Tstr: Unconditionally append a hidden NULstrz2

Allocating one more byte shouldn't be a significant problem of memory
use.  On the other hand, this reduces a few branches, simplifying code.
Also, all callers can rely on these strings being terminated, without
having to rely on a flag that may be set very far away.

Cc: Andrew Clayton <a.clayton@nginx.com>
Cc: Zhidao Hong <z.hong@f5.com>
Cc: Andrei Zeliankou <zelenkov@nginx.com>
Cc: "Valentin V. Bartenev" <vbartenev@gmail.com>
Cc: Dan Callahan <d.callahan@f5.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

6 files changed, 15 insertions, 41 deletions

diff --git a/src/nxt_http_static.c b/src/nxt_http_static.c
index 50e3c6c7..b123547f 100644
--- a/src/nxt_http_static.c
+++ b/src/nxt_http_static.c
@@ -105,7 +105,7 @@ nxt_http_static_init(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
         cv = nxt_conf_get_array_element_or_itself(acf->share, i);
         nxt_conf_get_string(cv, &str);
 
-        tstr = nxt_tstr_compile(rtcf->tstr_state, &str, NXT_TSTR_STRZ);
+        tstr = nxt_tstr_compile(rtcf->tstr_state, &str, 0);
         if (nxt_slow_path(tstr == NULL)) {
             return NXT_ERROR;
         }
@@ -131,8 +131,7 @@ nxt_http_static_init(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
         nxt_str_t   chr, shr;
         nxt_bool_t  is_const;
 
-        conf->chroot = nxt_tstr_compile(rtcf->tstr_state, &acf->chroot,
-                                        NXT_TSTR_STRZ);
+        conf->chroot = nxt_tstr_compile(rtcf->tstr_state, &acf->chroot, 0);
         if (nxt_slow_path(conf->chroot == NULL)) {
             return NXT_ERROR;
         }
diff --git a/src/nxt_js.c b/src/nxt_js.c
index 74663660..a945264b 100644
--- a/src/nxt_js.c
+++ b/src/nxt_js.c
@@ -232,7 +232,7 @@ nxt_js_add_module(nxt_js_conf_t *jcf, nxt_str_t *name, nxt_str_t *text)
 
 
 nxt_js_t *
-nxt_js_add_tpl(nxt_js_conf_t *jcf, nxt_str_t *str, nxt_bool_t strz)
+nxt_js_add_tpl(nxt_js_conf_t *jcf, nxt_str_t *str)
 {
     size_t     size;
     u_char     *p, *start;
@@ -243,16 +243,9 @@ nxt_js_add_tpl(nxt_js_conf_t *jcf, nxt_str_t *str, nxt_bool_t strz)
                                             "args, headers, cookies) {"
                                             "    return ");
 
-    /*
-     * Appending a terminating null character if strz is true.
-     */
     static nxt_str_t  strz_str = nxt_string(" + '\\x00'");
 
-    size = func_str.length + str->length + 1;
-
-    if (strz) {
-        size += strz_str.length;
-    }
+    size = func_str.length + str->length + 1 + strz_str.length;
 
     start = nxt_mp_nget(jcf->pool, size);
     if (nxt_slow_path(start == NULL)) {
@@ -263,10 +256,7 @@ nxt_js_add_tpl(nxt_js_conf_t *jcf, nxt_str_t *str, nxt_bool_t strz)
 
     p = nxt_cpymem(p, func_str.start, func_str.length);
     p = nxt_cpymem(p, str->start, str->length);
-
-    if (strz) {
-        p = nxt_cpymem(p, strz_str.start, strz_str.length);
-    }
+    p = nxt_cpymem(p, strz_str.start, strz_str.length);
 
     *p++ = '}';
 
@@ -474,7 +464,7 @@ nxt_js_call(nxt_task_t *task, nxt_js_conf_t *jcf, nxt_js_cache_t *cache,
 
     ret = njs_vm_value_string(vm, &res, njs_value_arg(&retval));
 
-    str->length = res.length;
+    str->length = res.length - 1;
     str->start = res.start;
 
     return NXT_OK;
diff --git a/src/nxt_js.h b/src/nxt_js.h
index 48f036b8..653b72b6 100644
--- a/src/nxt_js.h
+++ b/src/nxt_js.h
@@ -28,7 +28,7 @@ void nxt_js_conf_release(nxt_js_conf_t *jcf);
 void nxt_js_set_proto(nxt_js_conf_t *jcf, njs_external_t *proto, nxt_uint_t n);
 nxt_int_t nxt_js_add_module(nxt_js_conf_t *jcf, nxt_str_t *name,
     nxt_str_t *text);
-nxt_js_t *nxt_js_add_tpl(nxt_js_conf_t *jcf, nxt_str_t *str, nxt_bool_t strz);
+nxt_js_t *nxt_js_add_tpl(nxt_js_conf_t *jcf, nxt_str_t *str);
 nxt_int_t nxt_js_compile(nxt_js_conf_t *jcf);
 nxt_int_t nxt_js_test(nxt_js_conf_t *jcf, nxt_str_t *str, u_char *error);
 nxt_int_t nxt_js_call(nxt_task_t *task, nxt_js_conf_t *jcf,
diff --git a/src/nxt_tstr.c b/src/nxt_tstr.c
index edf6860a..568b9589 100644
--- a/src/nxt_tstr.c
+++ b/src/nxt_tstr.c
@@ -86,27 +86,21 @@ nxt_tstr_compile(nxt_tstr_state_t *state, nxt_str_t *str,
 {
     u_char      *p;
     nxt_tstr_t  *tstr;
-    nxt_bool_t  strz;
-
-    strz = (flags & NXT_TSTR_STRZ) != 0;
 
     tstr = nxt_mp_get(state->pool, sizeof(nxt_tstr_t));
     if (nxt_slow_path(tstr == NULL)) {
         return NULL;
     }
 
-    tstr->str.length = str->length + strz;
+    tstr->str.length = str->length;
 
-    tstr->str.start = nxt_mp_nget(state->pool, tstr->str.length);
+    tstr->str.start = nxt_mp_nget(state->pool, tstr->str.length + 1);
     if (nxt_slow_path(tstr->str.start == NULL)) {
         return NULL;
     }
 
     p = nxt_cpymem(tstr->str.start, str->start, str->length);
-
-    if (strz) {
-        *p = '\0';
-    }
+    *p = '\0';
 
     tstr->flags = flags;
 
@@ -120,7 +114,7 @@ nxt_tstr_compile(nxt_tstr_state_t *state, nxt_str_t *str,
 
         nxt_tstr_str(tstr, &tpl);
 
-        tstr->u.js = nxt_js_add_tpl(state->jcf, &tpl, strz);
+        tstr->u.js = nxt_js_add_tpl(state->jcf, &tpl);
         if (nxt_slow_path(tstr->u.js == NULL)) {
             return NULL;
         }
@@ -213,10 +207,6 @@ void
 nxt_tstr_str(nxt_tstr_t *tstr, nxt_str_t *str)
 {
     *str = tstr->str;
-
-    if (tstr->flags & NXT_TSTR_STRZ) {
-        str->length--;
-    }
 }
 
 
@@ -283,10 +273,6 @@ nxt_tstr_query(nxt_task_t *task, nxt_tstr_query_t *query, nxt_tstr_t *tstr,
 #endif
     }
 
-    if (tstr->flags & NXT_TSTR_STRZ) {
-        val->length--;
-    }
-
 #if (NXT_DEBUG)
     nxt_str_t  str;
 
diff --git a/src/nxt_tstr.h b/src/nxt_tstr.h
index 3e842f81..d8f45417 100644
--- a/src/nxt_tstr.h
+++ b/src/nxt_tstr.h
@@ -32,7 +32,6 @@ typedef struct {
 
 
 typedef enum {
-    NXT_TSTR_STRZ       = 1 << 0,
     NXT_TSTR_LOGGING    = 1 << 1,
 } nxt_tstr_flags_t;
 
diff --git a/src/nxt_var.c b/src/nxt_var.c
index 729de788..fb70b5aa 100644
--- a/src/nxt_var.c
+++ b/src/nxt_var.c
@@ -322,7 +322,7 @@ nxt_var_compile(nxt_tstr_state_t *state, nxt_str_t *str)
     n = 0;
 
     p = str->start;
-    end = p + str->length;
+    end = p + str->length + 1;
 
     while (p < end) {
         p = nxt_var_next_part(p, end, &part);
@@ -335,20 +335,20 @@ nxt_var_compile(nxt_tstr_state_t *state, nxt_str_t *str)
         }
     }
 
-    size = sizeof(nxt_var_t) + n * sizeof(nxt_var_sub_t) + str->length;
+    size = sizeof(nxt_var_t) + n * sizeof(nxt_var_sub_t) + str->length + 1;
 
     var = nxt_mp_get(state->pool, size);
     if (nxt_slow_path(var == NULL)) {
         return NULL;
     }
 
-    var->length = str->length;
+    var->length = str->length + 1;
     var->vars = n;
 
     subs = nxt_var_subs(var);
     src = nxt_var_raw_start(var);
 
-    nxt_memcpy(src, str->start, str->length);
+    nxt_memcpy(src, str->start, str->length + 1);
 
     n = 0;
     p = str->start;