 timeout.tv_sec < 0 ||
544 (timeout.tv_sec == 0 && timeout.tv_usec == 0)
545 ) break;
546 select(fd+1, &fds, NULL, NULL, &timeout);
547 }
548 }
549 lua_pushnil(L);
550 lua_pushnil(L);
551 return 2;
552 }
554 // method "create_list" of database handles:
555 static int mondelefant_conn_create_list(lua_State *L) {
556 // ensure that first argument is a database connection:
557 luaL_checkudata(L, 1, MONDELEFANT_CONN_MT_REGKEY);
558 // if no second argument is given, use an empty table:
559 if (lua_isnoneornil(L, 2)) {
560 lua_settop(L, 1);
561 lua_newtable(L); // 2
562 } else {
563 luaL_checktype(L, 2, LUA_TTABLE);
564 lua_settop(L, 2);
565 }
566 // set meta-table for database result lists/objects:
567 luaL_setmetatable(L, MONDELEFANT_RESULT_MT_REGKEY);
568 // set "_connection" attribute to self:
569 lua_pushvalue(L, 1); // 3
570 lua_setfield(L, 2, "_connection");
571 // set "_type" attribute to string "list":
572 lua_pushliteral(L, "list"); // 3
573 lua_setfield(L, 2, "_type");
574 // set "_class" attribute to default class:
575 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 3
576 lua_setfield(L, 2, "_class");
577 // return created database result list:
578 return 1;
579 }
581 // method "create_object" of database handles:
582 static int mondelefant_conn_create_object(lua_State *L) {
583 // ensure that first argument is a database connection:
584 luaL_checkudata(L, 1, MONDELEFANT_CONN_MT_REGKEY);
585 // create new table on stack position 2:
586 lua_settop(L, 1);
587 lua_newtable(L); // 2
588 // set meta-table for database result lists/objects:
589 luaL_setmetatable(L, MONDELEFANT_RESULT_MT_REGKEY);
590 // set "_connection" attribute to self:
591 lua_pushvalue(L, 1); // 3
592 lua_setfield(L, 2, "_connection");
593 // set "_type" attribute to string "object":
594 lua_pushliteral(L, "object"); // 3
595 lua_setfield(L, 2, "_type"); // "object" or "list"
596 // set "_class" attribute to default class:
597 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 3
598 lua_setfield(L, 2, "_class");
599 // create empty tables for "_data", "_dirty" and "_ref" attributes:
600 lua_newtable(L); // 3
601 lua_setfield(L, 2, "_data");
602 lua_newtable(L); // 3
603 lua_setfield(L, 2, "_dirty");
604 lua_newtable(L); // 3
605 lua_setfield(L, 2, "_ref"); // nil=no info, false=nil, else table
606 // create column proxy (field "_col" in result object):
607 lua_newtable(L); // 3
608 luaL_setmetatable(L, MONDELEFANT_COLUMNS_MT_REGKEY);
609 lua_pushvalue(L, 2); // 4
610 lua_rawsetp(L, 3, MONDELEFANT_COLUMNS_RESULT_LUKEY);
611 lua_setfield(L, 2, "_col");
612 // return created database result object (from stack position 2):
613 return 1;
614 }
616 // method "quote_string" of database handles:
617 static int mondelefant_conn_quote_string(lua_State *L) {
618 mondelefant_conn_t *conn;
619 const char *input;
620 size_t input_len;
621 luaL_Buffer buf;
622 char *output;
623 size_t output_len;
624 // get database connection object:
625 conn = mondelefant_get_conn(L, 1);
626 // get second argument, which must be a string:
627 input = luaL_checklstring(L, 2, &input_len);
628 // throw error, if string is too long:
629 if (input_len > (SIZE_MAX / sizeof(char) - 3) / 2) {
630 return luaL_error(L, "String to be escaped is too long.");
631 }
632 // allocate memory for quoted string:
633 output = luaL_buffinitsize(L, &buf, (2 * input_len + 3) * sizeof(char));
634 // do escaping by calling PQescapeStringConn and enclosing result with
635 // single quotes:
636 output[0] = '\'';
637 output_len = PQescapeStringConn(
638 conn->pgconn, output + 1, input, input_len, NULL
639 );
640 output[output_len + 1] = '\'';
641 output[output_len + 2] = 0;
642 // create Lua string:
643 luaL_addsize(&buf, output_len + 2);
644 luaL_pushresult(&buf);
645 // return Lua string:
646 return 1;
647 }
649 // method "quote_binary" of database handles:
650 static int mondelefant_conn_quote_binary(lua_State *L) {
651 mondelefant_conn_t *conn;
652 const char *input;
653 size_t input_len;
654 char *output;
655 size_t output_len;
656 luaL_Buffer buf;
657 // get database connection object:
658 conn = mondelefant_get_conn(L, 1);
659 // get second argument, which must be a string:
660 input = luaL_checklstring(L, 2, &input_len);
661 // avoid cumulating memory leaks in case of previous out-of-memory errors:
662 if (conn->todo_PQfreemem) {
663 PQfreemem(conn->todo_PQfreemem);
664 conn->todo_PQfreemem = NULL;
665 }
666 // call PQescapeByteaConn, which allocates memory itself:
667 output = (char *)PQescapeByteaConn(
668 conn->pgconn, (const unsigned char *)input, input_len, &output_len
669 );
670 if (!output) {
671 lua_gc(L, LUA_GCCOLLECT, 0);
672 output = (char *)PQescapeByteaConn(
673 conn->pgconn, (const unsigned char *)input, input_len, &output_len
674 );
675 if (!output) {
676 return luaL_error(L, "Could not allocate memory for binary quoting.");
677 }
678 }
679 // ensure call of PQfreemem in case of out-of-memory errors:
680 conn->todo_PQfreemem = output;
681 // create Lua string enclosed by single quotes:
682 luaL_buffinit(L, &buf);
683 luaL_addchar(&buf, '\'');
684 luaL_addlstring(&buf, output, output_len - 1);
685 luaL_addchar(&buf, '\'');
686 luaL_pushresult(&buf);
687 // free memory allocated by PQescapeByteaConn:
688 PQfreemem(output);
689 // avoid double call of PQfreemem later:
690 conn->todo_PQfreemem = NULL;
691 // return Lua string:
692 return 1;
693 }
695 // method "assemble_command" of database handles:
696 static int mondelefant_conn_assemble_command(lua_State *L) {
697 int paramidx = 2;
698 const char *template;
699 size_t template_pos = 0;
700 luaL_Buffer buf;
701 // get database connection object:
702 mondelefant_get_conn(L, 1);
703 // if second argument is a string, return this string:
704 if (lua_type(L, 2) == LUA_TSTRING) {
705 lua_settop(L, 2);
706 return 1;
707 }
708 // if second argument has __tostring meta-method,
709 // then use this method and return its result:
710 if (luaL_callmeta(L, 2, "__tostring")) return 1;
711 // otherwise, require that second argument is a table:
712 luaL_checktype(L, 2, LUA_TTABLE);
713 // set stack top:
714 lua_settop(L, 2);
715 // get first element of table, which must be a string:
716 lua_rawgeti(L, 2, 1); // 3
717 luaL_argcheck(L,
718 lua_isstring(L, 3),
719 2,
720 "First entry of SQL command structure is not a string."
721 );
722 template = lua_tostring(L, 3);
723 // get value of "input_converter" attribute of database connection:
724 lua_pushliteral(L, "input_converter"); // 4
725 lua_gettable(L, 1); // input_converter at stack position 4
726 // reserve space on Lua stack:
727 lua_pushnil(L); // free space at stack position 5
728 lua_pushnil(L); // free space at stack position 6
729 // initialize Lua buffer for result string:
730 luaL_buffinit(L, &buf);
731 // fill buffer in loop:
732 while (1) {
733 // variable declaration:
734 char c;
735 // get next character:
736 c = template[template_pos++];
737 // break, when character is NULL byte:
738 if (!c) break;
739 // question-mark and dollar-sign are special characters:
740 if (c == '?' || c == '$') { // special character found
741 // check, if same character follows:
742 if (template[template_pos] == c) { // special character is escaped
743 // consume two characters of input and add one character to buffer:
744 template_pos++;
745 luaL_addchar(&buf, c);
746 } else { // special character is not escaped
747 luaL_Buffer keybuf;
748 int subcmd;
749 // set 'subcmd' = true, if special character was a dollar-sign,
750 // set 'subcmd' = false, if special character was a question-mark:
751 subcmd = (c == '$');
752 // read any number of alpha numeric chars or underscores
753 // and store them on Lua stack:
754 luaL_buffinit(L, &keybuf);
755 while (1) {
756 c = template[template_pos];
757 if (
758 (c < 'A' || c > 'Z') &&
759 (c < 'a' || c > 'z') &&
760 (c < '0' || c > '9') &&
761 (c != '_')
762 ) break;
763 luaL_addchar(&keybuf, c);
764 template_pos++;
765 }
766 luaL_pushresult(&keybuf);
767 // check, if any characters matched:
768 if (lua_rawlen(L, -1)) {
769 // if any alpha numeric chars or underscores were found,
770 // push them on stack as a Lua string and use them to lookup
771 // value from second argument:
772 lua_pushvalue(L, -1); // save key on stack
773 lua_gettable(L, 2); // fetch value (raw-value)
774 } else {
775 // otherwise push nil and use numeric lookup based on 'paramidx':
776 lua_pop(L, 1);
777 lua_pushnil(L); // put nil on key position
778 lua_rawgeti(L, 2, paramidx++); // fetch value (raw-value)
779 }
780 // Lua stack contains: ..., <buffer>, key, raw-value
781 // branch according to type of special character ("?" or "$"):
782 if (subcmd) { // dollar-sign
783 size_t i;
784 size_t count;
785 // store fetched value (which is supposed to be sub-structure)
786 // on Lua stack position 5 and drop key:
787 lua_replace(L, 5);
788 lua_pop(L, 1);
789 // Lua stack contains: ..., <buffer>
790 // check, if fetched value is really a sub-structure:
791 luaL_argcheck(L,
792 !lua_isnil(L, 5),
793 2,
794 "SQL sub-structure not found."
795 );
796 luaL_argcheck(L,
797 lua_type(L, 5) == LUA_TTABLE,
798 2,
799 "SQL sub-structure must be a table."
800 );
801 // Lua stack contains: ..., <buffer>
802 // get value of "sep" attribute of sub-structure,
803 // and place it on Lua stack position 6:
804 lua_getfield(L, 5, "sep");
805 lua_replace(L, 6);
806 // if seperator is nil, then use ", " as default,
807 // if seperator is neither nil nor a string, then throw error:
808 if (lua_isnil(L, 6)) {
809 lua_pushstring(L, ", ");
810 lua_replace(L, 6);
811 } else {
812 luaL_argcheck(L,
813 lua_isstring(L, 6),
814 2,
815 "Seperator of SQL sub-structure has to be a string."
816 );
817 }
818 // iterate over items of sub-structure:
819 count = lua_rawlen(L, 5);
820 for (i = 0; i < count; i++) {
821 // add seperator, unless this is the first run:
822 if (i) {
823 lua_pushvalue(L, 6);
824 luaL_addvalue(&buf);
825 }
826 // recursivly apply assemble function and add results to buffer:
827 lua_pushcfunction(L, mondelefant_conn_assemble_command);
828 lua_pushvalue(L, 1);
829 lua_rawgeti(L, 5, i+1);
830 lua_call(L, 2, 1);
831 luaL_addvalue(&buf);
832 }
833 } else { // question-mark
834 if (lua_toboolean(L, 4)) {
835 // call input_converter with connection handle, raw-value and
836 // an info-table which contains a "field_name" entry with the
837 // used key:
838 lua_pushvalue(L, 4);
839 lua_pushvalue(L, 1);
840 lua_pushvalue(L, -3);
841 lua_newtable(L);
842 lua_pushvalue(L, -6);
843 lua_setfield(L, -2, "field_name");
844 lua_call(L, 3, 1);
845 // Lua stack contains: ..., <buffer>, key, raw-value, final-value
846 // remove key and raw-value:
847 lua_remove(L, -2);
848 lua_remove(L, -2);
849 // Lua stack contains: ..., <buffer>, final-value
850 // throw error, if final-value is not a string:
851 if (!lua_isstring(L, -1)) {
852 return luaL_error(L, "input_converter returned non-string.");
853 }
854 } else {
855 // remove key from stack:
856 lua_remove(L, -2);
857 // Lua stack contains: ..., <buffer>, raw-value
858 // branch according to type of value:
859 // NOTE: Lua automatically converts numbers to strings
860 if (lua_isnil(L, -1)) { // value is nil
861 // push string "NULL" to stack:
862 lua_pushliteral(L, "NULL");
863 } else if (lua_type(L, -1) == LUA_TBOOLEAN) { // value is boolean
864 // push strings "TRUE" or "FALSE" to stack:
865 lua_pushstring(L, lua_toboolean(L, -1) ? "TRUE" : "FALSE");
866 } else if (lua_isstring(L, -1)) { // value is string or number
867 // push output of "quote_string" method of database connection
868 // to stack:
869 lua_tostring(L, -1);
870 lua_pushcfunction(L, mondelefant_conn_quote_string);
871 lua_pushvalue(L, 1);
872 lua_pushvalue(L, -3);
873 lua_call(L, 2, 1);
874 } else { // value is of other type
875 // throw error:
876 return luaL_error(L,
877 "Unable to convert SQL value due to unknown type "
878 "or missing input_converter."
879 );
880 }
881 // Lua stack contains: ..., <buffer>, raw-value, final-value
882 // remove raw-value:
883 lua_remove(L, -2);
884 // Lua stack contains: ..., <buffer>, final-value
885 }
886 // append final-value to buffer:
887 luaL_addvalue(&buf);
888 }
889 }
890 } else { // character is not special
891 // just copy character:
892 luaL_addchar(&buf, c);
893 }
894 }
895 // return string in buffer:
896 luaL_pushresult(&buf);
897 return 1;
898 }
900 // max number of SQL statements executed by one "query" method call:
901 #define MONDELEFANT_MAX_COMMAND_COUNT 64
902 // max number of columns in a database result:
903 #define MONDELEFANT_MAX_COLUMN_COUNT 1024
904 // enum values for 'modes' array in C-function below:
905 #define MONDELEFANT_QUERY_MODE_LIST 1
906 #define MONDELEFANT_QUERY_MODE_OBJECT 2
907 #define MONDELEFANT_QUERY_MODE_OPT_OBJECT 3
909 // method "try_query" of database handles:
910 static int mondelefant_conn_try_query(lua_State *L) {
911 mondelefant_conn_t *conn;
912 int command_count;
913 int command_idx;
914 int modes[MONDELEFANT_MAX_COMMAND_COUNT];
915 luaL_Buffer buf;
916 int sent_success;
917 PGresult *res;
918 int rows, cols, row, col;
919 // get database connection object:
920 conn = mondelefant_get_conn(L, 1);
921 // calculate number of commands (2 arguments for one command):
922 command_count = lua_gettop(L) / 2;
923 // push nil on stack, which is needed, if last mode was ommitted:
924 lua_pushnil(L);
925 // throw error, if number of commands is too high:
926 if (command_count > MONDELEFANT_MAX_COMMAND_COUNT) {
927 return luaL_error(L, "Exceeded maximum command count in one query.");
928 }
929 // create SQL string, store query modes and push SQL string on stack:
930 luaL_buffinit(L, &buf);
931 for (command_idx = 0; command_idx < command_count; command_idx++) {
932 int mode;
933 int mode_idx; // stack index of mode string
934 if (command_idx) luaL_addchar(&buf, ' ');
935 lua_pushcfunction(L, mondelefant_conn_assemble_command);
936 lua_pushvalue(L, 1);
937 lua_pushvalue(L, 2 + 2 * command_idx);
938 lua_call(L, 2, 1);
939 luaL_addvalue(&buf);
940 luaL_addchar(&buf, ';');
941 mode_idx = 3 + 2 * command_idx;
942 if (lua_isnil(L, mode_idx)) {
943 mode = MONDELEFANT_QUERY_MODE_LIST;
944 } else {
945 const char *modestr;
946 modestr = luaL_checkstring(L, mode_idx);
947 if (!strcmp(modestr, "list")) {
948 mode = MONDELEFANT_QUERY_MODE_LIST;
949 } else if (!strcmp(modestr, "object")) {
950 mode = MONDELEFANT_QUERY_MODE_OBJECT;
951 } else if (!strcmp(modestr, "opt_object")) {
952 mode = MONDELEFANT_QUERY_MODE_OPT_OBJECT;
953 } else {
954 return luaL_argerror(L, mode_idx, "unknown query mode");
955 }
956 }
957 modes[command_idx] = mode;
958 }
959 luaL_pushresult(&buf); // stack position unknown
960 lua_replace(L, 2); // SQL command string to stack position 2
961 // call sql_tracer, if set:
962 lua_settop(L, 2);
963 lua_getfield(L, 1, "sql_tracer"); // tracer at stack position 3
964 if (lua_toboolean(L, 3)) {
965 lua_pushvalue(L, 1); // 4
966 lua_pushvalue(L, 2); // 5
967 lua_call(L, 2, 1); // trace callback at stack position 3
968 }
969 // NOTE: If no tracer was found, then nil or false is stored at stack
970 // position 3.
971 // call PQsendQuery function and store result in 'sent_success' variable:
972 sent_success = PQsendQuery(conn->pgconn, lua_tostring(L, 2));
973 // create preliminary result table:
974 lua_newtable(L); // results in table at stack position 4
975 // iterate over results using function PQgetResult to fill result table:
976 for (command_idx = 0; ; command_idx++) {
977 int mode;
978 char binary[MONDELEFANT_MAX_COLUMN_COUNT];
979 ExecStatusType pgstatus;
980 // fetch mode which was given for the command:
981 mode = modes[command_idx];
982 // if PQsendQuery call was successful, then fetch result data:
983 if (sent_success) {
984 // avoid cumulating memory leaks in case of previous out-of-memory errors:
985 if (conn->todo_PQclear) {
986 PQclear(conn->todo_PQclear);
987 conn->todo_PQclear = NULL;
988 }
989 // NOTE: PQgetResult called one extra time. Break only, if all
990 // queries have been processed and PQgetResult returned NULL.
991 res = PQgetResult(conn->pgconn);
992 if (command_idx >= command_count && !res) break;
993 if (res) {
994 pgstatus = PQresultStatus(res);
995 rows = PQntuples(res);
996 cols = PQnfields(res);
997 // ensure call of PQclear in case of Lua errors:
998 conn->todo_PQclear = res;
999 }
1001 // handle errors:
1002 if (
1003 !sent_success || command_idx >= command_count || !res ||
1004 (pgstatus != PGRES_TUPLES_OK && pgstatus != PGRES_COMMAND_OK) ||
1005 (rows < 1 && mode == MONDELEFANT_QUERY_MODE_OBJECT) ||
1006 (rows > 1 && mode != MONDELEFANT_QUERY_MODE_LIST)
1007 ) {
1008 const char *command;
1009 command = lua_tostring(L, 2);
1010 lua_newtable(L); // 5
1011 luaL_setmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY);
1012 lua_pushvalue(L, 1);
1013 lua_setfield(L, 5, "connection");
1014 lua_pushvalue(L, 2);
1015 lua_setfield(L, 5, "sql_command");
1016 if (!sent_success) {
1017 lua_pushliteral(L, MONDELEFANT_ERRCODE_CONNECTION);
1018 lua_setfield(L, 5, "code");
1019 mondelefant_push_first_line(L, PQerrorMessage(conn->pgconn));
1020 lua_setfield(L, 5, "message");
1021 } else {
1022 lua_pushinteger(L, command_idx + 1);
1023 lua_setfield(L, 5, "command_number");
1024 if (!res) {
1025 lua_pushliteral(L, MONDELEFANT_ERRCODE_RESULTCOUNT_LOW);
1026 lua_setfield(L, 5, "code");
1027 lua_pushliteral(L, "Received too few database result sets.");
1028 lua_setfield(L, 5, "message");
1029 } else if (command_idx >= command_count) {
1030 lua_pushliteral(L, MONDELEFANT_ERRCODE_RESULTCOUNT_HIGH);
1031 lua_setfield(L, 5, "code");
1032 lua_pushliteral(L, "Received too many database result sets.");
1033 lua_setfield(L, 5, "message");
1034 } else if (
1035 pgstatus != PGRES_TUPLES_OK && pgstatus != PGRES_COMMAND_OK
1036 ) {
1037 const char *sqlstate;
1038 const char *errmsg;
1039 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SEVERITY));
1040 lua_setfield(L, 5, "pg_severity");
1041 sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
1042 if (sqlstate) {
1043 lua_pushstring(L, sqlstate);
1044 lua_setfield(L, 5, "pg_sqlstate");
1045 lua_pushstring(L, mondelefant_translate_errcode(sqlstate));
1046 lua_setfield(L, 5, "code");
1047 } else {
1048 lua_pushliteral(L, MONDELEFANT_ERRCODE_UNKNOWN);
1049 lua_setfield(L, 5, "code");
1051 errmsg = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY);
1052 if (errmsg) {
1053 mondelefant_push_first_line(L, errmsg);
1054 lua_setfield(L, 5, "message");
1055 lua_pushstring(L, errmsg);
1056 lua_setfield(L, 5, "pg_message_primary");
1057 } else {
1058 lua_pushliteral(L,
1059 "Error while fetching result, but no error message given."
1060 );
1061 lua_setfield(L, 5, "message");
1063 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL));
1064 lua_setfield(L, 5, "pg_message_detail");
1065 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_MESSAGE_HINT));
1066 lua_setfield(L, 5, "pg_message_hint");
1067 // NOTE: "position" and "pg_internal_position" are recalculated to
1068 // byte offsets, as Lua 5.2 is not Unicode aware.
1070 char *tmp;
1071 tmp = PQresultErrorField(res, PG_DIAG_STATEMENT_POSITION);
1072 if (tmp) {
1073 int pos;
1074 pos = atoi(tmp) - 1;
1075 if (conn->server_encoding == MONDELEFANT_SERVER_ENCODING_UTF8) {
1076 pos = utf8_position_to_byte(command, pos);
1078 lua_pushinteger(L, pos + 1);
1079 lua_setfield(L, 5, "position");
1083 const char *internal_query;
1084 internal_query = PQresultErrorField(res, PG_DIAG_INTERNAL_QUERY);
1085 lua_pushstring(L, internal_query);
1086 lua_setfield(L, 5, "pg_internal_query");
1087 char *tmp;
1088 tmp = PQresultErrorField(res, PG_DIAG_INTERNAL_POSITION);
1089 if (tmp) {
1090 int pos;
1091 pos = atoi(tmp) - 1;
1092 if (conn->server_encoding == MONDELEFANT_SERVER_ENCODING_UTF8) {
1093 pos = utf8_position_to_byte(internal_query, pos);
1095 lua_pushinteger(L, pos + 1);
1096 lua_setfield(L, 5, "pg_internal_position");
1099 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_CONTEXT));
1100 lua_setfield(L, 5, "pg_context");
1101 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_FILE));
1102 lua_setfield(L, 5, "pg_source_file");
1103 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_LINE));
1104 lua_setfield(L, 5, "pg_source_line");
1105 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_FUNCTION));
1106 lua_setfield(L, 5, "pg_source_function");
1107 } else if (rows < 1 && mode == MONDELEFANT_QUERY_MODE_OBJECT) {
1108 lua_pushliteral(L, MONDELEFANT_ERRCODE_QUERY1_NO_ROWS);
1109 lua_setfield(L, 5, "code");
1110 lua_pushliteral(L, "Expected one row, but got empty set.");
1111 lua_setfield(L, 5, "message");
1112 } else if (rows > 1 && mode != MONDELEFANT_QUERY_MODE_LIST) {
1113 lua_pushliteral(L, MONDELEFANT_ERRCODE_QUERY1_MULTIPLE_ROWS);
1114 lua_setfield(L, 5, "code");
1115 lua_pushliteral(L, "Got more than one result row.");
1116 lua_setfield(L, 5, "message");
1117 } else {
1118 // should not happen
1119 abort();
1121 if (res) {
1122 PQclear(res);
1123 while ((res = PQgetResult(conn->pgconn))) PQclear(res);
1124 // avoid double call of PQclear later:
1125 conn->todo_PQclear = NULL;
1128 if (lua_toboolean(L, 3)) {
1129 lua_pushvalue(L, 3);
1130 lua_pushvalue(L, 5);
1131 lua_call(L, 1, 0);
1133 return 1;
1135 // call "create_list" or "create_object" method of database handle,
1136 // result will be at stack position 5:
1137 if (modes[command_idx] == MONDELEFANT_QUERY_MODE_LIST) {
1138 lua_pushcfunction(L, mondelefant_conn_create_list); // 5
1139 lua_pushvalue(L, 1); // 6
1140 lua_call(L, 1, 1); // 5
1141 } else {
1142 lua_pushcfunction(L, mondelefant_conn_create_object); // 5
1143 lua_pushvalue(L, 1); // 6
1144 lua_call(L, 1, 1); // 5
1146 // set "_column_info":
1147 lua_newtable(L); // 6
1148 for (col = 0; col < cols; col++) {
1149 lua_newtable(L); // 7
1150 lua_pushstring(L, PQfname(res, col)); // 8
1151 lua_pushvalue(L, 8); // 9
1152 lua_pushvalue(L, 7); // 10
1153 lua_rawset(L, 6);
1154 lua_setfield(L, 7, "field_name");
1155 // _column_info entry (for current column) on stack position 7
1157 Oid tmp;
1158 tmp = PQftable(res, col);
1159 if (tmp == InvalidOid) lua_pushnil(L);
1160 else lua_pushinteger(L, tmp);
1161 lua_setfield(L, 7, "table_oid");
1164 int tmp;
1165 tmp = PQftablecol(res, col);
1166 if (tmp == 0) lua_pushnil(L);
1167 else lua_pushinteger(L, tmp);
1168 lua_setfield(L, 7, "table_column_number");
1171 Oid tmp;
1172 tmp = PQftype(res, col);
1173 binary[col] = (tmp == MONDELEFANT_POSTGRESQL_BINARY_OID);
1174 lua_pushinteger(L, tmp);
1175 lua_setfield(L, 7, "type_oid");
1176 lua_pushstring(L, mondelefant_oid_to_typestr(tmp));
1177 lua_setfield(L, 7, "type");
1180 int tmp;
1181 tmp = PQfmod(res, col);
1182 if (tmp == -1) lua_pushnil(L);
1183 else lua_pushinteger(L, tmp);
1184 lua_setfield(L, 7, "type_modifier");
1186 lua_rawseti(L, 6, col+1);
1188 lua_setfield(L, 5, "_column_info");
1189 // set "_rows_affected":
1191 char *tmp;
1192 tmp = PQcmdTuples(res);
1193 if (tmp[0]) {
1194 lua_pushinteger(L, atoi(tmp));
1195 lua_setfield(L, 5, "_rows_affected");
1198 // set "_oid":
1200 Oid tmp;
1201 tmp = PQoidValue(res);
1202 if (tmp != InvalidOid) {
1203 lua_pushinteger(L, tmp);
1204 lua_setfield(L, 5, "_oid");
1207 // copy data as strings or nil, while performing binary unescaping
1208 // automatically:
1209 if (modes[command_idx] == MONDELEFANT_QUERY_MODE_LIST) {
1210 for (row = 0; row < rows; row++) {
1211 lua_pushcfunction(L, mondelefant_conn_create_object); // 6
1212 lua_pushvalue(L, 1); // 7
1213 lua_call(L, 1, 1); // 6
1214 for (col = 0; col < cols; col++) {
1215 if (PQgetisnull(res, row, col)) {
1216 lua_pushnil(L);
1217 } else if (binary[col]) {
1218 size_t binlen;
1219 char *binval;
1220 // avoid cumulating memory leaks in case of previous out-of-memory errors:
1221 if (conn->todo_PQfreemem) {
1222 PQfreemem(conn->todo_PQfreemem);
1223 conn->todo_PQfreemem = NULL;
1225 // Unescape binary data:
1226 binval = (char *)PQunescapeBytea(
1227 (unsigned char *)PQgetvalue(res, row, col), &binlen
1228 );
1229 if (!binval) {
1230 return luaL_error(L,
1231 "Could not allocate memory for binary unescaping."
1232 );
1234 // ensure call of PQfreemem in case of out-of-memory error:
1235 conn->todo_PQfreemem = binval;
1236 // create Lua string:
1237 lua_pushlstring(L, binval, binlen);
1238 // free memory allocated by PQunescapeBytea:
1239 PQfreemem(binval);
1240 // avoid double call of PQfreemem later:
1241 conn->todo_PQfreemem = NULL;
1242 } else {
1243 lua_pushstring(L, PQgetvalue(res, row, col));
1245 lua_rawseti(L, 6, col+1);
1247 lua_rawseti(L, 5, row+1);
1249 } else if (rows == 1) {
1250 for (col = 0; col < cols; col++) {
1251 if (PQgetisnull(res, 0, col)) {
1252 lua_pushnil(L);
1253 } else if (binary[col]) {
1254 size_t binlen;
1255 char *binval;
1256 // avoid cumulating memory leaks in case of previous out-of-memory errors:
1257 if (conn->todo_PQfreemem) {
1258 PQfreemem(conn->todo_PQfreemem);
1259 conn->todo_PQfreemem = NULL;
1261 // Unescape binary data:
1262 binval = (char *)PQunescapeBytea(
1263 (unsigned char *)PQgetvalue(res, 0, col), &binlen
1264 );
1265 if (!binval) {
1266 return luaL_error(L,
1267 "Could not allocate memory for binary unescaping."
1268 );
1270 // ensure call of PQfreemem in case of out-of-memory error:
1271 conn->todo_PQfreemem = binval;
1272 // create Lua string:
1273 lua_pushlstring(L, binval, binlen);
1274 // free memory allocated by PQunescapeBytea:
1275 PQfreemem(binval);
1276 // avoid double call of PQfreemem later:
1277 conn->todo_PQfreemem = NULL;
1278 } else {
1279 lua_pushstring(L, PQgetvalue(res, 0, col));
1281 lua_rawseti(L, 5, col+1);
1283 } else {
1284 // no row in optrow mode
1285 lua_pop(L, 1);
1286 lua_pushnil(L);
1288 // save result in result list:
1289 lua_rawseti(L, 4, command_idx+1);
1290 // extra assertion:
1291 if (lua_gettop(L) != 4) abort(); // should not happen
1292 // free memory acquired by libpq:
1293 PQclear(res);
1294 // avoid double call of PQclear later:
1295 conn->todo_PQclear = NULL;
1297 // trace callback at stack position 3
1298 // result at stack position 4 (top of stack)
1299 // if a trace callback is existent, then call:
1300 if (lua_toboolean(L, 3)) {
1301 lua_pushvalue(L, 3);
1302 lua_call(L, 0, 0);
1304 // put result at stack position 3:
1305 lua_replace(L, 3);
1306 // get output converter to stack position 4:
1307 lua_getfield(L, 1, "output_converter");
1308 // get mutability state saver to stack position 5:
1309 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY);
1310 lua_getfield(L, -1, "save_mutability_state");
1311 lua_replace(L, -2);
1312 // apply output converters and fill "_data" table according to column names:
1313 for (command_idx = 0; command_idx < command_count; command_idx++) {
1314 int mode;
1315 mode = modes[command_idx];
1316 lua_rawgeti(L, 3, command_idx+1); // raw result at stack position 6
1317 if (lua_toboolean(L, 6)) {
1318 lua_getfield(L, 6, "_column_info"); // column_info list at position 7
1319 cols = lua_rawlen(L, 7);
1320 if (mode == MONDELEFANT_QUERY_MODE_LIST) {
1321 rows = lua_rawlen(L, 6);
1322 for (row = 0; row < rows; row++) {
1323 lua_rawgeti(L, 6, row+1); // row at stack position 8
1324 lua_getfield(L, 8, "_data"); // _data table at stack position 9
1325 lua_getfield(L, 8, "_dirty"); // _dirty table at stack position 10
1326 for (col = 0; col < cols; col++) {
1327 lua_rawgeti(L, 7, col+1); // this column info at position 11
1328 lua_getfield(L, 11, "field_name"); // 12
1329 if (lua_toboolean(L, 4)) {
1330 lua_pushvalue(L, 4); // output-converter
1331 lua_pushvalue(L, 1); // connection
1332 lua_rawgeti(L, 8, col+1); // raw-value
1333 lua_pushvalue(L, 11); // this column info
1334 lua_call(L, 3, 1); // converted value at position 13
1335 } else {
1336 lua_rawgeti(L, 8, col+1); // raw-value at position 13
1338 if (lua_toboolean(L, 5)) { // handle mutable values?
1339 lua_pushvalue(L, 12); // copy of field name
1340 lua_pushvalue(L, 5); // mutability state saver function
1341 lua_pushvalue(L, 13); // copy of value
1342 lua_call(L, 1, 1); // calculated mutability state of value
1343 lua_rawset(L, 10); // store mutability state in _dirty table
1345 lua_pushvalue(L, 13); // 14
1346 lua_rawseti(L, 8, col+1);
1347 lua_rawset(L, 9);
1348 lua_settop(L, 10);
1350 lua_settop(L, 7);
1352 } else {
1353 lua_getfield(L, 6, "_data"); // _data table at stack position 8
1354 lua_getfield(L, 6, "_dirty"); // _dirty table at stack position 9
1355 for (col = 0; col < cols; col++) {
1356 lua_rawgeti(L, 7, col+1); // this column info at position 10
1357 lua_getfield(L, 10, "field_name"); // 11
1358 if (lua_toboolean(L, 4)) {
1359 lua_pushvalue(L, 4); // output-converter
1360 lua_pushvalue(L, 1); // connection
1361 lua_rawgeti(L, 6, col+1); // raw-value
1362 lua_pushvalue(L, 10); // this column info
1363 lua_call(L, 3, 1); // converted value at position 12
1364 } else {
1365 lua_rawgeti(L, 6, col+1); // raw-value at position 12
1367 if (lua_toboolean(L, 5)) { // handle mutable values?
1368 lua_pushvalue(L, 11); // copy of field name
1369 lua_pushvalue(L, 5); // mutability state saver function
1370 lua_pushvalue(L, 12); // copy of value
1371 lua_call(L, 1, 1); // calculated mutability state of value
1372 lua_rawset(L, 9); // store mutability state in _dirty table
1374 lua_pushvalue(L, 12); // 13
1375 lua_rawseti(L, 6, col+1);
1376 lua_rawset(L, 8);
1377 lua_settop(L, 9);
1381 lua_settop(L, 5);
1383 // return nil as first result value, followed by result lists/objects:
1384 lua_settop(L, 3);
1385 lua_pushnil(L);
1386 for (command_idx = 0; command_idx < command_count; command_idx++) {
1387 lua_rawgeti(L, 3, command_idx+1);
1389 return command_count+1;
1392 // meta-method "__tostring" of error objects:
1393 static int mondelefant_errorobject_tostring(lua_State *L) {
1394 const char *errclass;
1395 const char *errmsg;
1396 luaL_checktype(L, 1, LUA_TTABLE);
1397 lua_settop(L, 1);
1398 lua_getfield(L, 1, "code"); // 2
1399 lua_getfield(L, 1, "message"); // 3
1400 errclass = lua_tostring(L, 2);
1401 errmsg = lua_tostring(L, 3);
1402 if (!errclass) errclass = "(null)";
1403 if (!errmsg) errclass = "(null)";
1404 lua_pushfstring(L, "database error of class \"%s\": %s", errclass, errmsg);
1405 return 1;
1408 // method "is_kind_of" of error objects:
1409 static int mondelefant_errorobject_is_kind_of(lua_State *L) {
1410 const char *errclass;
1411 luaL_checktype(L, 1, LUA_TTABLE);
1412 errclass = luaL_checkstring(L, 2);
1413 lua_settop(L, 2);
1414 lua_getfield(L, 1, "code"); // 3
1415 luaL_argcheck(L,
1416 lua_type(L, 3) == LUA_TSTRING,
1417 1,
1418 "field 'code' of error object is not a string"
1419 );
1420 lua_pushboolean(L,
1421 mondelefant_check_error_class(lua_tostring(L, 3), errclass)
1422 );
1423 return 1;
1426 // method "wait" of database handles:
1427 static int mondelefant_conn_wait(lua_State *L) {
1428 int argc;
1429 // count number of arguments:
1430 argc = lua_gettop(L);
1431 // insert "try_wait" function/method at stack position 1:
1432 lua_pushcfunction(L, mondelefant_conn_try_wait);
1433 lua_insert(L, 1);
1434 // call "try_wait" method:
1435 lua_call(L, argc, LUA_MULTRET); // results (with error) starting at index 1
1436 // check, if error occurred:
1437 if (lua_toboolean(L, 1)) {
1438 // raise error
1439 lua_settop(L, 1);
1440 return lua_error(L);
1441 } else {
1442 // return everything but nil error object:
1443 return lua_gettop(L) - 1;
1447 // method "query" of database handles:
1448 static int mondelefant_conn_query(lua_State *L) {
1449 int argc;
1450 // count number of arguments:
1451 argc = lua_gettop(L);
1452 // insert "try_query" function/method at stack position 1:
1453 lua_pushcfunction(L, mondelefant_conn_try_query);
1454 lua_insert(L, 1);
1455 // call "try_query" method:
1456 lua_call(L, argc, LUA_MULTRET); // results (with error) starting at index 1
1457 // check, if error occurred:
1458 if (lua_toboolean(L, 1)) {
1459 // raise error
1460 lua_settop(L, 1);
1461 return lua_error(L);
1462 } else {
1463 // return everything but nil error object:
1464 return lua_gettop(L) - 1;
1468 // library function "set_class":
1469 static int mondelefant_set_class(lua_State *L) {
1470 // ensure that first argument is a database result list/object:
1471 lua_settop(L, 2);
1472 lua_getmetatable(L, 1); // 3
1473 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_RESULT_MT_REGKEY); // 4
1474 luaL_argcheck(L, lua_compare(L, 3, 4, LUA_OPEQ), 1, "not a database result");
1475 // ensure that second argument is a database class (model):
1476 lua_settop(L, 2);
1477 lua_getmetatable(L, 2); // 3
1478 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_MT_REGKEY); // 4
1479 luaL_argcheck(L, lua_compare(L, 3, 4, LUA_OPEQ), 2, "not a database class");
1480 // set attribute "_class" of result list/object to given class:
1481 lua_settop(L, 2);
1482 lua_pushvalue(L, 2); // 3
1483 lua_setfield(L, 1, "_class");
1484 // test, if database result is a list (and not a single object):
1485 lua_getfield(L, 1, "_type"); // 3
1486 lua_pushliteral(L, "list"); // 4
1487 if (lua_rawequal(L, 3, 4)) {
1488 int i;
1489 // set attribute "_class" of all elements to given class:
1490 for (i=0; i < lua_rawlen(L, 1); i++) {
1491 lua_settop(L, 2);
1492 lua_rawgeti(L, 1, i+1); // 3
1493 lua_pushvalue(L, 2); // 4
1494 lua_setfield(L, 3, "_class");
1497 // return first argument:
1498 lua_settop(L, 1);
1499 return 1;
1502 // library function "new_class":
1503 static int mondelefant_new_class(lua_State *L) {
1504 // if no argument is given, use an empty table:
1505 if (lua_isnoneornil(L, 1)) {
1506 lua_settop(L, 0);
1507 lua_newtable(L); // 1
1508 } else {
1509 luaL_checktype(L, 1, LUA_TTABLE);
1510 lua_settop(L, 1);
1512 // set meta-table for database classes (models):
1513 luaL_setmetatable(L, MONDELEFANT_CLASS_MT_REGKEY);
1514 // check, if "prototype" attribute is not set:
1515 lua_pushliteral(L, "prototype"); // 2
1516 lua_rawget(L, 1); // 2
1517 if (!lua_toboolean(L, 2)) {
1518 // set "prototype" attribute to default prototype:
1519 lua_pushliteral(L, "prototype"); // 3
1520 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 4
1521 lua_rawset(L, 1);
1523 // set "object" attribute to empty table, unless it is already set:
1524 lua_settop(L, 1);
1525 lua_pushliteral(L, "object"); // 2
1526 lua_rawget(L, 1); // 2
1527 if (!lua_toboolean(L, 2)) {
1528 lua_pushliteral(L, "object"); // 3
1529 lua_newtable(L); // 4
1530 lua_rawset(L, 1);
1532 // set "object_get" attribute to empty table, unless it is already set:
1533 lua_settop(L, 1);
1534 lua_pushliteral(L, "object_get"); // 2
1535 lua_rawget(L, 1); // 2
1536 if (!lua_toboolean(L, 2)) {
1537 lua_pushliteral(L, "object_get"); // 3
1538 lua_newtable(L); // 4
1539 lua_rawset(L, 1);
1541 // set "object_set" attribute to empty table, unless it is already set:
1542 lua_settop(L, 1);
1543 lua_pushliteral(L, "object_set"); // 2
1544 lua_rawget(L, 1); // 2
1545 if (!lua_toboolean(L, 2)) {
1546 lua_pushliteral(L, "object_set"); // 3
1547 lua_newtable(L); // 4
1548 lua_rawset(L, 1);
1550 // set "list" attribute to empty table, unless it is already set:
1551 lua_settop(L, 1);
1552 lua_pushliteral(L, "list"); // 2
1553 lua_rawget(L, 1); // 2
1554 if (!lua_toboolean(L, 2)) {
1555 lua_pushliteral(L, "list"); // 3
1556 lua_newtable(L); // 4
1557 lua_rawset(L, 1);
1559 // set "references" attribute to empty table, unless it is already set:
1560 lua_settop(L, 1);
1561 lua_pushliteral(L, "references"); // 2
1562 lua_rawget(L, 1); // 2
1563 if (!lua_toboolean(L, 2)) {
1564 lua_pushliteral(L, "references"); // 3
1565 lua_newtable(L); // 4
1566 lua_rawset(L, 1);
1568 // set "foreign_keys" attribute to empty table, unless it is already set:
1569 lua_settop(L, 1);
1570 lua_pushliteral(L, "foreign_keys"); // 2
1571 lua_rawget(L, 1); // 2
1572 if (!lua_toboolean(L, 2)) {
1573 lua_pushliteral(L, "foreign_keys"); // 3
1574 lua_newtable(L); // 4
1575 lua_rawset(L, 1);
1577 // return table:
1578 lua_settop(L, 1);
1579 return 1;
1582 // method "get_reference" of classes (models):
1583 static int mondelefant_class_get_reference(lua_State *L) {
1584 lua_settop(L, 2);
1585 while (lua_toboolean(L, 1)) {
1586 // get "references" table:
1587 lua_getfield(L, 1, "references"); // 3
1588 // perform lookup:
1589 lua_pushvalue(L, 2); // 4
1590 lua_gettable(L, 3); // 4
1591 // return result, if lookup was successful:
1592 if (!lua_isnil(L, 4)) return 1;
1593 // replace current table by its prototype:
1594 lua_settop(L, 2);
1595 lua_pushliteral(L, "prototype"); // 3
1596 lua_rawget(L, 1); // 3
1597 lua_replace(L, 1);
1599 // return nothing:
1600 return 0;
1603 // method "iterate_over_references" of classes (models):
1604 static int mondelefant_class_iterate_over_references(lua_State *L) {
1605 return luaL_error(L, "Reference iterator not implemented yet."); // TODO
1608 // method "get_foreign_key_reference_name" of classes (models):
1609 static int mondelefant_class_get_foreign_key_reference_name(lua_State *L) {
1610 lua_settop(L, 2);
1611 while (lua_toboolean(L, 1)) {
1612 // get "foreign_keys" table:
1613 lua_getfield(L, 1, "foreign_keys"); // 3
1614 // perform lookup:
1615 lua_pushvalue(L, 2); // 4
1616 lua_gettable(L, 3); // 4
1617 // return result, if lookup was successful:
1618 if (!lua_isnil(L, 4)) return 1;
1619 // replace current table by its prototype:
1620 lua_settop(L, 2);
1621 lua_pushliteral(L, "prototype"); // 3
1622 lua_rawget(L, 1); // 3
1623 lua_replace(L, 1);
1625 // return nothing:
1626 return 0;
1629 // meta-method "__index" of database result lists and objects:
1630 static int mondelefant_result_index(lua_State *L) {
1631 const char *result_type;
1632 // only lookup, when key is a string not beginning with an underscore:
1633 if (lua_type(L, 2) != LUA_TSTRING || lua_tostring(L, 2)[0] == '_') {
1634 return 0;
1636 // class on stack position 3:
1637 lua_settop(L, 2);
1638 lua_getfield(L, 1, "_class"); // 3
1639 // get value of "_type" attribute:
1640 lua_getfield(L, 1, "_type"); // 4
1641 result_type = lua_tostring(L, 4);
1642 // different lookup for lists and objects:
1643 if (result_type && !strcmp(result_type, "object")) { // object
1644 lua_settop(L, 3);
1645 // try inherited attributes, methods or getter functions:
1646 lua_pushvalue(L, 3); // 4
1647 while (lua_toboolean(L, 4)) {
1648 lua_getfield(L, 4, "object"); // 5
1649 lua_pushvalue(L, 2); // 6
1650 lua_gettable(L, 5); // 6
1651 if (!lua_isnil(L, 6)) return 1;
1652 lua_settop(L, 4);
1653 lua_getfield(L, 4, "object_get"); // 5
1654 lua_pushvalue(L, 2); // 6
1655 lua_gettable(L, 5); // 6
1656 if (lua_toboolean(L, 6)) {
1657 lua_pushvalue(L, 1); // 7
1658 lua_call(L, 1, 1); // 6
1659 return 1;
1661 lua_settop(L, 4);
1662 lua_pushliteral(L, "prototype"); // 5
1663 lua_rawget(L, 4); // 5
1664 lua_replace(L, 4);
1666 lua_settop(L, 3);
1667 // try primary keys of referenced objects:
1668 lua_pushcfunction(L,
1669 mondelefant_class_get_foreign_key_reference_name
1670 ); // 4
1671 lua_pushvalue(L, 3); // 5
1672 lua_pushvalue(L, 2); // 6
1673 lua_call(L, 2, 1); // 4
1674 if (!lua_isnil(L, 4)) {
1675 // reference name at stack position 4
1676 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1677 lua_pushvalue(L, 3); // 6
1678 lua_pushvalue(L, 4); // 7
1679 lua_call(L, 2, 1); // reference info at stack position 5
1680 lua_getfield(L, 1, "_ref"); // 6
1681 lua_getfield(L, 5, "ref"); // 7
1682 lua_gettable(L, 6); // 7
1683 if (!lua_isnil(L, 7)) {
1684 if (lua_toboolean(L, 7)) {
1685 lua_getfield(L, 5, "that_key"); // 8
1686 if (lua_isnil(L, 8)) {
1687 return luaL_error(L, "Missing 'that_key' entry in model reference.");
1689 lua_gettable(L, 7); // 8
1690 } else {
1691 lua_pushnil(L);
1693 return 1;
1696 lua_settop(L, 3);
1697 lua_getfield(L, 1, "_data"); // _data table on stack position 4
1698 // try cached referenced object (or cached NULL reference):
1699 lua_getfield(L, 1, "_ref"); // 5
1700 lua_pushvalue(L, 2); // 6
1701 lua_gettable(L, 5); // 6
1702 if (lua_isboolean(L, 6) && !lua_toboolean(L, 6)) {
1703 lua_pushnil(L);
1704 return 1;
1705 } else if (!lua_isnil(L, 6)) {
1706 return 1;
1708 lua_settop(L, 4);
1709 // try to load a referenced object:
1710 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1711 lua_pushvalue(L, 3); // 6
1712 lua_pushvalue(L, 2); // 7
1713 lua_call(L, 2, 1); // 5
1714 if (!lua_isnil(L, 5)) {
1715 lua_settop(L, 2);
1716 lua_getfield(L, 1, "load"); // 3
1717 lua_pushvalue(L, 1); // 4 (self)
1718 lua_pushvalue(L, 2); // 5
1719 lua_call(L, 2, 0);
1720 lua_settop(L, 2);
1721 lua_getfield(L, 1, "_ref"); // 3
1722 lua_pushvalue(L, 2); // 4
1723 lua_gettable(L, 3); // 4
1724 if (lua_isboolean(L, 4) && !lua_toboolean(L, 4)) lua_pushnil(L); // TODO: use special object instead of false
1725 return 1;
1727 lua_settop(L, 4);
1728 // check if proxy access to document in special column is enabled:
1729 lua_getfield(L, 3, "document_column"); // 5
1730 if (lua_toboolean(L, 5)) {
1731 // if yes, then proxy access:
1732 lua_gettable(L, 4); // 5
1733 if (!lua_isnil(L, 5)) {
1734 lua_pushvalue(L, 2); // 6
1735 lua_gettable(L, 5); // 6
1737 } else {
1738 // else use _data table:
1739 lua_pushvalue(L, 2); // 6
1740 lua_gettable(L, 4); // 6
1742 return 1; // return element at stack position 5 or 6
1743 } else if (result_type && !strcmp(result_type, "list")) { // list
1744 lua_settop(L, 3);
1745 // try inherited list attributes or methods:
1746 while (lua_toboolean(L, 3)) {
1747 lua_getfield(L, 3, "list"); // 4
1748 lua_pushvalue(L, 2); // 5
1749 lua_gettable(L, 4); // 5
1750 if (!lua_isnil(L, 5)) return 1;
1751 lua_settop(L, 3);
1752 lua_pushliteral(L, "prototype"); // 4
1753 lua_rawget(L, 3); // 4
1754 lua_replace(L, 3);
1757 // return nothing:
1758 return 0;
1761 // meta-method "__newindex" of database result lists and objects:
1762 static int mondelefant_result_newindex(lua_State *L) {
1763 const char *result_type;
1764 // perform rawset, unless key is a string not starting with underscore:
1765 lua_settop(L, 3);
1766 if (lua_type(L, 2) != LUA_TSTRING || lua_tostring(L, 2)[0] == '_') {
1767 lua_rawset(L, 1);
1768 return 1;
1770 // class on stack position 4:
1771 lua_settop(L, 3);
1772 lua_getfield(L, 1, "_class"); // 4
1773 // get value of "_type" attribute:
1774 lua_getfield(L, 1, "_type"); // 5
1775 result_type = lua_tostring(L, 5);
1776 // distinguish between lists and objects:
1777 if (result_type && !strcmp(result_type, "object")) { // objects
1778 lua_settop(L, 4);
1779 // try object setter functions:
1780 lua_pushvalue(L, 4); // 5
1781 while (lua_toboolean(L, 5)) {
1782 lua_getfield(L, 5, "object_set"); // 6
1783 lua_pushvalue(L, 2); // 7
1784 lua_gettable(L, 6); // 7
1785 if (lua_toboolean(L, 7)) {
1786 lua_pushvalue(L, 1); // 8
1787 lua_pushvalue(L, 3); // 9
1788 lua_call(L, 2, 0);
1789 return 0;
1791 lua_settop(L, 5);
1792 lua_pushliteral(L, "prototype"); // 6
1793 lua_rawget(L, 5); // 6
1794 lua_replace(L, 5);
1796 lua_settop(L, 4);
1797 lua_getfield(L, 1, "_data"); // _data table on stack position 5
1798 // check, if a object reference is changed:
1799 lua_pushcfunction(L, mondelefant_class_get_reference); // 6
1800 lua_pushvalue(L, 4); // 7
1801 lua_pushvalue(L, 2); // 8
1802 lua_call(L, 2, 1); // 6
1803 if (!lua_isnil(L, 6)) {
1804 // special handling of 1:1 references (primary side):
1805 lua_getfield(L, 6, "mode"); // 7
1806 if (lua_isstring(L, 7) && !strcmp(lua_tostring(L, 7), "11")) {
1807 lua_getfield(L, 6, "primary"); // 8
1808 if (lua_toboolean(L, 8)) {
1809 if (!lua_isnil(L, 3)) {
1810 // set backward reference:
1811 lua_getfield(L, 6, "back_ref"); // 9
1812 if (lua_toboolean(L, 9)) {
1813 lua_pushvalue(L, 1); // 10
1814 lua_settable(L, 3);
1817 // do nothing else:
1818 return 0;
1821 lua_settop(L, 6);
1822 // store object in _ref table (use false for nil): // TODO: use special object instead of false
1823 lua_getfield(L, 1, "_ref"); // 7
1824 lua_pushvalue(L, 2); // 8
1825 if (lua_isnil(L, 3)) lua_pushboolean(L, 0); // 9
1826 else lua_pushvalue(L, 3); // 9
1827 lua_settable(L, 7);
1828 lua_settop(L, 6);
1829 // special handling of 1:1 references (secondary side):
1830 lua_getfield(L, 6, "mode"); // 7
1831 if (lua_isstring(L, 7) && !strcmp(lua_tostring(L, 7), "11")) {
1832 lua_settop(L, 6);
1833 if (!lua_isnil(L, 3)) {
1834 // store object in other _ref table (use false for nil): // TODO: use special object instead of false
1835 lua_getfield(L, 3, "_ref"); // 7
1836 lua_getfield(L, 6, "back_ref"); // 8
1837 if (lua_toboolean(L, 8)) {
1838 lua_pushvalue(L, 1); // 9
1839 lua_settable(L, 7);
1843 lua_settop(L, 6);
1844 // delete referencing key from _data table:
1845 lua_getfield(L, 6, "this_key"); // 7
1846 if (lua_isnil(L, 7)) {
1847 return luaL_error(L, "Missing 'this_key' entry in model reference.");
1849 lua_pushvalue(L, 7); // 8
1850 lua_pushnil(L); // 9
1851 lua_settable(L, 5);
1852 lua_getfield(L, 1, "_dirty"); // 8
1853 lua_pushvalue(L, 7); // 9
1854 lua_pushboolean(L, 1); // 10
1855 lua_settable(L, 8);
1856 return 0;
1858 lua_settop(L, 5);
1859 // check proxy access to document in special column:
1860 lua_getfield(L, 4, "document_column"); // 6
1861 if (lua_toboolean(L, 6)) {
1862 lua_gettable(L, 5); // 6
1863 if (lua_isnil(L, 6)) {
1864 return luaL_error(L, "Cannot write to document column: document is nil");
1866 lua_pushvalue(L, 2); // 7
1867 lua_pushvalue(L, 3); // 8
1868 lua_settable(L, 6);
1869 return 0;
1871 lua_settop(L, 5);
1872 // store value in data field info:
1873 lua_pushvalue(L, 2); // 6
1874 lua_pushvalue(L, 3); // 7
1875 lua_settable(L, 5);
1876 lua_settop(L, 4);
1877 // mark field as dirty (needs to be UPDATEd on save):
1878 lua_getfield(L, 1, "_dirty"); // 5
1879 lua_pushvalue(L, 2); // 6
1880 lua_pushboolean(L, 1); // 7
1881 lua_settable(L, 5);
1882 lua_settop(L, 4);
1883 // reset reference cache, if neccessary:
1884 lua_pushcfunction(L,
1885 mondelefant_class_get_foreign_key_reference_name
1886 ); // 5
1887 lua_pushvalue(L, 4); // 6
1888 lua_pushvalue(L, 2); // 7
1889 lua_call(L, 2, 1); // 5
1890 if (!lua_isnil(L, 5)) {
1891 lua_getfield(L, 1, "_ref"); // 6
1892 lua_pushvalue(L, 5); // 7
1893 lua_pushnil(L); // 8
1894 lua_settable(L, 6);
1896 return 0;
1897 } else { // non-objects (i.e. lists)
1898 // perform rawset:
1899 lua_settop(L, 3);
1900 lua_rawset(L, 1);
1901 return 0;
1905 // meta-method "__index" of column proxy:
1906 static int mondelefant_columns_index(lua_State *L) {
1907 luaL_checktype(L, 1, LUA_TTABLE);
1908 lua_settop(L, 2);
1909 lua_rawgetp(L, 1, MONDELEFANT_COLUMNS_RESULT_LUKEY); // 3
1910 // try primary keys of referenced objects:
1911 lua_pushcfunction(L,
1912 mondelefant_class_get_foreign_key_reference_name
1913 ); // 4
1914 lua_getfield(L, 3, "_class"); // 5
1915 lua_pushvalue(L, 2); // 6
1916 lua_call(L, 2, 1); // 4
1917 if (!lua_isnil(L, 4)) {
1918 // reference name at stack position 4
1919 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1920 lua_getfield(L, 3, "_class"); // 6
1921 lua_pushvalue(L, 4); // 7
1922 lua_call(L, 2, 1); // reference info at stack position 5
1923 lua_getfield(L, 3, "_ref"); // 6
1924 lua_getfield(L, 5, "ref"); // 7
1925 lua_gettable(L, 6); // 7
1926 if (!lua_isnil(L, 7)) {
1927 if (lua_toboolean(L, 7)) {
1928 lua_getfield(L, 5, "that_key"); // 8
1929 if (lua_isnil(L, 8)) {
1930 return luaL_error(L, "Missing 'that_key' entry in model reference.");
1932 lua_gettable(L, 7); // 8
1933 } else {
1934 lua_pushnil(L);
1936 return 1;
1939 lua_settop(L, 3);
1940 // if not successful, use _data table:
1941 lua_getfield(L, 3, "_data"); // 4
1942 lua_pushvalue(L, 2); // 5
1943 lua_gettable(L, 4); // 5
1944 return 1;
1947 // meta-method "__newindex" of column proxy:
1948 static int mondelefant_columns_newindex(lua_State *L) {
1949 luaL_checktype(L, 1, LUA_TTABLE);
1950 lua_settop(L, 3);
1951 lua_rawgetp(L, 1, MONDELEFANT_COLUMNS_RESULT_LUKEY); // 4
1952 // reset reference cache, if neccessary:
1953 lua_pushcfunction(L,
1954 mondelefant_class_get_foreign_key_reference_name
1955 ); // 5
1956 lua_getfield(L, 4, "_class"); // 6
1957 lua_pushvalue(L, 2); // 7
1958 lua_call(L, 2, 1); // 5
1959 if (!lua_isnil(L, 5)) {
1960 lua_getfield(L, 4, "_ref"); // 6
1961 lua_pushvalue(L, 5); // 7
1962 lua_pushnil(L); // 8
1963 lua_settable(L, 6);
1965 lua_settop(L, 4);
1966 // set _data and _dirty:
1967 lua_getfield(L, 4, "_data"); // 5
1968 lua_getfield(L, 4, "_dirty"); // 6
1969 lua_pushvalue(L, 2);
1970 lua_pushvalue(L, 3);
1971 lua_settable(L, 5);
1972 lua_pushvalue(L, 2);
1973 lua_pushboolean(L, 1);
1974 lua_settable(L, 6);
1975 return 0;
1978 // meta-method "__index" of classes (models):
1979 static int mondelefant_class_index(lua_State *L) {
1980 // perform lookup in prototype:
1981 lua_settop(L, 2);
1982 lua_pushliteral(L, "prototype"); // 3
1983 lua_rawget(L, 1); // 3
1984 lua_pushvalue(L, 2); // 4
1985 lua_gettable(L, 3); // 4
1986 return 1;
1989 // registration information for functions of library:
1990 static const struct luaL_Reg mondelefant_module_functions[] = {
1991 {"connect", mondelefant_connect},
1992 {"set_class", mondelefant_set_class},
1993 {"new_class", mondelefant_new_class},
1994 {NULL, NULL}
1995 };
1997 // registration information for meta-methods of database connections:
1998 static const struct luaL_Reg mondelefant_conn_mt_functions[] = {
1999 {"__gc", mondelefant_conn_free},
2000 {"__index", mondelefant_conn_index},
2001 {"__newindex", mondelefant_conn_newindex},
2002 {NULL, NULL}
2003 };
2005 // registration information for methods of database connections:
2006 static const struct luaL_Reg mondelefant_conn_methods[] = {
2007 {"close", mondelefant_conn_close},
2008 {"is_ok", mondelefant_conn_is_ok},
2009 {"get_transaction_status", mondelefant_conn_get_transaction_status},
2010 {"try_wait", mondelefant_conn_try_wait},
2011 {"wait", mondelefant_conn_wait},
2012 {"create_list", mondelefant_conn_create_list},
2013 {"create_object", mondelefant_conn_create_object},
2014 {"quote_string", mondelefant_conn_quote_string},
2015 {"quote_binary", mondelefant_conn_quote_binary},
2016 {"assemble_command", mondelefant_conn_assemble_command},
2017 {"try_query", mondelefant_conn_try_query},
2018 {"query", mondelefant_conn_query},
2019 {NULL, NULL}
2020 };
2022 // registration information for meta-methods of error objects:
2023 static const struct luaL_Reg mondelefant_errorobject_mt_functions[] = {
2024 {"__tostring", mondelefant_errorobject_tostring},
2025 {NULL, NULL}
2026 };
2028 // registration information for methods of error objects:
2029 static const struct luaL_Reg mondelefant_errorobject_methods[] = {
2030 {"escalate", lua_error},
2031 {"is_kind_of", mondelefant_errorobject_is_kind_of},
2032 {NULL, NULL}
2033 };
2035 // registration information for meta-methods of database result lists/objects:
2036 static const struct luaL_Reg mondelefant_result_mt_functions[] = {
2037 {"__index", mondelefant_result_index},
2038 {"__newindex", mondelefant_result_newindex},
2039 {NULL, NULL}
2040 };
2042 // registration information for meta-methods of classes (models):
2043 static const struct luaL_Reg mondelefant_class_mt_functions[] = {
2044 {"__index", mondelefant_class_index},
2045 {NULL, NULL}
2046 };
2048 // registration information for methods of classes (models):
2049 static const struct luaL_Reg mondelefant_class_methods[] = {
2050 {"get_reference", mondelefant_class_get_reference},
2051 {"iterate_over_references", mondelefant_class_iterate_over_references},
2052 {"get_foreign_key_reference_name",
2053 mondelefant_class_get_foreign_key_reference_name},
2054 {NULL, NULL}
2055 };
2057 // registration information for methods of database result objects (not lists!):
2058 static const struct luaL_Reg mondelefant_object_methods[] = {
2059 {NULL, NULL}
2060 };
2062 // registration information for methods of database result lists (not single objects!):
2063 static const struct luaL_Reg mondelefant_list_methods[] = {
2064 {NULL, NULL}
2065 };
2067 // registration information for meta-methods of column proxy:
2068 static const struct luaL_Reg mondelefant_columns_mt_functions[] = {
2069 {"__index", mondelefant_columns_index},
2070 {"__newindex", mondelefant_columns_newindex},
2071 {NULL, NULL}
2072 };
2074 // luaopen function to initialize/register library:
2075 int luaopen_mondelefant_native(lua_State *L) {
2076 lua_settop(L, 0);
2078 lua_newtable(L); // meta-table for columns proxy
2079 luaL_setfuncs(L, mondelefant_columns_mt_functions, 0);
2080 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_COLUMNS_MT_REGKEY);
2082 lua_newtable(L); // module at stack position 1
2083 luaL_setfuncs(L, mondelefant_module_functions, 0);
2085 lua_pushvalue(L, 1); // 2
2086 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY);
2088 lua_newtable(L); // 2
2089 // NOTE: only PostgreSQL is supported yet:
2090 luaL_setfuncs(L, mondelefant_conn_methods, 0);
2091 lua_setfield(L, 1, "postgresql_connection_prototype");
2092 lua_newtable(L); // 2
2093 lua_setfield(L, 1, "connection_prototype");
2095 luaL_newmetatable(L, MONDELEFANT_CONN_MT_REGKEY); // 2
2096 luaL_setfuncs(L, mondelefant_conn_mt_functions, 0);
2097 lua_settop(L, 1);
2098 luaL_newmetatable(L, MONDELEFANT_RESULT_MT_REGKEY); // 2
2099 luaL_setfuncs(L, mondelefant_result_mt_functions, 0);
2100 lua_setfield(L, 1, "result_metatable");
2101 luaL_newmetatable(L, MONDELEFANT_CLASS_MT_REGKEY); // 2
2102 luaL_setfuncs(L, mondelefant_class_mt_functions, 0);
2103 lua_setfield(L, 1, "class_metatable");
2105 lua_newtable(L); // 2
2106 luaL_setfuncs(L, mondelefant_class_methods, 0);
2107 lua_newtable(L); // 3
2108 luaL_setfuncs(L, mondelefant_object_methods, 0);
2109 lua_setfield(L, 2, "object");
2110 lua_newtable(L); // 3
2111 lua_setfield(L, 2, "object_get");
2112 lua_newtable(L); // 3
2113 lua_setfield(L, 2, "object_set");
2114 lua_newtable(L); // 3
2115 luaL_setfuncs(L, mondelefant_list_methods, 0);
2116 lua_setfield(L, 2, "list");
2117 lua_newtable(L); // 3
2118 lua_setfield(L, 2, "references");
2119 lua_newtable(L); // 3
2120 lua_setfield(L, 2, "foreign_keys");
2121 lua_pushvalue(L, 2); // 3
2122 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY);
2123 lua_setfield(L, 1, "class_prototype");
2125 luaL_newmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY); // 2
2126 luaL_setfuncs(L, mondelefant_errorobject_mt_functions, 0);
2127 lua_newtable(L); // 3
2128 luaL_setfuncs(L, mondelefant_errorobject_methods, 0);
2129 lua_setfield(L, 2, "__index");
2130 lua_setfield(L, 1, "errorobject_metatable");
2132 return 1;

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