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view libraries/mondelefant/mondelefant_native.c @ 439:29b1f7a04934
Updated documentation
| author | jbe |
|---|---|
| date | Fri Feb 05 01:26:00 2016 +0100 (2016-02-05) |
| parents | 1dbbe4c62f08 |
| children | 66d7a0ac9c9d |
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 // create new table on stack position 2:
538 lua_settop(L, 1);
539 lua_newtable(L); // 2
540 // set meta-table for database result lists/objects:
541 luaL_setmetatable(L, MONDELEFANT_RESULT_MT_REGKEY);
542 // set "_connection" attribute to self:
543 lua_pushvalue(L, 1); // 3
544 lua_setfield(L, 2, "_connection");
545 // set "_type" attribute to string "list":
546 lua_pushliteral(L, "list"); // 3
547 lua_setfield(L, 2, "_type");
548 // set "_class" attribute to default class:
549 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 3
550 lua_setfield(L, 2, "_class");
551 // return created database result list:
552 return 1;
553 }
555 // method "create_object" of database handles:
556 static int mondelefant_conn_create_object(lua_State *L) {
557 // ensure that first argument is a database connection:
558 luaL_checkudata(L, 1, MONDELEFANT_CONN_MT_REGKEY);
559 // create new table on stack position 2:
560 lua_settop(L, 1);
561 lua_newtable(L); // 2
562 // set meta-table for database result lists/objects:
563 luaL_setmetatable(L, MONDELEFANT_RESULT_MT_REGKEY);
564 // set "_connection" attribute to self:
565 lua_pushvalue(L, 1); // 3
566 lua_setfield(L, 2, "_connection");
567 // set "_type" attribute to string "object":
568 lua_pushliteral(L, "object"); // 3
569 lua_setfield(L, 2, "_type"); // "object" or "list"
570 // set "_class" attribute to default class:
571 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 3
572 lua_setfield(L, 2, "_class");
573 // create empty tables for "_data", "_dirty" and "_ref" attributes:
574 lua_newtable(L); // 3
575 lua_setfield(L, 2, "_data");
576 lua_newtable(L); // 3
577 lua_setfield(L, 2, "_dirty");
578 lua_newtable(L); // 3
579 lua_setfield(L, 2, "_ref"); // nil=no info, false=nil, else table
580 // create column proxy (field "_col" in result object):
581 lua_newtable(L); // 3
582 luaL_setmetatable(L, MONDELEFANT_COLUMNS_MT_REGKEY);
583 lua_pushvalue(L, 2); // 4
584 lua_rawsetp(L, 3, MONDELEFANT_COLUMNS_RESULT_LUKEY);
585 lua_setfield(L, 2, "_col");
586 // return created database result object (from stack position 2):
587 return 1;
588 }
590 // method "quote_string" of database handles:
591 static int mondelefant_conn_quote_string(lua_State *L) {
592 mondelefant_conn_t *conn;
593 const char *input;
594 size_t input_len;
595 luaL_Buffer buf;
596 char *output;
597 size_t output_len;
598 // get database connection object:
599 conn = mondelefant_get_conn(L, 1);
600 // get second argument, which must be a string:
601 input = luaL_checklstring(L, 2, &input_len);
602 // throw error, if string is too long:
603 if (input_len > (SIZE_MAX / sizeof(char) - 3) / 2) {
604 return luaL_error(L, "String to be escaped is too long.");
605 }
606 // allocate memory for quoted string:
607 output = luaL_buffinitsize(L, &buf, (2 * input_len + 3) * sizeof(char));
608 // do escaping by calling PQescapeStringConn and enclosing result with
609 // single quotes:
610 output[0] = '\'';
611 output_len = PQescapeStringConn(
612 conn->pgconn, output + 1, input, input_len, NULL
613 );
614 output[output_len + 1] = '\'';
615 output[output_len + 2] = 0;
616 // create Lua string:
617 luaL_addsize(&buf, output_len + 2);
618 luaL_pushresult(&buf);
619 // return Lua string:
620 return 1;
621 }
623 // method "quote_binary" of database handles:
624 static int mondelefant_conn_quote_binary(lua_State *L) {
625 mondelefant_conn_t *conn;
626 const char *input;
627 size_t input_len;
628 char *output;
629 size_t output_len;
630 luaL_Buffer buf;
631 // get database connection object:
632 conn = mondelefant_get_conn(L, 1);
633 // get second argument, which must be a string:
634 input = luaL_checklstring(L, 2, &input_len);
635 // avoid cumulating memory leaks in case of previous out-of-memory errors:
636 if (conn->todo_PQfreemem) {
637 PQfreemem(conn->todo_PQfreemem);
638 conn->todo_PQfreemem = NULL;
639 }
640 // call PQescapeByteaConn, which allocates memory itself:
641 output = (char *)PQescapeByteaConn(
642 conn->pgconn, (const unsigned char *)input, input_len, &output_len
643 );
644 if (!output) {
645 lua_gc(L, LUA_GCCOLLECT, 0);
646 output = (char *)PQescapeByteaConn(
647 conn->pgconn, (const unsigned char *)input, input_len, &output_len
648 );
649 if (!output) {
650 return luaL_error(L, "Could not allocate memory for binary quoting.");
651 }
652 }
653 // ensure call of PQfreemem in case of out-of-memory errors:
654 conn->todo_PQfreemem = output;
655 // create Lua string enclosed by single quotes:
656 luaL_buffinit(L, &buf);
657 luaL_addchar(&buf, '\'');
658 luaL_addlstring(&buf, output, output_len - 1);
659 luaL_addchar(&buf, '\'');
660 luaL_pushresult(&buf);
661 // free memory allocated by PQescapeByteaConn:
662 PQfreemem(output);
663 // avoid double call of PQfreemem later:
664 conn->todo_PQfreemem = NULL;
665 // return Lua string:
666 return 1;
667 }
669 // method "assemble_command" of database handles:
670 static int mondelefant_conn_assemble_command(lua_State *L) {
671 mondelefant_conn_t *conn;
672 int paramidx = 2;
673 const char *template;
674 size_t template_pos = 0;
675 luaL_Buffer buf;
676 // get database connection object:
677 conn = mondelefant_get_conn(L, 1);
678 // if second argument is a string, return this string:
679 if (lua_type(L, 2) == LUA_TSTRING) {
680 lua_settop(L, 2);
681 return 1;
682 }
683 // if second argument has __tostring meta-method,
684 // then use this method and return its result:
685 if (luaL_callmeta(L, 2, "__tostring")) return 1;
686 // otherwise, require that second argument is a table:
687 luaL_checktype(L, 2, LUA_TTABLE);
688 // set stack top:
689 lua_settop(L, 2);
690 // get first element of table, which must be a string:
691 lua_rawgeti(L, 2, 1); // 3
692 luaL_argcheck(L,
693 lua_isstring(L, 3),
694 2,
695 "First entry of SQL command structure is not a string."
696 );
697 template = lua_tostring(L, 3);
698 // get value of "input_converter" attribute of database connection:
699 lua_pushliteral(L, "input_converter"); // 4
700 lua_gettable(L, 1); // input_converter at stack position 4
701 // reserve space on Lua stack:
702 lua_pushnil(L); // free space at stack position 5
703 lua_pushnil(L); // free space at stack position 6
704 // initialize Lua buffer for result string:
705 luaL_buffinit(L, &buf);
706 // fill buffer in loop:
707 while (1) {
708 // variable declaration:
709 char c;
710 // get next character:
711 c = template[template_pos++];
712 // break, when character is NULL byte:
713 if (!c) break;
714 // question-mark and dollar-sign are special characters:
715 if (c == '?' || c == '$') { // special character found
716 // check, if same character follows:
717 if (template[template_pos] == c) { // special character is escaped
718 // consume two characters of input and add one character to buffer:
719 template_pos++;
720 luaL_addchar(&buf, c);
721 } else { // special character is not escaped
722 luaL_Buffer keybuf;
723 int subcmd;
724 // set 'subcmd' = true, if special character was a dollar-sign,
725 // set 'subcmd' = false, if special character was a question-mark:
726 subcmd = (c == '$');
727 // read any number of alpha numeric chars or underscores
728 // and store them on Lua stack:
729 luaL_buffinit(L, &keybuf);
730 while (1) {
731 c = template[template_pos];
732 if (
733 (c < 'A' || c > 'Z') &&
734 (c < 'a' || c > 'z') &&
735 (c < '0' || c > '9') &&
736 (c != '_')
737 ) break;
738 luaL_addchar(&keybuf, c);
739 template_pos++;
740 }
741 luaL_pushresult(&keybuf);
742 // check, if any characters matched:
743 if (lua_rawlen(L, -1)) {
744 // if any alpha numeric chars or underscores were found,
745 // push them on stack as a Lua string and use them to lookup
746 // value from second argument:
747 lua_pushvalue(L, -1); // save key on stack
748 lua_gettable(L, 2); // fetch value (raw-value)
749 } else {
750 // otherwise push nil and use numeric lookup based on 'paramidx':
751 lua_pop(L, 1);
752 lua_pushnil(L); // put nil on key position
753 lua_rawgeti(L, 2, paramidx++); // fetch value (raw-value)
754 }
755 // Lua stack contains: ..., <buffer>, key, raw-value
756 // branch according to type of special character ("?" or "$"):
757 if (subcmd) { // dollar-sign
758 size_t i;
759 size_t count;
760 // store fetched value (which is supposed to be sub-structure)
761 // on Lua stack position 5 and drop key:
762 lua_replace(L, 5);
763 lua_pop(L, 1);
764 // Lua stack contains: ..., <buffer>
765 // check, if fetched value is really a sub-structure:
766 luaL_argcheck(L,
767 !lua_isnil(L, 5),
768 2,
769 "SQL sub-structure not found."
770 );
771 luaL_argcheck(L,
772 lua_type(L, 5) == LUA_TTABLE,
773 2,
774 "SQL sub-structure must be a table."
775 );
776 // Lua stack contains: ..., <buffer>
777 // get value of "sep" attribute of sub-structure,
778 // and place it on Lua stack position 6:
779 lua_getfield(L, 5, "sep");
780 lua_replace(L, 6);
781 // if seperator is nil, then use ", " as default,
782 // if seperator is neither nil nor a string, then throw error:
783 if (lua_isnil(L, 6)) {
784 lua_pushstring(L, ", ");
785 lua_replace(L, 6);
786 } else {
787 luaL_argcheck(L,
788 lua_isstring(L, 6),
789 2,
790 "Seperator of SQL sub-structure has to be a string."
791 );
792 }
793 // iterate over items of sub-structure:
794 count = lua_rawlen(L, 5);
795 for (i = 0; i < count; i++) {
796 // add seperator, unless this is the first run:
797 if (i) {
798 lua_pushvalue(L, 6);
799 luaL_addvalue(&buf);
800 }
801 // recursivly apply assemble function and add results to buffer:
802 lua_pushcfunction(L, mondelefant_conn_assemble_command);
803 lua_pushvalue(L, 1);
804 lua_rawgeti(L, 5, i+1);
805 lua_call(L, 2, 1);
806 luaL_addvalue(&buf);
807 }
808 } else { // question-mark
809 if (lua_toboolean(L, 4)) {
810 // call input_converter with connection handle, raw-value and
811 // an info-table which contains a "field_name" entry with the
812 // used key:
813 lua_pushvalue(L, 4);
814 lua_pushvalue(L, 1);
815 lua_pushvalue(L, -3);
816 lua_newtable(L);
817 lua_pushvalue(L, -6);
818 lua_setfield(L, -2, "field_name");
819 lua_call(L, 3, 1);
820 // Lua stack contains: ..., <buffer>, key, raw-value, final-value
821 // remove key and raw-value:
822 lua_remove(L, -2);
823 lua_remove(L, -2);
824 // Lua stack contains: ..., <buffer>, final-value
825 // throw error, if final-value is not a string:
826 if (!lua_isstring(L, -1)) {
827 return luaL_error(L, "input_converter returned non-string.");
828 }
829 } else {
830 // remove key from stack:
831 lua_remove(L, -2);
832 // Lua stack contains: ..., <buffer>, raw-value
833 // branch according to type of value:
834 // NOTE: Lua automatically converts numbers to strings
835 if (lua_isnil(L, -1)) { // value is nil
836 // push string "NULL" to stack:
837 lua_pushliteral(L, "NULL");
838 } else if (lua_type(L, -1) == LUA_TBOOLEAN) { // value is boolean
839 // push strings "TRUE" or "FALSE" to stack:
840 lua_pushstring(L, lua_toboolean(L, -1) ? "TRUE" : "FALSE");
841 } else if (lua_isstring(L, -1)) { // value is string or number
842 // push output of "quote_string" method of database connection
843 // to stack:
844 lua_tostring(L, -1);
845 lua_pushcfunction(L, mondelefant_conn_quote_string);
846 lua_pushvalue(L, 1);
847 lua_pushvalue(L, -3);
848 lua_call(L, 2, 1);
849 } else { // value is of other type
850 // throw error:
851 return luaL_error(L,
852 "Unable to convert SQL value due to unknown type "
853 "or missing input_converter."
854 );
855 }
856 // Lua stack contains: ..., <buffer>, raw-value, final-value
857 // remove raw-value:
858 lua_remove(L, -2);
859 // Lua stack contains: ..., <buffer>, final-value
860 }
861 // append final-value to buffer:
862 luaL_addvalue(&buf);
863 }
864 }
865 } else { // character is not special
866 // just copy character:
867 luaL_addchar(&buf, c);
868 }
869 }
870 // return string in buffer:
871 luaL_pushresult(&buf);
872 return 1;
873 }
875 // max number of SQL statements executed by one "query" method call:
876 #define MONDELEFANT_MAX_COMMAND_COUNT 64
877 // max number of columns in a database result:
878 #define MONDELEFANT_MAX_COLUMN_COUNT 1024
879 // enum values for 'modes' array in C-function below:
880 #define MONDELEFANT_QUERY_MODE_LIST 1
881 #define MONDELEFANT_QUERY_MODE_OBJECT 2
882 #define MONDELEFANT_QUERY_MODE_OPT_OBJECT 3
884 // method "try_query" of database handles:
885 static int mondelefant_conn_try_query(lua_State *L) {
886 mondelefant_conn_t *conn;
887 int command_count;
888 int command_idx;
889 int modes[MONDELEFANT_MAX_COMMAND_COUNT];
890 luaL_Buffer buf;
891 int sent_success;
892 PGresult *res;
893 int rows, cols, row, col;
894 // get database connection object:
895 conn = mondelefant_get_conn(L, 1);
896 // calculate number of commands (2 arguments for one command):
897 command_count = lua_gettop(L) / 2;
898 // push nil on stack, which is needed, if last mode was ommitted:
899 lua_pushnil(L);
900 // throw error, if number of commands is too high:
901 if (command_count > MONDELEFANT_MAX_COMMAND_COUNT) {
902 return luaL_error(L, "Exceeded maximum command count in one query.");
903 }
904 // create SQL string, store query modes and push SQL string on stack:
905 luaL_buffinit(L, &buf);
906 for (command_idx = 0; command_idx < command_count; command_idx++) {
907 int mode;
908 int mode_idx; // stack index of mode string
909 if (command_idx) luaL_addchar(&buf, ' ');
910 lua_pushcfunction(L, mondelefant_conn_assemble_command);
911 lua_pushvalue(L, 1);
912 lua_pushvalue(L, 2 + 2 * command_idx);
913 lua_call(L, 2, 1);
914 luaL_addvalue(&buf);
915 luaL_addchar(&buf, ';');
916 mode_idx = 3 + 2 * command_idx;
917 if (lua_isnil(L, mode_idx)) {
918 mode = MONDELEFANT_QUERY_MODE_LIST;
919 } else {
920 const char *modestr;
921 modestr = luaL_checkstring(L, mode_idx);
922 if (!strcmp(modestr, "list")) {
923 mode = MONDELEFANT_QUERY_MODE_LIST;
924 } else if (!strcmp(modestr, "object")) {
925 mode = MONDELEFANT_QUERY_MODE_OBJECT;
926 } else if (!strcmp(modestr, "opt_object")) {
927 mode = MONDELEFANT_QUERY_MODE_OPT_OBJECT;
928 } else {
929 return luaL_argerror(L, mode_idx, "unknown query mode");
930 }
931 }
932 modes[command_idx] = mode;
933 }
934 luaL_pushresult(&buf); // stack position unknown
935 lua_replace(L, 2); // SQL command string to stack position 2
936 // call sql_tracer, if set:
937 lua_settop(L, 2);
938 lua_getfield(L, 1, "sql_tracer"); // tracer at stack position 3
939 if (lua_toboolean(L, 3)) {
940 lua_pushvalue(L, 1); // 4
941 lua_pushvalue(L, 2); // 5
942 lua_call(L, 2, 1); // trace callback at stack position 3
943 }
944 // NOTE: If no tracer was found, then nil or false is stored at stack
945 // position 3.
946 // call PQsendQuery function and store result in 'sent_success' variable:
947 sent_success = PQsendQuery(conn->pgconn, lua_tostring(L, 2));
948 // create preliminary result table:
949 lua_newtable(L); // results in table at stack position 4
950 // iterate over results using function PQgetResult to fill result table:
951 for (command_idx = 0; ; command_idx++) {
952 int mode;
953 char binary[MONDELEFANT_MAX_COLUMN_COUNT];
954 ExecStatusType pgstatus;
955 // fetch mode which was given for the command:
956 mode = modes[command_idx];
957 // if PQsendQuery call was successful, then fetch result data:
958 if (sent_success) {
959 // avoid cumulating memory leaks in case of previous out-of-memory errors:
960 if (conn->todo_PQclear) {
961 PQclear(conn->todo_PQclear);
962 conn->todo_PQclear = NULL;
963 }
964 // NOTE: PQgetResult called one extra time. Break only, if all
965 // queries have been processed and PQgetResult returned NULL.
966 res = PQgetResult(conn->pgconn);
967 if (command_idx >= command_count && !res) break;
968 if (res) {
969 pgstatus = PQresultStatus(res);
970 rows = PQntuples(res);
971 cols = PQnfields(res);
972 // ensure call of PQclear in case of Lua errors:
973 conn->todo_PQclear = res;
974 }
975 }
976 // handle errors:
977 if (
978 !sent_success || command_idx >= command_count || !res ||
979 (pgstatus != PGRES_TUPLES_OK && pgstatus != PGRES_COMMAND_OK) ||
980 (rows < 1 && mode == MONDELEFANT_QUERY_MODE_OBJECT) ||
981 (rows > 1 && mode != MONDELEFANT_QUERY_MODE_LIST)
982 ) {
983 const char *command;
984 command = lua_tostring(L, 2);
985 lua_newtable(L); // 5
986 luaL_setmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY);
987 lua_pushvalue(L, 1);
988 lua_setfield(L, 5, "connection");
989 lua_pushvalue(L, 2);
990 lua_setfield(L, 5, "sql_command");
991 if (!sent_success) {
992 lua_pushliteral(L, MONDELEFANT_ERRCODE_CONNECTION);
993 lua_setfield(L, 5, "code");
994 mondelefant_push_first_line(L, PQerrorMessage(conn->pgconn));
995 lua_setfield(L, 5, "message");
996 } else {
997 lua_pushinteger(L, command_idx + 1);
998 lua_setfield(L, 5, "command_number");
999 if (!res) {
1000 lua_pushliteral(L, MONDELEFANT_ERRCODE_RESULTCOUNT_LOW);
1001 lua_setfield(L, 5, "code");
1002 lua_pushliteral(L, "Received too few database result sets.");
1003 lua_setfield(L, 5, "message");
1004 } else if (command_idx >= command_count) {
1005 lua_pushliteral(L, MONDELEFANT_ERRCODE_RESULTCOUNT_HIGH);
1006 lua_setfield(L, 5, "code");
1007 lua_pushliteral(L, "Received too many database result sets.");
1008 lua_setfield(L, 5, "message");
1009 } else if (
1010 pgstatus != PGRES_TUPLES_OK && pgstatus != PGRES_COMMAND_OK
1011 ) {
1012 const char *sqlstate;
1013 const char *errmsg;
1014 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SEVERITY));
1015 lua_setfield(L, 5, "pg_severity");
1016 sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
1017 if (sqlstate) {
1018 lua_pushstring(L, sqlstate);
1019 lua_setfield(L, 5, "pg_sqlstate");
1020 lua_pushstring(L, mondelefant_translate_errcode(sqlstate));
1021 lua_setfield(L, 5, "code");
1022 } else {
1023 lua_pushliteral(L, MONDELEFANT_ERRCODE_UNKNOWN);
1024 lua_setfield(L, 5, "code");
1025 }
1026 errmsg = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY);
1027 if (errmsg) {
1028 mondelefant_push_first_line(L, errmsg);
1029 lua_setfield(L, 5, "message");
1030 lua_pushstring(L, errmsg);
1031 lua_setfield(L, 5, "pg_message_primary");
1032 } else {
1033 lua_pushliteral(L,
1034 "Error while fetching result, but no error message given."
1035 );
1036 lua_setfield(L, 5, "message");
1037 }
1038 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL));
1039 lua_setfield(L, 5, "pg_message_detail");
1040 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_MESSAGE_HINT));
1041 lua_setfield(L, 5, "pg_message_hint");
1042 // NOTE: "position" and "pg_internal_position" are recalculated to
1043 // byte offsets, as Lua 5.2 is not Unicode aware.
1044 {
1045 char *tmp;
1046 tmp = PQresultErrorField(res, PG_DIAG_STATEMENT_POSITION);
1047 if (tmp) {
1048 int pos;
1049 pos = atoi(tmp) - 1;
1050 if (conn->server_encoding == MONDELEFANT_SERVER_ENCODING_UTF8) {
1051 pos = utf8_position_to_byte(command, pos);
1052 }
1053 lua_pushinteger(L, pos + 1);
1054 lua_setfield(L, 5, "position");
1055 }
1056 }
1057 {
1058 const char *internal_query;
1059 internal_query = PQresultErrorField(res, PG_DIAG_INTERNAL_QUERY);
1060 lua_pushstring(L, internal_query);
1061 lua_setfield(L, 5, "pg_internal_query");
1062 char *tmp;
1063 tmp = PQresultErrorField(res, PG_DIAG_INTERNAL_POSITION);
1064 if (tmp) {
1065 int pos;
1066 pos = atoi(tmp) - 1;
1067 if (conn->server_encoding == MONDELEFANT_SERVER_ENCODING_UTF8) {
1068 pos = utf8_position_to_byte(internal_query, pos);
1069 }
1070 lua_pushinteger(L, pos + 1);
1071 lua_setfield(L, 5, "pg_internal_position");
1072 }
1073 }
1074 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_CONTEXT));
1075 lua_setfield(L, 5, "pg_context");
1076 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_FILE));
1077 lua_setfield(L, 5, "pg_source_file");
1078 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_LINE));
1079 lua_setfield(L, 5, "pg_source_line");
1080 lua_pushstring(L, PQresultErrorField(res, PG_DIAG_SOURCE_FUNCTION));
1081 lua_setfield(L, 5, "pg_source_function");
1082 } else if (rows < 1 && mode == MONDELEFANT_QUERY_MODE_OBJECT) {
1083 lua_pushliteral(L, MONDELEFANT_ERRCODE_QUERY1_NO_ROWS);
1084 lua_setfield(L, 5, "code");
1085 lua_pushliteral(L, "Expected one row, but got empty set.");
1086 lua_setfield(L, 5, "message");
1087 } else if (rows > 1 && mode != MONDELEFANT_QUERY_MODE_LIST) {
1088 lua_pushliteral(L, MONDELEFANT_ERRCODE_QUERY1_MULTIPLE_ROWS);
1089 lua_setfield(L, 5, "code");
1090 lua_pushliteral(L, "Got more than one result row.");
1091 lua_setfield(L, 5, "message");
1092 } else {
1093 // should not happen
1094 abort();
1095 }
1096 if (res) {
1097 PQclear(res);
1098 while ((res = PQgetResult(conn->pgconn))) PQclear(res);
1099 // avoid double call of PQclear later:
1100 conn->todo_PQclear = NULL;
1101 }
1102 }
1103 if (lua_toboolean(L, 3)) {
1104 lua_pushvalue(L, 3);
1105 lua_pushvalue(L, 5);
1106 lua_call(L, 1, 0);
1107 }
1108 return 1;
1109 }
1110 // call "create_list" or "create_object" method of database handle,
1111 // result will be at stack position 5:
1112 if (modes[command_idx] == MONDELEFANT_QUERY_MODE_LIST) {
1113 lua_pushcfunction(L, mondelefant_conn_create_list); // 5
1114 lua_pushvalue(L, 1); // 6
1115 lua_call(L, 1, 1); // 5
1116 } else {
1117 lua_pushcfunction(L, mondelefant_conn_create_object); // 5
1118 lua_pushvalue(L, 1); // 6
1119 lua_call(L, 1, 1); // 5
1120 }
1121 // set "_column_info":
1122 lua_newtable(L); // 6
1123 for (col = 0; col < cols; col++) {
1124 lua_newtable(L); // 7
1125 lua_pushstring(L, PQfname(res, col)); // 8
1126 lua_pushvalue(L, 8); // 9
1127 lua_pushvalue(L, 7); // 10
1128 lua_rawset(L, 6);
1129 lua_setfield(L, 7, "field_name");
1130 // _column_info entry (for current column) on stack position 7
1131 {
1132 Oid tmp;
1133 tmp = PQftable(res, col);
1134 if (tmp == InvalidOid) lua_pushnil(L);
1135 else lua_pushinteger(L, tmp);
1136 lua_setfield(L, 7, "table_oid");
1137 }
1138 {
1139 int tmp;
1140 tmp = PQftablecol(res, col);
1141 if (tmp == 0) lua_pushnil(L);
1142 else lua_pushinteger(L, tmp);
1143 lua_setfield(L, 7, "table_column_number");
1144 }
1145 {
1146 Oid tmp;
1147 tmp = PQftype(res, col);
1148 binary[col] = (tmp == MONDELEFANT_POSTGRESQL_BINARY_OID);
1149 lua_pushinteger(L, tmp);
1150 lua_setfield(L, 7, "type_oid");
1151 lua_pushstring(L, mondelefant_oid_to_typestr(tmp));
1152 lua_setfield(L, 7, "type");
1153 }
1154 {
1155 int tmp;
1156 tmp = PQfmod(res, col);
1157 if (tmp == -1) lua_pushnil(L);
1158 else lua_pushinteger(L, tmp);
1159 lua_setfield(L, 7, "type_modifier");
1160 }
1161 lua_rawseti(L, 6, col+1);
1162 }
1163 lua_setfield(L, 5, "_column_info");
1164 // set "_rows_affected":
1165 {
1166 char *tmp;
1167 tmp = PQcmdTuples(res);
1168 if (tmp[0]) {
1169 lua_pushinteger(L, atoi(tmp));
1170 lua_setfield(L, 5, "_rows_affected");
1171 }
1172 }
1173 // set "_oid":
1174 {
1175 Oid tmp;
1176 tmp = PQoidValue(res);
1177 if (tmp != InvalidOid) {
1178 lua_pushinteger(L, tmp);
1179 lua_setfield(L, 5, "_oid");
1180 }
1181 }
1182 // copy data as strings or nil, while performing binary unescaping
1183 // automatically:
1184 if (modes[command_idx] == MONDELEFANT_QUERY_MODE_LIST) {
1185 for (row = 0; row < rows; row++) {
1186 lua_pushcfunction(L, mondelefant_conn_create_object); // 6
1187 lua_pushvalue(L, 1); // 7
1188 lua_call(L, 1, 1); // 6
1189 for (col = 0; col < cols; col++) {
1190 if (PQgetisnull(res, row, col)) {
1191 lua_pushnil(L);
1192 } else if (binary[col]) {
1193 size_t binlen;
1194 char *binval;
1195 // avoid cumulating memory leaks in case of previous out-of-memory errors:
1196 if (conn->todo_PQfreemem) {
1197 PQfreemem(conn->todo_PQfreemem);
1198 conn->todo_PQfreemem = NULL;
1199 }
1200 // Unescape binary data:
1201 binval = (char *)PQunescapeBytea(
1202 (unsigned char *)PQgetvalue(res, row, col), &binlen
1203 );
1204 if (!binval) {
1205 return luaL_error(L,
1206 "Could not allocate memory for binary unescaping."
1207 );
1208 }
1209 // ensure call of PQfreemem in case of out-of-memory error:
1210 conn->todo_PQfreemem = binval;
1211 // create Lua string:
1212 lua_pushlstring(L, binval, binlen);
1213 // free memory allocated by PQunescapeBytea:
1214 PQfreemem(binval);
1215 // avoid double call of PQfreemem later:
1216 conn->todo_PQfreemem = NULL;
1217 } else {
1218 lua_pushstring(L, PQgetvalue(res, row, col));
1219 }
1220 lua_rawseti(L, 6, col+1);
1221 }
1222 lua_rawseti(L, 5, row+1);
1223 }
1224 } else if (rows == 1) {
1225 for (col = 0; col < cols; col++) {
1226 if (PQgetisnull(res, 0, col)) {
1227 lua_pushnil(L);
1228 } else if (binary[col]) {
1229 size_t binlen;
1230 char *binval;
1231 // avoid cumulating memory leaks in case of previous out-of-memory errors:
1232 if (conn->todo_PQfreemem) {
1233 PQfreemem(conn->todo_PQfreemem);
1234 conn->todo_PQfreemem = NULL;
1235 }
1236 // Unescape binary data:
1237 binval = (char *)PQunescapeBytea(
1238 (unsigned char *)PQgetvalue(res, 0, col), &binlen
1239 );
1240 if (!binval) {
1241 return luaL_error(L,
1242 "Could not allocate memory for binary unescaping."
1243 );
1244 }
1245 // ensure call of PQfreemem in case of out-of-memory error:
1246 conn->todo_PQfreemem = binval;
1247 // create Lua string:
1248 lua_pushlstring(L, binval, binlen);
1249 // free memory allocated by PQunescapeBytea:
1250 PQfreemem(binval);
1251 // avoid double call of PQfreemem later:
1252 conn->todo_PQfreemem = NULL;
1253 } else {
1254 lua_pushstring(L, PQgetvalue(res, 0, col));
1255 }
1256 lua_rawseti(L, 5, col+1);
1257 }
1258 } else {
1259 // no row in optrow mode
1260 lua_pop(L, 1);
1261 lua_pushnil(L);
1262 }
1263 // save result in result list:
1264 lua_rawseti(L, 4, command_idx+1);
1265 // extra assertion:
1266 if (lua_gettop(L) != 4) abort(); // should not happen
1267 // free memory acquired by libpq:
1268 PQclear(res);
1269 // avoid double call of PQclear later:
1270 conn->todo_PQclear = NULL;
1271 }
1272 // trace callback at stack position 3
1273 // result at stack position 4 (top of stack)
1274 // if a trace callback is existent, then call:
1275 if (lua_toboolean(L, 3)) {
1276 lua_pushvalue(L, 3);
1277 lua_call(L, 0, 0);
1278 }
1279 // put result at stack position 3:
1280 lua_replace(L, 3);
1281 // get output converter to stack position 4:
1282 lua_getfield(L, 1, "output_converter");
1283 // get mutability state saver to stack position 5:
1284 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY);
1285 lua_getfield(L, -1, "save_mutability_state");
1286 lua_replace(L, -2);
1287 // apply output converters and fill "_data" table according to column names:
1288 for (command_idx = 0; command_idx < command_count; command_idx++) {
1289 int mode;
1290 mode = modes[command_idx];
1291 lua_rawgeti(L, 3, command_idx+1); // raw result at stack position 6
1292 if (lua_toboolean(L, 6)) {
1293 lua_getfield(L, 6, "_column_info"); // column_info list at position 7
1294 cols = lua_rawlen(L, 7);
1295 if (mode == MONDELEFANT_QUERY_MODE_LIST) {
1296 rows = lua_rawlen(L, 6);
1297 for (row = 0; row < rows; row++) {
1298 lua_rawgeti(L, 6, row+1); // row at stack position 8
1299 lua_getfield(L, 8, "_data"); // _data table at stack position 9
1300 lua_getfield(L, 8, "_dirty"); // _dirty table at stack position 10
1301 for (col = 0; col < cols; col++) {
1302 lua_rawgeti(L, 7, col+1); // this column info at position 11
1303 lua_getfield(L, 11, "field_name"); // 12
1304 if (lua_toboolean(L, 4)) {
1305 lua_pushvalue(L, 4); // output-converter
1306 lua_pushvalue(L, 1); // connection
1307 lua_rawgeti(L, 8, col+1); // raw-value
1308 lua_pushvalue(L, 11); // this column info
1309 lua_call(L, 3, 1); // converted value at position 13
1310 } else {
1311 lua_rawgeti(L, 8, col+1); // raw-value at position 13
1312 }
1313 if (lua_toboolean(L, 5)) { // handle mutable values?
1314 lua_pushvalue(L, 12); // copy of field name
1315 lua_pushvalue(L, 5); // mutability state saver function
1316 lua_pushvalue(L, 13); // copy of value
1317 lua_call(L, 1, 1); // calculated mutability state of value
1318 lua_rawset(L, 10); // store mutability state in _dirty table
1319 }
1320 lua_pushvalue(L, 13); // 14
1321 lua_rawseti(L, 8, col+1);
1322 lua_rawset(L, 9);
1323 lua_settop(L, 10);
1324 }
1325 lua_settop(L, 7);
1326 }
1327 } else {
1328 lua_getfield(L, 6, "_data"); // _data table at stack position 8
1329 lua_getfield(L, 6, "_dirty"); // _dirty table at stack position 9
1330 for (col = 0; col < cols; col++) {
1331 lua_rawgeti(L, 7, col+1); // this column info at position 10
1332 lua_getfield(L, 10, "field_name"); // 11
1333 if (lua_toboolean(L, 4)) {
1334 lua_pushvalue(L, 4); // output-converter
1335 lua_pushvalue(L, 1); // connection
1336 lua_rawgeti(L, 6, col+1); // raw-value
1337 lua_pushvalue(L, 10); // this column info
1338 lua_call(L, 3, 1); // converted value at position 12
1339 } else {
1340 lua_rawgeti(L, 6, col+1); // raw-value at position 12
1341 }
1342 if (lua_toboolean(L, 5)) { // handle mutable values?
1343 lua_pushvalue(L, 11); // copy of field name
1344 lua_pushvalue(L, 5); // mutability state saver function
1345 lua_pushvalue(L, 12); // copy of value
1346 lua_call(L, 1, 1); // calculated mutability state of value
1347 lua_rawset(L, 9); // store mutability state in _dirty table
1348 }
1349 lua_pushvalue(L, 12); // 13
1350 lua_rawseti(L, 6, col+1);
1351 lua_rawset(L, 8);
1352 lua_settop(L, 9);
1353 }
1354 }
1355 }
1356 lua_settop(L, 5);
1357 }
1358 // return nil as first result value, followed by result lists/objects:
1359 lua_settop(L, 3);
1360 lua_pushnil(L);
1361 for (command_idx = 0; command_idx < command_count; command_idx++) {
1362 lua_rawgeti(L, 3, command_idx+1);
1363 }
1364 return command_count+1;
1365 }
1367 // method "is_kind_of" of error objects:
1368 static int mondelefant_errorobject_is_kind_of(lua_State *L) {
1369 const char *errclass;
1370 luaL_checktype(L, 1, LUA_TTABLE);
1371 errclass = luaL_checkstring(L, 2);
1372 lua_settop(L, 2);
1373 lua_getfield(L, 1, "code"); // 3
1374 luaL_argcheck(L,
1375 lua_type(L, 3) == LUA_TSTRING,
1376 1,
1377 "field 'code' of error object is not a string"
1378 );
1379 lua_pushboolean(L,
1380 mondelefant_check_error_class(lua_tostring(L, 3), errclass)
1381 );
1382 return 1;
1383 }
1385 // method "wait" of database handles:
1386 static int mondelefant_conn_wait(lua_State *L) {
1387 int argc;
1388 // count number of arguments:
1389 argc = lua_gettop(L);
1390 // insert "try_wait" function/method at stack position 1:
1391 lua_pushcfunction(L, mondelefant_conn_try_wait);
1392 lua_insert(L, 1);
1393 // call "try_wait" method:
1394 lua_call(L, argc, LUA_MULTRET); // results (with error) starting at index 1
1395 // check, if error occurred:
1396 if (lua_toboolean(L, 1)) {
1397 // raise error
1398 lua_settop(L, 1);
1399 return lua_error(L);
1400 } else {
1401 // return everything but nil error object:
1402 return lua_gettop(L) - 1;
1403 }
1404 }
1406 // method "query" of database handles:
1407 static int mondelefant_conn_query(lua_State *L) {
1408 int argc;
1409 // count number of arguments:
1410 argc = lua_gettop(L);
1411 // insert "try_query" function/method at stack position 1:
1412 lua_pushcfunction(L, mondelefant_conn_try_query);
1413 lua_insert(L, 1);
1414 // call "try_query" method:
1415 lua_call(L, argc, LUA_MULTRET); // results (with error) starting at index 1
1416 // check, if error occurred:
1417 if (lua_toboolean(L, 1)) {
1418 // raise error
1419 lua_settop(L, 1);
1420 return lua_error(L);
1421 } else {
1422 // return everything but nil error object:
1423 return lua_gettop(L) - 1;
1424 }
1425 }
1427 // library function "set_class":
1428 static int mondelefant_set_class(lua_State *L) {
1429 // ensure that first argument is a database result list/object:
1430 lua_settop(L, 2);
1431 lua_getmetatable(L, 1); // 3
1432 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_RESULT_MT_REGKEY); // 4
1433 luaL_argcheck(L, lua_compare(L, 3, 4, LUA_OPEQ), 1, "not a database result");
1434 // ensure that second argument is a database class (model):
1435 lua_settop(L, 2);
1436 lua_getmetatable(L, 2); // 3
1437 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_MT_REGKEY); // 4
1438 luaL_argcheck(L, lua_compare(L, 3, 4, LUA_OPEQ), 2, "not a database class");
1439 // set attribute "_class" of result list/object to given class:
1440 lua_settop(L, 2);
1441 lua_pushvalue(L, 2); // 3
1442 lua_setfield(L, 1, "_class");
1443 // test, if database result is a list (and not a single object):
1444 lua_getfield(L, 1, "_type"); // 3
1445 lua_pushliteral(L, "list"); // 4
1446 if (lua_rawequal(L, 3, 4)) {
1447 int i;
1448 // set attribute "_class" of all elements to given class:
1449 for (i=0; i < lua_rawlen(L, 1); i++) {
1450 lua_settop(L, 2);
1451 lua_rawgeti(L, 1, i+1); // 3
1452 lua_pushvalue(L, 2); // 4
1453 lua_setfield(L, 3, "_class");
1454 }
1455 }
1456 // return first argument:
1457 lua_settop(L, 1);
1458 return 1;
1459 }
1461 // library function "new_class":
1462 static int mondelefant_new_class(lua_State *L) {
1463 // if no argument is given, use an empty table:
1464 if (lua_isnoneornil(L, 1)) {
1465 lua_settop(L, 0);
1466 lua_newtable(L); // 1
1467 } else {
1468 luaL_checktype(L, 1, LUA_TTABLE);
1469 lua_settop(L, 1);
1470 }
1471 // set meta-table for database classes (models):
1472 luaL_setmetatable(L, MONDELEFANT_CLASS_MT_REGKEY);
1473 // check, if "prototype" attribute is not set:
1474 lua_pushliteral(L, "prototype"); // 2
1475 lua_rawget(L, 1); // 2
1476 if (!lua_toboolean(L, 2)) {
1477 // set "prototype" attribute to default prototype:
1478 lua_pushliteral(L, "prototype"); // 3
1479 lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY); // 4
1480 lua_rawset(L, 1);
1481 }
1482 // set "object" attribute to empty table, unless it is already set:
1483 lua_settop(L, 1);
1484 lua_pushliteral(L, "object"); // 2
1485 lua_rawget(L, 1); // 2
1486 if (!lua_toboolean(L, 2)) {
1487 lua_pushliteral(L, "object"); // 3
1488 lua_newtable(L); // 4
1489 lua_rawset(L, 1);
1490 }
1491 // set "object_get" attribute to empty table, unless it is already set:
1492 lua_settop(L, 1);
1493 lua_pushliteral(L, "object_get"); // 2
1494 lua_rawget(L, 1); // 2
1495 if (!lua_toboolean(L, 2)) {
1496 lua_pushliteral(L, "object_get"); // 3
1497 lua_newtable(L); // 4
1498 lua_rawset(L, 1);
1499 }
1500 // set "object_set" attribute to empty table, unless it is already set:
1501 lua_settop(L, 1);
1502 lua_pushliteral(L, "object_set"); // 2
1503 lua_rawget(L, 1); // 2
1504 if (!lua_toboolean(L, 2)) {
1505 lua_pushliteral(L, "object_set"); // 3
1506 lua_newtable(L); // 4
1507 lua_rawset(L, 1);
1508 }
1509 // set "list" attribute to empty table, unless it is already set:
1510 lua_settop(L, 1);
1511 lua_pushliteral(L, "list"); // 2
1512 lua_rawget(L, 1); // 2
1513 if (!lua_toboolean(L, 2)) {
1514 lua_pushliteral(L, "list"); // 3
1515 lua_newtable(L); // 4
1516 lua_rawset(L, 1);
1517 }
1518 // set "references" attribute to empty table, unless it is already set:
1519 lua_settop(L, 1);
1520 lua_pushliteral(L, "references"); // 2
1521 lua_rawget(L, 1); // 2
1522 if (!lua_toboolean(L, 2)) {
1523 lua_pushliteral(L, "references"); // 3
1524 lua_newtable(L); // 4
1525 lua_rawset(L, 1);
1526 }
1527 // set "foreign_keys" attribute to empty table, unless it is already set:
1528 lua_settop(L, 1);
1529 lua_pushliteral(L, "foreign_keys"); // 2
1530 lua_rawget(L, 1); // 2
1531 if (!lua_toboolean(L, 2)) {
1532 lua_pushliteral(L, "foreign_keys"); // 3
1533 lua_newtable(L); // 4
1534 lua_rawset(L, 1);
1535 }
1536 // return table:
1537 lua_settop(L, 1);
1538 return 1;
1539 }
1541 // method "get_reference" of classes (models):
1542 static int mondelefant_class_get_reference(lua_State *L) {
1543 lua_settop(L, 2);
1544 while (lua_toboolean(L, 1)) {
1545 // get "references" table:
1546 lua_getfield(L, 1, "references"); // 3
1547 // perform lookup:
1548 lua_pushvalue(L, 2); // 4
1549 lua_gettable(L, 3); // 4
1550 // return result, if lookup was successful:
1551 if (!lua_isnil(L, 4)) return 1;
1552 // replace current table by its prototype:
1553 lua_settop(L, 2);
1554 lua_pushliteral(L, "prototype"); // 3
1555 lua_rawget(L, 1); // 3
1556 lua_replace(L, 1);
1557 }
1558 // return nothing:
1559 return 0;
1560 }
1562 // method "iterate_over_references" of classes (models):
1563 static int mondelefant_class_iterate_over_references(lua_State *L) {
1564 return luaL_error(L, "Reference iterator not implemented yet."); // TODO
1565 }
1567 // method "get_foreign_key_reference_name" of classes (models):
1568 static int mondelefant_class_get_foreign_key_reference_name(lua_State *L) {
1569 lua_settop(L, 2);
1570 while (lua_toboolean(L, 1)) {
1571 // get "foreign_keys" table:
1572 lua_getfield(L, 1, "foreign_keys"); // 3
1573 // perform lookup:
1574 lua_pushvalue(L, 2); // 4
1575 lua_gettable(L, 3); // 4
1576 // return result, if lookup was successful:
1577 if (!lua_isnil(L, 4)) return 1;
1578 // replace current table by its prototype:
1579 lua_settop(L, 2);
1580 lua_pushliteral(L, "prototype"); // 3
1581 lua_rawget(L, 1); // 3
1582 lua_replace(L, 1);
1583 }
1584 // return nothing:
1585 return 0;
1586 }
1588 // meta-method "__index" of database result lists and objects:
1589 static int mondelefant_result_index(lua_State *L) {
1590 const char *result_type;
1591 // only lookup, when key is a string not beginning with an underscore:
1592 if (lua_type(L, 2) != LUA_TSTRING || lua_tostring(L, 2)[0] == '_') {
1593 return 0;
1594 }
1595 // class on stack position 3:
1596 lua_settop(L, 2);
1597 lua_getfield(L, 1, "_class"); // 3
1598 // get value of "_type" attribute:
1599 lua_getfield(L, 1, "_type"); // 4
1600 result_type = lua_tostring(L, 4);
1601 // different lookup for lists and objects:
1602 if (result_type && !strcmp(result_type, "object")) { // object
1603 lua_settop(L, 3);
1604 // try inherited attributes, methods or getter functions:
1605 lua_pushvalue(L, 3); // 4
1606 while (lua_toboolean(L, 4)) {
1607 lua_getfield(L, 4, "object"); // 5
1608 lua_pushvalue(L, 2); // 6
1609 lua_gettable(L, 5); // 6
1610 if (!lua_isnil(L, 6)) return 1;
1611 lua_settop(L, 4);
1612 lua_getfield(L, 4, "object_get"); // 5
1613 lua_pushvalue(L, 2); // 6
1614 lua_gettable(L, 5); // 6
1615 if (lua_toboolean(L, 6)) {
1616 lua_pushvalue(L, 1); // 7
1617 lua_call(L, 1, 1); // 6
1618 return 1;
1619 }
1620 lua_settop(L, 4);
1621 lua_pushliteral(L, "prototype"); // 5
1622 lua_rawget(L, 4); // 5
1623 lua_replace(L, 4);
1624 }
1625 lua_settop(L, 3);
1626 // try primary keys of referenced objects:
1627 lua_pushcfunction(L,
1628 mondelefant_class_get_foreign_key_reference_name
1629 ); // 4
1630 lua_pushvalue(L, 3); // 5
1631 lua_pushvalue(L, 2); // 6
1632 lua_call(L, 2, 1); // 4
1633 if (!lua_isnil(L, 4)) {
1634 // reference name at stack position 4
1635 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1636 lua_pushvalue(L, 3); // 6
1637 lua_pushvalue(L, 4); // 7
1638 lua_call(L, 2, 1); // reference info at stack position 5
1639 lua_getfield(L, 1, "_ref"); // 6
1640 lua_getfield(L, 5, "ref"); // 7
1641 lua_gettable(L, 6); // 7
1642 if (!lua_isnil(L, 7)) {
1643 if (lua_toboolean(L, 7)) {
1644 lua_getfield(L, 5, "that_key"); // 8
1645 if (lua_isnil(L, 8)) {
1646 return luaL_error(L, "Missing 'that_key' entry in model reference.");
1647 }
1648 lua_gettable(L, 7); // 8
1649 } else {
1650 lua_pushnil(L);
1651 }
1652 return 1;
1653 }
1654 }
1655 lua_settop(L, 3);
1656 lua_getfield(L, 1, "_data"); // _data table on stack position 4
1657 // try cached referenced object (or cached NULL reference):
1658 lua_getfield(L, 1, "_ref"); // 5
1659 lua_pushvalue(L, 2); // 6
1660 lua_gettable(L, 5); // 6
1661 if (lua_isboolean(L, 6) && !lua_toboolean(L, 6)) {
1662 lua_pushnil(L);
1663 return 1;
1664 } else if (!lua_isnil(L, 6)) {
1665 return 1;
1666 }
1667 lua_settop(L, 4);
1668 // try to load a referenced object:
1669 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1670 lua_pushvalue(L, 3); // 6
1671 lua_pushvalue(L, 2); // 7
1672 lua_call(L, 2, 1); // 5
1673 if (!lua_isnil(L, 5)) {
1674 lua_settop(L, 2);
1675 lua_getfield(L, 1, "load"); // 3
1676 lua_pushvalue(L, 1); // 4 (self)
1677 lua_pushvalue(L, 2); // 5
1678 lua_call(L, 2, 0);
1679 lua_settop(L, 2);
1680 lua_getfield(L, 1, "_ref"); // 3
1681 lua_pushvalue(L, 2); // 4
1682 lua_gettable(L, 3); // 4
1683 if (lua_isboolean(L, 4) && !lua_toboolean(L, 4)) lua_pushnil(L); // TODO: use special object instead of false
1684 return 1;
1685 }
1686 lua_settop(L, 4);
1687 // check if proxy access to document in special column is enabled:
1688 lua_getfield(L, 3, "document_column"); // 5
1689 if (lua_toboolean(L, 5)) {
1690 // if yes, then proxy access:
1691 lua_gettable(L, 4); // 5
1692 if (!lua_isnil(L, 5)) {
1693 lua_pushvalue(L, 2); // 6
1694 lua_gettable(L, 5); // 6
1695 }
1696 } else {
1697 // else use _data table:
1698 lua_pushvalue(L, 2); // 6
1699 lua_gettable(L, 4); // 6
1700 }
1701 return 1; // return element at stack position 5 or 6
1702 } else if (result_type && !strcmp(result_type, "list")) { // list
1703 lua_settop(L, 3);
1704 // try inherited list attributes or methods:
1705 while (lua_toboolean(L, 3)) {
1706 lua_getfield(L, 3, "list"); // 4
1707 lua_pushvalue(L, 2); // 5
1708 lua_gettable(L, 4); // 5
1709 if (!lua_isnil(L, 5)) return 1;
1710 lua_settop(L, 3);
1711 lua_pushliteral(L, "prototype"); // 4
1712 lua_rawget(L, 3); // 4
1713 lua_replace(L, 3);
1714 }
1715 }
1716 // return nothing:
1717 return 0;
1718 }
1720 // meta-method "__newindex" of database result lists and objects:
1721 static int mondelefant_result_newindex(lua_State *L) {
1722 const char *result_type;
1723 // perform rawset, unless key is a string not starting with underscore:
1724 lua_settop(L, 3);
1725 if (lua_type(L, 2) != LUA_TSTRING || lua_tostring(L, 2)[0] == '_') {
1726 lua_rawset(L, 1);
1727 return 1;
1728 }
1729 // class on stack position 4:
1730 lua_settop(L, 3);
1731 lua_getfield(L, 1, "_class"); // 4
1732 // get value of "_type" attribute:
1733 lua_getfield(L, 1, "_type"); // 5
1734 result_type = lua_tostring(L, 5);
1735 // distinguish between lists and objects:
1736 if (result_type && !strcmp(result_type, "object")) { // objects
1737 lua_settop(L, 4);
1738 // try object setter functions:
1739 lua_pushvalue(L, 4); // 5
1740 while (lua_toboolean(L, 5)) {
1741 lua_getfield(L, 5, "object_set"); // 6
1742 lua_pushvalue(L, 2); // 7
1743 lua_gettable(L, 6); // 7
1744 if (lua_toboolean(L, 7)) {
1745 lua_pushvalue(L, 1); // 8
1746 lua_pushvalue(L, 3); // 9
1747 lua_call(L, 2, 0);
1748 return 0;
1749 }
1750 lua_settop(L, 5);
1751 lua_pushliteral(L, "prototype"); // 6
1752 lua_rawget(L, 5); // 6
1753 lua_replace(L, 5);
1754 }
1755 lua_settop(L, 4);
1756 lua_getfield(L, 1, "_data"); // _data table on stack position 5
1757 // check, if a object reference is changed:
1758 lua_pushcfunction(L, mondelefant_class_get_reference); // 6
1759 lua_pushvalue(L, 4); // 7
1760 lua_pushvalue(L, 2); // 8
1761 lua_call(L, 2, 1); // 6
1762 if (!lua_isnil(L, 6)) {
1763 // store object in _ref table (use false for nil): // TODO: use special object instead of false
1764 lua_getfield(L, 1, "_ref"); // 7
1765 lua_pushvalue(L, 2); // 8
1766 if (lua_isnil(L, 3)) lua_pushboolean(L, 0); // 9
1767 else lua_pushvalue(L, 3); // 9
1768 lua_settable(L, 7);
1769 lua_settop(L, 6);
1770 // delete referencing key from _data table:
1771 lua_getfield(L, 6, "this_key"); // 7
1772 if (lua_isnil(L, 7)) {
1773 return luaL_error(L, "Missing 'this_key' entry in model reference.");
1774 }
1775 lua_pushvalue(L, 7); // 8
1776 lua_pushnil(L); // 9
1777 lua_settable(L, 5);
1778 lua_getfield(L, 1, "_dirty"); // 8
1779 lua_pushvalue(L, 7); // 9
1780 lua_pushboolean(L, 1); // 10
1781 lua_settable(L, 8);
1782 return 0;
1783 }
1784 lua_settop(L, 5);
1785 // check proxy access to document in special column:
1786 lua_getfield(L, 4, "document_column"); // 6
1787 if (lua_toboolean(L, 6)) {
1788 lua_gettable(L, 5); // 6
1789 if (lua_isnil(L, 6)) {
1790 return luaL_error(L, "Cannot write to document column: document is nil");
1791 }
1792 lua_pushvalue(L, 2); // 7
1793 lua_pushvalue(L, 3); // 8
1794 lua_settable(L, 6);
1795 return 0;
1796 }
1797 lua_settop(L, 5);
1798 // store value in data field info:
1799 lua_pushvalue(L, 2); // 6
1800 lua_pushvalue(L, 3); // 7
1801 lua_settable(L, 5);
1802 lua_settop(L, 4);
1803 // mark field as dirty (needs to be UPDATEd on save):
1804 lua_getfield(L, 1, "_dirty"); // 5
1805 lua_pushvalue(L, 2); // 6
1806 lua_pushboolean(L, 1); // 7
1807 lua_settable(L, 5);
1808 lua_settop(L, 4);
1809 // reset reference cache, if neccessary:
1810 lua_pushcfunction(L,
1811 mondelefant_class_get_foreign_key_reference_name
1812 ); // 5
1813 lua_pushvalue(L, 4); // 6
1814 lua_pushvalue(L, 2); // 7
1815 lua_call(L, 2, 1); // 5
1816 if (!lua_isnil(L, 5)) {
1817 lua_getfield(L, 1, "_ref"); // 6
1818 lua_pushvalue(L, 5); // 7
1819 lua_pushnil(L); // 8
1820 lua_settable(L, 6);
1821 }
1822 return 0;
1823 } else { // non-objects (i.e. lists)
1824 // perform rawset:
1825 lua_settop(L, 3);
1826 lua_rawset(L, 1);
1827 return 0;
1828 }
1829 }
1831 // meta-method "__index" of column proxy:
1832 static int mondelefant_columns_index(lua_State *L) {
1833 luaL_checktype(L, 1, LUA_TTABLE);
1834 lua_settop(L, 2);
1835 lua_rawgetp(L, 1, MONDELEFANT_COLUMNS_RESULT_LUKEY); // 3
1836 // try primary keys of referenced objects:
1837 lua_pushcfunction(L,
1838 mondelefant_class_get_foreign_key_reference_name
1839 ); // 4
1840 lua_getfield(L, 3, "_class"); // 5
1841 lua_pushvalue(L, 2); // 6
1842 lua_call(L, 2, 1); // 4
1843 if (!lua_isnil(L, 4)) {
1844 // reference name at stack position 4
1845 lua_pushcfunction(L, mondelefant_class_get_reference); // 5
1846 lua_getfield(L, 3, "_class"); // 6
1847 lua_pushvalue(L, 4); // 7
1848 lua_call(L, 2, 1); // reference info at stack position 5
1849 lua_getfield(L, 3, "_ref"); // 6
1850 lua_getfield(L, 5, "ref"); // 7
1851 lua_gettable(L, 6); // 7
1852 if (!lua_isnil(L, 7)) {
1853 if (lua_toboolean(L, 7)) {
1854 lua_getfield(L, 5, "that_key"); // 8
1855 if (lua_isnil(L, 8)) {
1856 return luaL_error(L, "Missing 'that_key' entry in model reference.");
1857 }
1858 lua_gettable(L, 7); // 8
1859 } else {
1860 lua_pushnil(L);
1861 }
1862 return 1;
1863 }
1864 }
1865 lua_settop(L, 3);
1866 // if not successful, use _data table:
1867 lua_getfield(L, 3, "_data"); // 4
1868 lua_pushvalue(L, 2); // 5
1869 lua_gettable(L, 4); // 5
1870 return 1;
1871 }
1873 // meta-method "__newindex" of column proxy:
1874 static int mondelefant_columns_newindex(lua_State *L) {
1875 luaL_checktype(L, 1, LUA_TTABLE);
1876 lua_settop(L, 3);
1877 lua_rawgetp(L, 1, MONDELEFANT_COLUMNS_RESULT_LUKEY); // 4
1878 // reset reference cache, if neccessary:
1879 lua_pushcfunction(L,
1880 mondelefant_class_get_foreign_key_reference_name
1881 ); // 5
1882 lua_getfield(L, 4, "_class"); // 6
1883 lua_pushvalue(L, 2); // 7
1884 lua_call(L, 2, 1); // 5
1885 if (!lua_isnil(L, 5)) {
1886 lua_getfield(L, 4, "_ref"); // 6
1887 lua_pushvalue(L, 5); // 7
1888 lua_pushnil(L); // 8
1889 lua_settable(L, 6);
1890 }
1891 lua_settop(L, 4);
1892 // set _data and _dirty:
1893 lua_getfield(L, 4, "_data"); // 5
1894 lua_getfield(L, 4, "_dirty"); // 6
1895 lua_pushvalue(L, 2);
1896 lua_pushvalue(L, 3);
1897 lua_settable(L, 5);
1898 lua_pushvalue(L, 2);
1899 lua_pushboolean(L, 1);
1900 lua_settable(L, 6);
1901 return 0;
1902 }
1904 // meta-method "__index" of classes (models):
1905 static int mondelefant_class_index(lua_State *L) {
1906 // perform lookup in prototype:
1907 lua_settop(L, 2);
1908 lua_pushliteral(L, "prototype"); // 3
1909 lua_rawget(L, 1); // 3
1910 lua_pushvalue(L, 2); // 4
1911 lua_gettable(L, 3); // 4
1912 return 1;
1913 }
1915 // registration information for functions of library:
1916 static const struct luaL_Reg mondelefant_module_functions[] = {
1917 {"connect", mondelefant_connect},
1918 {"set_class", mondelefant_set_class},
1919 {"new_class", mondelefant_new_class},
1920 {NULL, NULL}
1921 };
1923 // registration information for meta-methods of database connections:
1924 static const struct luaL_Reg mondelefant_conn_mt_functions[] = {
1925 {"__gc", mondelefant_conn_free},
1926 {"__index", mondelefant_conn_index},
1927 {"__newindex", mondelefant_conn_newindex},
1928 {NULL, NULL}
1929 };
1931 // registration information for methods of database connections:
1932 static const struct luaL_Reg mondelefant_conn_methods[] = {
1933 {"close", mondelefant_conn_close},
1934 {"is_ok", mondelefant_conn_is_ok},
1935 {"get_transaction_status", mondelefant_conn_get_transaction_status},
1936 {"try_wait", mondelefant_conn_try_wait},
1937 {"wait", mondelefant_conn_wait},
1938 {"create_list", mondelefant_conn_create_list},
1939 {"create_object", mondelefant_conn_create_object},
1940 {"quote_string", mondelefant_conn_quote_string},
1941 {"quote_binary", mondelefant_conn_quote_binary},
1942 {"assemble_command", mondelefant_conn_assemble_command},
1943 {"try_query", mondelefant_conn_try_query},
1944 {"query", mondelefant_conn_query},
1945 {NULL, NULL}
1946 };
1948 // registration information for meta-methods of error objects:
1949 static const struct luaL_Reg mondelefant_errorobject_mt_functions[] = {
1950 {NULL, NULL}
1951 };
1953 // registration information for methods of error objects:
1954 static const struct luaL_Reg mondelefant_errorobject_methods[] = {
1955 {"escalate", lua_error},
1956 {"is_kind_of", mondelefant_errorobject_is_kind_of},
1957 {NULL, NULL}
1958 };
1960 // registration information for meta-methods of database result lists/objects:
1961 static const struct luaL_Reg mondelefant_result_mt_functions[] = {
1962 {"__index", mondelefant_result_index},
1963 {"__newindex", mondelefant_result_newindex},
1964 {NULL, NULL}
1965 };
1967 // registration information for meta-methods of classes (models):
1968 static const struct luaL_Reg mondelefant_class_mt_functions[] = {
1969 {"__index", mondelefant_class_index},
1970 {NULL, NULL}
1971 };
1973 // registration information for methods of classes (models):
1974 static const struct luaL_Reg mondelefant_class_methods[] = {
1975 {"get_reference", mondelefant_class_get_reference},
1976 {"iterate_over_references", mondelefant_class_iterate_over_references},
1977 {"get_foreign_key_reference_name",
1978 mondelefant_class_get_foreign_key_reference_name},
1979 {NULL, NULL}
1980 };
1982 // registration information for methods of database result objects (not lists!):
1983 static const struct luaL_Reg mondelefant_object_methods[] = {
1984 {NULL, NULL}
1985 };
1987 // registration information for methods of database result lists (not single objects!):
1988 static const struct luaL_Reg mondelefant_list_methods[] = {
1989 {NULL, NULL}
1990 };
1992 // registration information for meta-methods of column proxy:
1993 static const struct luaL_Reg mondelefant_columns_mt_functions[] = {
1994 {"__index", mondelefant_columns_index},
1995 {"__newindex", mondelefant_columns_newindex},
1996 {NULL, NULL}
1997 };
1999 // luaopen function to initialize/register library:
2000 int luaopen_mondelefant_native(lua_State *L) {
2001 lua_settop(L, 0);
2003 lua_newtable(L); // meta-table for columns proxy
2004 luaL_setfuncs(L, mondelefant_columns_mt_functions, 0);
2005 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_COLUMNS_MT_REGKEY);
2007 lua_newtable(L); // module at stack position 1
2008 luaL_setfuncs(L, mondelefant_module_functions, 0);
2010 lua_pushvalue(L, 1); // 2
2011 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_MODULE_REGKEY);
2013 lua_newtable(L); // 2
2014 // NOTE: only PostgreSQL is supported yet:
2015 luaL_setfuncs(L, mondelefant_conn_methods, 0);
2016 lua_setfield(L, 1, "postgresql_connection_prototype");
2017 lua_newtable(L); // 2
2018 lua_setfield(L, 1, "connection_prototype");
2020 luaL_newmetatable(L, MONDELEFANT_CONN_MT_REGKEY); // 2
2021 luaL_setfuncs(L, mondelefant_conn_mt_functions, 0);
2022 lua_settop(L, 1);
2023 luaL_newmetatable(L, MONDELEFANT_RESULT_MT_REGKEY); // 2
2024 luaL_setfuncs(L, mondelefant_result_mt_functions, 0);
2025 lua_setfield(L, 1, "result_metatable");
2026 luaL_newmetatable(L, MONDELEFANT_CLASS_MT_REGKEY); // 2
2027 luaL_setfuncs(L, mondelefant_class_mt_functions, 0);
2028 lua_setfield(L, 1, "class_metatable");
2030 lua_newtable(L); // 2
2031 luaL_setfuncs(L, mondelefant_class_methods, 0);
2032 lua_newtable(L); // 3
2033 luaL_setfuncs(L, mondelefant_object_methods, 0);
2034 lua_setfield(L, 2, "object");
2035 lua_newtable(L); // 3
2036 lua_setfield(L, 2, "object_get");
2037 lua_newtable(L); // 3
2038 lua_setfield(L, 2, "object_set");
2039 lua_newtable(L); // 3
2040 luaL_setfuncs(L, mondelefant_list_methods, 0);
2041 lua_setfield(L, 2, "list");
2042 lua_newtable(L); // 3
2043 lua_setfield(L, 2, "references");
2044 lua_newtable(L); // 3
2045 lua_setfield(L, 2, "foreign_keys");
2046 lua_pushvalue(L, 2); // 3
2047 lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY);
2048 lua_setfield(L, 1, "class_prototype");
2050 luaL_newmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY); // 2
2051 luaL_setfuncs(L, mondelefant_errorobject_mt_functions, 0);
2052 lua_newtable(L); // 3
2053 luaL_setfuncs(L, mondelefant_errorobject_methods, 0);
2054 lua_setfield(L, 2, "__index");
2055 lua_setfield(L, 1, "errorobject_metatable");
2057 return 1;
2058 }