/********************************************************************** * plperl.c - perl as a procedural language for PostgreSQL * * IDENTIFICATION * * This software is copyrighted by Mark Hollomon * but is shameless cribbed from pltcl.c by Jan Weick. * * The author hereby grants permission to use, copy, modify, * distribute, and license this software and its documentation * for any purpose, provided that existing copyright notices are * retained in all copies and that this notice is included * verbatim in any distributions. No written agreement, license, * or royalty fee is required for any of the authorized uses. * Modifications to this software may be copyrighted by their * author and need not follow the licensing terms described * here, provided that the new terms are clearly indicated on * the first page of each file where they apply. * * IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR * CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS * SOFTWARE, ITS DOCUMENTATION, OR ANY DERIVATIVES THEREOF, EVEN * IF THE AUTHOR HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH * DAMAGE. * * THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR * PURPOSE, AND NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON * AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAVE NO * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, * ENHANCEMENTS, OR MODIFICATIONS. * * IDENTIFICATION * $PostgreSQL: pgsql/src/pl/plperl/plperl.c,v 1.41 2003/11/29 19:52:12 pgsql Exp $ * **********************************************************************/ #include "postgres.h" /* system stuff */ #include #include #include /* postgreSQL stuff */ #include "executor/spi.h" #include "commands/trigger.h" #include "fmgr.h" #include "access/heapam.h" #include "tcop/tcopprot.h" #include "utils/syscache.h" #include "catalog/pg_language.h" #include "catalog/pg_proc.h" #include "catalog/pg_type.h" /* perl stuff */ #include "EXTERN.h" #include "perl.h" #include "XSUB.h" #include "ppport.h" /* just in case these symbols aren't provided */ #ifndef pTHX_ #define pTHX_ #define pTHX void #endif /********************************************************************** * The information we cache about loaded procedures **********************************************************************/ typedef struct plperl_proc_desc { char *proname; TransactionId fn_xmin; CommandId fn_cmin; bool lanpltrusted; FmgrInfo result_in_func; Oid result_in_elem; int nargs; FmgrInfo arg_out_func[FUNC_MAX_ARGS]; Oid arg_out_elem[FUNC_MAX_ARGS]; int arg_is_rel[FUNC_MAX_ARGS]; SV *reference; } plperl_proc_desc; /********************************************************************** * Global data **********************************************************************/ static int plperl_firstcall = 1; static PerlInterpreter *plperl_interp = NULL; static HV *plperl_proc_hash = NULL; /********************************************************************** * Forward declarations **********************************************************************/ static void plperl_init_all(void); static void plperl_init_interp(void); Datum plperl_call_handler(PG_FUNCTION_ARGS); void plperl_init(void); static Datum plperl_func_handler(PG_FUNCTION_ARGS); static plperl_proc_desc *compile_plperl_function(Oid fn_oid, bool is_trigger); static SV *plperl_build_tuple_argument(HeapTuple tuple, TupleDesc tupdesc); static void plperl_init_shared_libs(pTHX); /* * This routine is a crock, and so is everyplace that calls it. The problem * is that the cached form of plperl functions/queries is allocated permanently * (mostly via malloc()) and never released until backend exit. Subsidiary * data structures such as fmgr info records therefore must live forever * as well. A better implementation would store all this stuff in a per- * function memory context that could be reclaimed at need. In the meantime, * fmgr_info_cxt must be called specifying TopMemoryContext so that whatever * it might allocate, and whatever the eventual function might allocate using * fn_mcxt, will live forever too. */ static void perm_fmgr_info(Oid functionId, FmgrInfo *finfo) { fmgr_info_cxt(functionId, finfo, TopMemoryContext); } /********************************************************************** * plperl_init() - Initialize everything that can be * safely initialized during postmaster * startup. * * DO NOT make this static --- it has to be callable by preload **********************************************************************/ void plperl_init(void) { /************************************************************ * Do initialization only once ************************************************************/ if (!plperl_firstcall) return; /************************************************************ * Free the proc hash table ************************************************************/ if (plperl_proc_hash != NULL) { hv_undef(plperl_proc_hash); SvREFCNT_dec((SV *) plperl_proc_hash); plperl_proc_hash = NULL; } /************************************************************ * Destroy the existing Perl interpreter ************************************************************/ if (plperl_interp != NULL) { perl_destruct(plperl_interp); perl_free(plperl_interp); plperl_interp = NULL; } /************************************************************ * Now recreate a new Perl interpreter ************************************************************/ plperl_init_interp(); plperl_firstcall = 0; } /********************************************************************** * plperl_init_all() - Initialize all **********************************************************************/ static void plperl_init_all(void) { /************************************************************ * Execute postmaster-startup safe initialization ************************************************************/ if (plperl_firstcall) plperl_init(); /************************************************************ * Any other initialization that must be done each time a new * backend starts -- currently none ************************************************************/ } /********************************************************************** * plperl_init_interp() - Create the Perl interpreter **********************************************************************/ static void plperl_init_interp(void) { char *embedding[3] = { "", "-e", /* * no commas between the next 5 please. They are supposed to be * one string */ "require Safe; SPI::bootstrap();" "sub ::mksafefunc { my $x = new Safe; $x->permit_only(':default');$x->permit(':base_math');" "$x->share(qw[&elog &DEBUG &LOG &INFO &NOTICE &WARNING &ERROR]);" " return $x->reval(qq[sub { $_[0] }]); }" "sub ::mkunsafefunc {return eval(qq[ sub { $_[0] } ]); }" }; plperl_interp = perl_alloc(); if (!plperl_interp) elog(ERROR, "could not allocate perl interpreter"); perl_construct(plperl_interp); perl_parse(plperl_interp, plperl_init_shared_libs, 3, embedding, NULL); perl_run(plperl_interp); /************************************************************ * Initialize the proc and query hash tables ************************************************************/ plperl_proc_hash = newHV(); } /********************************************************************** * plperl_call_handler - This is the only visible function * of the PL interpreter. The PostgreSQL * function manager and trigger manager * call this function for execution of * perl procedures. **********************************************************************/ PG_FUNCTION_INFO_V1(plperl_call_handler); /* keep non-static */ Datum plperl_call_handler(PG_FUNCTION_ARGS) { Datum retval; /************************************************************ * Initialize interpreter ************************************************************/ plperl_init_all(); /************************************************************ * Connect to SPI manager ************************************************************/ if (SPI_connect() != SPI_OK_CONNECT) elog(ERROR, "could not connect to SPI manager"); /************************************************************ * Determine if called as function or trigger and * call appropriate subhandler ************************************************************/ if (CALLED_AS_TRIGGER(fcinfo)) { ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot use perl in triggers yet"))); /* * retval = PointerGetDatum(plperl_trigger_handler(fcinfo)); */ /* make the compiler happy */ retval = (Datum) 0; } else retval = plperl_func_handler(fcinfo); return retval; } /********************************************************************** * plperl_create_sub() - calls the perl interpreter to * create the anonymous subroutine whose text is in the SV. * Returns the SV containing the RV to the closure. **********************************************************************/ static SV * plperl_create_sub(char *s, bool trusted) { dSP; SV *subref; int count; ENTER; SAVETMPS; PUSHMARK(SP); XPUSHs(sv_2mortal(newSVpv(s, 0))); PUTBACK; /* * G_KEEPERR seems to be needed here, else we don't recognize compile * errors properly. Perhaps it's because there's another level of * eval inside mksafefunc? */ count = perl_call_pv((trusted ? "mksafefunc" : "mkunsafefunc"), G_SCALAR | G_EVAL | G_KEEPERR); SPAGAIN; if (count != 1) { PUTBACK; FREETMPS; LEAVE; elog(ERROR, "didn't get a return item from mksafefunc"); } if (SvTRUE(ERRSV)) { POPs; PUTBACK; FREETMPS; LEAVE; elog(ERROR, "creation of function failed: %s", SvPV(ERRSV, PL_na)); } /* * need to make a deep copy of the return. it comes off the stack as a * temporary. */ subref = newSVsv(POPs); if (!SvROK(subref)) { PUTBACK; FREETMPS; LEAVE; /* * subref is our responsibility because it is not mortal */ SvREFCNT_dec(subref); elog(ERROR, "didn't get a code ref"); } PUTBACK; FREETMPS; LEAVE; return subref; } /********************************************************************** * plperl_init_shared_libs() - * * We cannot use the DynaLoader directly to get at the Opcode * module (used by Safe.pm). So, we link Opcode into ourselves * and do the initialization behind perl's back. * **********************************************************************/ EXTERN_C void boot_DynaLoader(pTHX_ CV * cv); EXTERN_C void boot_SPI(pTHX_ CV * cv); static void plperl_init_shared_libs(pTHX) { char *file = __FILE__; newXS("DynaLoader::boot_DynaLoader", boot_DynaLoader, file); newXS("SPI::bootstrap", boot_SPI, file); } /********************************************************************** * plperl_call_perl_func() - calls a perl function through the RV * stored in the prodesc structure. massages the input parms properly **********************************************************************/ static SV * plperl_call_perl_func(plperl_proc_desc * desc, FunctionCallInfo fcinfo) { dSP; SV *retval; int i; int count; ENTER; SAVETMPS; PUSHMARK(SP); for (i = 0; i < desc->nargs; i++) { if (desc->arg_is_rel[i]) { TupleTableSlot *slot = (TupleTableSlot *) fcinfo->arg[i]; SV *hashref; Assert(slot != NULL && !fcinfo->argnull[i]); /* * plperl_build_tuple_argument better return a mortal SV. */ hashref = plperl_build_tuple_argument(slot->val, slot->ttc_tupleDescriptor); XPUSHs(hashref); } else { if (fcinfo->argnull[i]) XPUSHs(&PL_sv_undef); else { char *tmp; tmp = DatumGetCString(FunctionCall3(&(desc->arg_out_func[i]), fcinfo->arg[i], ObjectIdGetDatum(desc->arg_out_elem[i]), Int32GetDatum(-1))); XPUSHs(sv_2mortal(newSVpv(tmp, 0))); pfree(tmp); } } } PUTBACK; /* Do NOT use G_KEEPERR here */ count = perl_call_sv(desc->reference, G_SCALAR | G_EVAL); SPAGAIN; if (count != 1) { PUTBACK; FREETMPS; LEAVE; elog(ERROR, "didn't get a return item from function"); } if (SvTRUE(ERRSV)) { POPs; PUTBACK; FREETMPS; LEAVE; elog(ERROR, "error from function: %s", SvPV(ERRSV, PL_na)); } retval = newSVsv(POPs); PUTBACK; FREETMPS; LEAVE; return retval; } /********************************************************************** * plperl_func_handler() - Handler for regular function calls **********************************************************************/ static Datum plperl_func_handler(PG_FUNCTION_ARGS) { plperl_proc_desc *prodesc; SV *perlret; Datum retval; /* Find or compile the function */ prodesc = compile_plperl_function(fcinfo->flinfo->fn_oid, false); /************************************************************ * Call the Perl function ************************************************************/ perlret = plperl_call_perl_func(prodesc, fcinfo); /************************************************************ * Disconnect from SPI manager and then create the return * values datum (if the input function does a palloc for it * this must not be allocated in the SPI memory context * because SPI_finish would free it). ************************************************************/ if (SPI_finish() != SPI_OK_FINISH) elog(ERROR, "SPI_finish() failed"); if (!(perlret && SvOK(perlret))) { /* return NULL if Perl code returned undef */ retval = (Datum) 0; fcinfo->isnull = true; } else { retval = FunctionCall3(&prodesc->result_in_func, PointerGetDatum(SvPV(perlret, PL_na)), ObjectIdGetDatum(prodesc->result_in_elem), Int32GetDatum(-1)); } SvREFCNT_dec(perlret); return retval; } /********************************************************************** * compile_plperl_function - compile (or hopefully just look up) function **********************************************************************/ static plperl_proc_desc * compile_plperl_function(Oid fn_oid, bool is_trigger) { HeapTuple procTup; Form_pg_proc procStruct; char internal_proname[64]; int proname_len; plperl_proc_desc *prodesc = NULL; int i; /* We'll need the pg_proc tuple in any case... */ procTup = SearchSysCache(PROCOID, ObjectIdGetDatum(fn_oid), 0, 0, 0); if (!HeapTupleIsValid(procTup)) elog(ERROR, "cache lookup failed for function %u", fn_oid); procStruct = (Form_pg_proc) GETSTRUCT(procTup); /************************************************************ * Build our internal proc name from the functions Oid ************************************************************/ if (!is_trigger) sprintf(internal_proname, "__PLPerl_proc_%u", fn_oid); else sprintf(internal_proname, "__PLPerl_proc_%u_trigger", fn_oid); proname_len = strlen(internal_proname); /************************************************************ * Lookup the internal proc name in the hashtable ************************************************************/ if (hv_exists(plperl_proc_hash, internal_proname, proname_len)) { bool uptodate; prodesc = (plperl_proc_desc *) SvIV(*hv_fetch(plperl_proc_hash, internal_proname, proname_len, 0)); /************************************************************ * If it's present, must check whether it's still up to date. * This is needed because CREATE OR REPLACE FUNCTION can modify the * function's pg_proc entry without changing its OID. ************************************************************/ uptodate = (prodesc->fn_xmin == HeapTupleHeaderGetXmin(procTup->t_data) && prodesc->fn_cmin == HeapTupleHeaderGetCmin(procTup->t_data)); if (!uptodate) { /* need we delete old entry? */ prodesc = NULL; } } /************************************************************ * If we haven't found it in the hashtable, we analyze * the functions arguments and returntype and store * the in-/out-functions in the prodesc block and create * a new hashtable entry for it. * * Then we load the procedure into the Perl interpreter. ************************************************************/ if (prodesc == NULL) { HeapTuple langTup; HeapTuple typeTup; Form_pg_language langStruct; Form_pg_type typeStruct; char *proc_source; /************************************************************ * Allocate a new procedure description block ************************************************************/ prodesc = (plperl_proc_desc *) malloc(sizeof(plperl_proc_desc)); if (prodesc == NULL) ereport(ERROR, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of memory"))); MemSet(prodesc, 0, sizeof(plperl_proc_desc)); prodesc->proname = strdup(internal_proname); prodesc->fn_xmin = HeapTupleHeaderGetXmin(procTup->t_data); prodesc->fn_cmin = HeapTupleHeaderGetCmin(procTup->t_data); /************************************************************ * Lookup the pg_language tuple by Oid ************************************************************/ langTup = SearchSysCache(LANGOID, ObjectIdGetDatum(procStruct->prolang), 0, 0, 0); if (!HeapTupleIsValid(langTup)) { free(prodesc->proname); free(prodesc); elog(ERROR, "cache lookup failed for language %u", procStruct->prolang); } langStruct = (Form_pg_language) GETSTRUCT(langTup); prodesc->lanpltrusted = langStruct->lanpltrusted; ReleaseSysCache(langTup); /************************************************************ * Get the required information for input conversion of the * return value. ************************************************************/ if (!is_trigger) { typeTup = SearchSysCache(TYPEOID, ObjectIdGetDatum(procStruct->prorettype), 0, 0, 0); if (!HeapTupleIsValid(typeTup)) { free(prodesc->proname); free(prodesc); elog(ERROR, "cache lookup failed for type %u", procStruct->prorettype); } typeStruct = (Form_pg_type) GETSTRUCT(typeTup); /* Disallow pseudotype result, except VOID */ if (typeStruct->typtype == 'p') { if (procStruct->prorettype == VOIDOID) /* okay */ ; else if (procStruct->prorettype == TRIGGEROID) { free(prodesc->proname); free(prodesc); ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("trigger functions may only be called as triggers"))); } else { free(prodesc->proname); free(prodesc); ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("plperl functions cannot return type %s", format_type_be(procStruct->prorettype)))); } } if (typeStruct->typrelid != InvalidOid) { free(prodesc->proname); free(prodesc); ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("plperl functions cannot return tuples yet"))); } perm_fmgr_info(typeStruct->typinput, &(prodesc->result_in_func)); prodesc->result_in_elem = typeStruct->typelem; ReleaseSysCache(typeTup); } /************************************************************ * Get the required information for output conversion * of all procedure arguments ************************************************************/ if (!is_trigger) { prodesc->nargs = procStruct->pronargs; for (i = 0; i < prodesc->nargs; i++) { typeTup = SearchSysCache(TYPEOID, ObjectIdGetDatum(procStruct->proargtypes[i]), 0, 0, 0); if (!HeapTupleIsValid(typeTup)) { free(prodesc->proname); free(prodesc); elog(ERROR, "cache lookup failed for type %u", procStruct->proargtypes[i]); } typeStruct = (Form_pg_type) GETSTRUCT(typeTup); /* Disallow pseudotype argument */ if (typeStruct->typtype == 'p') { free(prodesc->proname); free(prodesc); ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("plperl functions cannot take type %s", format_type_be(procStruct->proargtypes[i])))); } if (typeStruct->typrelid != InvalidOid) prodesc->arg_is_rel[i] = 1; else prodesc->arg_is_rel[i] = 0; perm_fmgr_info(typeStruct->typoutput, &(prodesc->arg_out_func[i])); prodesc->arg_out_elem[i] = typeStruct->typelem; ReleaseSysCache(typeTup); } } /************************************************************ * create the text of the anonymous subroutine. * we do not use a named subroutine so that we can call directly * through the reference. * ************************************************************/ proc_source = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(&procStruct->prosrc))); /************************************************************ * Create the procedure in the interpreter ************************************************************/ prodesc->reference = plperl_create_sub(proc_source, prodesc->lanpltrusted); pfree(proc_source); if (!prodesc->reference) { free(prodesc->proname); free(prodesc); elog(ERROR, "could not create internal procedure \"%s\"", internal_proname); } /************************************************************ * Add the proc description block to the hashtable ************************************************************/ hv_store(plperl_proc_hash, internal_proname, proname_len, newSViv((IV) prodesc), 0); } ReleaseSysCache(procTup); return prodesc; } /********************************************************************** * plperl_build_tuple_argument() - Build a string for a ref to a hash * from all attributes of a given tuple **********************************************************************/ static SV * plperl_build_tuple_argument(HeapTuple tuple, TupleDesc tupdesc) { int i; SV *output; Datum attr; bool isnull; char *attname; char *outputstr; HeapTuple typeTup; Oid typoutput; Oid typelem; output = sv_2mortal(newSVpv("{", 0)); for (i = 0; i < tupdesc->natts; i++) { /* ignore dropped attributes */ if (tupdesc->attrs[i]->attisdropped) continue; /************************************************************ * Get the attribute name ************************************************************/ attname = tupdesc->attrs[i]->attname.data; /************************************************************ * Get the attributes value ************************************************************/ attr = heap_getattr(tuple, i + 1, tupdesc, &isnull); /************************************************************ * If it is null it will be set to undef in the hash. ************************************************************/ if (isnull) { sv_catpvf(output, "'%s' => undef,", attname); continue; } /************************************************************ * Lookup the attribute type in the syscache * for the output function ************************************************************/ typeTup = SearchSysCache(TYPEOID, ObjectIdGetDatum(tupdesc->attrs[i]->atttypid), 0, 0, 0); if (!HeapTupleIsValid(typeTup)) elog(ERROR, "cache lookup failed for type %u", tupdesc->attrs[i]->atttypid); typoutput = ((Form_pg_type) GETSTRUCT(typeTup))->typoutput; typelem = ((Form_pg_type) GETSTRUCT(typeTup))->typelem; ReleaseSysCache(typeTup); /************************************************************ * Append the attribute name and the value to the list. ************************************************************/ outputstr = DatumGetCString(OidFunctionCall3(typoutput, attr, ObjectIdGetDatum(typelem), Int32GetDatum(tupdesc->attrs[i]->atttypmod))); sv_catpvf(output, "'%s' => '%s',", attname, outputstr); pfree(outputstr); } sv_catpv(output, "}"); output = perl_eval_pv(SvPV(output, PL_na), TRUE); return output; }