Clean up psql variable code a little: eliminate unnecessary tests in

GetVariable() and be consistent about treatment of the list header.
Motivated by noticing strspn() taking an unreasonable percentage of
runtime --- the call removed from GetVariable() was the only one that
could be in a high-usage path ...

diff --git a/src/bin/psql/variables.c b/src/bin/psql/variables.c
index 26b9f8b..e0e416e 100644 (file)
--- a/src/bin/psql/variables.c
+++ b/src/bin/psql/variables.c
@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2006, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/variables.c,v 1.24 2006/06/14 16:49:03 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/variables.c,v 1.25 2006/06/21 16:05:11 tgl Exp $
  */
 #include "postgres_fe.h"
 #include "common.h"
@@ -29,15 +29,13 @@ GetVariable(VariableSpace space, const char *name)
        if (!space)
                return NULL;
 
-       if (strspn(name, VALID_VARIABLE_CHARS) != strlen(name))
-               return NULL;
-
-       for (current = space; current; current = current->next)
+       for (current = space->next; current; current = current->next)
        {
-               psql_assert(current->name);
-               psql_assert(current->value);
                if (strcmp(current->name, name) == 0)
+               {
+                       psql_assert(current->value);
                        return current->value;
+               }
        }
 
        return NULL;
@@ -126,6 +124,9 @@ PrintVariables(VariableSpace space)
 {
        struct _variable *ptr;
 
+       if (!space)
+               return;
+
        for (ptr = space->next; ptr; ptr = ptr->next)
        {
                printf("%s = '%s'\n", ptr->name, ptr->value);
@@ -143,18 +144,19 @@ SetVariable(VariableSpace space, const char *name, const char *value)
        if (!space)
                return false;
 
-       if (!value)
-               return DeleteVariable(space, name);
-
        if (strspn(name, VALID_VARIABLE_CHARS) != strlen(name))
                return false;
 
-       for (current = space, previous = NULL; current; previous = current, current = current->next)
+       if (!value)
+               return DeleteVariable(space, name);
+
+       for (previous = space, current = space->next;
+                current;
+                previous = current, current = current->next)
        {
-               psql_assert(current->name);
-               psql_assert(current->value);
                if (strcmp(current->name, name) == 0)
                {
+                       psql_assert(current->value);
                        free(current->value);
                        current->value = pg_strdup(value);
                        return true;
@@ -182,19 +184,16 @@ DeleteVariable(VariableSpace space, const char *name)
        if (!space)
                return false;
 
-       if (strspn(name, VALID_VARIABLE_CHARS) != strlen(name))
-               return false;
-
-       for (current = space, previous = NULL; current; previous = current, current = current->next)
+       for (previous = space, current = space->next;
+                current;
+                previous = current, current = current->next)
        {
-               psql_assert(current->name);
-               psql_assert(current->value);
                if (strcmp(current->name, name) == 0)
                {
+                       psql_assert(current->value);
+                       previous->next = current->next;
                        free(current->name);
                        free(current->value);
-                       if (previous)
-                               previous->next = current->next;
                        free(current);
                        return true;
                }