From d0b4399d81f39decccb23fa38f772b71b51bf96a Mon Sep 17 00:00:00 2001 From: Neil Conway Date: Wed, 26 May 2004 04:41:50 +0000 Subject: Reimplement the linked list data structure used throughout the backend. In the past, we used a 'Lispy' linked list implementation: a "list" was merely a pointer to the head node of the list. The problem with that design is that it makes lappend() and length() linear time. This patch fixes that problem (and others) by maintaining a count of the list length and a pointer to the tail node along with each head node pointer. A "list" is now a pointer to a structure containing some meta-data about the list; the head and tail pointers in that structure refer to ListCell structures that maintain the actual linked list of nodes. The function names of the list API have also been changed to, I hope, be more logically consistent. By default, the old function names are still available; they will be disabled-by-default once the rest of the tree has been updated to use the new API names. --- src/backend/commands/user.c | 46 ++++++++++++++++++++++----------------------- 1 file changed, 23 insertions(+), 23 deletions(-) (limited to 'src/backend/commands/user.c') diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c index 476e7e1865e..255428fadc7 100644 --- a/src/backend/commands/user.c +++ b/src/backend/commands/user.c @@ -6,7 +6,7 @@ * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/backend/commands/user.c,v 1.140 2004/05/06 16:59:16 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/commands/user.c,v 1.141 2004/05/26 04:41:12 neilc Exp $ * *------------------------------------------------------------------------- */ @@ -491,8 +491,8 @@ CreateUser(CreateUserStmt *stmt) sysid_exists = false, havesysid = false; int max_id; - List *item, - *option; + ListCell *item; + ListCell *option; char *password = NULL; /* PostgreSQL user password */ bool encrypt_password = Password_encryption; /* encrypt password? */ char encrypted_password[MD5_PASSWD_LEN + 1]; @@ -715,7 +715,7 @@ CreateUser(CreateUserStmt *stmt) ags.name = strVal(lfirst(item)); /* the group name to add * this in */ ags.action = +1; - ags.listUsers = makeList1(makeInteger(sysid)); + ags.listUsers = list_make1(makeInteger(sysid)); AlterGroup(&ags, "CREATE USER"); } @@ -746,7 +746,7 @@ AlterUser(AlterUserStmt *stmt) TupleDesc pg_shadow_dsc; HeapTuple tuple, new_tuple; - List *option; + ListCell *option; char *password = NULL; /* PostgreSQL user password */ bool encrypt_password = Password_encryption; /* encrypt password? */ char encrypted_password[MD5_PASSWD_LEN + 1]; @@ -1017,7 +1017,7 @@ DropUser(DropUserStmt *stmt) { Relation pg_shadow_rel; TupleDesc pg_shadow_dsc; - List *item; + ListCell *item; if (!superuser()) ereport(ERROR, @@ -1122,7 +1122,7 @@ DropUser(DropUserStmt *stmt) /* the group name from which to try to drop the user: */ ags.name = pstrdup(NameStr(((Form_pg_group) GETSTRUCT(tmp_tuple))->groname)); ags.action = -1; - ags.listUsers = makeList1(makeInteger(usesysid)); + ags.listUsers = list_make1(makeInteger(usesysid)); AlterGroup(&ags, "DROP USER"); } heap_endscan(scan); @@ -1283,9 +1283,9 @@ CreateGroup(CreateGroupStmt *stmt) int max_id; Datum new_record[Natts_pg_group]; char new_record_nulls[Natts_pg_group]; - List *item, - *option, - *newlist = NIL; + ListCell *item; + ListCell *option; + List *newlist = NIL; IdList *grolist; int sysid = 0; List *userElts = NIL; @@ -1397,8 +1397,8 @@ CreateGroup(CreateGroupStmt *stmt) const char *groupuser = strVal(lfirst(item)); int32 userid = get_usesysid(groupuser); - if (!intMember(userid, newlist)) - newlist = lappendi(newlist, userid); + if (!list_member_int(newlist, userid)) + newlist = lappend_int(newlist, userid); } /* build an array to insert */ @@ -1454,8 +1454,8 @@ AlterGroup(AlterGroupStmt *stmt, const char *tag) IdList *oldarray; Datum datum; bool null; - List *newlist, - *item; + List *newlist; + ListCell *item; /* * Make sure the user can do this. @@ -1525,8 +1525,8 @@ AlterGroup(AlterGroupStmt *stmt, const char *tag) sysid = 0; /* keep compiler quiet */ } - if (!intMember(sysid, newlist)) - newlist = lappendi(newlist, sysid); + if (!list_member_int(newlist, sysid)) + newlist = lappend_int(newlist, sysid); } /* Do the update */ @@ -1565,8 +1565,8 @@ AlterGroup(AlterGroupStmt *stmt, const char *tag) /* for dropuser we already know the uid */ sysid = intVal(lfirst(item)); } - if (intMember(sysid, newlist)) - newlist = lremovei(sysid, newlist); + if (list_member_int(newlist, sysid)) + newlist = list_delete_int(newlist, sysid); else if (!is_dropuser) ereport(WARNING, (errcode(ERRCODE_WARNING), @@ -1636,9 +1636,9 @@ UpdateGroupMembership(Relation group_rel, HeapTuple group_tuple, static IdList * IdListToArray(List *members) { - int nmembers = length(members); + int nmembers = list_length(members); IdList *newarray; - List *item; + ListCell *item; int i; newarray = palloc(ARR_OVERHEAD(1) + nmembers * sizeof(int32)); @@ -1650,7 +1650,7 @@ IdListToArray(List *members) ARR_DIMS(newarray)[0] = nmembers; /* axis is this long */ i = 0; foreach(item, members) - ((int *) ARR_DATA_PTR(newarray))[i++] = lfirsti(item); + ((int *) ARR_DATA_PTR(newarray))[i++] = lfirst_int(item); return newarray; } @@ -1679,8 +1679,8 @@ IdArrayToList(IdList *oldarray) sysid = ((int32 *) ARR_DATA_PTR(oldarray))[i]; /* filter out any duplicates --- probably a waste of time */ - if (!intMember(sysid, newlist)) - newlist = lappendi(newlist, sysid); + if (!list_member_int(newlist, sysid)) + newlist = lappend_int(newlist, sysid); } return newlist; -- cgit v1.2.3