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executable file 432 lines (363 sloc) 10.491 kb
/*
* PL/R - PostgreSQL support for R as a
* procedural language (PL)
*
* Copyright (c) 2003-2006 by Joseph E. Conway
* ALL RIGHTS RESERVED
*
* Joe Conway <mail@joeconway.com>
*
* Based on pltcl by Jan Wieck
* and inspired by REmbeddedPostgres by
* Duncan Temple Lang <duncan@research.bell-labs.com>
* http://www.omegahat.org/RSPostgres/
*
* License: GPL version 2 or newer. http://www.gnu.org/copyleft/gpl.html
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* pg_backend_support.c - Postgres backend support functions
*/
#include "plr.h"
#include "miscadmin.h"
#include "optimizer/clauses.h"
#include "utils/memutils.h"
/* GUC variable */
extern char *Dynamic_library_path;
/* compiled function hash table */
extern HTAB *plr_HashTable;
/*
* static declarations
*/
static char *get_lib_pathstr(Oid funcid);
static char *expand_dynamic_library_name(const char *name);
static char *substitute_libpath_macro(const char *name);
static char *find_in_dynamic_libpath(const char *basename);
static bool file_exists(const char *name);
/*
* Compute the hashkey for a given function invocation
*
* The hashkey is returned into the caller-provided storage at *hashkey.
*/
void
compute_function_hashkey(FunctionCallInfo fcinfo,
Form_pg_proc procStruct,
plr_func_hashkey *hashkey)
{
int i;
/* Make sure any unused bytes of the struct are zero */
MemSet(hashkey, 0, sizeof(plr_func_hashkey));
/* get function OID */
hashkey->funcOid = fcinfo->flinfo->fn_oid;
/* if trigger, get relation OID */
if (CALLED_AS_TRIGGER(fcinfo))
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
hashkey->trigrelOid = RelationGetRelid(trigdata->tg_relation);
}
/* get the argument types */
for (i = 0; i < procStruct->pronargs; i++)
{
Oid argtypeid = PROARGTYPES(i);
/*
* Check for polymorphic arguments. If found, use the actual
* parameter type from the caller's FuncExpr node, if we have one.
*
* We can support arguments of type ANY the same way as normal
* polymorphic arguments.
*/
if (argtypeid == ANYARRAYOID || argtypeid == ANYELEMENTOID ||
argtypeid == ANYOID)
{
argtypeid = get_fn_expr_argtype(fcinfo->flinfo, i);
if (!OidIsValid(argtypeid))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("could not determine actual argument "
"type for polymorphic function \"%s\"",
NameStr(procStruct->proname))));
}
hashkey->argtypes[i] = argtypeid;
}
}
void
plr_HashTableInit(void)
{
HASHCTL ctl;
memset(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(plr_func_hashkey);
ctl.entrysize = sizeof(plr_HashEnt);
ctl.hash = tag_hash;
plr_HashTable = hash_create("PLR function cache",
FUNCS_PER_USER,
&ctl,
HASH_ELEM | HASH_FUNCTION);
}
plr_function *
plr_HashTableLookup(plr_func_hashkey *func_key)
{
plr_HashEnt *hentry;
hentry = (plr_HashEnt*) hash_search(plr_HashTable,
(void *) func_key,
HASH_FIND,
NULL);
if (hentry)
return hentry->function;
else
return (plr_function *) NULL;
}
void
plr_HashTableInsert(plr_function *function,
plr_func_hashkey *func_key)
{
plr_HashEnt *hentry;
bool found;
hentry = (plr_HashEnt*) hash_search(plr_HashTable,
(void *) func_key,
HASH_ENTER,
&found);
if (hentry == NULL)
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
if (found)
elog(WARNING, "trying to insert a function that exists");
hentry->function = function;
/* prepare back link from function to hashtable key */
function->fn_hashkey = &hentry->key;
}
void
plr_HashTableDelete(plr_function *function)
{
plr_HashEnt *hentry;
hentry = (plr_HashEnt*) hash_search(plr_HashTable,
(void *) function->fn_hashkey,
HASH_REMOVE,
NULL);
if (hentry == NULL)
elog(WARNING, "trying to delete function that does not exist");
}
static char *
get_lib_pathstr(Oid funcid)
{
HeapTuple procedureTuple;
Form_pg_proc procedureStruct;
Oid language;
HeapTuple languageTuple;
Form_pg_language languageStruct;
Oid lang_funcid;
Datum tmp;
bool isnull;
char *raw_path;
char *cooked_path;
/* get the pg_proc entry */
procedureTuple = SearchSysCache(PROCOID,
ObjectIdGetDatum(funcid),
0, 0, 0);
if (!HeapTupleIsValid(procedureTuple))
/* internal error */
elog(ERROR, "cache lookup failed for function %u", funcid);
procedureStruct = (Form_pg_proc) GETSTRUCT(procedureTuple);
/* now get the pg_language entry */
language = procedureStruct->prolang;
ReleaseSysCache(procedureTuple);
languageTuple = SearchSysCache(LANGOID,
ObjectIdGetDatum(language),
0, 0, 0);
if (!HeapTupleIsValid(languageTuple))
/* internal error */
elog(ERROR, "cache lookup failed for language %u", language);
languageStruct = (Form_pg_language) GETSTRUCT(languageTuple);
lang_funcid = languageStruct->lanplcallfoid;
ReleaseSysCache(languageTuple);
/* finally, get the pg_proc entry for the language handler */
procedureTuple = SearchSysCache(PROCOID,
ObjectIdGetDatum(lang_funcid),
0, 0, 0);
if (!HeapTupleIsValid(procedureTuple))
/* internal error */
elog(ERROR, "cache lookup failed for function %u", lang_funcid);
procedureStruct = (Form_pg_proc) GETSTRUCT(procedureTuple);
tmp = SysCacheGetAttr(PROCOID, procedureTuple, Anum_pg_proc_probin, &isnull);
raw_path = DatumGetCString(DirectFunctionCall1(byteaout, tmp));
cooked_path = expand_dynamic_library_name(raw_path);
if (!cooked_path)
cooked_path = pstrdup(raw_path);
ReleaseSysCache(procedureTuple);
return cooked_path;
}
char *
get_load_self_ref_cmd(Oid funcid)
{
char *libstr = get_lib_pathstr(funcid);
char *buf = NULL;
if (libstr)
buf = (char *) palloc(strlen(libstr) + 12 + 1);
else
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not find path to PL/R shared library")));
sprintf(buf, "dyn.load(\"%s\")", libstr);
return buf;
}
void
perm_fmgr_info(Oid functionId, FmgrInfo *finfo)
{
fmgr_info_cxt(functionId, finfo, TopMemoryContext);
INIT_AUX_FMGR_ATTS;
}
static bool
file_exists(const char *name)
{
struct stat st;
AssertArg(name != NULL);
if (stat(name, &st) == 0)
return S_ISDIR(st.st_mode) ? false : true;
else if (!(errno == ENOENT || errno == ENOTDIR || errno == EACCES))
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not access file \"%s\": %m", name)));
return false;
}
#ifndef DLSUFFIX
#error "DLSUFFIX must be defined to compile this file."
#endif
/*
* If name contains a slash, check if the file exists, if so return
* the name. Else (no slash) try to expand using search path (see
* find_in_dynamic_libpath below); if that works, return the fully
* expanded file name. If the previous failed, append DLSUFFIX and
* try again. If all fails, return NULL.
*
* A non-NULL result will always be freshly palloc'd.
*/
static char *
expand_dynamic_library_name(const char *name)
{
bool have_slash;
char *new;
char *full;
AssertArg(name);
have_slash = (strchr(name, '/') != NULL);
if (!have_slash)
{
full = find_in_dynamic_libpath(name);
if (full)
return full;
}
else
{
full = substitute_libpath_macro(name);
if (file_exists(full))
return full;
pfree(full);
}
new = palloc(strlen(name) + strlen(DLSUFFIX) + 1);
strcpy(new, name);
strcat(new, DLSUFFIX);
if (!have_slash)
{
full = find_in_dynamic_libpath(new);
pfree(new);
if (full)
return full;
}
else
{
full = substitute_libpath_macro(new);
pfree(new);
if (file_exists(full))
return full;
pfree(full);
}
return NULL;
}
/*
* Substitute for any macros appearing in the given string.
* Result is always freshly palloc'd.
*/
static char *
substitute_libpath_macro(const char *name)
{
const char *sep_ptr;
char *ret;
AssertArg(name != NULL);
if (name[0] != '$')
return pstrdup(name);
if ((sep_ptr = first_dir_separator(name)) == NULL)
sep_ptr = name + strlen(name);
if (strlen("$libdir") != sep_ptr - name ||
strncmp(name, "$libdir", strlen("$libdir")) != 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_NAME),
errmsg("invalid macro name in dynamic library path: %s", name)));
ret = palloc(strlen(pkglib_path) + strlen(sep_ptr) + 1);
strcpy(ret, pkglib_path);
strcat(ret, sep_ptr);
return ret;
}
/*
* Search for a file called 'basename' in the colon-separated search
* path Dynamic_library_path. If the file is found, the full file name
* is returned in freshly palloc'd memory. If the file is not found,
* return NULL.
*/
static char *
find_in_dynamic_libpath(const char *basename)
{
const char *p;
size_t baselen;
AssertArg(basename != NULL);
AssertArg(strchr(basename, '/') == NULL);
AssertState(Dynamic_library_path != NULL);
p = Dynamic_library_path;
if (strlen(p) == 0)
return NULL;
baselen = strlen(basename);
for (;;)
{
size_t len;
char *piece;
char *mangled;
char *full;
len = strcspn(p, ":");
if (len == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_NAME),
errmsg("zero-length component in DYNAMIC_LIBRARY_PATH")));
piece = palloc(len + 1);
strncpy(piece, p, len);
piece[len] = '\0';
mangled = substitute_libpath_macro(piece);
pfree(piece);
/* only absolute paths */
if (mangled[0] != '/')
ereport(ERROR,
(errcode(ERRCODE_INVALID_NAME),
errmsg("DYNAMIC_LIBRARY_PATH component is not absolute")));
full = palloc(strlen(mangled) + 1 + baselen + 1);
sprintf(full, "%s/%s", mangled, basename);
pfree(mangled);
elog(DEBUG2, "find_in_dynamic_libpath: trying %s", full);
if (file_exists(full))
return full;
pfree(full);
if (p[len] == '\0')
break;
else
p += len + 1;
}
return NULL;
}
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