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view libraries/mondelefant/mondelefant_native.c @ 416:046927075270
Proxy table to directly access column-values of a database row (e.g. if document_column is set or for reserved method names)
| author | jbe |
|---|---|
| date | Sat Jan 09 19:29:36 2016 +0100 (2016-01-09) |
| parents | 0dff5e2f659c |
| children | 03f4f905a41a |
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 = 0;
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 luaL_argcheck(L, lua_isstring(L, -1), 1, "value in table is not a string");
232 value = lua_tolstring(L, -1, &value_len);
233 lua_replace(L, 3);
234 lua_pop(L, 1);
235 lua_replace(L, 2);
236 if (need_seperator) luaL_addchar(&buf, ' ');
237 // NOTE: numbers will be converted to strings automatically here,
238 // but perhaps this will change in future versions of lua
239 lua_pushvalue(L, 2);
240 luaL_addvalue(&buf);
241 luaL_addchar(&buf, '=');
242 luaL_addchar(&buf, '\'');
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 which is the top of stack:
255 lua_replace(L, 1);
256 }
257 // use conninfo string on stack position 1:
258 conninfo = lua_tostring(L, 1);
259 // create userdata on stack position 2:
260 lua_settop(L, 1);
261 conn = lua_newuserdata(L, sizeof(*conn)); // 2
262 // call PQconnectdb function of libpq:
263 conn->pgconn = PQconnectdb(conninfo);
264 // try emergency garbage collection on first failure:
265 if (!conn->pgconn) {
266 lua_gc(L, LUA_GCCOLLECT, 0);
267 conn->pgconn = PQconnectdb(conninfo);
268 // throw error in case of (unexpected) error of PQconnectdb call:
269 if (!conn->pgconn) return luaL_error(L,
270 "Error in libpq while creating 'PGconn' structure."
271 );
272 }
273 // set metatable for userdata (ensure PQfinish on unexpected error below):
274 luaL_setmetatable(L, MONDELEFANT_CONN_MT_REGKEY);
275 // check result of PQconnectdb call:
276 if (PQstatus(conn->pgconn) != CONNECTION_OK) {
277 lua_pushnil(L); // 3
278 mondelefant_push_first_line(L, PQerrorMessage(conn->pgconn)); // 4
279 lua_newtable(L); // 5
280 luaL_setmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY);
281 lua_pushliteral(L, MONDELEFANT_ERRCODE_CONNECTION);
282 lua_setfield(L, 5, "code");
283 lua_pushvalue(L, 4);
284 lua_setfield(L, 5, "message");
285 // manual PQfinish (do not wait until garbage collection):
286 PQfinish(conn->pgconn);
287 conn->pgconn = NULL;
288 return 3;
289 }
290 // set 'server_encoding' in C-struct of userdata:
291 {
292 const char *charset;
293 charset = PQparameterStatus(conn->pgconn, "server_encoding");
294 if (charset && !strcmp(charset, "UTF8")) {
295 conn->server_encoding = MONDELEFANT_SERVER_ENCODING_UTF8;
296 } else {
297 conn->server_encoding = MONDELEFANT_SERVER_ENCODING_ASCII;
298 }
299 }
300 // create and associate userdata table:
301 lua_newtable(L);
302 lua_setuservalue(L, 2);
303 // store key "fd" with file descriptor of connection:
304 lua_pushinteger(L, PQsocket(conn->pgconn));
305 lua_setfield(L, 2, "fd");
306 // store key "engine" with value "postgresql" as connection specific data:
307 lua_pushliteral(L, "postgresql");
308 lua_setfield(L, 2, "engine");
309 // return userdata:
310 return 1;
311 }
313 // returns pointer to libpq handle 'pgconn' of userdata at given index
314 // (or throws error, if database connection has been closed):
315 static mondelefant_conn_t *mondelefant_get_conn(lua_State *L, int index) {
316 mondelefant_conn_t *conn;
317 conn = luaL_checkudata(L, index, MONDELEFANT_CONN_MT_REGKEY);
318 if (!conn->pgconn) {
319 luaL_error(L, "PostgreSQL connection has been closed.");
320 return NULL;
321 }
322 return conn;
323 }
325 // meta-method "__index" of database handles (userdata):
326 static int mondelefant_conn_index(lua_State *L) {
327 // try table for connection specific data:
328 lua_settop(L, 2);
329 lua_getuservalue(L, 1); // 3
330 lua_pushvalue(L, 2); // 4
331 lua_gettable(L, 3); // 4
332 if (!lua_isnil(L, 4)) return 1;
333 // try to use prototype stored in connection specific data:
334 lua_settop(L, 3);
335 lua_getfield(L, 3, "prototype"); // 4
336 if (lua_toboolean(L, 4)) {
337 lua_pushvalue(L, 2); // 5
338 lua_gettable(L, 4); // 5
339 if (!lua_isnil(L, 5)) return 1;
340 }
341 // try to use "postgresql_connection_prototype" of library:
342 lua_settop(L, 2);
343 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY); // 3
344 lua_getfield(L, 3, "postgresql_connection_prototype"); // 4
345 if (lua_toboolean(L, 4)) {
346 lua_pushvalue(L, 2); // 5
347 lua_gettable(L, 4); // 5
348 if (!lua_isnil(L, 5)) return 1;
349 }
350 // try to use "connection_prototype" of library:
351 lua_settop(L, 3);
352 lua_getfield(L, 3, "connection_prototype"); // 4
353 if (lua_toboolean(L, 4)) {
354 lua_pushvalue(L, 2); // 5
355 lua_gettable(L, 4); // 5
356 if (!lua_isnil(L, 5)) return 1;
357 }
358 // give up and return nothing:
359 return 0;
360 }
362 // meta-method "__newindex" of database handles (userdata):
363 static int mondelefant_conn_newindex(lua_State *L) {
364 // store key-value pair in table for connection specific data:
365 lua_settop(L, 3);
366 lua_getuservalue(L, 1); // 4
367 lua_pushvalue(L, 2);
368 lua_pushvalue(L, 3);
369 lua_settable(L, 4);
370 // return nothing:
371 return 0;
372 }
374 // meta-method "__gc" of database handles:
375 static int mondelefant_conn_free(lua_State *L) {
376 mondelefant_conn_t *conn;
377 conn = luaL_checkudata(L, 1, MONDELEFANT_CONN_MT_REGKEY);
378 if (conn->todo_PQfreemem) {
379 PQfreemem(conn->todo_PQfreemem);
380 conn->todo_PQfreemem = NULL;
381 }
382 if (conn->todo_PQclear) {
383 PQclear(conn->todo_PQclear);
384 conn->todo_PQclear = NULL;
385 }
386 if (conn->pgconn) {
387 PQfinish(conn->pgconn);
388 conn->pgconn = NULL;
389 }
390 return 0;
391 }
393 // method "close" of database handles:
394 static int mondelefant_conn_close(lua_State *L) {
395 mondelefant_conn_t *conn;
396 conn = mondelefant_get_conn(L, 1);
397 PQfinish(conn->pgconn);
398 conn->pgconn = NULL;
399 lua_pushnil(L);
400 lua_setfield(L, 1, "fd"); // set "fd" attribute to nil
401 return 0;
402 }
404 // method "is_okay" of database handles:
405 static int mondelefant_conn_is_ok(lua_State *L) {
406 mondelefant_conn_t *conn;
407 conn = mondelefant_get_conn(L, 1);
408 lua_pushboolean(L, PQstatus(conn->pgconn) == CONNECTION_OK);
409 return 1;
410 }
412 // method "get_transaction_status" of database handles:
413 static int mondelefant_conn_get_transaction_status(lua_State *L) {
414 mondelefant_conn_t *conn;
415 conn = mondelefant_get_conn(L, 1);
416 switch (PQtransactionStatus(conn->pgconn)) {
417 case PQTRANS_IDLE:
418 lua_pushliteral(L, "idle");
419 break;
420 case PQTRANS_ACTIVE:
421 lua_pushliteral(L, "active");
422 break;
423 case PQTRANS_INTRANS:
424 lua_pushliteral(L, "intrans");
425 break;
426 case PQTRANS_INERROR:
427 lua_pushliteral(L, "inerror");
428 break;
429 default:
430 lua_pushliteral(L, "unknown");
431 }
432 return 1;
433 }
435 // method "try_wait" of database handles:
436 static int mondelefant_conn_try_wait(lua_State *L) {
437 mondelefant_conn_t *conn;
438 int infinite, nonblock = 0;
439 struct timespec wakeup;
440 int fd;
441 fd_set fds;
442 conn = mondelefant_get_conn(L, 1);
443 infinite = lua_isnoneornil(L, 2);
444 if (!infinite) {
445 lua_Number n;
446 int isnum;
447 n = lua_tonumberx(L, 2, &isnum);
448 if (isnum && n>0 && n<=86400*366) {
449 if (clock_gettime(CLOCK_MONOTONIC, &wakeup)) {
450 return luaL_error(L, "Could not access CLOCK_MONOTONIC");
451 }
452 wakeup.tv_sec += n;
453 wakeup.tv_nsec += 1000000000 * (n - (time_t)n);
454 if (wakeup.tv_nsec >= 1000000000) {
455 wakeup.tv_sec += 1;
456 wakeup.tv_nsec -= 1000000000;
457 }
458 } else if (isnum && n==0) {
459 nonblock = 1;
460 } else {
461 luaL_argcheck(L, 0, 2, "not a valid timeout");
462 }
463 }
464 lua_settop(L, 1);
465 if (!nonblock) {
466 fd = PQsocket(conn->pgconn);
467 FD_ZERO(&fds);
468 FD_SET(fd, &fds);
469 }
470 while (true) {
471 {
472 PGnotify *notify;
473 if (!PQconsumeInput(conn->pgconn)) {
474 lua_newtable(L); // 2
475 luaL_setmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY);
476 lua_pushliteral(L, MONDELEFANT_ERRCODE_CONNECTION);
477 lua_setfield(L, 2, "code");
478 mondelefant_push_first_line(L, PQerrorMessage(conn->pgconn)); // 3
479 lua_setfield(L, 2, "message");
480 return 1;
481 }
482 // avoid cumulating memory leaks in case of previous out-of-memory errors:
483 if (conn->todo_PQfreemem) {
484 PQfreemem(conn->todo_PQfreemem);
485 conn->todo_PQfreemem = NULL;
486 }
487 notify = PQnotifies(conn->pgconn);
488 if (notify) {
489 // ensure call of PQfreemem in case of out-of-memory errors:
490 conn->todo_PQfreemem = notify;
491 // do Lua operations:
492 lua_pushnil(L);
493 lua_pushstring(L, notify->relname);
494 lua_pushstring(L, notify->extra);
495 lua_pushinteger(L, notify->be_pid);
496 // free memory allocated by PQnotifies:
497 PQfreemem(notify);
498 // avoid double call of PQfreemem later:
499 conn->todo_PQfreemem = NULL;
500 return 4;
501 }
502 }
503 if (infinite) {
504 select(fd+1, &fds, NULL, NULL, NULL);
505 } else if (nonblock) {
506 break;
507 } else {
508 struct timespec tp;
509 struct timeval timeout = { 0, };
510 if (clock_gettime(CLOCK_MONOTONIC, &tp)) {
511 return luaL_error(L, "Could not access CLOCK_MONOTONIC");
512 }
513 tp.tv_sec = wakeup.tv_sec - tp.tv_sec;
514 tp.tv_nsec = wakeup.tv_nsec - tp.tv_nsec;
515 if (tp.tv_nsec < 0) {
516 tp.tv_sec -= 1;
517 tp.tv_nsec += 1000000000;
518 }
519 timeout.tv_sec = tp.tv_sec;
520 timeout.tv_usec = (tp.tv_nsec + 500) / 1000;
521 if (
522 timeout.tv_sec < 0 ||
523 (timeout.tv_sec == 0 && timeout.tv_usec == 0)
524 ) break;
525 select(fd+1, &fds, NULL, NULL, &timeout);
526 }
527 }
528 lua_pushnil(L);
529 lua_pushnil(L);
530 return 2;
531 }
533 // method "create_list" of database handles:
534 static int mondelefant_conn_create_list(lua_State *L) {
535 // ensure that first argument is a database connection:
536 luaL_checkudata(L, 1, MONDELEFANT_CONN_MT_REGKEY);
537 // if no second argument is given, use an empty table:
538 if (lua_isnoneornil(L, 2)) {
539 lua_settop(L, 1);
540 lua_newtable(L); // 2
541 } else {
542 luaL_checktype(L, 2, LUA_TTABLE);
543 lua_settop(L, 2);
544 }
545 // set meta-table for database result lists/objects:
546 luaL_setmetatable(L, MONDELEFANT_RESULT_MT_REGKEY);
547 // set "_connection" attribute to self:
548 lua_pushvalue(L, 1); // 3
549 lua_setfield(L, 2, "_connection");
550 // set "_type" attribute to string "list":
551 lua_pushliteral(L, "list"); // 3
552 lua_setfield(L, 2, "_type");
553 // return created database result list:
554 return 1;
555 }
557 // method "create_object" of database handles:
558 static int mondelefant_conn_create_object(lua_State *L) {
559 // ensure that first argument is a database connection:
560 luaL_checkudata(L, 1, MONDELEFANT_CONN_MT_REGKEY);
561 // if no second argument is given, use an empty table:
562 if (lua_isnoneornil(L, 2)) {
563 lua_settop(L, 1);
564 lua_newtable(L); // 2
565 } else {
566 luaL_checktype(L, 2, LUA_TTABLE);
567 lua_settop(L, 2);
568 }
569 // set meta-table for database result lists/objects:
570 luaL_setmetatable(L, MONDELEFANT_RESULT_MT_REGKEY);
571 // set "_connection" attribute to self:
572 lua_pushvalue(L, 1); // 3
573 lua_setfield(L, 2, "_connection");
574 // set "_type" attribute to string "object":
575 lua_pushliteral(L, "object"); // 3
576 lua_setfield(L, 2, "_type"); // "object" or "list"
577 // create empty tables for "_data", "_dirty" and "_ref" attributes:
578 lua_newtable(L); // 3
579 lua_setfield(L, 2, "_data");
580 lua_newtable(L); // 3
581 lua_setfield(L, 2, "_dirty");
582 lua_newtable(L); // 3
583 lua_setfield(L, 2, "_ref"); // nil=no info, false=nil, else table
584 // create column proxy (field "columns" in result object):
585 lua_newtable(L); // 3
586 luaL_setmetatable(L, MONDELEFANT_COLUMNS_MT_REGKEY);
587 lua_pushvalue(L, 2); // 4
588 lua_rawsetp(L, 3, MONDELEFANT_COLUMNS_RESULT_LUKEY);
589 lua_setfield(L, 2, "columns");
590 // return created database result object (from stack position 2):
591 return 1;
592 }
594 // method "quote_string" of database handles:
595 static int mondelefant_conn_quote_string(lua_State *L) {
596 mondelefant_conn_t *conn;
597 const char *input;
598 size_t input_len;
599 luaL_Buffer buf;
600 char *output;
601 size_t output_len;
602 // get database connection object:
603 conn = mondelefant_get_conn(L, 1);
604 // get second argument, which must be a string:
605 input = luaL_checklstring(L, 2, &input_len);
606 // throw error, if string is too long:
607 if (input_len > (SIZE_MAX / sizeof(char) - 3) / 2) {
608 return luaL_error(L, "String to be escaped is too long.");
609 }
610 // allocate memory for quoted string:
611 output = luaL_buffinitsize(L, &buf, (2 * input_len + 3) * sizeof(char));
612 // do escaping by calling PQescapeStringConn and enclosing result with
613 // single quotes:
614 output[0] = '\'';
615 output_len = PQescapeStringConn(
616 conn->pgconn, output + 1, input, input_len, NULL
617 );
618 output[output_len + 1] = '\'';
619 output[output_len + 2] = 0;
620 // create Lua string:
621 luaL_addsize(&buf, output_len + 2);
622 // return Lua string:
623 return 1;
624 }
626 // method "quote_binary" of database handles:
627 static int mondelefant_conn_quote_binary(lua_State *L) {
628 mondelefant_conn_t *conn;
629 const char *input;
630 size_t input_len;
631 char *output;
632 size_t output_len;
633 luaL_Buffer buf;
634 // get database connection object:
635 conn = mondelefant_get_conn(L, 1);
636 // get second argument, which must be a string:
637 input = luaL_checklstring(L, 2, &input_len);
638 // avoid cumulating memory leaks in case of previous out-of-memory errors:
639 if (conn->todo_PQfreemem) {
640 PQfreemem(conn->todo_PQfreemem);
641 conn->todo_PQfreemem = NULL;
642 }
643 // call PQescapeByteaConn, which allocates memory itself:
644 output = (char *)PQescapeByteaConn(
645 conn->pgconn, (const unsigned char *)input, input_len, &output_len
646 );
647 if (!output) {
648 lua_gc(L, LUA_GCCOLLECT, 0);
649 output = (char *)PQescapeByteaConn(
650 conn->pgconn, (const unsigned char *)input, input_len, &output_len
651 );
652 if (!output) {
653 return luaL_error(L, "Could not allocate memory for binary quoting.");
654 }
655 }
656 // ensure call of PQfreemem in case of out-of-memory errors:
657 conn->todo_PQfreemem = output;
658 // create Lua string enclosed by single quotes:
659 luaL_buffinit(L, &buf);
660 luaL_addchar(&buf, '\'');
661 luaL_addlstring(&buf, output, output_len - 1);
662 luaL_addchar(&buf, '\'');
663 luaL_pushresult(&buf);
664 // free memory allocated by PQescapeByteaConn:
665 PQfreemem(output);
666 // avoid double call of PQfreemem later:
667 conn->todo_PQfreemem = NULL;
668 // return Lua string:
669 return 1;
670 }
672 // method "assemble_command" of database handles:
673 static int mondelefant_conn_assemble_command(lua_State *L) {
674 mondelefant_conn_t *conn;
675 int paramidx = 2;
676 const char *template;
677 size_t template_pos = 0;
678 luaL_Buffer buf;
679 // get database connection object:
680 conn = mondelefant_get_conn(L, 1);
681 // if second argument is a string, return this string:
682 if (lua_type(L, 2) == LUA_TSTRING) {
683 lua_settop(L, 2);
684 return 1;
685 }
686 // if second argument has __tostring meta-method,
687 // then use this method and return its result:
688 if (luaL_callmeta(L, 2, "__tostring")) return 1;
689 // otherwise, require that second argument is a table:
690 luaL_checktype(L, 2, LUA_TTABLE);
691 // set stack top:
692 lua_settop(L, 2);
693 // get first element of table, which must be a string:
694 lua_rawgeti(L, 2, 1); // 3
695 luaL_argcheck(L,
696 lua_isstring(L, 3),
697 2,
698 "First entry of SQL command structure is not a string."
699 );
700 template = lua_tostring(L, 3);
701 // get value of "input_converter" attribute of database connection:
702 lua_pushliteral(L, "input_converter"); // 4
703 lua_gettable(L, 1); // input_converter at stack position 4
704 // reserve space on Lua stack:
705 lua_pushnil(L); // free space at stack position 5
706 lua_pushnil(L); // free space at stack position 6
707 // initialize Lua buffer for result string:
708 luaL_buffinit(L, &buf);
709 // fill buffer in loop:
710 while (1) {
711 // variable declaration:
712 char c;
713 // get next character:
714 c = template[template_pos++];
715 // break, when character is NULL byte:
716 if (!c) break;
717 // question-mark and dollar-sign are special characters:
718 if (c == '?' || c == '$') { // special character found
719 // check, if same character follows:
720 if (template[template_pos] == c) { // special character is escaped
721 // consume two characters of input and add one character to buffer:
722 template_pos++;
723 luaL_addchar(&buf, c);
724 } else { // special character is not escaped
725 luaL_Buffer keybuf;
726 int subcmd;
727 // set 'subcmd' = true, if special character was a dollar-sign,
728 // set 'subcmd' = false, if special character was a question-mark:
729 subcmd = (c == '$');
730 // read any number of alpha numeric chars or underscores
731 // and store them on Lua stack:
732 luaL_buffinit(L, &keybuf);
733 while (1) {
734 c = template[template_pos];
735 if (
736 (c < 'A' || c > 'Z') &&
737 (c < 'a' || c > 'z') &&
738 (c < '0' || c > '9') &&
739 (c != '_')
740 ) break;
741 luaL_addchar(&keybuf, c);
742 template_pos++;
743 }
744 luaL_pushresult(&keybuf);
745 // check, if any characters matched:
746 if (lua_rawlen(L, -1)) {
747 // if any alpha numeric chars or underscores were found,
748 // push them on stack as a Lua string and use them to lookup
749 // value from second argument:
750 lua_pushvalue(L, -1); // save key on stack
751 lua_gettable(L, 2); // fetch value (raw-value)
752 } else {
753 // otherwise push nil and use numeric lookup based on 'paramidx':
754 lua_pop(L, 1);
755 lua_pushnil(L); // put nil on key position
756 lua_rawgeti(L, 2, paramidx++); // fetch value (raw-value)
757 }
758 // Lua stack contains: ..., <buffer>, key, raw-value
759 // branch according to type of special character ("?" or "$"):
760 if (subcmd) { // dollar-sign
761 size_t i;
762 size_t count;
763 // store fetched value (which is supposed to be sub-structure)
764 // on Lua stack position 5 and drop key:
765 lua_replace(L, 5);
766 lua_pop(L, 1);
767 // Lua stack contains: ..., <buffer>
768 // check, if fetched value is really a sub-structure:
769 luaL_argcheck(L,
770 !lua_isnil(L, 5),
771 2,
772 "SQL sub-structure not found."
773 );
774 luaL_argcheck(L,
775 lua_type(L, 5) == LUA_TTABLE,
776 2,
777 "SQL sub-structure must be a table."
778 );
779 // Lua stack contains: ..., <buffer>
780 // get value of "sep" attribute of sub-structure,
781 // and place it on Lua stack position 6:
782 lua_getfield(L, 5, "sep");
783 lua_replace(L, 6);
784 // if seperator is nil, then use ", " as default,
785 // if seperator is neither nil nor a string, then throw error:
786 if (lua_isnil(L, 6)) {
787 lua_pushstring(L, ", ");
788 lua_replace(L, 6);
789 } else {
790 luaL_argcheck(L,
791 lua_isstring(L, 6),
792 2,
793 "Seperator of SQL sub-structure has to be a string."
794 );
795 }
796 // iterate over items of sub-structure:
797 count = lua_rawlen(L, 5);
798 for (i = 0; i < count; i++) {
799 // add seperator, unless this is the first run:
800 if (i) {
801 lua_pushvalue(L, 6);
802 luaL_addvalue(&buf);
803 }
804 // recursivly apply assemble function and add results to buffer:
805 lua_pushcfunction(L, mondelefant_conn_assemble_command);
806 lua_pushvalue(L, 1);
807 lua_rawgeti(L, 5, i+1);
808 lua_call(L, 2, 1);
809 luaL_addvalue(&buf);
810 }
811 } else { // question-mark
812 if (lua_toboolean(L, 4)) {
813 // call input_converter with connection handle, raw-value and
814 // an info-table which contains a "field_name" entry with the
815 // used key:
816 lua_pushvalue(L, 4);
817 lua_pushvalue(L, 1);
818 lua_pushvalue(L, -3);
819 lua_newtable(L);
820 lua_pushvalue(L, -6);
821 lua_setfield(L, -2, "field_name");
822 lua_call(L, 3, 1);
823 // Lua stack contains: ..., <buffer>, key, raw-value, final-value
824 // remove key and raw-value:
825 lua_remove(L, -2);
826 lua_remove(L, -2);
827 // Lua stack contains: ..., <buffer>, final-value
828 // throw error, if final-value is not a string:
829 if (!lua_isstring(L, -1)) {
830 return luaL_error(L, "input_converter returned non-string.");
831 }
832 } else {
833 // remove key from stack:
834 lua_remove(L, -2);
835 // Lua stack contains: ..., <buffer>, raw-value
836 // branch according to type of value:
837 // NOTE: Lua automatically converts numbers to strings
838 if (lua_isnil(L, -1)) { // value is nil
839 // push string "NULL" to stack:
840 lua_pushliteral(L, "NULL");
841 } else if (lua_type(L, -1) == LUA_TBOOLEAN) { // value is boolean
842 // push strings "TRUE" or "FALSE" to stack:
843 lua_pushstring(L, lua_toboolean(L, -1) ? "TRUE" : "FALSE");
844 } else if (lua_isstring(L, -1)) { // value is string or number
845 // push output of "quote_string" method of database connection
846 // to stack:
847 lua_tostring(L, -1);
848 lua_pushcfunction(L, mondelefant_conn_quote_string);
849 lua_pushvalue(L, 1);
850 lua_pushvalue(L, -3);
851 lua_call(L, 2, 1);
852 } else { // value is of other type
853 // throw error:
854 return luaL_error(L,
855 "Unable to convert SQL value due to unknown type "
856 "or missing input_converter."
857 );
858 }
859 // Lua stack contains: ..., <buffer>, raw-value, final-value
860 // remove raw-value:
861 lua_remove(L, -2);
862 // Lua stack contains: ..., <buffer>, final-value
863 }
864 // append final-value to buffer:
865 luaL_addvalue(&buf);
866 }
867 }
868 } else { // character is not special
869 // just copy character:
870 luaL_addchar(&buf, c);
871 }
872 }
873 // return string in buffer:
874 luaL_pushresult(&buf);
875 return 1;
876 }
878 // max number of SQL statements executed by one "query" method call:
879 #define MONDELEFANT_MAX_COMMAND_COUNT 64
880 // max number of columns in a database result:
881 #define MONDELEFANT_MAX_COLUMN_COUNT 1024
882 // enum values for 'modes' array in C-function below:
883 #define MONDELEFANT_QUERY_MODE_LIST 1
884 #define MONDELEFANT_QUERY_MODE_OBJECT 2
885 #define MONDELEFANT_QUERY_MODE_OPT_OBJECT 3
887 // method "try_query" of database handles:
888 static int mondelefant_conn_try_query(lua_State *L) {
889 mondelefant_conn_t *conn;
890 int command_count;
891 int command_idx;
892 int modes[MONDELEFANT_MAX_COMMAND_COUNT];
893 luaL_Buffer buf;
894 int sent_success;
895 PGresult *res;
896 int rows, cols, row, col;
897 // get database connection object:
898 conn = mondelefant_get_conn(L, 1);
899 // calculate number of commands (2 arguments for one command):
900 command_count = lua_gettop(L) / 2;
901 // push nil on stack, which is needed, if last mode was ommitted:
902 lua_pushnil(L);
903 // throw error, if number of commands is too high:
904 if (command_count > MONDELEFANT_MAX_COMMAND_COUNT) {
905 return luaL_error(L, "Exceeded maximum command count in one query.");
906 }
907 // create SQL string, store query modes and push SQL string on stack:
908 luaL_buffinit(L, &buf);
909 for (command_idx = 0; command_idx < command_count; command_idx++) {
910 int mode;
911 int mode_idx; // stack index of mode string
912 if (command_idx) luaL_addchar(&buf, ' ');
913 lua_pushcfunction(L, mondelefant_conn_assemble_command);
914 lua_pushvalue(L, 1);
915 lua_pushvalue(L, 2 + 2 * command_idx);
916 lua_call(L, 2, 1);
917 luaL_addvalue(&buf);
918 luaL_addchar(&buf, ';');
919 mode_idx = 3 + 2 * command_idx;
920 if (lua_isnil(L, mode_idx)) {
921 mode = MONDELEFANT_QUERY_MODE_LIST;
922 } else {
923 const char *modestr;
924 modestr = luaL_checkstring(L, mode_idx);
925 if (!strcmp(modestr, "list")) {
926 mode = MONDELEFANT_QUERY_MODE_LIST;
927 } else if (!strcmp(modestr, "object")) {
928 mode = MONDELEFANT_QUERY_MODE_OBJECT;
929 } else if (!strcmp(modestr, "opt_object")) {
930 mode = MONDELEFANT_QUERY_MODE_OPT_OBJECT;
931 } else {
932 return luaL_argerror(L, mode_idx, "unknown query mode");
933 }
934 }
935 modes[command_idx] = mode;
936 }
937 luaL_pushresult(&buf); // stack position unknown
938 lua_replace(L, 2); // SQL command string to stack position 2
939 // call sql_tracer, if set:
940 lua_settop(L, 2);
941 lua_getfield(L, 1, "sql_tracer"); // tracer at stack position 3
942 if (lua_toboolean(L, 3)) {
943 lua_pushvalue(L, 1); // 4
944 lua_pushvalue(L, 2); // 5
945 lua_call(L, 2, 1); // trace callback at stack position 3
946 }
947 // NOTE: If no tracer was found, then nil or false is stored at stack
948 // position 3.
949 // call PQsendQuery function and store result in 'sent_success' variable:
950 sent_success = PQsendQuery(conn->pgconn, lua_tostring(L, 2));
951 // create preliminary result table:
952 lua_newtable(L); // results in table at stack position 4
953 // iterate over results using function PQgetResult to fill result table:
954 for (command_idx = 0; ; command_idx++) {
955 int mode;
956 char binary[MONDELEFANT_MAX_COLUMN_COUNT];
957 ExecStatusType pgstatus;
958 // fetch mode which was given for the command:
959 mode = modes[command_idx];
960 // if PQsendQuery call was successful, then fetch result data:
961 if (sent_success) {
962 // avoid cumulating memory leaks in case of previous out-of-memory errors:
963 if (conn->todo_PQclear) {
964 PQclear(conn->todo_PQclear);
965 conn->todo_PQclear = NULL;
966 }
967 // NOTE: PQgetResult called one extra time. Break only, if all
968 // queries have been processed and PQgetResult returned NULL.
969 res = PQgetResult(conn->pgconn);
970 if (command_idx >= command_count && !res) break;
971 if (res) {
972 pgstatus = PQresultStatus(res);
973 rows = PQntuples(res);
974 cols = PQnfields(res);
975 // ensure call of PQclear in case of Lua errors:
976 conn->todo_PQclear = res;
977 }
978 }
979 // handle errors:
980 if (
981 !sent_success || command_idx >= command_count || !res ||
982 (pgstatus != PGRES_TUPLES_OK && pgstatus != PGRES_COMMAND_OK) ||
983 (rows < 1 && mode == MONDELEFANT_QUERY_MODE_OBJECT) ||
984 (rows > 1 && mode != MONDELEFANT_QUERY_MODE_LIST)
985 ) {
986 const char *command;
987 command = lua_tostring(L, 2);
988 lua_newtable(L); // 5
989 luaL_setmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY);
990 lua_pushvalue(L, 1);
991 lua_setfield(L, 5, "connection");
992 lua_pushvalue(L, 2);
993 lua_setfield(L, 5, "sql_command");
994 if (!sent_success) {
995 lua_pushliteral(L, MONDELEFANT_ERRCODE_CONNECTION);
996 lua_setfield(L, 5, "code");
997 mondelefant_push_first_line(L, PQerrorMessage(conn->pgconn));
998 lua_setfield(L, 5, "message");
999 } else {
1000 lua_pushinteger(L, command_idx + 1);
1001 lua_setfield(L, 5, "command_number");
1002 if (!res) {
1003 lua_pushliteral(L, MONDELEFANT_ERRCODE_RESULTCOUNT_LOW);
1004 lua_setfield(L, 5, "code");
1005 lua_pushliteral(L, "Received too few database result sets.");
1006 lua_setfield(L, 5, "message");
1007 } else if (command_idx >= command_count) {
1008 lua_pushliteral(L, MONDELEFANT_ERRCODE_RESULTCOUNT_HIGH);
1009 lua_setfield(L, 5, "code");
1010 lua_pushliteral(L, "Received too many database result sets.");
1011 lua_setfield(L, 5, "message");
1012 } else if (
1013 pgstatus != PGRES_TUPLES_OK && pgstatus != PGRES_COMMAND_OK
1014 ) {
1015 const char *sqlstate;
1016 const char *errmsg;
1017 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SEVERITY));
1018 lua_setfield(L, 5, "pg_severity");
1019 sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
1020 if (sqlstate) {
1021 lua_pushstring(L, sqlstate);
1022 lua_setfield(L, 5, "pg_sqlstate");
1023 lua_pushstring(L, mondelefant_translate_errcode(sqlstate));
1024 lua_setfield(L, 5, "code");
1025 } else {
1026 lua_pushliteral(L, MONDELEFANT_ERRCODE_UNKNOWN);
1027 lua_setfield(L, 5, "code");
1028 }
1029 errmsg = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY);
1030 if (errmsg) {
1031 mondelefant_push_first_line(L, errmsg);
1032 lua_setfield(L, 5, "message");
1033 lua_pushstring(L, errmsg);
1034 lua_setfield(L, 5, "pg_message_primary");
1035 } else {
1036 lua_pushliteral(L,
1037 "Error while fetching result, but no error message given."
1038 );
1039 lua_setfield(L, 5, "message");
1040 }
1041 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL));
1042 lua_setfield(L, 5, "pg_message_detail");
1043 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_MESSAGE_HINT));
1044 lua_setfield(L, 5, "pg_message_hint");
1045 // NOTE: "position" and "pg_internal_position" are recalculated to
1046 // byte offsets, as Lua 5.2 is not Unicode aware.
1047 {
1048 char *tmp;
1049 tmp = PQresultErrorField(res, PG_DIAG_STATEMENT_POSITION);
1050 if (tmp) {
1051 int pos;
1052 pos = atoi(tmp) - 1;
1053 if (conn->server_encoding == MONDELEFANT_SERVER_ENCODING_UTF8) {
1054 pos = utf8_position_to_byte(command, pos);
1055 }
1056 lua_pushinteger(L, pos + 1);
1057 lua_setfield(L, 5, "position");
1058 }
1059 }
1060 {
1061 const char *internal_query;
1062 internal_query = PQresultErrorField(res, PG_DIAG_INTERNAL_QUERY);
1063 lua_pushstring(L, internal_query);
1064 lua_setfield(L, 5, "pg_internal_query");
1065 char *tmp;
1066 tmp = PQresultErrorField(res, PG_DIAG_INTERNAL_POSITION);
1067 if (tmp) {
1068 int pos;
1069 pos = atoi(tmp) - 1;
1070 if (conn->server_encoding == MONDELEFANT_SERVER_ENCODING_UTF8) {
1071 pos = utf8_position_to_byte(internal_query, pos);
1072 }
1073 lua_pushinteger(L, pos + 1);
1074 lua_setfield(L, 5, "pg_internal_position");
1075 }
1076 }
1077 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_CONTEXT));
1078 lua_setfield(L, 5, "pg_context");
1079 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_FILE));
1080 lua_setfield(L, 5, "pg_source_file");
1081 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_LINE));
1082 lua_setfield(L, 5, "pg_source_line");
1083 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_FUNCTION));
1084 lua_setfield(L, 5, "pg_source_function");
1085 } else if (rows < 1 && mode == MONDELEFANT_QUERY_MODE_OBJECT) {
1086 lua_pushliteral(L, MONDELEFANT_ERRCODE_QUERY1_NO_ROWS);
1087 lua_setfield(L, 5, "code");
1088 lua_pushliteral(L, "Expected one row, but got empty set.");
1089 lua_setfield(L, 5, "message");
1090 } else if (rows > 1 && mode != MONDELEFANT_QUERY_MODE_LIST) {
1091 lua_pushliteral(L, MONDELEFANT_ERRCODE_QUERY1_MULTIPLE_ROWS);
1092 lua_setfield(L, 5, "code");
1093 lua_pushliteral(L, "Got more than one result row.");
1094 lua_setfield(L, 5, "message");
1095 } else {
1096 // should not happen
1097 abort();
1098 }
1099 if (res) {
1100 PQclear(res);
1101 while ((res = PQgetResult(conn->pgconn))) PQclear(res);
1102 // avoid double call of PQclear later:
1103 conn->todo_PQclear = NULL;
1104 }
1105 }
1106 if (lua_toboolean(L, 3)) {
1107 lua_pushvalue(L, 3);
1108 lua_pushvalue(L, 5);
1109 lua_call(L, 1, 0);
1110 }
1111 return 1;
1112 }
1113 // call "create_list" or "create_object" method of database handle,
1114 // result will be at stack position 5:
1115 if (modes[command_idx] == MONDELEFANT_QUERY_MODE_LIST) {
1116 lua_pushcfunction(L, mondelefant_conn_create_list); // 5
1117 lua_pushvalue(L, 1); // 6
1118 lua_call(L, 1, 1); // 5
1119 } else {
1120 lua_pushcfunction(L, mondelefant_conn_create_object); // 5
1121 lua_pushvalue(L, 1); // 6
1122 lua_call(L, 1, 1); // 5
1123 }
1124 // set "_column_info":
1125 lua_newtable(L); // 6
1126 for (col = 0; col < cols; col++) {
1127 lua_newtable(L); // 7
1128 lua_pushstring(L, PQfname(res, col)); // 8
1129 lua_pushvalue(L, 8); // 9
1130 lua_pushvalue(L, 7); // 10
1131 lua_rawset(L, 6);
1132 lua_setfield(L, 7, "field_name");
1133 // _column_info entry (for current column) on stack position 7
1134 {
1135 Oid tmp;
1136 tmp = PQftable(res, col);
1137 if (tmp == InvalidOid) lua_pushnil(L);
1138 else lua_pushinteger(L, tmp);
1139 lua_setfield(L, 7, "table_oid");
1140 }
1141 {
1142 int tmp;
1143 tmp = PQftablecol(res, col);
1144 if (tmp == 0) lua_pushnil(L);
1145 else lua_pushinteger(L, tmp);
1146 lua_setfield(L, 7, "table_column_number");
1147 }
1148 {
1149 Oid tmp;
1150 tmp = PQftype(res, col);
1151 binary[col] = (tmp == MONDELEFANT_POSTGRESQL_BINARY_OID);
1152 lua_pushinteger(L, tmp);
1153 lua_setfield(L, 7, "type_oid");
1154 lua_pushstring(L, mondelefant_oid_to_typestr(tmp));
1155 lua_setfield(L, 7, "type");
1156 }
1157 {
1158 int tmp;
1159 tmp = PQfmod(res, col);
1160 if (tmp == -1) lua_pushnil(L);
1161 else lua_pushinteger(L, tmp);
1162 lua_setfield(L, 7, "type_modifier");
1163 }
1164 lua_rawseti(L, 6, col+1);
1165 }
1166 lua_setfield(L, 5, "_column_info");
1167 // set "_rows_affected":
1168 {
1169 char *tmp;
1170 tmp = PQcmdTuples(res);
1171 if (tmp[0]) {
1172 lua_pushinteger(L, atoi(tmp));
1173 lua_setfield(L, 5, "_rows_affected");
1174 }
1175 }
1176 // set "_oid":
1177 {
1178 Oid tmp;
1179 tmp = PQoidValue(res);
1180 if (tmp != InvalidOid) {
1181 lua_pushinteger(L, tmp);
1182 lua_setfield(L, 5, "_oid");
1183 }
1184 }
1185 // copy data as strings or nil, while performing binary unescaping
1186 // automatically:
1187 if (modes[command_idx] == MONDELEFANT_QUERY_MODE_LIST) {
1188 for (row = 0; row < rows; row++) {
1189 lua_pushcfunction(L, mondelefant_conn_create_object); // 6
1190 lua_pushvalue(L, 1); // 7
1191 lua_call(L, 1, 1); // 6
1192 for (col = 0; col < cols; col++) {
1193 if (PQgetisnull(res, row, col)) {
1194 lua_pushnil(L);
1195 } else if (binary[col]) {
1196 size_t binlen;
1197 char *binval;
1198 // avoid cumulating memory leaks in case of previous out-of-memory errors:
1199 if (conn->todo_PQfreemem) {
1200 PQfreemem(conn->todo_PQfreemem);
1201 conn->todo_PQfreemem = NULL;
1202 }
1203 // Unescape binary data:
1204 binval = (char *)PQunescapeBytea(
1205 (unsigned char *)PQgetvalue(res, row, col), &binlen
1206 );
1207 if (!binval) {
1208 return luaL_error(L,
1209 "Could not allocate memory for binary unescaping."
1210 );
1211 }
1212 // ensure call of PQfreemem in case of out-of-memory error:
1213 conn->todo_PQfreemem = binval;
1214 // create Lua string:
1215 lua_pushlstring(L, binval, binlen);
1216 // free memory allocated by PQunescapeBytea:
1217 PQfreemem(binval);
1218 // avoid double call of PQfreemem later:
1219 conn->todo_PQfreemem = NULL;
1220 } else {
1221 lua_pushstring(L, PQgetvalue(res, row, col));
1222 }
1223 lua_rawseti(L, 6, col+1);
1224 }
1225 lua_rawseti(L, 5, row+1);
1226 }
1227 } else if (rows == 1) {
1228 for (col = 0; col < cols; col++) {
1229 if (PQgetisnull(res, 0, col)) {
1230 lua_pushnil(L);
1231 } else if (binary[col]) {
1232 size_t binlen;
1233 char *binval;
1234 // avoid cumulating memory leaks in case of previous out-of-memory errors:
1235 if (conn->todo_PQfreemem) {
1236 PQfreemem(conn->todo_PQfreemem);
1237 conn->todo_PQfreemem = NULL;
1238 }
1239 // Unescape binary data:
1240 binval = (char *)PQunescapeBytea(
1241 (unsigned char *)PQgetvalue(res, 0, col), &binlen
1242 );
1243 if (!binval) {
1244 return luaL_error(L,
1245 "Could not allocate memory for binary unescaping."
1246 );
1247 }
1248 // ensure call of PQfreemem in case of out-of-memory error:
1249 conn->todo_PQfreemem = binval;
1250 // create Lua string:
1251 lua_pushlstring(L, binval, binlen);
1252 // free memory allocated by PQunescapeBytea:
1253 PQfreemem(binval);
1254 // avoid double call of PQfreemem later:
1255 conn->todo_PQfreemem = NULL;
1256 } else {
1257 lua_pushstring(L, PQgetvalue(res, 0, col));
1258 }
1259 lua_rawseti(L, 5, col+1);
1260 }
1261 } else {
1262 // no row in optrow mode
1263 lua_pop(L, 1);
1264 lua_pushnil(L);
1265 }
1266 // save result in result list:
1267 lua_rawseti(L, 4, command_idx+1);
1268 // extra assertion:
1269 if (lua_gettop(L) != 4) abort(); // should not happen
1270 // free memory acquired by libpq:
1271 PQclear(res);
1272 // avoid double call of PQclear later:
1273 conn->todo_PQclear = NULL;
1274 }
1275 // trace callback at stack position 3
1276 // result at stack position 4 (top of stack)
1277 // if a trace callback is existent, then call:
1278 if (lua_toboolean(L, 3)) {
1279 lua_pushvalue(L, 3);
1280 lua_call(L, 0, 0);
1281 }
1282 // put result at stack position 3:
1283 lua_replace(L, 3);
1284 // get output converter to stack position 4:
1285 lua_getfield(L, 1, "output_converter");
1286 // get mutability state saver to stack position 5:
1287 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY);
1288 lua_getfield(L, -1, "save_mutability_state");
1289 lua_replace(L, -2);
1290 // apply output converters and fill "_data" table according to column names:
1291 for (command_idx = 0; command_idx < command_count; command_idx++) {
1292 int mode;
1293 mode = modes[command_idx];
1294 lua_rawgeti(L, 3, command_idx+1); // raw result at stack position 6
1295 if (lua_toboolean(L, 6)) {
1296 lua_getfield(L, 6, "_column_info"); // column_info list at position 7
1297 cols = lua_rawlen(L, 7);
1298 if (mode == MONDELEFANT_QUERY_MODE_LIST) {
1299 rows = lua_rawlen(L, 6);
1300 for (row = 0; row < rows; row++) {
1301 lua_rawgeti(L, 6, row+1); // row at stack position 8
1302 lua_getfield(L, 8, "_data"); // _data table at stack position 9
1303 lua_getfield(L, 8, "_dirty"); // _dirty table at stack position 10
1304 for (col = 0; col < cols; col++) {
1305 lua_rawgeti(L, 7, col+1); // this column info at position 11
1306 lua_getfield(L, 11, "field_name"); // 12
1307 if (lua_toboolean(L, 4)) {
1308 lua_pushvalue(L, 4); // output-converter
1309 lua_pushvalue(L, 1); // connection
1310 lua_rawgeti(L, 8, col+1); // raw-value
1311 lua_pushvalue(L, 11); // this column info
1312 lua_call(L, 3, 1); // converted value at position 13
1313 } else {
1314 lua_rawgeti(L, 8, col+1); // raw-value at position 13
1315 }
1316 if (lua_toboolean(L, 5)) { // handle mutable values?
1317 lua_pushvalue(L, 12); // copy of field name
1318 lua_pushvalue(L, 5); // mutability state saver function
1319 lua_pushvalue(L, 13); // copy of value
1320 lua_call(L, 1, 1); // calculated mutability state of value
1321 lua_rawset(L, 10); // store mutability state in _dirty table
1322 }
1323 lua_pushvalue(L, 13); // 14
1324 lua_rawseti(L, 8, col+1);
1325 lua_rawset(L, 9);
1326 lua_settop(L, 10);
1327 }
1328 lua_settop(L, 7);
1329 }
1330 } else {
1331 lua_getfield(L, 6, "_data"); // _data table at stack position 8
1332 lua_getfield(L, 6, "_dirty"); // _dirty table at stack position 9
1333 for (col = 0; col < cols; col++) {
1334 lua_rawgeti(L, 7, col+1); // this column info at position 10
1335 lua_getfield(L, 10, "field_name"); // 11
1336 if (lua_toboolean(L, 4)) {
1337 lua_pushvalue(L, 4); // output-converter
1338 lua_pushvalue(L, 1); // connection
1339 lua_rawgeti(L, 6, col+1); // raw-value
1340 lua_pushvalue(L, 10); // this column info
1341 lua_call(L, 3, 1); // converted value at position 12
1342 } else {
1343 lua_rawgeti(L, 6, col+1); // raw-value at position 12
1344 }
1345 if (lua_toboolean(L, 5)) { // handle mutable values?
1346 lua_pushvalue(L, 11); // copy of field name
1347 lua_pushvalue(L, 5); // mutability state saver function
1348 lua_pushvalue(L, 12); // copy of value
1349 lua_call(L, 1, 1); // calculated mutability state of value
1350 lua_rawset(L, 9); // store mutability state in _dirty table
1351 }
1352 lua_pushvalue(L, 12); // 13
1353 lua_rawseti(L, 6, col+1);
1354 lua_rawset(L, 8);
1355 lua_settop(L, 9);
1356 }
1357 }
1358 }
1359 lua_settop(L, 5);
1360 }
1361 // return nil as first result value, followed by result lists/objects:
1362 lua_settop(L, 3);
1363 lua_pushnil(L);
1364 for (command_idx = 0; command_idx < command_count; command_idx++) {
1365 lua_rawgeti(L, 3, command_idx+1);
1366 }
1367 return command_count+1;
1368 }
1370 // method "is_kind_of" of error objects:
1371 static int mondelefant_errorobject_is_kind_of(lua_State *L) {
1372 const char *errclass;
1373 luaL_checktype(L, 1, LUA_TTABLE);
1374 errclass = luaL_checkstring(L, 2);
1375 lua_settop(L, 2);
1376 lua_getfield(L, 1, "code"); // 3
1377 luaL_argcheck(L,
1378 lua_type(L, 3) == LUA_TSTRING,
1379 1,
1380 "field 'code' of error object is not a string"
1381 );
1382 lua_pushboolean(L,
1383 mondelefant_check_error_class(lua_tostring(L, 3), errclass)
1384 );
1385 return 1;
1386 }
1388 // method "wait" of database handles:
1389 static int mondelefant_conn_wait(lua_State *L) {
1390 int argc;
1391 // count number of arguments:
1392 argc = lua_gettop(L);
1393 // insert "try_wait" function/method at stack position 1:
1394 lua_pushcfunction(L, mondelefant_conn_try_wait);
1395 lua_insert(L, 1);
1396 // call "try_wait" method:
1397 lua_call(L, argc, LUA_MULTRET); // results (with error) starting at index 1
1398 // check, if error occurred:
1399 if (lua_toboolean(L, 1)) {
1400 // raise error
1401 lua_settop(L, 1);
1402 return lua_error(L);
1403 } else {
1404 // return everything but nil error object:
1405 return lua_gettop(L) - 1;
1406 }
1407 }
1409 // method "query" of database handles:
1410 static int mondelefant_conn_query(lua_State *L) {
1411 int argc;
1412 // count number of arguments:
1413 argc = lua_gettop(L);
1414 // insert "try_query" function/method at stack position 1:
1415 lua_pushcfunction(L, mondelefant_conn_try_query);
1416 lua_insert(L, 1);
1417 // call "try_query" method:
1418 lua_call(L, argc, LUA_MULTRET); // results (with error) starting at index 1
1419 // check, if error occurred:
1420 if (lua_toboolean(L, 1)) {
1421 // raise error
1422 lua_settop(L, 1);
1423 return lua_error(L);
1424 } else {
1425 // return everything but nil error object:
1426 return lua_gettop(L) - 1;
1427 }
1428 }
1430 // library function "set_class":
1431 static int mondelefant_set_class(lua_State *L) {
1432 // ensure that first argument is a database result list/object:
1433 lua_settop(L, 2);
1434 lua_getmetatable(L, 1); // 3
1435 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_RESULT_MT_REGKEY); // 4
1436 luaL_argcheck(L, lua_compare(L, 3, 4, LUA_OPEQ), 1, "not a database result");
1437 // ensure that second argument is a database class (model):
1438 lua_settop(L, 2);
1439 lua_getmetatable(L, 2); // 3
1440 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_MT_REGKEY); // 4
1441 luaL_argcheck(L, lua_compare(L, 3, 4, LUA_OPEQ), 2, "not a database class");
1442 // set attribute "_class" of result list/object to given class:
1443 lua_settop(L, 2);
1444 lua_pushvalue(L, 2); // 3
1445 lua_setfield(L, 1, "_class");
1446 // test, if database result is a list (and not a single object):
1447 lua_getfield(L, 1, "_type"); // 3
1448 lua_pushliteral(L, "list"); // 4
1449 if (lua_rawequal(L, 3, 4)) {
1450 int i;
1451 // set attribute "_class" of all elements to given class:
1452 for (i=0; i < lua_rawlen(L, 1); i++) {
1453 lua_settop(L, 2);
1454 lua_rawgeti(L, 1, i+1); // 3
1455 lua_pushvalue(L, 2); // 4
1456 lua_setfield(L, 3, "_class");
1457 }
1458 }
1459 // return first argument:
1460 lua_settop(L, 1);
1461 return 1;
1462 }
1464 // library function "new_class":
1465 static int mondelefant_new_class(lua_State *L) {
1466 // if no argument is given, use an empty table:
1467 if (lua_isnoneornil(L, 1)) {
1468 lua_settop(L, 0);
1469 lua_newtable(L); // 1
1470 } else {
1471 luaL_checktype(L, 1, LUA_TTABLE);
1472 lua_settop(L, 1);
1473 }
1474 // set meta-table for database classes (models):
1475 luaL_setmetatable(L, MONDELEFANT_CLASS_MT_REGKEY);
1476 // check, if "prototype" attribute is not set:
1477 lua_pushliteral(L, "prototype"); // 2
1478 lua_rawget(L, 1); // 2
1479 if (!lua_toboolean(L, 2)) {
1480 // set "prototype" attribute to default prototype:
1481 lua_pushliteral(L, "prototype"); // 3
1482 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 4
1483 lua_rawset(L, 1);
1484 }
1485 // set "object" attribute to empty table, unless it is already set:
1486 lua_settop(L, 1);
1487 lua_pushliteral(L, "object"); // 2
1488 lua_rawget(L, 1); // 2
1489 if (!lua_toboolean(L, 2)) {
1490 lua_pushliteral(L, "object"); // 3
1491 lua_newtable(L); // 4
1492 lua_rawset(L, 1);
1493 }
1494 // set "object_get" attribute to empty table, unless it is already set:
1495 lua_settop(L, 1);
1496 lua_pushliteral(L, "object_get"); // 2
1497 lua_rawget(L, 1); // 2
1498 if (!lua_toboolean(L, 2)) {
1499 lua_pushliteral(L, "object_get"); // 3
1500 lua_newtable(L); // 4
1501 lua_rawset(L, 1);
1502 }
1503 // set "object_set" attribute to empty table, unless it is already set:
1504 lua_settop(L, 1);
1505 lua_pushliteral(L, "object_set"); // 2
1506 lua_rawget(L, 1); // 2
1507 if (!lua_toboolean(L, 2)) {
1508 lua_pushliteral(L, "object_set"); // 3
1509 lua_newtable(L); // 4
1510 lua_rawset(L, 1);
1511 }
1512 // set "list" attribute to empty table, unless it is already set:
1513 lua_settop(L, 1);
1514 lua_pushliteral(L, "list"); // 2
1515 lua_rawget(L, 1); // 2
1516 if (!lua_toboolean(L, 2)) {
1517 lua_pushliteral(L, "list"); // 3
1518 lua_newtable(L); // 4
1519 lua_rawset(L, 1);
1520 }
1521 // set "references" attribute to empty table, unless it is already set:
1522 lua_settop(L, 1);
1523 lua_pushliteral(L, "references"); // 2
1524 lua_rawget(L, 1); // 2
1525 if (!lua_toboolean(L, 2)) {
1526 lua_pushliteral(L, "references"); // 3
1527 lua_newtable(L); // 4
1528 lua_rawset(L, 1);
1529 }
1530 // set "foreign_keys" attribute to empty table, unless it is already set:
1531 lua_settop(L, 1);
1532 lua_pushliteral(L, "foreign_keys"); // 2
1533 lua_rawget(L, 1); // 2
1534 if (!lua_toboolean(L, 2)) {
1535 lua_pushliteral(L, "foreign_keys"); // 3
1536 lua_newtable(L); // 4
1537 lua_rawset(L, 1);
1538 }
1539 // return table:
1540 lua_settop(L, 1);
1541 return 1;
1542 }
1544 // method "get_reference" of classes (models):
1545 static int mondelefant_class_get_reference(lua_State *L) {
1546 lua_settop(L, 2);
1547 while (lua_toboolean(L, 1)) {
1548 // get "references" table:
1549 lua_getfield(L, 1, "references"); // 3
1550 // perform lookup:
1551 lua_pushvalue(L, 2); // 4
1552 lua_gettable(L, 3); // 4
1553 // return result, if lookup was successful:
1554 if (!lua_isnil(L, 4)) return 1;
1555 // replace current table by its prototype:
1556 lua_settop(L, 2);
1557 lua_pushliteral(L, "prototype"); // 3
1558 lua_rawget(L, 1); // 3
1559 lua_replace(L, 1);
1560 }
1561 // return nothing:
1562 return 0;
1563 }
1565 // method "iterate_over_references" of classes (models):
1566 static int mondelefant_class_iterate_over_references(lua_State *L) {
1567 return luaL_error(L, "Reference iterator not implemented yet."); // TODO
1568 }
1570 // method "get_foreign_key_reference_name" of classes (models):
1571 static int mondelefant_class_get_foreign_key_reference_name(lua_State *L) {
1572 lua_settop(L, 2);
1573 while (lua_toboolean(L, 1)) {
1574 // get "foreign_keys" table:
1575 lua_getfield(L, 1, "foreign_keys"); // 3
1576 // perform lookup:
1577 lua_pushvalue(L, 2); // 4
1578 lua_gettable(L, 3); // 4
1579 // return result, if lookup was successful:
1580 if (!lua_isnil(L, 4)) return 1;
1581 // replace current table by its prototype:
1582 lua_settop(L, 2);
1583 lua_pushliteral(L, "prototype"); // 3
1584 lua_rawget(L, 1); // 3
1585 lua_replace(L, 1);
1586 }
1587 // return nothing:
1588 return 0;
1589 }
1591 // meta-method "__index" of database result lists and objects:
1592 static int mondelefant_result_index(lua_State *L) {
1593 const char *result_type;
1594 // only lookup, when key is a string not beginning with an underscore:
1595 if (lua_type(L, 2) != LUA_TSTRING || lua_tostring(L, 2)[0] == '_') {
1596 return 0;
1597 }
1598 // value of "_class" attribute or default class on stack position 3:
1599 lua_settop(L, 2);
1600 lua_getfield(L, 1, "_class"); // 3
1601 if (!lua_toboolean(L, 3)) {
1602 lua_settop(L, 2);
1603 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 3
1604 }
1605 // get value of "_type" attribute:
1606 lua_getfield(L, 1, "_type"); // 4
1607 result_type = lua_tostring(L, 4);
1608 // different lookup for lists and objects:
1609 if (result_type && !strcmp(result_type, "object")) { // object
1610 lua_settop(L, 3);
1611 // try inherited attributes, methods or getter functions:
1612 lua_pushvalue(L, 3); // 4
1613 while (lua_toboolean(L, 4)) {
1614 lua_getfield(L, 4, "object"); // 5
1615 lua_pushvalue(L, 2); // 6
1616 lua_gettable(L, 5); // 6
1617 if (!lua_isnil(L, 6)) return 1;
1618 lua_settop(L, 4);
1619 lua_getfield(L, 4, "object_get"); // 5
1620 lua_pushvalue(L, 2); // 6
1621 lua_gettable(L, 5); // 6
1622 if (lua_toboolean(L, 6)) {
1623 lua_pushvalue(L, 1); // 7
1624 lua_call(L, 1, 1); // 6
1625 return 1;
1626 }
1627 lua_settop(L, 4);
1628 lua_pushliteral(L, "prototype"); // 5
1629 lua_rawget(L, 4); // 5
1630 lua_replace(L, 4);
1631 }
1632 lua_settop(L, 3);
1633 // try primary keys of referenced objects:
1634 lua_pushcfunction(L,
1635 mondelefant_class_get_foreign_key_reference_name
1636 ); // 4
1637 lua_pushvalue(L, 3); // 5
1638 lua_pushvalue(L, 2); // 6
1639 lua_call(L, 2, 1); // 4
1640 if (!lua_isnil(L, 4)) {
1641 // reference name at stack position 4
1642 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1643 lua_pushvalue(L, 3); // 6
1644 lua_pushvalue(L, 4); // 7
1645 lua_call(L, 2, 1); // reference info at stack position 5
1646 lua_getfield(L, 1, "_ref"); // 6
1647 lua_getfield(L, 5, "ref"); // 7
1648 lua_gettable(L, 6); // 7
1649 if (!lua_isnil(L, 7)) {
1650 if (lua_toboolean(L, 7)) {
1651 lua_getfield(L, 5, "that_key"); // 8
1652 if (lua_isnil(L, 8)) {
1653 return luaL_error(L, "Missing 'that_key' entry in model reference.");
1654 }
1655 lua_gettable(L, 7); // 8
1656 } else {
1657 lua_pushnil(L);
1658 }
1659 return 1;
1660 }
1661 }
1662 lua_settop(L, 3);
1663 lua_getfield(L, 1, "_data"); // _data table on stack position 4
1664 // try cached referenced object (or cached NULL reference):
1665 lua_getfield(L, 1, "_ref"); // 5
1666 lua_pushvalue(L, 2); // 6
1667 lua_gettable(L, 5); // 6
1668 if (lua_isboolean(L, 6) && !lua_toboolean(L, 6)) {
1669 lua_pushnil(L);
1670 return 1;
1671 } else if (!lua_isnil(L, 6)) {
1672 return 1;
1673 }
1674 lua_settop(L, 4);
1675 // try to load a referenced object:
1676 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1677 lua_pushvalue(L, 3); // 6
1678 lua_pushvalue(L, 2); // 7
1679 lua_call(L, 2, 1); // 5
1680 if (!lua_isnil(L, 5)) {
1681 lua_settop(L, 2);
1682 lua_getfield(L, 1, "load"); // 3
1683 lua_pushvalue(L, 1); // 4 (self)
1684 lua_pushvalue(L, 2); // 5
1685 lua_call(L, 2, 0);
1686 lua_settop(L, 2);
1687 lua_getfield(L, 1, "_ref"); // 3
1688 lua_pushvalue(L, 2); // 4
1689 lua_gettable(L, 3); // 4
1690 if (lua_isboolean(L, 4) && !lua_toboolean(L, 4)) lua_pushnil(L); // TODO: use special object instead of false
1691 return 1;
1692 }
1693 lua_settop(L, 4);
1694 // check if proxy access to document in special column is enabled:
1695 lua_getfield(L, 3, "document_column"); // 5
1696 if (lua_toboolean(L, 5)) {
1697 // if yes, then proxy access:
1698 lua_gettable(L, 4); // 5
1699 if (!lua_isnil(L, 5)) {
1700 lua_pushvalue(L, 2); // 6
1701 lua_gettable(L, 5); // 6
1702 }
1703 } else {
1704 // else use _data table:
1705 lua_pushvalue(L, 2); // 6
1706 lua_gettable(L, 4); // 6
1707 }
1708 return 1; // return element at stack position 5 or 6
1709 } else if (result_type && !strcmp(result_type, "list")) { // list
1710 lua_settop(L, 3);
1711 // try inherited list attributes or methods:
1712 while (lua_toboolean(L, 3)) {
1713 lua_getfield(L, 3, "list"); // 4
1714 lua_pushvalue(L, 2); // 5
1715 lua_gettable(L, 4); // 5
1716 if (!lua_isnil(L, 5)) return 1;
1717 lua_settop(L, 3);
1718 lua_pushliteral(L, "prototype"); // 4
1719 lua_rawget(L, 3); // 4
1720 lua_replace(L, 3);
1721 }
1722 }
1723 // return nothing:
1724 return 0;
1725 }
1727 // meta-method "__newindex" of database result lists and objects:
1728 static int mondelefant_result_newindex(lua_State *L) {
1729 const char *result_type;
1730 // perform rawset, unless key is a string not starting with underscore:
1731 lua_settop(L, 3);
1732 if (lua_type(L, 2) != LUA_TSTRING || lua_tostring(L, 2)[0] == '_') {
1733 lua_rawset(L, 1);
1734 return 1;
1735 }
1736 // value of "_class" attribute or default class on stack position 4:
1737 lua_settop(L, 3);
1738 lua_getfield(L, 1, "_class"); // 4
1739 if (!lua_toboolean(L, 4)) {
1740 lua_settop(L, 3);
1741 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 4
1742 }
1743 // get value of "_type" attribute:
1744 lua_getfield(L, 1, "_type"); // 5
1745 result_type = lua_tostring(L, 5);
1746 // distinguish between lists and objects:
1747 if (result_type && !strcmp(result_type, "object")) { // objects
1748 lua_settop(L, 4);
1749 // try object setter functions:
1750 lua_pushvalue(L, 4); // 5
1751 while (lua_toboolean(L, 5)) {
1752 lua_getfield(L, 5, "object_set"); // 6
1753 lua_pushvalue(L, 2); // 7
1754 lua_gettable(L, 6); // 7
1755 if (lua_toboolean(L, 7)) {
1756 lua_pushvalue(L, 1); // 8
1757 lua_pushvalue(L, 3); // 9
1758 lua_call(L, 2, 0);
1759 return 0;
1760 }
1761 lua_settop(L, 5);
1762 lua_pushliteral(L, "prototype"); // 6
1763 lua_rawget(L, 5); // 6
1764 lua_replace(L, 5);
1765 }
1766 lua_settop(L, 4);
1767 lua_getfield(L, 1, "_data"); // _data table on stack position 5
1768 // check, if a object reference is changed:
1769 lua_pushcfunction(L, mondelefant_class_get_reference); // 6
1770 lua_pushvalue(L, 4); // 7
1771 lua_pushvalue(L, 2); // 8
1772 lua_call(L, 2, 1); // 6
1773 if (!lua_isnil(L, 6)) {
1774 // store object in _ref table (use false for nil): // TODO: use special object instead of false
1775 lua_getfield(L, 1, "_ref"); // 7
1776 lua_pushvalue(L, 2); // 8
1777 if (lua_isnil(L, 3)) lua_pushboolean(L, 0); // 9
1778 else lua_pushvalue(L, 3); // 9
1779 lua_settable(L, 7);
1780 lua_settop(L, 6);
1781 // delete referencing key from _data table:
1782 lua_getfield(L, 6, "this_key"); // 7
1783 if (lua_isnil(L, 7)) {
1784 return luaL_error(L, "Missing 'this_key' entry in model reference.");
1785 }
1786 lua_pushvalue(L, 7); // 8
1787 lua_pushnil(L); // 9
1788 lua_settable(L, 5);
1789 lua_getfield(L, 1, "_dirty"); // 8
1790 lua_pushvalue(L, 7); // 9
1791 lua_pushboolean(L, 1); // 10
1792 lua_settable(L, 8);
1793 return 0;
1794 }
1795 lua_settop(L, 5);
1796 // check proxy access to document in special column:
1797 lua_getfield(L, 4, "document_column"); // 6
1798 if (lua_toboolean(L, 6)) {
1799 lua_gettable(L, 5); // 6
1800 if (lua_isnil(L, 6)) {
1801 return luaL_error(L, "Cannot write to document column: document is nil");
1802 }
1803 lua_pushvalue(L, 2); // 7
1804 lua_pushvalue(L, 3); // 8
1805 lua_settable(L, 6);
1806 return 0;
1807 }
1808 lua_settop(L, 5);
1809 // store value in data field info:
1810 lua_pushvalue(L, 2); // 6
1811 lua_pushvalue(L, 3); // 7
1812 lua_settable(L, 5);
1813 lua_settop(L, 4);
1814 // mark field as dirty (needs to be UPDATEd on save):
1815 lua_getfield(L, 1, "_dirty"); // 5
1816 lua_pushvalue(L, 2); // 6
1817 lua_pushboolean(L, 1); // 7
1818 lua_settable(L, 5);
1819 lua_settop(L, 4);
1820 // reset reference cache, if neccessary:
1821 lua_pushcfunction(L,
1822 mondelefant_class_get_foreign_key_reference_name
1823 ); // 5
1824 lua_pushvalue(L, 4); // 6
1825 lua_pushvalue(L, 2); // 7
1826 lua_call(L, 2, 1); // 5
1827 if (!lua_isnil(L, 5)) {
1828 lua_getfield(L, 1, "_ref"); // 6
1829 lua_pushvalue(L, 5); // 7
1830 lua_pushnil(L); // 8
1831 lua_settable(L, 6);
1832 }
1833 return 0;
1834 } else { // non-objects (i.e. lists)
1835 // perform rawset:
1836 lua_settop(L, 3);
1837 lua_rawset(L, 1);
1838 return 0;
1839 }
1840 }
1842 // meta-method "__index" of column proxy:
1843 static int mondelefant_columns_index(lua_State *L) {
1844 luaL_checktype(L, 1, LUA_TTABLE);
1845 lua_settop(L, 2);
1846 lua_rawgetp(L, 1, MONDELEFANT_COLUMNS_RESULT_LUKEY); // 3
1847 lua_getfield(L, 3, "_data"); // 4
1848 lua_pushvalue(L, 2); // 5
1849 lua_gettable(L, 4); // 5
1850 return 1;
1851 }
1853 // meta-method "__newindex" of column proxy:
1854 static int mondelefant_columns_newindex(lua_State *L) {
1855 luaL_checktype(L, 1, LUA_TTABLE);
1856 lua_settop(L, 3);
1857 lua_rawgetp(L, 1, MONDELEFANT_COLUMNS_RESULT_LUKEY); // 4
1858 lua_getfield(L, 4, "_data"); // 5
1859 lua_getfield(L, 4, "_dirty"); // 6
1860 lua_pushvalue(L, 2);
1861 lua_pushvalue(L, 3);
1862 lua_settable(L, 5);
1863 lua_pushvalue(L, 2);
1864 lua_pushboolean(L, 1);
1865 lua_settable(L, 6);
1866 return 0;
1867 }
1869 // meta-method "__index" of classes (models):
1870 static int mondelefant_class_index(lua_State *L) {
1871 // perform lookup in prototype:
1872 lua_settop(L, 2);
1873 lua_pushliteral(L, "prototype"); // 3
1874 lua_rawget(L, 1); // 3
1875 lua_pushvalue(L, 2); // 4
1876 lua_gettable(L, 3); // 4
1877 return 1;
1878 }
1880 // registration information for functions of library:
1881 static const struct luaL_Reg mondelefant_module_functions[] = {
1882 {"connect", mondelefant_connect},
1883 {"set_class", mondelefant_set_class},
1884 {"new_class", mondelefant_new_class},
1885 {NULL, NULL}
1886 };
1888 // registration information for meta-methods of database connections:
1889 static const struct luaL_Reg mondelefant_conn_mt_functions[] = {
1890 {"__gc", mondelefant_conn_free},
1891 {"__index", mondelefant_conn_index},
1892 {"__newindex", mondelefant_conn_newindex},
1893 {NULL, NULL}
1894 };
1896 // registration information for methods of database connections:
1897 static const struct luaL_Reg mondelefant_conn_methods[] = {
1898 {"close", mondelefant_conn_close},
1899 {"is_ok", mondelefant_conn_is_ok},
1900 {"get_transaction_status", mondelefant_conn_get_transaction_status},
1901 {"try_wait", mondelefant_conn_try_wait},
1902 {"wait", mondelefant_conn_wait},
1903 {"create_list", mondelefant_conn_create_list},
1904 {"create_object", mondelefant_conn_create_object},
1905 {"quote_string", mondelefant_conn_quote_string},
1906 {"quote_binary", mondelefant_conn_quote_binary},
1907 {"assemble_command", mondelefant_conn_assemble_command},
1908 {"try_query", mondelefant_conn_try_query},
1909 {"query", mondelefant_conn_query},
1910 {NULL, NULL}
1911 };
1913 // registration information for meta-methods of error objects:
1914 static const struct luaL_Reg mondelefant_errorobject_mt_functions[] = {
1915 {NULL, NULL}
1916 };
1918 // registration information for methods of error objects:
1919 static const struct luaL_Reg mondelefant_errorobject_methods[] = {
1920 {"escalate", lua_error},
1921 {"is_kind_of", mondelefant_errorobject_is_kind_of},
1922 {NULL, NULL}
1923 };
1925 // registration information for meta-methods of database result lists/objects:
1926 static const struct luaL_Reg mondelefant_result_mt_functions[] = {
1927 {"__index", mondelefant_result_index},
1928 {"__newindex", mondelefant_result_newindex},
1929 {NULL, NULL}
1930 };
1932 // registration information for meta-methods of classes (models):
1933 static const struct luaL_Reg mondelefant_class_mt_functions[] = {
1934 {"__index", mondelefant_class_index},
1935 {NULL, NULL}
1936 };
1938 // registration information for methods of classes (models):
1939 static const struct luaL_Reg mondelefant_class_methods[] = {
1940 {"get_reference", mondelefant_class_get_reference},
1941 {"iterate_over_references", mondelefant_class_iterate_over_references},
1942 {"get_foreign_key_reference_name",
1943 mondelefant_class_get_foreign_key_reference_name},
1944 {NULL, NULL}
1945 };
1947 // registration information for methods of database result objects (not lists!):
1948 static const struct luaL_Reg mondelefant_object_methods[] = {
1949 {NULL, NULL}
1950 };
1952 // registration information for methods of database result lists (not single objects!):
1953 static const struct luaL_Reg mondelefant_list_methods[] = {
1954 {NULL, NULL}
1955 };
1957 // registration information for meta-methods of column proxy:
1958 static const struct luaL_Reg mondelefant_columns_mt_functions[] = {
1959 {"__index", mondelefant_columns_index},
1960 {"__newindex", mondelefant_columns_newindex},
1961 {NULL, NULL}
1962 };
1964 // luaopen function to initialize/register library:
1965 int luaopen_mondelefant_native(lua_State *L) {
1966 lua_settop(L, 0);
1968 lua_newtable(L); // meta-table for columns proxy
1969 luaL_setfuncs(L, mondelefant_columns_mt_functions, 0);
1970 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_COLUMNS_MT_REGKEY);
1972 lua_newtable(L); // module at stack position 1
1973 luaL_setfuncs(L, mondelefant_module_functions, 0);
1975 lua_pushvalue(L, 1); // 2
1976 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY);
1978 lua_newtable(L); // 2
1979 // NOTE: only PostgreSQL is supported yet:
1980 luaL_setfuncs(L, mondelefant_conn_methods, 0);
1981 lua_setfield(L, 1, "postgresql_connection_prototype");
1982 lua_newtable(L); // 2
1983 lua_setfield(L, 1, "connection_prototype");
1985 luaL_newmetatable(L, MONDELEFANT_CONN_MT_REGKEY); // 2
1986 luaL_setfuncs(L, mondelefant_conn_mt_functions, 0);
1987 lua_settop(L, 1);
1988 luaL_newmetatable(L, MONDELEFANT_RESULT_MT_REGKEY); // 2
1989 luaL_setfuncs(L, mondelefant_result_mt_functions, 0);
1990 lua_setfield(L, 1, "result_metatable");
1991 luaL_newmetatable(L, MONDELEFANT_CLASS_MT_REGKEY); // 2
1992 luaL_setfuncs(L, mondelefant_class_mt_functions, 0);
1993 lua_setfield(L, 1, "class_metatable");
1995 lua_newtable(L); // 2
1996 luaL_setfuncs(L, mondelefant_class_methods, 0);
1997 lua_newtable(L); // 3
1998 luaL_setfuncs(L, mondelefant_object_methods, 0);
1999 lua_setfield(L, 2, "object");
2000 lua_newtable(L); // 3
2001 lua_setfield(L, 2, "object_get");
2002 lua_newtable(L); // 3
2003 lua_setfield(L, 2, "object_set");
2004 lua_newtable(L); // 3
2005 luaL_setfuncs(L, mondelefant_list_methods, 0);
2006 lua_setfield(L, 2, "list");
2007 lua_newtable(L); // 3
2008 lua_setfield(L, 2, "references");
2009 lua_newtable(L); // 3
2010 lua_setfield(L, 2, "foreign_keys");
2011 lua_pushvalue(L, 2); // 3
2012 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY);
2013 lua_setfield(L, 1, "class_prototype");
2015 luaL_newmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY); // 2
2016 luaL_setfuncs(L, mondelefant_errorobject_mt_functions, 0);
2017 lua_newtable(L); // 3
2018 luaL_setfuncs(L, mondelefant_errorobject_methods, 0);
2019 lua_setfield(L, 2, "__index");
2020 lua_setfield(L, 1, "errorobject_metatable");
2022 return 1;
2023 }