/*------------------------------------------------------------------------- * * dfmgr.c-- * Dynamic function manager code. * * Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * /usr/local/devel/pglite/cvs/src/backend/utils/fmgr/dfmgr.c,v 1.5 1995/07/13 23:46:04 jolly Exp * *------------------------------------------------------------------------- */ #include #include #include #include #include "postgres.h" #include "fmgr.h" /* generated by Gen_fmgrtab.sh */ #include "utils/dynamic_loader.h" #include "utils/elog.h" #include "utils/builtins.h" #include "access/heapam.h" #include "nodes/pg_list.h" #include "port-protos.h" /* system specific function prototypes */ #include "catalog/catname.h" #include "utils/syscache.h" #include "catalog/pg_proc.h" static DynamicFileList *file_list = (DynamicFileList *) NULL; static DynamicFileList *file_tail = (DynamicFileList *) NULL; #define NOT_EQUAL(A, B) (((A).st_ino != (B).inode) \ || ((A).st_dev != (B).device)) static Oid procedureId_save = -1; static int pronargs_save; static func_ptr user_fn_save = (func_ptr) NULL; static func_ptr handle_load(char *filename, char *funcname); func_ptr fmgr_dynamic(Oid procedureId, int *pronargs) { HeapTuple procedureTuple; Form_pg_proc procedureStruct; char *proname; char *probinattr, *probinstring; func_ptr user_fn, handle_load(); Relation rdesc; bool isnull; if (procedureId == procedureId_save) { *pronargs = pronargs_save; return(user_fn_save); } /* * The procedure isn't a builtin, so we'll have to do a catalog * lookup to find its pg_proc entry. */ procedureTuple = SearchSysCacheTuple(PROOID, (char *) procedureId, NULL, NULL, NULL); if (!HeapTupleIsValid(procedureTuple)) { elog(WARN, "fmgr: Cache lookup failed for procedure %d\n", procedureId); return((func_ptr) NULL); } procedureStruct = (Form_pg_proc) GETSTRUCT(procedureTuple); proname = procedureStruct->proname.data; pronargs_save = *pronargs = procedureStruct->pronargs; /* * Extract the procedure info from the pg_proc tuple. * Since probin is varlena, do a amgetattr() on the procedure * tuple. To do that, we need the rdesc for the procedure * relation, so... */ /* open pg_procedure */ rdesc = heap_openr(ProcedureRelationName); if (!RelationIsValid(rdesc)) { elog(WARN, "fmgr: Could not open relation %s", ProcedureRelationName->data); return((func_ptr) NULL); } probinattr = heap_getattr(procedureTuple, (Buffer) 0, Anum_pg_proc_probin, rdesc->rd_att, &isnull); if (!PointerIsValid(probinattr) /*|| isnull*/) { heap_close(rdesc); elog(WARN, "fmgr: Could not extract probin for %d from %s", procedureId, ProcedureRelationName->data); return((func_ptr) NULL); } probinstring = textout((struct varlena *) probinattr); user_fn = handle_load(probinstring, proname); procedureId_save = procedureId; user_fn_save = user_fn; return(user_fn); } static func_ptr handle_load(char *filename, char *funcname) { DynamicFileList *file_scanner = (DynamicFileList *) NULL; func_ptr retval = (func_ptr) NULL; char *load_error; #ifdef WIN32 struct _stat stat_buf; #else struct stat stat_buf; #endif /* WIN32 */ /* * Do this because loading files may screw up the dynamic function * manager otherwise. */ procedureId_save = -1; /* * Scan the list of loaded FILES to see if the function * has been loaded. */ if (filename != (char *) NULL) { for (file_scanner = file_list; file_scanner != (DynamicFileList *) NULL && file_scanner->filename != (char *) NULL && strcmp(filename, file_scanner->filename) != 0; file_scanner = file_scanner->next) ; if (file_scanner == (DynamicFileList *) NULL) { if (stat(filename, &stat_buf) == -1) { elog(WARN, "stat failed on file %s", filename); } for (file_scanner = file_list; file_scanner != (DynamicFileList *) NULL && (NOT_EQUAL(stat_buf, *file_scanner)); file_scanner = file_scanner->next) ; /* * Same files - different paths (ie, symlink or link) */ if (file_scanner != (DynamicFileList *) NULL) (void) strcpy(file_scanner->filename, filename); } } else { file_scanner = (DynamicFileList *) NULL; } /* * File not loaded yet. */ if (file_scanner == (DynamicFileList *) NULL) { if (file_list == (DynamicFileList *) NULL) { file_list = (DynamicFileList *) malloc(sizeof(DynamicFileList)); file_scanner = file_list; } else { file_tail->next = (DynamicFileList *) malloc(sizeof(DynamicFileList)); file_scanner = file_tail->next; } memset((char *) file_scanner, 0, sizeof(DynamicFileList)); (void) strcpy(file_scanner->filename, filename); #ifndef WIN32 file_scanner->device = stat_buf.st_dev; file_scanner->inode = stat_buf.st_ino; #endif /* WIN32 */ file_scanner->next = (DynamicFileList *) NULL; file_scanner->handle = pg_dlopen(filename); if (file_scanner->handle == (void *)NULL) { load_error = pg_dlerror(); if (file_scanner == file_list) { file_list = (DynamicFileList *) NULL; } else { file_tail->next = (DynamicFileList *) NULL; } free((char *) file_scanner); elog(WARN, "Load of file %s failed: %s", filename, load_error); } /* * Just load the file - we are done with that so return. */ file_tail = file_scanner; if (funcname == (char *) NULL) return((func_ptr) NULL); } retval = pg_dlsym(file_scanner->handle, funcname); if (retval == (func_ptr) NULL) { elog(WARN, "Can't find function %s in file %s", funcname, filename); } return(retval); } /* * This function loads files by the following: * * If the file is already loaded: * o Zero out that file's loaded space (so it doesn't screw up linking) * o Free all space associated with that file * o Free that file's descriptor. * * Now load the file by calling handle_load with a NULL argument as the * function. */ void load_file(char *filename) { DynamicFileList *file_scanner, *p; #ifdef WIN32 struct _stat stat_buf; #else struct stat stat_buf; #endif /* WIN32 */ int done = 0; if (stat(filename, &stat_buf) == -1) { elog(WARN, "stat failed on file %s", filename); } if (file_list != (DynamicFileList *) NULL && !NOT_EQUAL(stat_buf, *file_list)) { file_scanner = file_list; file_list = file_list->next; pg_dlclose(file_scanner->handle); free((char *) file_scanner); } else if (file_list != (DynamicFileList *) NULL) { file_scanner = file_list; while (!done) { if (file_scanner->next == (DynamicFileList *) NULL) { done = 1; } else if (!NOT_EQUAL(stat_buf, *(file_scanner->next))) { done = 1; } else { file_scanner = file_scanner->next; } } if (file_scanner->next != (DynamicFileList *) NULL) { p = file_scanner->next; file_scanner->next = file_scanner->next->next; pg_dlclose(file_scanner->handle); free((char *)p); } } handle_load(filename, (char *) NULL); }