MINOR: vars: Parse optional conditions passed to the set-var converter
This patch adds the parsing of the optional condition parameters that
can be passed to the set-var converter. Those conditions will not be
taken into account yet in the var_set function so conditions passed as
parameters will not have any effect. This is true for any condition
apart from the "ifexists" one that is also used to replace the
VF_UPDATEONLY flag that was used to prevent proc scope variable creation
from a LUA module.
diff --git a/src/vars.c b/src/vars.c
index 375b31b..6fb39cc 100644
--- a/src/vars.c
+++ b/src/vars.c
@@ -36,6 +36,26 @@
static unsigned int var_check_limit = 0;
static uint64_t var_name_hash_seed = 0;
+/* Structure and array matching set-var conditions to their respective flag
+ * value.
+ */
+struct var_set_condition {
+ const char *cond_str;
+ uint flag;
+};
+
+static struct var_set_condition conditions_array[] = {
+ { "ifexists", VF_COND_IFEXISTS },
+ { "ifnotexists", VF_COND_IFNOTEXISTS },
+ { "ifempty", VF_COND_IFEMPTY },
+ { "ifnotempty", VF_COND_IFNOTEMPTY },
+ { "ifset", VF_COND_IFSET },
+ { "ifnotset", VF_COND_IFNOTSET },
+ { "ifgt", VF_COND_IFGT },
+ { "iflt", VF_COND_IFLT },
+ { NULL, 0 }
+};
+
/* returns the struct vars pointer for a session, stream and scope, or NULL if
* it does not exist.
*/
@@ -329,10 +349,18 @@
* a bool (which is memory-less).
*
* Flags is a bitfield that may contain one of the following flags:
- * - VF_UPDATEONLY: the variable may only be updated but not created.
* - VF_CREATEONLY: do nothing if the variable already exists (success).
* - VF_PERMANENT: this flag will be passed to the variable upon creation
*
+ * - VF_COND_IFEXISTS: only set variable if it already exists
+ * - VF_COND_IFNOTEXISTS: only set variable if it did not exist yet
+ * - VF_COND_IFEMPTY: only set variable if sample is empty
+ * - VF_COND_IFNOTEMPTY: only set variable if sample is not empty
+ * - VF_COND_IFSET: only set variable if its type is not SMP_TYPE_ANY
+ * - VF_COND_IFNOTSET: only set variable if its type is ANY
+ * - VF_COND_IFGT: only set variable if its value is greater than the sample's
+ * - VF_COND_IFLT: ony set variable if its value is less than the sample's
+ *
* It returns 0 on failure, non-zero on success.
*/
static int var_set(uint64_t name_hash, enum vars_scope scope, struct sample *smp, uint flags)
@@ -357,7 +385,7 @@
goto unlock;
}
} else {
- if (flags & VF_UPDATEONLY)
+ if (flags & VF_COND_IFEXISTS)
goto unlock;
/* Check memory available. */
@@ -469,10 +497,44 @@
return 1;
}
+
+/*
+ * Convert a string set-var condition into its numerical value.
+ * The corresponding bit is set in the <cond_bitmap> parameter if the
+ * <cond> is known.
+ * Returns 1 in case of success.
+ */
+static int vars_parse_cond_param(const struct buffer *cond, uint *cond_bitmap, char **err)
+{
+ struct var_set_condition *cond_elt = &conditions_array[0];
+
+ /* The conditions array is NULL terminated. */
+ while (cond_elt->cond_str) {
+ if (chunk_strcmp(cond, cond_elt->cond_str) == 0) {
+ *cond_bitmap |= cond_elt->flag;
+ break;
+ }
+ ++cond_elt;
+ }
+
+ if (cond_elt->cond_str == NULL && err)
+ memprintf(err, "unknown condition \"%.*s\"", (int)cond->data, cond->area);
+
+ return cond_elt->cond_str != NULL;
+}
+
/* Returns 0 if fails, else returns 1. */
static int smp_conv_store(const struct arg *args, struct sample *smp, void *private)
{
- return var_set(args[0].data.var.name_hash, args[0].data.var.scope, smp, 0);
+ uint conditions = 0;
+ int cond_idx = 1;
+
+ while (args[cond_idx].type == ARGT_STR) {
+ if (vars_parse_cond_param(&args[cond_idx++].data.str, &conditions, NULL) == 0)
+ break;
+ }
+
+ return var_set(args[0].data.var.name_hash, args[0].data.var.scope, smp, conditions);
}
/* Returns 0 if fails, else returns 1. */
@@ -529,7 +591,7 @@
return 0;
/* Variable creation is allowed for all scopes apart from the PROC one. */
- return var_set(hash, scope, smp, (scope == SCOPE_PROC) ? VF_UPDATEONLY : 0);
+ return var_set(hash, scope, smp, (scope == SCOPE_PROC) ? VF_COND_IFEXISTS : 0);
}
@@ -765,7 +827,14 @@
static int conv_check_var(struct arg *args, struct sample_conv *conv,
const char *file, int line, char **err_msg)
{
- return vars_check_arg(&args[0], err_msg);
+ int cond_idx = 1;
+ uint conditions = 0;
+ int retval = vars_check_arg(&args[0], err_msg);
+
+ while (retval && args[cond_idx].type == ARGT_STR)
+ retval = vars_parse_cond_param(&args[cond_idx++].data.str, &conditions, err_msg);
+
+ return retval;
}
/* This function is a common parser for using variables. It understands
@@ -1219,7 +1288,7 @@
INITCALL1(STG_REGISTER, sample_register_fetches, &sample_fetch_keywords);
static struct sample_conv_kw_list sample_conv_kws = {ILH, {
- { "set-var", smp_conv_store, ARG1(1,STR), conv_check_var, SMP_T_ANY, SMP_T_ANY },
+ { "set-var", smp_conv_store, ARG5(1,STR,STR,STR,STR,STR), conv_check_var, SMP_T_ANY, SMP_T_ANY },
{ "unset-var", smp_conv_clear, ARG1(1,STR), conv_check_var, SMP_T_ANY, SMP_T_ANY },
{ /* END */ },
}};