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Diffstat (limited to 'src/test/modules/plsample/plsample.c')
| -rw-r--r-- | src/test/modules/plsample/plsample.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/src/test/modules/plsample/plsample.c b/src/test/modules/plsample/plsample.c new file mode 100644 index 0000000..6fc33c7 --- /dev/null +++ b/src/test/modules/plsample/plsample.c @@ -0,0 +1,187 @@ +/*------------------------------------------------------------------------- + * + * plsample.c + * Handler for the PL/Sample procedural language + * + * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/test/modules/plsample/plsample.c + * + *------------------------------------------------------------------------- + */ + +#include "postgres.h" + +#include "catalog/pg_proc.h" +#include "catalog/pg_type.h" +#include "commands/event_trigger.h" +#include "commands/trigger.h" +#include "funcapi.h" +#include "utils/builtins.h" +#include "utils/lsyscache.h" +#include "utils/syscache.h" + +PG_MODULE_MAGIC; + +PG_FUNCTION_INFO_V1(plsample_call_handler); + +static Datum plsample_func_handler(PG_FUNCTION_ARGS); + +/* + * Handle function, procedure, and trigger calls. + */ +Datum +plsample_call_handler(PG_FUNCTION_ARGS) +{ + Datum retval = (Datum) 0; + + PG_TRY(); + { + /* + * Determine if called as function or trigger and call appropriate + * subhandler. + */ + if (CALLED_AS_TRIGGER(fcinfo)) + { + /* + * This function has been called as a trigger function, where + * (TriggerData *) fcinfo->context includes the information of the + * context. + */ + } + else if (CALLED_AS_EVENT_TRIGGER(fcinfo)) + { + /* + * This function is called as an event trigger function, where + * (EventTriggerData *) fcinfo->context includes the information + * of the context. + */ + } + else + { + /* Regular function handler */ + retval = plsample_func_handler(fcinfo); + } + } + PG_FINALLY(); + { + } + PG_END_TRY(); + + return retval; +} + +/* + * plsample_func_handler + * + * Function called by the call handler for function execution. + */ +static Datum +plsample_func_handler(PG_FUNCTION_ARGS) +{ + HeapTuple pl_tuple; + Datum ret; + char *source; + bool isnull; + FmgrInfo *arg_out_func; + Form_pg_type type_struct; + HeapTuple type_tuple; + Form_pg_proc pl_struct; + volatile MemoryContext proc_cxt = NULL; + Oid *argtypes; + char **argnames; + char *argmodes; + char *proname; + Form_pg_type pg_type_entry; + Oid result_typioparam; + Oid prorettype; + FmgrInfo result_in_func; + int numargs; + + /* Fetch the source text of the function. */ + pl_tuple = SearchSysCache(PROCOID, + ObjectIdGetDatum(fcinfo->flinfo->fn_oid), 0, 0, 0); + if (!HeapTupleIsValid(pl_tuple)) + elog(ERROR, "cache lookup failed for function %u", + fcinfo->flinfo->fn_oid); + + /* + * Extract and print the source text of the function. This can be used as + * a base for the function validation and execution. + */ + pl_struct = (Form_pg_proc) GETSTRUCT(pl_tuple); + proname = pstrdup(NameStr(pl_struct->proname)); + ret = SysCacheGetAttr(PROCOID, pl_tuple, Anum_pg_proc_prosrc, &isnull); + if (isnull) + elog(ERROR, "could not find source text of function \"%s\"", + proname); + source = DatumGetCString(DirectFunctionCall1(textout, ret)); + ereport(NOTICE, + (errmsg("source text of function \"%s\": %s", + proname, source))); + + /* + * Allocate a context that will hold all the Postgres data for the + * procedure. + */ + proc_cxt = AllocSetContextCreate(TopMemoryContext, + "PL/Sample function", + ALLOCSET_SMALL_SIZES); + + arg_out_func = (FmgrInfo *) palloc0(fcinfo->nargs * sizeof(FmgrInfo)); + numargs = get_func_arg_info(pl_tuple, &argtypes, &argnames, &argmodes); + + /* + * Iterate through all of the function arguments, printing each input + * value. + */ + for (int i = 0; i < numargs; i++) + { + Oid argtype = pl_struct->proargtypes.values[i]; + char *value; + + type_tuple = SearchSysCache1(TYPEOID, ObjectIdGetDatum(argtype)); + if (!HeapTupleIsValid(type_tuple)) + elog(ERROR, "cache lookup failed for type %u", argtype); + + type_struct = (Form_pg_type) GETSTRUCT(type_tuple); + fmgr_info_cxt(type_struct->typoutput, &(arg_out_func[i]), proc_cxt); + ReleaseSysCache(type_tuple); + + value = OutputFunctionCall(&arg_out_func[i], fcinfo->args[i].value); + ereport(NOTICE, + (errmsg("argument: %d; name: %s; value: %s", + i, argnames[i], value))); + } + + /* Type of the result */ + prorettype = pl_struct->prorettype; + ReleaseSysCache(pl_tuple); + + /* + * Get the required information for input conversion of the return value. + * + * If the function uses VOID as result, it is better to return NULL. + * Anyway, let's be honest. This is just a template, so there is not much + * we can do here. This returns NULL except if the result type is text, + * where the result is the source text of the function. + */ + if (prorettype != TEXTOID) + PG_RETURN_NULL(); + + type_tuple = SearchSysCache1(TYPEOID, + ObjectIdGetDatum(prorettype)); + if (!HeapTupleIsValid(type_tuple)) + elog(ERROR, "cache lookup failed for type %u", prorettype); + pg_type_entry = (Form_pg_type) GETSTRUCT(type_tuple); + result_typioparam = getTypeIOParam(type_tuple); + + fmgr_info_cxt(pg_type_entry->typinput, &result_in_func, proc_cxt); + ReleaseSysCache(type_tuple); + + ret = InputFunctionCall(&result_in_func, source, result_typioparam, -1); + PG_RETURN_DATUM(ret); +} |