MINOR: vars: make vars_get_by_* support an optional default value
In preparation for support default values when fetching variables, we
need to update the internal API to pass an extra argument to functions
vars_get_by_{name,desc} to provide an optional default value. This
patch does this and always passes NULL in this argument. var_to_smp()
was extended to fall back to this value when available.
diff --git a/include/haproxy/vars.h b/include/haproxy/vars.h
index f809c62..0647cf3 100644
--- a/include/haproxy/vars.h
+++ b/include/haproxy/vars.h
@@ -34,11 +34,11 @@
unsigned int var_clear(struct var *var);
void vars_prune(struct vars *vars, struct session *sess, struct stream *strm);
void vars_prune_per_sess(struct vars *vars);
-int vars_get_by_name(const char *name, size_t len, struct sample *smp);
+int vars_get_by_name(const char *name, size_t len, struct sample *smp, const struct buffer *def);
int vars_set_by_name_ifexist(const char *name, size_t len, struct sample *smp);
int vars_set_by_name(const char *name, size_t len, struct sample *smp);
int vars_unset_by_name_ifexist(const char *name, size_t len, struct sample *smp);
-int vars_get_by_desc(const struct var_desc *var_desc, struct sample *smp);
+int vars_get_by_desc(const struct var_desc *var_desc, struct sample *smp, const struct buffer *def);
int vars_check_arg(struct arg *arg, char **err);
#endif
diff --git a/src/hlua.c b/src/hlua.c
index 039ebec..72d2324 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -4382,7 +4382,7 @@
s = luactx->htxn.s;
smp_set_owner(&smp, s->be, s->sess, s, 0);
- if (!vars_get_by_name(name, len, &smp)) {
+ if (!vars_get_by_name(name, len, &smp, NULL)) {
lua_pushnil(L);
return 1;
}
@@ -4869,7 +4869,7 @@
s = luactx->htxn.s;
smp_set_owner(&smp, s->be, s->sess, s, 0);
- if (!vars_get_by_name(name, len, &smp)) {
+ if (!vars_get_by_name(name, len, &smp, NULL)) {
lua_pushnil(L);
return 1;
}
@@ -6966,7 +6966,7 @@
name = MAY_LJMP(luaL_checklstring(L, 2, &len));
smp_set_owner(&smp, htxn->p, htxn->s->sess, htxn->s, htxn->dir & SMP_OPT_DIR);
- if (!vars_get_by_name(name, len, &smp)) {
+ if (!vars_get_by_name(name, len, &smp, NULL)) {
lua_pushnil(L);
return 1;
}
diff --git a/src/sample.c b/src/sample.c
index a0727d2..e4bb318 100644
--- a/src/sample.c
+++ b/src/sample.c
@@ -1747,7 +1747,7 @@
smp->flags = SMP_F_CONST;
return 1;
case ARGT_VAR:
- if (!vars_get_by_desc(&arg->data.var, smp))
+ if (!vars_get_by_desc(&arg->data.var, smp, NULL))
return 0;
if (!sample_casts[smp->data.type][SMP_T_STR])
return 0;
@@ -2990,7 +2990,7 @@
smp->data.u.sint = arg->data.sint;
return 1;
case ARGT_VAR:
- if (!vars_get_by_desc(&arg->data.var, smp))
+ if (!vars_get_by_desc(&arg->data.var, smp, NULL))
return 0;
if (!sample_casts[smp->data.type][SMP_T_SINT])
return 0;
@@ -3317,7 +3317,7 @@
* into a string.
*/
smp_set_owner(&tmp, smp->px, smp->sess, smp->strm, smp->opt);
- if (arg_p[1].type == ARGT_VAR && vars_get_by_desc(&arg_p[1].data.var, &tmp) &&
+ if (arg_p[1].type == ARGT_VAR && vars_get_by_desc(&arg_p[1].data.var, &tmp, NULL) &&
(sample_casts[tmp.data.type][SMP_T_STR] == c_none ||
sample_casts[tmp.data.type][SMP_T_STR](&tmp))) {
@@ -3377,7 +3377,7 @@
smp_set_owner(&tmp, smp->px, smp->sess, smp->strm, smp->opt);
if (arg_p[0].type != ARGT_VAR)
return 0;
- if (!vars_get_by_desc(&arg_p[0].data.var, &tmp))
+ if (!vars_get_by_desc(&arg_p[0].data.var, &tmp, NULL))
return 0;
if (!sample_casts[tmp.data.type][SMP_T_STR](&tmp))
return 0;
@@ -3415,7 +3415,7 @@
smp_set_owner(&tmp, smp->px, smp->sess, smp->strm, smp->opt);
if (arg_p[0].type != ARGT_VAR)
return 0;
- if (!vars_get_by_desc(&arg_p[0].data.var, &tmp))
+ if (!vars_get_by_desc(&arg_p[0].data.var, &tmp, NULL))
return 0;
if (!sample_casts[tmp.data.type][SMP_T_BIN](&tmp))
return 0;
diff --git a/src/vars.c b/src/vars.c
index 236466b..df421f7 100644
--- a/src/vars.c
+++ b/src/vars.c
@@ -340,7 +340,7 @@
{
const struct var_desc *var_desc = &args[0].data.var;
- return vars_get_by_desc(var_desc, smp);
+ return vars_get_by_desc(var_desc, smp, NULL);
}
/* This function search in the <head> a variable with the same
@@ -574,10 +574,11 @@
* release the variables lock ASAP (so a pre-allocated chunk is obtained
* via get_trash_shunk()). The variables' lock is used for reads.
*
- * The function returns 0 if the variable was not found, otherwise 1
- * with the sample filled.
+ * The function returns 0 if the variable was not found and no default
+ * value was provided in <def>, otherwise 1 with the sample filled.
+ * Default values are always returned as strings.
*/
-static int var_to_smp(struct vars *vars, const char *name, struct sample *smp)
+static int var_to_smp(struct vars *vars, const char *name, struct sample *smp, const struct buffer *def)
{
struct var *var;
@@ -585,12 +586,19 @@
HA_RWLOCK_RDLOCK(VARS_LOCK, &vars->rwlock);
var = var_get(vars, name);
if (!var) {
- HA_RWLOCK_RDUNLOCK(VARS_LOCK, &vars->rwlock);
- return 0;
+ if (!def) {
+ HA_RWLOCK_RDUNLOCK(VARS_LOCK, &vars->rwlock);
+ return 0;
+ }
+
+ /* not found but we have a default value */
+ smp->data.type = SMP_T_STR;
+ smp->data.u.str = *def;
}
+ else
+ smp->data = var->data;
/* Copy sample. */
- smp->data = var->data;
smp_dup(smp);
HA_RWLOCK_RDUNLOCK(VARS_LOCK, &vars->rwlock);
@@ -603,9 +611,13 @@
* and it therefore uses a pre-allocated trash chunk as returned by
* get_trash_chunk().
*
+ * If the variable is not valid in this scope, 0 is always returned.
+ * If the variable is valid but not found, either the default value
+ * <def> is returned if not NULL, or zero is returned.
+ *
* Returns 1 if the sample is filled, otherwise it returns 0.
*/
-int vars_get_by_name(const char *name, size_t len, struct sample *smp)
+int vars_get_by_name(const char *name, size_t len, struct sample *smp, const struct buffer *def)
{
struct vars *vars;
enum vars_scope scope;
@@ -620,7 +632,8 @@
if (!vars || vars->scope != scope)
return 0;
- return var_to_smp(vars, name, smp);
+
+ return var_to_smp(vars, name, smp, def);
}
/* This function fills a sample with the content of the variable described
@@ -630,9 +643,13 @@
* and it therefore uses a pre-allocated trash chunk as returned by
* get_trash_chunk().
*
+ * If the variable is not valid in this scope, 0 is always returned.
+ * If the variable is valid but not found, either the default value
+ * <def> is returned if not NULL, or zero is returned.
+ *
* Returns 1 if the sample is filled, otherwise it returns 0.
*/
-int vars_get_by_desc(const struct var_desc *var_desc, struct sample *smp)
+int vars_get_by_desc(const struct var_desc *var_desc, struct sample *smp, const struct buffer *def)
{
struct vars *vars;
@@ -643,7 +660,7 @@
if (!vars || vars->scope != var_desc->scope)
return 0;
- return var_to_smp(vars, var_desc->name, smp);
+ return var_to_smp(vars, var_desc->name, smp, def);
}
/* Always returns ACT_RET_CONT even if an error occurs. */
@@ -739,7 +756,7 @@
/* This two function checks the variable name and replace the
* configuration string name by the global string name. its
* the same string, but the global pointer can be easy to
- * compare.
+ * compare. They return non-zero on success, zero on failure.
*
* The first function checks a sample-fetch and the second
* checks a converter.
@@ -989,7 +1006,7 @@
if (!vars || vars->scope != SCOPE_PROC)
return 0;
- if (!vars_get_by_name(args[2], strlen(args[2]), &smp))
+ if (!vars_get_by_name(args[2], strlen(args[2]), &smp, NULL))
return cli_err(appctx, "Variable not found.\n");
/* the sample returned by vars_get_by_name() is allocated into a trash