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view libraries/mondelefant/mondelefant_native.c @ 466:2751b6b81c23

Minor efficiency enhancement in <db_object>:try_save() method
author jbe
date Mon Nov 07 19:32:51 2016 +0100 (2016-11-07)
parents 66d7a0ac9c9d
children 07e7e218d8df
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 // set "_class" attribute to default class:
554 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 3
555 lua_setfield(L, 2, "_class");
556 // return created database result list:
557 return 1;
558 }
560 // method "create_object" of database handles:
561 static int mondelefant_conn_create_object(lua_State *L) {
562 // ensure that first argument is a database connection:
563 luaL_checkudata(L, 1, MONDELEFANT_CONN_MT_REGKEY);
564 // create new table on stack position 2:
565 lua_settop(L, 1);
566 lua_newtable(L); // 2
567 // set meta-table for database result lists/objects:
568 luaL_setmetatable(L, MONDELEFANT_RESULT_MT_REGKEY);
569 // set "_connection" attribute to self:
570 lua_pushvalue(L, 1); // 3
571 lua_setfield(L, 2, "_connection");
572 // set "_type" attribute to string "object":
573 lua_pushliteral(L, "object"); // 3
574 lua_setfield(L, 2, "_type"); // "object" or "list"
575 // set "_class" attribute to default class:
576 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 3
577 lua_setfield(L, 2, "_class");
578 // create empty tables for "_data", "_dirty" and "_ref" attributes:
579 lua_newtable(L); // 3
580 lua_setfield(L, 2, "_data");
581 lua_newtable(L); // 3
582 lua_setfield(L, 2, "_dirty");
583 lua_newtable(L); // 3
584 lua_setfield(L, 2, "_ref"); // nil=no info, false=nil, else table
585 // create column proxy (field "_col" in result object):
586 lua_newtable(L); // 3
587 luaL_setmetatable(L, MONDELEFANT_COLUMNS_MT_REGKEY);
588 lua_pushvalue(L, 2); // 4
589 lua_rawsetp(L, 3, MONDELEFANT_COLUMNS_RESULT_LUKEY);
590 lua_setfield(L, 2, "_col");
591 // return created database result object (from stack position 2):
592 return 1;
593 }
595 // method "quote_string" of database handles:
596 static int mondelefant_conn_quote_string(lua_State *L) {
597 mondelefant_conn_t *conn;
598 const char *input;
599 size_t input_len;
600 luaL_Buffer buf;
601 char *output;
602 size_t output_len;
603 // get database connection object:
604 conn = mondelefant_get_conn(L, 1);
605 // get second argument, which must be a string:
606 input = luaL_checklstring(L, 2, &input_len);
607 // throw error, if string is too long:
608 if (input_len > (SIZE_MAX / sizeof(char) - 3) / 2) {
609 return luaL_error(L, "String to be escaped is too long.");
610 }
611 // allocate memory for quoted string:
612 output = luaL_buffinitsize(L, &buf, (2 * input_len + 3) * sizeof(char));
613 // do escaping by calling PQescapeStringConn and enclosing result with
614 // single quotes:
615 output[0] = '\'';
616 output_len = PQescapeStringConn(
617 conn->pgconn, output + 1, input, input_len, NULL
618 );
619 output[output_len + 1] = '\'';
620 output[output_len + 2] = 0;
621 // create Lua string:
622 luaL_addsize(&buf, output_len + 2);
623 luaL_pushresult(&buf);
624 // return Lua string:
625 return 1;
626 }
628 // method "quote_binary" of database handles:
629 static int mondelefant_conn_quote_binary(lua_State *L) {
630 mondelefant_conn_t *conn;
631 const char *input;
632 size_t input_len;
633 char *output;
634 size_t output_len;
635 luaL_Buffer buf;
636 // get database connection object:
637 conn = mondelefant_get_conn(L, 1);
638 // get second argument, which must be a string:
639 input = luaL_checklstring(L, 2, &input_len);
640 // avoid cumulating memory leaks in case of previous out-of-memory errors:
641 if (conn->todo_PQfreemem) {
642 PQfreemem(conn->todo_PQfreemem);
643 conn->todo_PQfreemem = NULL;
644 }
645 // call PQescapeByteaConn, which allocates memory itself:
646 output = (char *)PQescapeByteaConn(
647 conn->pgconn, (const unsigned char *)input, input_len, &output_len
648 );
649 if (!output) {
650 lua_gc(L, LUA_GCCOLLECT, 0);
651 output = (char *)PQescapeByteaConn(
652 conn->pgconn, (const unsigned char *)input, input_len, &output_len
653 );
654 if (!output) {
655 return luaL_error(L, "Could not allocate memory for binary quoting.");
656 }
657 }
658 // ensure call of PQfreemem in case of out-of-memory errors:
659 conn->todo_PQfreemem = output;
660 // create Lua string enclosed by single quotes:
661 luaL_buffinit(L, &buf);
662 luaL_addchar(&buf, '\'');
663 luaL_addlstring(&buf, output, output_len - 1);
664 luaL_addchar(&buf, '\'');
665 luaL_pushresult(&buf);
666 // free memory allocated by PQescapeByteaConn:
667 PQfreemem(output);
668 // avoid double call of PQfreemem later:
669 conn->todo_PQfreemem = NULL;
670 // return Lua string:
671 return 1;
672 }
674 // method "assemble_command" of database handles:
675 static int mondelefant_conn_assemble_command(lua_State *L) {
676 mondelefant_conn_t *conn;
677 int paramidx = 2;
678 const char *template;
679 size_t template_pos = 0;
680 luaL_Buffer buf;
681 // get database connection object:
682 conn = mondelefant_get_conn(L, 1);
683 // if second argument is a string, return this string:
684 if (lua_type(L, 2) == LUA_TSTRING) {
685 lua_settop(L, 2);
686 return 1;
687 }
688 // if second argument has __tostring meta-method,
689 // then use this method and return its result:
690 if (luaL_callmeta(L, 2, "__tostring")) return 1;
691 // otherwise, require that second argument is a table:
692 luaL_checktype(L, 2, LUA_TTABLE);
693 // set stack top:
694 lua_settop(L, 2);
695 // get first element of table, which must be a string:
696 lua_rawgeti(L, 2, 1); // 3
697 luaL_argcheck(L,
698 lua_isstring(L, 3),
699 2,
700 "First entry of SQL command structure is not a string."
701 );
702 template = lua_tostring(L, 3);
703 // get value of "input_converter" attribute of database connection:
704 lua_pushliteral(L, "input_converter"); // 4
705 lua_gettable(L, 1); // input_converter at stack position 4
706 // reserve space on Lua stack:
707 lua_pushnil(L); // free space at stack position 5
708 lua_pushnil(L); // free space at stack position 6
709 // initialize Lua buffer for result string:
710 luaL_buffinit(L, &buf);
711 // fill buffer in loop:
712 while (1) {
713 // variable declaration:
714 char c;
715 // get next character:
716 c = template[template_pos++];
717 // break, when character is NULL byte:
718 if (!c) break;
719 // question-mark and dollar-sign are special characters:
720 if (c == '?' || c == '$') { // special character found
721 // check, if same character follows:
722 if (template[template_pos] == c) { // special character is escaped
723 // consume two characters of input and add one character to buffer:
724 template_pos++;
725 luaL_addchar(&buf, c);
726 } else { // special character is not escaped
727 luaL_Buffer keybuf;
728 int subcmd;
729 // set 'subcmd' = true, if special character was a dollar-sign,
730 // set 'subcmd' = false, if special character was a question-mark:
731 subcmd = (c == '$');
732 // read any number of alpha numeric chars or underscores
733 // and store them on Lua stack:
734 luaL_buffinit(L, &keybuf);
735 while (1) {
736 c = template[template_pos];
737 if (
738 (c < 'A' || c > 'Z') &&
739 (c < 'a' || c > 'z') &&
740 (c < '0' || c > '9') &&
741 (c != '_')
742 ) break;
743 luaL_addchar(&keybuf, c);
744 template_pos++;
745 }
746 luaL_pushresult(&keybuf);
747 // check, if any characters matched:
748 if (lua_rawlen(L, -1)) {
749 // if any alpha numeric chars or underscores were found,
750 // push them on stack as a Lua string and use them to lookup
751 // value from second argument:
752 lua_pushvalue(L, -1); // save key on stack
753 lua_gettable(L, 2); // fetch value (raw-value)
754 } else {
755 // otherwise push nil and use numeric lookup based on 'paramidx':
756 lua_pop(L, 1);
757 lua_pushnil(L); // put nil on key position
758 lua_rawgeti(L, 2, paramidx++); // fetch value (raw-value)
759 }
760 // Lua stack contains: ..., <buffer>, key, raw-value
761 // branch according to type of special character ("?" or "$"):
762 if (subcmd) { // dollar-sign
763 size_t i;
764 size_t count;
765 // store fetched value (which is supposed to be sub-structure)
766 // on Lua stack position 5 and drop key:
767 lua_replace(L, 5);
768 lua_pop(L, 1);
769 // Lua stack contains: ..., <buffer>
770 // check, if fetched value is really a sub-structure:
771 luaL_argcheck(L,
772 !lua_isnil(L, 5),
773 2,
774 "SQL sub-structure not found."
775 );
776 luaL_argcheck(L,
777 lua_type(L, 5) == LUA_TTABLE,
778 2,
779 "SQL sub-structure must be a table."
780 );
781 // Lua stack contains: ..., <buffer>
782 // get value of "sep" attribute of sub-structure,
783 // and place it on Lua stack position 6:
784 lua_getfield(L, 5, "sep");
785 lua_replace(L, 6);
786 // if seperator is nil, then use ", " as default,
787 // if seperator is neither nil nor a string, then throw error:
788 if (lua_isnil(L, 6)) {
789 lua_pushstring(L, ", ");
790 lua_replace(L, 6);
791 } else {
792 luaL_argcheck(L,
793 lua_isstring(L, 6),
794 2,
795 "Seperator of SQL sub-structure has to be a string."
796 );
797 }
798 // iterate over items of sub-structure:
799 count = lua_rawlen(L, 5);
800 for (i = 0; i < count; i++) {
801 // add seperator, unless this is the first run:
802 if (i) {
803 lua_pushvalue(L, 6);
804 luaL_addvalue(&buf);
805 }
806 // recursivly apply assemble function and add results to buffer:
807 lua_pushcfunction(L, mondelefant_conn_assemble_command);
808 lua_pushvalue(L, 1);
809 lua_rawgeti(L, 5, i+1);
810 lua_call(L, 2, 1);
811 luaL_addvalue(&buf);
812 }
813 } else { // question-mark
814 if (lua_toboolean(L, 4)) {
815 // call input_converter with connection handle, raw-value and
816 // an info-table which contains a "field_name" entry with the
817 // used key:
818 lua_pushvalue(L, 4);
819 lua_pushvalue(L, 1);
820 lua_pushvalue(L, -3);
821 lua_newtable(L);
822 lua_pushvalue(L, -6);
823 lua_setfield(L, -2, "field_name");
824 lua_call(L, 3, 1);
825 // Lua stack contains: ..., <buffer>, key, raw-value, final-value
826 // remove key and raw-value:
827 lua_remove(L, -2);
828 lua_remove(L, -2);
829 // Lua stack contains: ..., <buffer>, final-value
830 // throw error, if final-value is not a string:
831 if (!lua_isstring(L, -1)) {
832 return luaL_error(L, "input_converter returned non-string.");
833 }
834 } else {
835 // remove key from stack:
836 lua_remove(L, -2);
837 // Lua stack contains: ..., <buffer>, raw-value
838 // branch according to type of value:
839 // NOTE: Lua automatically converts numbers to strings
840 if (lua_isnil(L, -1)) { // value is nil
841 // push string "NULL" to stack:
842 lua_pushliteral(L, "NULL");
843 } else if (lua_type(L, -1) == LUA_TBOOLEAN) { // value is boolean
844 // push strings "TRUE" or "FALSE" to stack:
845 lua_pushstring(L, lua_toboolean(L, -1) ? "TRUE" : "FALSE");
846 } else if (lua_isstring(L, -1)) { // value is string or number
847 // push output of "quote_string" method of database connection
848 // to stack:
849 lua_tostring(L, -1);
850 lua_pushcfunction(L, mondelefant_conn_quote_string);
851 lua_pushvalue(L, 1);
852 lua_pushvalue(L, -3);
853 lua_call(L, 2, 1);
854 } else { // value is of other type
855 // throw error:
856 return luaL_error(L,
857 "Unable to convert SQL value due to unknown type "
858 "or missing input_converter."
859 );
860 }
861 // Lua stack contains: ..., <buffer>, raw-value, final-value
862 // remove raw-value:
863 lua_remove(L, -2);
864 // Lua stack contains: ..., <buffer>, final-value
865 }
866 // append final-value to buffer:
867 luaL_addvalue(&buf);
868 }
869 }
870 } else { // character is not special
871 // just copy character:
872 luaL_addchar(&buf, c);
873 }
874 }
875 // return string in buffer:
876 luaL_pushresult(&buf);
877 return 1;
878 }
880 // max number of SQL statements executed by one "query" method call:
881 #define MONDELEFANT_MAX_COMMAND_COUNT 64
882 // max number of columns in a database result:
883 #define MONDELEFANT_MAX_COLUMN_COUNT 1024
884 // enum values for 'modes' array in C-function below:
885 #define MONDELEFANT_QUERY_MODE_LIST 1
886 #define MONDELEFANT_QUERY_MODE_OBJECT 2
887 #define MONDELEFANT_QUERY_MODE_OPT_OBJECT 3
889 // method "try_query" of database handles:
890 static int mondelefant_conn_try_query(lua_State *L) {
891 mondelefant_conn_t *conn;
892 int command_count;
893 int command_idx;
894 int modes[MONDELEFANT_MAX_COMMAND_COUNT];
895 luaL_Buffer buf;
896 int sent_success;
897 PGresult *res;
898 int rows, cols, row, col;
899 // get database connection object:
900 conn = mondelefant_get_conn(L, 1);
901 // calculate number of commands (2 arguments for one command):
902 command_count = lua_gettop(L) / 2;
903 // push nil on stack, which is needed, if last mode was ommitted:
904 lua_pushnil(L);
905 // throw error, if number of commands is too high:
906 if (command_count > MONDELEFANT_MAX_COMMAND_COUNT) {
907 return luaL_error(L, "Exceeded maximum command count in one query.");
908 }
909 // create SQL string, store query modes and push SQL string on stack:
910 luaL_buffinit(L, &buf);
911 for (command_idx = 0; command_idx < command_count; command_idx++) {
912 int mode;
913 int mode_idx; // stack index of mode string
914 if (command_idx) luaL_addchar(&buf, ' ');
915 lua_pushcfunction(L, mondelefant_conn_assemble_command);
916 lua_pushvalue(L, 1);
917 lua_pushvalue(L, 2 + 2 * command_idx);
918 lua_call(L, 2, 1);
919 luaL_addvalue(&buf);
920 luaL_addchar(&buf, ';');
921 mode_idx = 3 + 2 * command_idx;
922 if (lua_isnil(L, mode_idx)) {
923 mode = MONDELEFANT_QUERY_MODE_LIST;
924 } else {
925 const char *modestr;
926 modestr = luaL_checkstring(L, mode_idx);
927 if (!strcmp(modestr, "list")) {
928 mode = MONDELEFANT_QUERY_MODE_LIST;
929 } else if (!strcmp(modestr, "object")) {
930 mode = MONDELEFANT_QUERY_MODE_OBJECT;
931 } else if (!strcmp(modestr, "opt_object")) {
932 mode = MONDELEFANT_QUERY_MODE_OPT_OBJECT;
933 } else {
934 return luaL_argerror(L, mode_idx, "unknown query mode");
935 }
936 }
937 modes[command_idx] = mode;
938 }
939 luaL_pushresult(&buf); // stack position unknown
940 lua_replace(L, 2); // SQL command string to stack position 2
941 // call sql_tracer, if set:
942 lua_settop(L, 2);
943 lua_getfield(L, 1, "sql_tracer"); // tracer at stack position 3
944 if (lua_toboolean(L, 3)) {
945 lua_pushvalue(L, 1); // 4
946 lua_pushvalue(L, 2); // 5
947 lua_call(L, 2, 1); // trace callback at stack position 3
948 }
949 // NOTE: If no tracer was found, then nil or false is stored at stack
950 // position 3.
951 // call PQsendQuery function and store result in 'sent_success' variable:
952 sent_success = PQsendQuery(conn->pgconn, lua_tostring(L, 2));
953 // create preliminary result table:
954 lua_newtable(L); // results in table at stack position 4
955 // iterate over results using function PQgetResult to fill result table:
956 for (command_idx = 0; ; command_idx++) {
957 int mode;
958 char binary[MONDELEFANT_MAX_COLUMN_COUNT];
959 ExecStatusType pgstatus;
960 // fetch mode which was given for the command:
961 mode = modes[command_idx];
962 // if PQsendQuery call was successful, then fetch result data:
963 if (sent_success) {
964 // avoid cumulating memory leaks in case of previous out-of-memory errors:
965 if (conn->todo_PQclear) {
966 PQclear(conn->todo_PQclear);
967 conn->todo_PQclear = NULL;
968 }
969 // NOTE: PQgetResult called one extra time. Break only, if all
970 // queries have been processed and PQgetResult returned NULL.
971 res = PQgetResult(conn->pgconn);
972 if (command_idx >= command_count && !res) break;
973 if (res) {
974 pgstatus = PQresultStatus(res);
975 rows = PQntuples(res);
976 cols = PQnfields(res);
977 // ensure call of PQclear in case of Lua errors:
978 conn->todo_PQclear = res;
979 }
980 }
981 // handle errors:
982 if (
983 !sent_success || command_idx >= command_count || !res ||
984 (pgstatus != PGRES_TUPLES_OK && pgstatus != PGRES_COMMAND_OK) ||
985 (rows < 1 && mode == MONDELEFANT_QUERY_MODE_OBJECT) ||
986 (rows > 1 && mode != MONDELEFANT_QUERY_MODE_LIST)
987 ) {
988 const char *command;
989 command = lua_tostring(L, 2);
990 lua_newtable(L); // 5
991 luaL_setmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY);
992 lua_pushvalue(L, 1);
993 lua_setfield(L, 5, "connection");
994 lua_pushvalue(L, 2);
995 lua_setfield(L, 5, "sql_command");
996 if (!sent_success) {
997 lua_pushliteral(L, MONDELEFANT_ERRCODE_CONNECTION);
998 lua_setfield(L, 5, "code");
999 mondelefant_push_first_line(L, PQerrorMessage(conn->pgconn));
1000 lua_setfield(L, 5, "message");
1001 } else {
1002 lua_pushinteger(L, command_idx + 1);
1003 lua_setfield(L, 5, "command_number");
1004 if (!res) {
1005 lua_pushliteral(L, MONDELEFANT_ERRCODE_RESULTCOUNT_LOW);
1006 lua_setfield(L, 5, "code");
1007 lua_pushliteral(L, "Received too few database result sets.");
1008 lua_setfield(L, 5, "message");
1009 } else if (command_idx >= command_count) {
1010 lua_pushliteral(L, MONDELEFANT_ERRCODE_RESULTCOUNT_HIGH);
1011 lua_setfield(L, 5, "code");
1012 lua_pushliteral(L, "Received too many database result sets.");
1013 lua_setfield(L, 5, "message");
1014 } else if (
1015 pgstatus != PGRES_TUPLES_OK && pgstatus != PGRES_COMMAND_OK
1016 ) {
1017 const char *sqlstate;
1018 const char *errmsg;
1019 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SEVERITY));
1020 lua_setfield(L, 5, "pg_severity");
1021 sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
1022 if (sqlstate) {
1023 lua_pushstring(L, sqlstate);
1024 lua_setfield(L, 5, "pg_sqlstate");
1025 lua_pushstring(L, mondelefant_translate_errcode(sqlstate));
1026 lua_setfield(L, 5, "code");
1027 } else {
1028 lua_pushliteral(L, MONDELEFANT_ERRCODE_UNKNOWN);
1029 lua_setfield(L, 5, "code");
1031 errmsg = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY);
1032 if (errmsg) {
1033 mondelefant_push_first_line(L, errmsg);
1034 lua_setfield(L, 5, "message");
1035 lua_pushstring(L, errmsg);
1036 lua_setfield(L, 5, "pg_message_primary");
1037 } else {
1038 lua_pushliteral(L,
1039 "Error while fetching result, but no error message given."
1040 );
1041 lua_setfield(L, 5, "message");
1043 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL));
1044 lua_setfield(L, 5, "pg_message_detail");
1045 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_MESSAGE_HINT));
1046 lua_setfield(L, 5, "pg_message_hint");
1047 // NOTE: "position" and "pg_internal_position" are recalculated to
1048 // byte offsets, as Lua 5.2 is not Unicode aware.
1050 char *tmp;
1051 tmp = PQresultErrorField(res, PG_DIAG_STATEMENT_POSITION);
1052 if (tmp) {
1053 int pos;
1054 pos = atoi(tmp) - 1;
1055 if (conn->server_encoding == MONDELEFANT_SERVER_ENCODING_UTF8) {
1056 pos = utf8_position_to_byte(command, pos);
1058 lua_pushinteger(L, pos + 1);
1059 lua_setfield(L, 5, "position");
1063 const char *internal_query;
1064 internal_query = PQresultErrorField(res, PG_DIAG_INTERNAL_QUERY);
1065 lua_pushstring(L, internal_query);
1066 lua_setfield(L, 5, "pg_internal_query");
1067 char *tmp;
1068 tmp = PQresultErrorField(res, PG_DIAG_INTERNAL_POSITION);
1069 if (tmp) {
1070 int pos;
1071 pos = atoi(tmp) - 1;
1072 if (conn->server_encoding == MONDELEFANT_SERVER_ENCODING_UTF8) {
1073 pos = utf8_position_to_byte(internal_query, pos);
1075 lua_pushinteger(L, pos + 1);
1076 lua_setfield(L, 5, "pg_internal_position");
1079 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_CONTEXT));
1080 lua_setfield(L, 5, "pg_context");
1081 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_FILE));
1082 lua_setfield(L, 5, "pg_source_file");
1083 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_LINE));
1084 lua_setfield(L, 5, "pg_source_line");
1085 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_FUNCTION));
1086 lua_setfield(L, 5, "pg_source_function");
1087 } else if (rows < 1 && mode == MONDELEFANT_QUERY_MODE_OBJECT) {
1088 lua_pushliteral(L, MONDELEFANT_ERRCODE_QUERY1_NO_ROWS);
1089 lua_setfield(L, 5, "code");
1090 lua_pushliteral(L, "Expected one row, but got empty set.");
1091 lua_setfield(L, 5, "message");
1092 } else if (rows > 1 && mode != MONDELEFANT_QUERY_MODE_LIST) {
1093 lua_pushliteral(L, MONDELEFANT_ERRCODE_QUERY1_MULTIPLE_ROWS);
1094 lua_setfield(L, 5, "code");
1095 lua_pushliteral(L, "Got more than one result row.");
1096 lua_setfield(L, 5, "message");
1097 } else {
1098 // should not happen
1099 abort();
1101 if (res) {
1102 PQclear(res);
1103 while ((res = PQgetResult(conn->pgconn))) PQclear(res);
1104 // avoid double call of PQclear later:
1105 conn->todo_PQclear = NULL;
1108 if (lua_toboolean(L, 3)) {
1109 lua_pushvalue(L, 3);
1110 lua_pushvalue(L, 5);
1111 lua_call(L, 1, 0);
1113 return 1;
1115 // call "create_list" or "create_object" method of database handle,
1116 // result will be at stack position 5:
1117 if (modes[command_idx] == MONDELEFANT_QUERY_MODE_LIST) {
1118 lua_pushcfunction(L, mondelefant_conn_create_list); // 5
1119 lua_pushvalue(L, 1); // 6
1120 lua_call(L, 1, 1); // 5
1121 } else {
1122 lua_pushcfunction(L, mondelefant_conn_create_object); // 5
1123 lua_pushvalue(L, 1); // 6
1124 lua_call(L, 1, 1); // 5
1126 // set "_column_info":
1127 lua_newtable(L); // 6
1128 for (col = 0; col < cols; col++) {
1129 lua_newtable(L); // 7
1130 lua_pushstring(L, PQfname(res, col)); // 8
1131 lua_pushvalue(L, 8); // 9
1132 lua_pushvalue(L, 7); // 10
1133 lua_rawset(L, 6);
1134 lua_setfield(L, 7, "field_name");
1135 // _column_info entry (for current column) on stack position 7
1137 Oid tmp;
1138 tmp = PQftable(res, col);
1139 if (tmp == InvalidOid) lua_pushnil(L);
1140 else lua_pushinteger(L, tmp);
1141 lua_setfield(L, 7, "table_oid");
1144 int tmp;
1145 tmp = PQftablecol(res, col);
1146 if (tmp == 0) lua_pushnil(L);
1147 else lua_pushinteger(L, tmp);
1148 lua_setfield(L, 7, "table_column_number");
1151 Oid tmp;
1152 tmp = PQftype(res, col);
1153 binary[col] = (tmp == MONDELEFANT_POSTGRESQL_BINARY_OID);
1154 lua_pushinteger(L, tmp);
1155 lua_setfield(L, 7, "type_oid");
1156 lua_pushstring(L, mondelefant_oid_to_typestr(tmp));
1157 lua_setfield(L, 7, "type");
1160 int tmp;
1161 tmp = PQfmod(res, col);
1162 if (tmp == -1) lua_pushnil(L);
1163 else lua_pushinteger(L, tmp);
1164 lua_setfield(L, 7, "type_modifier");
1166 lua_rawseti(L, 6, col+1);
1168 lua_setfield(L, 5, "_column_info");
1169 // set "_rows_affected":
1171 char *tmp;
1172 tmp = PQcmdTuples(res);
1173 if (tmp[0]) {
1174 lua_pushinteger(L, atoi(tmp));
1175 lua_setfield(L, 5, "_rows_affected");
1178 // set "_oid":
1180 Oid tmp;
1181 tmp = PQoidValue(res);
1182 if (tmp != InvalidOid) {
1183 lua_pushinteger(L, tmp);
1184 lua_setfield(L, 5, "_oid");
1187 // copy data as strings or nil, while performing binary unescaping
1188 // automatically:
1189 if (modes[command_idx] == MONDELEFANT_QUERY_MODE_LIST) {
1190 for (row = 0; row < rows; row++) {
1191 lua_pushcfunction(L, mondelefant_conn_create_object); // 6
1192 lua_pushvalue(L, 1); // 7
1193 lua_call(L, 1, 1); // 6
1194 for (col = 0; col < cols; col++) {
1195 if (PQgetisnull(res, row, col)) {
1196 lua_pushnil(L);
1197 } else if (binary[col]) {
1198 size_t binlen;
1199 char *binval;
1200 // avoid cumulating memory leaks in case of previous out-of-memory errors:
1201 if (conn->todo_PQfreemem) {
1202 PQfreemem(conn->todo_PQfreemem);
1203 conn->todo_PQfreemem = NULL;
1205 // Unescape binary data:
1206 binval = (char *)PQunescapeBytea(
1207 (unsigned char *)PQgetvalue(res, row, col), &binlen
1208 );
1209 if (!binval) {
1210 return luaL_error(L,
1211 "Could not allocate memory for binary unescaping."
1212 );
1214 // ensure call of PQfreemem in case of out-of-memory error:
1215 conn->todo_PQfreemem = binval;
1216 // create Lua string:
1217 lua_pushlstring(L, binval, binlen);
1218 // free memory allocated by PQunescapeBytea:
1219 PQfreemem(binval);
1220 // avoid double call of PQfreemem later:
1221 conn->todo_PQfreemem = NULL;
1222 } else {
1223 lua_pushstring(L, PQgetvalue(res, row, col));
1225 lua_rawseti(L, 6, col+1);
1227 lua_rawseti(L, 5, row+1);
1229 } else if (rows == 1) {
1230 for (col = 0; col < cols; col++) {
1231 if (PQgetisnull(res, 0, col)) {
1232 lua_pushnil(L);
1233 } else if (binary[col]) {
1234 size_t binlen;
1235 char *binval;
1236 // avoid cumulating memory leaks in case of previous out-of-memory errors:
1237 if (conn->todo_PQfreemem) {
1238 PQfreemem(conn->todo_PQfreemem);
1239 conn->todo_PQfreemem = NULL;
1241 // Unescape binary data:
1242 binval = (char *)PQunescapeBytea(
1243 (unsigned char *)PQgetvalue(res, 0, col), &binlen
1244 );
1245 if (!binval) {
1246 return luaL_error(L,
1247 "Could not allocate memory for binary unescaping."
1248 );
1250 // ensure call of PQfreemem in case of out-of-memory error:
1251 conn->todo_PQfreemem = binval;
1252 // create Lua string:
1253 lua_pushlstring(L, binval, binlen);
1254 // free memory allocated by PQunescapeBytea:
1255 PQfreemem(binval);
1256 // avoid double call of PQfreemem later:
1257 conn->todo_PQfreemem = NULL;
1258 } else {
1259 lua_pushstring(L, PQgetvalue(res, 0, col));
1261 lua_rawseti(L, 5, col+1);
1263 } else {
1264 // no row in optrow mode
1265 lua_pop(L, 1);
1266 lua_pushnil(L);
1268 // save result in result list:
1269 lua_rawseti(L, 4, command_idx+1);
1270 // extra assertion:
1271 if (lua_gettop(L) != 4) abort(); // should not happen
1272 // free memory acquired by libpq:
1273 PQclear(res);
1274 // avoid double call of PQclear later:
1275 conn->todo_PQclear = NULL;
1277 // trace callback at stack position 3
1278 // result at stack position 4 (top of stack)
1279 // if a trace callback is existent, then call:
1280 if (lua_toboolean(L, 3)) {
1281 lua_pushvalue(L, 3);
1282 lua_call(L, 0, 0);
1284 // put result at stack position 3:
1285 lua_replace(L, 3);
1286 // get output converter to stack position 4:
1287 lua_getfield(L, 1, "output_converter");
1288 // get mutability state saver to stack position 5:
1289 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY);
1290 lua_getfield(L, -1, "save_mutability_state");
1291 lua_replace(L, -2);
1292 // apply output converters and fill "_data" table according to column names:
1293 for (command_idx = 0; command_idx < command_count; command_idx++) {
1294 int mode;
1295 mode = modes[command_idx];
1296 lua_rawgeti(L, 3, command_idx+1); // raw result at stack position 6
1297 if (lua_toboolean(L, 6)) {
1298 lua_getfield(L, 6, "_column_info"); // column_info list at position 7
1299 cols = lua_rawlen(L, 7);
1300 if (mode == MONDELEFANT_QUERY_MODE_LIST) {
1301 rows = lua_rawlen(L, 6);
1302 for (row = 0; row < rows; row++) {
1303 lua_rawgeti(L, 6, row+1); // row at stack position 8
1304 lua_getfield(L, 8, "_data"); // _data table at stack position 9
1305 lua_getfield(L, 8, "_dirty"); // _dirty table at stack position 10
1306 for (col = 0; col < cols; col++) {
1307 lua_rawgeti(L, 7, col+1); // this column info at position 11
1308 lua_getfield(L, 11, "field_name"); // 12
1309 if (lua_toboolean(L, 4)) {
1310 lua_pushvalue(L, 4); // output-converter
1311 lua_pushvalue(L, 1); // connection
1312 lua_rawgeti(L, 8, col+1); // raw-value
1313 lua_pushvalue(L, 11); // this column info
1314 lua_call(L, 3, 1); // converted value at position 13
1315 } else {
1316 lua_rawgeti(L, 8, col+1); // raw-value at position 13
1318 if (lua_toboolean(L, 5)) { // handle mutable values?
1319 lua_pushvalue(L, 12); // copy of field name
1320 lua_pushvalue(L, 5); // mutability state saver function
1321 lua_pushvalue(L, 13); // copy of value
1322 lua_call(L, 1, 1); // calculated mutability state of value
1323 lua_rawset(L, 10); // store mutability state in _dirty table
1325 lua_pushvalue(L, 13); // 14
1326 lua_rawseti(L, 8, col+1);
1327 lua_rawset(L, 9);
1328 lua_settop(L, 10);
1330 lua_settop(L, 7);
1332 } else {
1333 lua_getfield(L, 6, "_data"); // _data table at stack position 8
1334 lua_getfield(L, 6, "_dirty"); // _dirty table at stack position 9
1335 for (col = 0; col < cols; col++) {
1336 lua_rawgeti(L, 7, col+1); // this column info at position 10
1337 lua_getfield(L, 10, "field_name"); // 11
1338 if (lua_toboolean(L, 4)) {
1339 lua_pushvalue(L, 4); // output-converter
1340 lua_pushvalue(L, 1); // connection
1341 lua_rawgeti(L, 6, col+1); // raw-value
1342 lua_pushvalue(L, 10); // this column info
1343 lua_call(L, 3, 1); // converted value at position 12
1344 } else {
1345 lua_rawgeti(L, 6, col+1); // raw-value at position 12
1347 if (lua_toboolean(L, 5)) { // handle mutable values?
1348 lua_pushvalue(L, 11); // copy of field name
1349 lua_pushvalue(L, 5); // mutability state saver function
1350 lua_pushvalue(L, 12); // copy of value
1351 lua_call(L, 1, 1); // calculated mutability state of value
1352 lua_rawset(L, 9); // store mutability state in _dirty table
1354 lua_pushvalue(L, 12); // 13
1355 lua_rawseti(L, 6, col+1);
1356 lua_rawset(L, 8);
1357 lua_settop(L, 9);
1361 lua_settop(L, 5);
1363 // return nil as first result value, followed by result lists/objects:
1364 lua_settop(L, 3);
1365 lua_pushnil(L);
1366 for (command_idx = 0; command_idx < command_count; command_idx++) {
1367 lua_rawgeti(L, 3, command_idx+1);
1369 return command_count+1;
1372 // method "is_kind_of" of error objects:
1373 static int mondelefant_errorobject_is_kind_of(lua_State *L) {
1374 const char *errclass;
1375 luaL_checktype(L, 1, LUA_TTABLE);
1376 errclass = luaL_checkstring(L, 2);
1377 lua_settop(L, 2);
1378 lua_getfield(L, 1, "code"); // 3
1379 luaL_argcheck(L,
1380 lua_type(L, 3) == LUA_TSTRING,
1381 1,
1382 "field 'code' of error object is not a string"
1383 );
1384 lua_pushboolean(L,
1385 mondelefant_check_error_class(lua_tostring(L, 3), errclass)
1386 );
1387 return 1;
1390 // method "wait" of database handles:
1391 static int mondelefant_conn_wait(lua_State *L) {
1392 int argc;
1393 // count number of arguments:
1394 argc = lua_gettop(L);
1395 // insert "try_wait" function/method at stack position 1:
1396 lua_pushcfunction(L, mondelefant_conn_try_wait);
1397 lua_insert(L, 1);
1398 // call "try_wait" method:
1399 lua_call(L, argc, LUA_MULTRET); // results (with error) starting at index 1
1400 // check, if error occurred:
1401 if (lua_toboolean(L, 1)) {
1402 // raise error
1403 lua_settop(L, 1);
1404 return lua_error(L);
1405 } else {
1406 // return everything but nil error object:
1407 return lua_gettop(L) - 1;
1411 // method "query" of database handles:
1412 static int mondelefant_conn_query(lua_State *L) {
1413 int argc;
1414 // count number of arguments:
1415 argc = lua_gettop(L);
1416 // insert "try_query" function/method at stack position 1:
1417 lua_pushcfunction(L, mondelefant_conn_try_query);
1418 lua_insert(L, 1);
1419 // call "try_query" method:
1420 lua_call(L, argc, LUA_MULTRET); // results (with error) starting at index 1
1421 // check, if error occurred:
1422 if (lua_toboolean(L, 1)) {
1423 // raise error
1424 lua_settop(L, 1);
1425 return lua_error(L);
1426 } else {
1427 // return everything but nil error object:
1428 return lua_gettop(L) - 1;
1432 // library function "set_class":
1433 static int mondelefant_set_class(lua_State *L) {
1434 // ensure that first argument is a database result list/object:
1435 lua_settop(L, 2);
1436 lua_getmetatable(L, 1); // 3
1437 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_RESULT_MT_REGKEY); // 4
1438 luaL_argcheck(L, lua_compare(L, 3, 4, LUA_OPEQ), 1, "not a database result");
1439 // ensure that second argument is a database class (model):
1440 lua_settop(L, 2);
1441 lua_getmetatable(L, 2); // 3
1442 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_MT_REGKEY); // 4
1443 luaL_argcheck(L, lua_compare(L, 3, 4, LUA_OPEQ), 2, "not a database class");
1444 // set attribute "_class" of result list/object to given class:
1445 lua_settop(L, 2);
1446 lua_pushvalue(L, 2); // 3
1447 lua_setfield(L, 1, "_class");
1448 // test, if database result is a list (and not a single object):
1449 lua_getfield(L, 1, "_type"); // 3
1450 lua_pushliteral(L, "list"); // 4
1451 if (lua_rawequal(L, 3, 4)) {
1452 int i;
1453 // set attribute "_class" of all elements to given class:
1454 for (i=0; i < lua_rawlen(L, 1); i++) {
1455 lua_settop(L, 2);
1456 lua_rawgeti(L, 1, i+1); // 3
1457 lua_pushvalue(L, 2); // 4
1458 lua_setfield(L, 3, "_class");
1461 // return first argument:
1462 lua_settop(L, 1);
1463 return 1;
1466 // library function "new_class":
1467 static int mondelefant_new_class(lua_State *L) {
1468 // if no argument is given, use an empty table:
1469 if (lua_isnoneornil(L, 1)) {
1470 lua_settop(L, 0);
1471 lua_newtable(L); // 1
1472 } else {
1473 luaL_checktype(L, 1, LUA_TTABLE);
1474 lua_settop(L, 1);
1476 // set meta-table for database classes (models):
1477 luaL_setmetatable(L, MONDELEFANT_CLASS_MT_REGKEY);
1478 // check, if "prototype" attribute is not set:
1479 lua_pushliteral(L, "prototype"); // 2
1480 lua_rawget(L, 1); // 2
1481 if (!lua_toboolean(L, 2)) {
1482 // set "prototype" attribute to default prototype:
1483 lua_pushliteral(L, "prototype"); // 3
1484 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 4
1485 lua_rawset(L, 1);
1487 // set "object" attribute to empty table, unless it is already set:
1488 lua_settop(L, 1);
1489 lua_pushliteral(L, "object"); // 2
1490 lua_rawget(L, 1); // 2
1491 if (!lua_toboolean(L, 2)) {
1492 lua_pushliteral(L, "object"); // 3
1493 lua_newtable(L); // 4
1494 lua_rawset(L, 1);
1496 // set "object_get" attribute to empty table, unless it is already set:
1497 lua_settop(L, 1);
1498 lua_pushliteral(L, "object_get"); // 2
1499 lua_rawget(L, 1); // 2
1500 if (!lua_toboolean(L, 2)) {
1501 lua_pushliteral(L, "object_get"); // 3
1502 lua_newtable(L); // 4
1503 lua_rawset(L, 1);
1505 // set "object_set" attribute to empty table, unless it is already set:
1506 lua_settop(L, 1);
1507 lua_pushliteral(L, "object_set"); // 2
1508 lua_rawget(L, 1); // 2
1509 if (!lua_toboolean(L, 2)) {
1510 lua_pushliteral(L, "object_set"); // 3
1511 lua_newtable(L); // 4
1512 lua_rawset(L, 1);
1514 // set "list" attribute to empty table, unless it is already set:
1515 lua_settop(L, 1);
1516 lua_pushliteral(L, "list"); // 2
1517 lua_rawget(L, 1); // 2
1518 if (!lua_toboolean(L, 2)) {
1519 lua_pushliteral(L, "list"); // 3
1520 lua_newtable(L); // 4
1521 lua_rawset(L, 1);
1523 // set "references" attribute to empty table, unless it is already set:
1524 lua_settop(L, 1);
1525 lua_pushliteral(L, "references"); // 2
1526 lua_rawget(L, 1); // 2
1527 if (!lua_toboolean(L, 2)) {
1528 lua_pushliteral(L, "references"); // 3
1529 lua_newtable(L); // 4
1530 lua_rawset(L, 1);
1532 // set "foreign_keys" attribute to empty table, unless it is already set:
1533 lua_settop(L, 1);
1534 lua_pushliteral(L, "foreign_keys"); // 2
1535 lua_rawget(L, 1); // 2
1536 if (!lua_toboolean(L, 2)) {
1537 lua_pushliteral(L, "foreign_keys"); // 3
1538 lua_newtable(L); // 4
1539 lua_rawset(L, 1);
1541 // return table:
1542 lua_settop(L, 1);
1543 return 1;
1546 // method "get_reference" of classes (models):
1547 static int mondelefant_class_get_reference(lua_State *L) {
1548 lua_settop(L, 2);
1549 while (lua_toboolean(L, 1)) {
1550 // get "references" table:
1551 lua_getfield(L, 1, "references"); // 3
1552 // perform lookup:
1553 lua_pushvalue(L, 2); // 4
1554 lua_gettable(L, 3); // 4
1555 // return result, if lookup was successful:
1556 if (!lua_isnil(L, 4)) return 1;
1557 // replace current table by its prototype:
1558 lua_settop(L, 2);
1559 lua_pushliteral(L, "prototype"); // 3
1560 lua_rawget(L, 1); // 3
1561 lua_replace(L, 1);
1563 // return nothing:
1564 return 0;
1567 // method "iterate_over_references" of classes (models):
1568 static int mondelefant_class_iterate_over_references(lua_State *L) {
1569 return luaL_error(L, "Reference iterator not implemented yet."); // TODO
1572 // method "get_foreign_key_reference_name" of classes (models):
1573 static int mondelefant_class_get_foreign_key_reference_name(lua_State *L) {
1574 lua_settop(L, 2);
1575 while (lua_toboolean(L, 1)) {
1576 // get "foreign_keys" table:
1577 lua_getfield(L, 1, "foreign_keys"); // 3
1578 // perform lookup:
1579 lua_pushvalue(L, 2); // 4
1580 lua_gettable(L, 3); // 4
1581 // return result, if lookup was successful:
1582 if (!lua_isnil(L, 4)) return 1;
1583 // replace current table by its prototype:
1584 lua_settop(L, 2);
1585 lua_pushliteral(L, "prototype"); // 3
1586 lua_rawget(L, 1); // 3
1587 lua_replace(L, 1);
1589 // return nothing:
1590 return 0;
1593 // meta-method "__index" of database result lists and objects:
1594 static int mondelefant_result_index(lua_State *L) {
1595 const char *result_type;
1596 // only lookup, when key is a string not beginning with an underscore:
1597 if (lua_type(L, 2) != LUA_TSTRING || lua_tostring(L, 2)[0] == '_') {
1598 return 0;
1600 // class on stack position 3:
1601 lua_settop(L, 2);
1602 lua_getfield(L, 1, "_class"); // 3
1603 // get value of "_type" attribute:
1604 lua_getfield(L, 1, "_type"); // 4
1605 result_type = lua_tostring(L, 4);
1606 // different lookup for lists and objects:
1607 if (result_type && !strcmp(result_type, "object")) { // object
1608 lua_settop(L, 3);
1609 // try inherited attributes, methods or getter functions:
1610 lua_pushvalue(L, 3); // 4
1611 while (lua_toboolean(L, 4)) {
1612 lua_getfield(L, 4, "object"); // 5
1613 lua_pushvalue(L, 2); // 6
1614 lua_gettable(L, 5); // 6
1615 if (!lua_isnil(L, 6)) return 1;
1616 lua_settop(L, 4);
1617 lua_getfield(L, 4, "object_get"); // 5
1618 lua_pushvalue(L, 2); // 6
1619 lua_gettable(L, 5); // 6
1620 if (lua_toboolean(L, 6)) {
1621 lua_pushvalue(L, 1); // 7
1622 lua_call(L, 1, 1); // 6
1623 return 1;
1625 lua_settop(L, 4);
1626 lua_pushliteral(L, "prototype"); // 5
1627 lua_rawget(L, 4); // 5
1628 lua_replace(L, 4);
1630 lua_settop(L, 3);
1631 // try primary keys of referenced objects:
1632 lua_pushcfunction(L,
1633 mondelefant_class_get_foreign_key_reference_name
1634 ); // 4
1635 lua_pushvalue(L, 3); // 5
1636 lua_pushvalue(L, 2); // 6
1637 lua_call(L, 2, 1); // 4
1638 if (!lua_isnil(L, 4)) {
1639 // reference name at stack position 4
1640 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1641 lua_pushvalue(L, 3); // 6
1642 lua_pushvalue(L, 4); // 7
1643 lua_call(L, 2, 1); // reference info at stack position 5
1644 lua_getfield(L, 1, "_ref"); // 6
1645 lua_getfield(L, 5, "ref"); // 7
1646 lua_gettable(L, 6); // 7
1647 if (!lua_isnil(L, 7)) {
1648 if (lua_toboolean(L, 7)) {
1649 lua_getfield(L, 5, "that_key"); // 8
1650 if (lua_isnil(L, 8)) {
1651 return luaL_error(L, "Missing 'that_key' entry in model reference.");
1653 lua_gettable(L, 7); // 8
1654 } else {
1655 lua_pushnil(L);
1657 return 1;
1660 lua_settop(L, 3);
1661 lua_getfield(L, 1, "_data"); // _data table on stack position 4
1662 // try cached referenced object (or cached NULL reference):
1663 lua_getfield(L, 1, "_ref"); // 5
1664 lua_pushvalue(L, 2); // 6
1665 lua_gettable(L, 5); // 6
1666 if (lua_isboolean(L, 6) && !lua_toboolean(L, 6)) {
1667 lua_pushnil(L);
1668 return 1;
1669 } else if (!lua_isnil(L, 6)) {
1670 return 1;
1672 lua_settop(L, 4);
1673 // try to load a referenced object:
1674 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1675 lua_pushvalue(L, 3); // 6
1676 lua_pushvalue(L, 2); // 7
1677 lua_call(L, 2, 1); // 5
1678 if (!lua_isnil(L, 5)) {
1679 lua_settop(L, 2);
1680 lua_getfield(L, 1, "load"); // 3
1681 lua_pushvalue(L, 1); // 4 (self)
1682 lua_pushvalue(L, 2); // 5
1683 lua_call(L, 2, 0);
1684 lua_settop(L, 2);
1685 lua_getfield(L, 1, "_ref"); // 3
1686 lua_pushvalue(L, 2); // 4
1687 lua_gettable(L, 3); // 4
1688 if (lua_isboolean(L, 4) && !lua_toboolean(L, 4)) lua_pushnil(L); // TODO: use special object instead of false
1689 return 1;
1691 lua_settop(L, 4);
1692 // check if proxy access to document in special column is enabled:
1693 lua_getfield(L, 3, "document_column"); // 5
1694 if (lua_toboolean(L, 5)) {
1695 // if yes, then proxy access:
1696 lua_gettable(L, 4); // 5
1697 if (!lua_isnil(L, 5)) {
1698 lua_pushvalue(L, 2); // 6
1699 lua_gettable(L, 5); // 6
1701 } else {
1702 // else use _data table:
1703 lua_pushvalue(L, 2); // 6
1704 lua_gettable(L, 4); // 6
1706 return 1; // return element at stack position 5 or 6
1707 } else if (result_type && !strcmp(result_type, "list")) { // list
1708 lua_settop(L, 3);
1709 // try inherited list attributes or methods:
1710 while (lua_toboolean(L, 3)) {
1711 lua_getfield(L, 3, "list"); // 4
1712 lua_pushvalue(L, 2); // 5
1713 lua_gettable(L, 4); // 5
1714 if (!lua_isnil(L, 5)) return 1;
1715 lua_settop(L, 3);
1716 lua_pushliteral(L, "prototype"); // 4
1717 lua_rawget(L, 3); // 4
1718 lua_replace(L, 3);
1721 // return nothing:
1722 return 0;
1725 // meta-method "__newindex" of database result lists and objects:
1726 static int mondelefant_result_newindex(lua_State *L) {
1727 const char *result_type;
1728 // perform rawset, unless key is a string not starting with underscore:
1729 lua_settop(L, 3);
1730 if (lua_type(L, 2) != LUA_TSTRING || lua_tostring(L, 2)[0] == '_') {
1731 lua_rawset(L, 1);
1732 return 1;
1734 // class on stack position 4:
1735 lua_settop(L, 3);
1736 lua_getfield(L, 1, "_class"); // 4
1737 // get value of "_type" attribute:
1738 lua_getfield(L, 1, "_type"); // 5
1739 result_type = lua_tostring(L, 5);
1740 // distinguish between lists and objects:
1741 if (result_type && !strcmp(result_type, "object")) { // objects
1742 lua_settop(L, 4);
1743 // try object setter functions:
1744 lua_pushvalue(L, 4); // 5
1745 while (lua_toboolean(L, 5)) {
1746 lua_getfield(L, 5, "object_set"); // 6
1747 lua_pushvalue(L, 2); // 7
1748 lua_gettable(L, 6); // 7
1749 if (lua_toboolean(L, 7)) {
1750 lua_pushvalue(L, 1); // 8
1751 lua_pushvalue(L, 3); // 9
1752 lua_call(L, 2, 0);
1753 return 0;
1755 lua_settop(L, 5);
1756 lua_pushliteral(L, "prototype"); // 6
1757 lua_rawget(L, 5); // 6
1758 lua_replace(L, 5);
1760 lua_settop(L, 4);
1761 lua_getfield(L, 1, "_data"); // _data table on stack position 5
1762 // check, if a object reference is changed:
1763 lua_pushcfunction(L, mondelefant_class_get_reference); // 6
1764 lua_pushvalue(L, 4); // 7
1765 lua_pushvalue(L, 2); // 8
1766 lua_call(L, 2, 1); // 6
1767 if (!lua_isnil(L, 6)) {
1768 // store object in _ref table (use false for nil): // TODO: use special object instead of false
1769 lua_getfield(L, 1, "_ref"); // 7
1770 lua_pushvalue(L, 2); // 8
1771 if (lua_isnil(L, 3)) lua_pushboolean(L, 0); // 9
1772 else lua_pushvalue(L, 3); // 9
1773 lua_settable(L, 7);
1774 lua_settop(L, 6);
1775 // delete referencing key from _data table:
1776 lua_getfield(L, 6, "this_key"); // 7
1777 if (lua_isnil(L, 7)) {
1778 return luaL_error(L, "Missing 'this_key' entry in model reference.");
1780 lua_pushvalue(L, 7); // 8
1781 lua_pushnil(L); // 9
1782 lua_settable(L, 5);
1783 lua_getfield(L, 1, "_dirty"); // 8
1784 lua_pushvalue(L, 7); // 9
1785 lua_pushboolean(L, 1); // 10
1786 lua_settable(L, 8);
1787 return 0;
1789 lua_settop(L, 5);
1790 // check proxy access to document in special column:
1791 lua_getfield(L, 4, "document_column"); // 6
1792 if (lua_toboolean(L, 6)) {
1793 lua_gettable(L, 5); // 6
1794 if (lua_isnil(L, 6)) {
1795 return luaL_error(L, "Cannot write to document column: document is nil");
1797 lua_pushvalue(L, 2); // 7
1798 lua_pushvalue(L, 3); // 8
1799 lua_settable(L, 6);
1800 return 0;
1802 lua_settop(L, 5);
1803 // store value in data field info:
1804 lua_pushvalue(L, 2); // 6
1805 lua_pushvalue(L, 3); // 7
1806 lua_settable(L, 5);
1807 lua_settop(L, 4);
1808 // mark field as dirty (needs to be UPDATEd on save):
1809 lua_getfield(L, 1, "_dirty"); // 5
1810 lua_pushvalue(L, 2); // 6
1811 lua_pushboolean(L, 1); // 7
1812 lua_settable(L, 5);
1813 lua_settop(L, 4);
1814 // reset reference cache, if neccessary:
1815 lua_pushcfunction(L,
1816 mondelefant_class_get_foreign_key_reference_name
1817 ); // 5
1818 lua_pushvalue(L, 4); // 6
1819 lua_pushvalue(L, 2); // 7
1820 lua_call(L, 2, 1); // 5
1821 if (!lua_isnil(L, 5)) {
1822 lua_getfield(L, 1, "_ref"); // 6
1823 lua_pushvalue(L, 5); // 7
1824 lua_pushnil(L); // 8
1825 lua_settable(L, 6);
1827 return 0;
1828 } else { // non-objects (i.e. lists)
1829 // perform rawset:
1830 lua_settop(L, 3);
1831 lua_rawset(L, 1);
1832 return 0;
1836 // meta-method "__index" of column proxy:
1837 static int mondelefant_columns_index(lua_State *L) {
1838 luaL_checktype(L, 1, LUA_TTABLE);
1839 lua_settop(L, 2);
1840 lua_rawgetp(L, 1, MONDELEFANT_COLUMNS_RESULT_LUKEY); // 3
1841 // try primary keys of referenced objects:
1842 lua_pushcfunction(L,
1843 mondelefant_class_get_foreign_key_reference_name
1844 ); // 4
1845 lua_getfield(L, 3, "_class"); // 5
1846 lua_pushvalue(L, 2); // 6
1847 lua_call(L, 2, 1); // 4
1848 if (!lua_isnil(L, 4)) {
1849 // reference name at stack position 4
1850 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1851 lua_getfield(L, 3, "_class"); // 6
1852 lua_pushvalue(L, 4); // 7
1853 lua_call(L, 2, 1); // reference info at stack position 5
1854 lua_getfield(L, 3, "_ref"); // 6
1855 lua_getfield(L, 5, "ref"); // 7
1856 lua_gettable(L, 6); // 7
1857 if (!lua_isnil(L, 7)) {
1858 if (lua_toboolean(L, 7)) {
1859 lua_getfield(L, 5, "that_key"); // 8
1860 if (lua_isnil(L, 8)) {
1861 return luaL_error(L, "Missing 'that_key' entry in model reference.");
1863 lua_gettable(L, 7); // 8
1864 } else {
1865 lua_pushnil(L);
1867 return 1;
1870 lua_settop(L, 3);
1871 // if not successful, use _data table:
1872 lua_getfield(L, 3, "_data"); // 4
1873 lua_pushvalue(L, 2); // 5
1874 lua_gettable(L, 4); // 5
1875 return 1;
1878 // meta-method "__newindex" of column proxy:
1879 static int mondelefant_columns_newindex(lua_State *L) {
1880 luaL_checktype(L, 1, LUA_TTABLE);
1881 lua_settop(L, 3);
1882 lua_rawgetp(L, 1, MONDELEFANT_COLUMNS_RESULT_LUKEY); // 4
1883 // reset reference cache, if neccessary:
1884 lua_pushcfunction(L,
1885 mondelefant_class_get_foreign_key_reference_name
1886 ); // 5
1887 lua_getfield(L, 4, "_class"); // 6
1888 lua_pushvalue(L, 2); // 7
1889 lua_call(L, 2, 1); // 5
1890 if (!lua_isnil(L, 5)) {
1891 lua_getfield(L, 4, "_ref"); // 6
1892 lua_pushvalue(L, 5); // 7
1893 lua_pushnil(L); // 8
1894 lua_settable(L, 6);
1896 lua_settop(L, 4);
1897 // set _data and _dirty:
1898 lua_getfield(L, 4, "_data"); // 5
1899 lua_getfield(L, 4, "_dirty"); // 6
1900 lua_pushvalue(L, 2);
1901 lua_pushvalue(L, 3);
1902 lua_settable(L, 5);
1903 lua_pushvalue(L, 2);
1904 lua_pushboolean(L, 1);
1905 lua_settable(L, 6);
1906 return 0;
1909 // meta-method "__index" of classes (models):
1910 static int mondelefant_class_index(lua_State *L) {
1911 // perform lookup in prototype:
1912 lua_settop(L, 2);
1913 lua_pushliteral(L, "prototype"); // 3
1914 lua_rawget(L, 1); // 3
1915 lua_pushvalue(L, 2); // 4
1916 lua_gettable(L, 3); // 4
1917 return 1;
1920 // registration information for functions of library:
1921 static const struct luaL_Reg mondelefant_module_functions[] = {
1922 {"connect", mondelefant_connect},
1923 {"set_class", mondelefant_set_class},
1924 {"new_class", mondelefant_new_class},
1925 {NULL, NULL}
1926 };
1928 // registration information for meta-methods of database connections:
1929 static const struct luaL_Reg mondelefant_conn_mt_functions[] = {
1930 {"__gc", mondelefant_conn_free},
1931 {"__index", mondelefant_conn_index},
1932 {"__newindex", mondelefant_conn_newindex},
1933 {NULL, NULL}
1934 };
1936 // registration information for methods of database connections:
1937 static const struct luaL_Reg mondelefant_conn_methods[] = {
1938 {"close", mondelefant_conn_close},
1939 {"is_ok", mondelefant_conn_is_ok},
1940 {"get_transaction_status", mondelefant_conn_get_transaction_status},
1941 {"try_wait", mondelefant_conn_try_wait},
1942 {"wait", mondelefant_conn_wait},
1943 {"create_list", mondelefant_conn_create_list},
1944 {"create_object", mondelefant_conn_create_object},
1945 {"quote_string", mondelefant_conn_quote_string},
1946 {"quote_binary", mondelefant_conn_quote_binary},
1947 {"assemble_command", mondelefant_conn_assemble_command},
1948 {"try_query", mondelefant_conn_try_query},
1949 {"query", mondelefant_conn_query},
1950 {NULL, NULL}
1951 };
1953 // registration information for meta-methods of error objects:
1954 static const struct luaL_Reg mondelefant_errorobject_mt_functions[] = {
1955 {NULL, NULL}
1956 };
1958 // registration information for methods of error objects:
1959 static const struct luaL_Reg mondelefant_errorobject_methods[] = {
1960 {"escalate", lua_error},
1961 {"is_kind_of", mondelefant_errorobject_is_kind_of},
1962 {NULL, NULL}
1963 };
1965 // registration information for meta-methods of database result lists/objects:
1966 static const struct luaL_Reg mondelefant_result_mt_functions[] = {
1967 {"__index", mondelefant_result_index},
1968 {"__newindex", mondelefant_result_newindex},
1969 {NULL, NULL}
1970 };
1972 // registration information for meta-methods of classes (models):
1973 static const struct luaL_Reg mondelefant_class_mt_functions[] = {
1974 {"__index", mondelefant_class_index},
1975 {NULL, NULL}
1976 };
1978 // registration information for methods of classes (models):
1979 static const struct luaL_Reg mondelefant_class_methods[] = {
1980 {"get_reference", mondelefant_class_get_reference},
1981 {"iterate_over_references", mondelefant_class_iterate_over_references},
1982 {"get_foreign_key_reference_name",
1983 mondelefant_class_get_foreign_key_reference_name},
1984 {NULL, NULL}
1985 };
1987 // registration information for methods of database result objects (not lists!):
1988 static const struct luaL_Reg mondelefant_object_methods[] = {
1989 {NULL, NULL}
1990 };
1992 // registration information for methods of database result lists (not single objects!):
1993 static const struct luaL_Reg mondelefant_list_methods[] = {
1994 {NULL, NULL}
1995 };
1997 // registration information for meta-methods of column proxy:
1998 static const struct luaL_Reg mondelefant_columns_mt_functions[] = {
1999 {"__index", mondelefant_columns_index},
2000 {"__newindex", mondelefant_columns_newindex},
2001 {NULL, NULL}
2002 };
2004 // luaopen function to initialize/register library:
2005 int luaopen_mondelefant_native(lua_State *L) {
2006 lua_settop(L, 0);
2008 lua_newtable(L); // meta-table for columns proxy
2009 luaL_setfuncs(L, mondelefant_columns_mt_functions, 0);
2010 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_COLUMNS_MT_REGKEY);
2012 lua_newtable(L); // module at stack position 1
2013 luaL_setfuncs(L, mondelefant_module_functions, 0);
2015 lua_pushvalue(L, 1); // 2
2016 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY);
2018 lua_newtable(L); // 2
2019 // NOTE: only PostgreSQL is supported yet:
2020 luaL_setfuncs(L, mondelefant_conn_methods, 0);
2021 lua_setfield(L, 1, "postgresql_connection_prototype");
2022 lua_newtable(L); // 2
2023 lua_setfield(L, 1, "connection_prototype");
2025 luaL_newmetatable(L, MONDELEFANT_CONN_MT_REGKEY); // 2
2026 luaL_setfuncs(L, mondelefant_conn_mt_functions, 0);
2027 lua_settop(L, 1);
2028 luaL_newmetatable(L, MONDELEFANT_RESULT_MT_REGKEY); // 2
2029 luaL_setfuncs(L, mondelefant_result_mt_functions, 0);
2030 lua_setfield(L, 1, "result_metatable");
2031 luaL_newmetatable(L, MONDELEFANT_CLASS_MT_REGKEY); // 2
2032 luaL_setfuncs(L, mondelefant_class_mt_functions, 0);
2033 lua_setfield(L, 1, "class_metatable");
2035 lua_newtable(L); // 2
2036 luaL_setfuncs(L, mondelefant_class_methods, 0);
2037 lua_newtable(L); // 3
2038 luaL_setfuncs(L, mondelefant_object_methods, 0);
2039 lua_setfield(L, 2, "object");
2040 lua_newtable(L); // 3
2041 lua_setfield(L, 2, "object_get");
2042 lua_newtable(L); // 3
2043 lua_setfield(L, 2, "object_set");
2044 lua_newtable(L); // 3
2045 luaL_setfuncs(L, mondelefant_list_methods, 0);
2046 lua_setfield(L, 2, "list");
2047 lua_newtable(L); // 3
2048 lua_setfield(L, 2, "references");
2049 lua_newtable(L); // 3
2050 lua_setfield(L, 2, "foreign_keys");
2051 lua_pushvalue(L, 2); // 3
2052 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY);
2053 lua_setfield(L, 1, "class_prototype");
2055 luaL_newmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY); // 2
2056 luaL_setfuncs(L, mondelefant_errorobject_mt_functions, 0);
2057 lua_newtable(L); // 3
2058 luaL_setfuncs(L, mondelefant_errorobject_methods, 0);
2059 lua_setfield(L, 2, "__index");
2060 lua_setfield(L, 1, "errorobject_metatable");
2062 return 1;

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