[patch] my_setenv speedup + fixes

Message-Id: <Pine.LNX.4.21.0111091808500.22397-100000@localhost>

p4raw-id: //depot/perl@12926

1 files changed, 32 insertions, 11 deletions

diff --git a/util.c b/util.c
index c5b32e342c..f1662c105e 100644
--- a/util.c
+++ b/util.c
@@ -1496,6 +1496,16 @@ Perl_vwarner(pTHX_ U32  err, const char* pat, va_list* args)
     }
 }
 
+/* since we've already done strlen() for both nam and val
+ * we can use that info to make things faster than
+ * sprintf(s, "%s=%s", nam, val)
+ */
+#define my_setenv_format(s, nam, nlen, val, vlen) \
+   Copy(nam, s, nlen, char); \
+   *(s+nlen) = '='; \
+   Copy(val, s+(nlen+1), vlen, char); \
+   *(s+(nlen+1+vlen)) = '\0'
+
 #ifdef USE_ENVIRON_ARRAY
        /* VMS' and EPOC's my_setenv() is in vms.c and epoc.c */
 #if !defined(WIN32) && !defined(NETWARE)
@@ -1505,6 +1515,7 @@ Perl_my_setenv(pTHX_ char *nam, char *val)
 #ifndef PERL_USE_SAFE_PUTENV
     /* most putenv()s leak, so we manipulate environ directly */
     register I32 i=setenv_getix(nam);		/* where does it go? */
+    int nlen, vlen;
 
     if (environ == PL_origenviron) {	/* need we copy environment? */
 	I32 j;
@@ -1515,8 +1526,9 @@ Perl_my_setenv(pTHX_ char *nam, char *val)
 	for (max = i; environ[max]; max++) ;
 	tmpenv = (char**)safesysmalloc((max+2) * sizeof(char*));
 	for (j=0; j<max; j++) {		/* copy environment */
-	    tmpenv[j] = (char*)safesysmalloc((strlen(environ[j])+1)*sizeof(char));
-	    strcpy(tmpenv[j], environ[j]);
+            int len = strlen(environ[j]);
+            tmpenv[j] = (char*)safesysmalloc((len+1)*sizeof(char));
+            Copy(environ[j], tmpenv[j], len+1, char);
 	}
 	tmpenv[max] = Nullch;
 	environ = tmpenv;		/* tell exec where it is now */
@@ -1535,18 +1547,26 @@ Perl_my_setenv(pTHX_ char *nam, char *val)
     }
     else
 	safesysfree(environ[i]);
-    environ[i] = (char*)safesysmalloc((strlen(nam)+strlen(val)+2) * sizeof(char));
+    nlen = strlen(nam);
+    vlen = strlen(val);
 
-    (void)sprintf(environ[i],"%s=%s",nam,val);/* all that work just for this */
+    environ[i] = (char*)safesysmalloc((nlen+vlen+2) * sizeof(char));
+    /* all that work just for this */
+    my_setenv_format(environ[i], nam, nlen, val, vlen);
 
 #else   /* PERL_USE_SAFE_PUTENV */
 #   if defined(__CYGWIN__)
     setenv(nam, val, 1);
 #   else
     char *new_env;
-
-    new_env = (char*)safesysmalloc((strlen(nam) + strlen(val) + 2) * sizeof(char));
-    (void)sprintf(new_env,"%s=%s",nam,val);/* all that work just for this */
+    int nlen = strlen(nam), vlen;
+    if (!val) {
+        val = "";
+    }
+    vlen = strlen(val);
+    new_env = (char*)safesysmalloc((nlen + vlen + 2) * sizeof(char));
+    /* all that work just for this */
+    my_setenv_format(new_env, nam, nlen, val, vlen);
     (void)putenv(new_env);
 #   endif /* __CYGWIN__ */
 #endif  /* PERL_USE_SAFE_PUTENV */
@@ -1558,13 +1578,14 @@ void
 Perl_my_setenv(pTHX_ char *nam,char *val)
 {
     register char *envstr;
-    STRLEN len = strlen(nam) + 3;
+    int nlen = strlen(nam), vlen;
+
     if (!val) {
 	val = "";
     }
-    len += strlen(val);
-    New(904, envstr, len, char);
-    (void)sprintf(envstr,"%s=%s",nam,val);
+    vlen = strlen(val);
+    New(904, envstr, nlen+vlen+2, char);
+    my_setenv_format(envstr, nam, nlen, val, vlen);
     (void)PerlEnv_putenv(envstr);
     Safefree(envstr);
 }