As discussed in GitHub issue #624 Lua scripts should not use
variables that are never going to be read, because the memory
for variable names is never going to be freed.
Add an optional `ifexist` parameter to the `set_var` function
that allows a Lua developer to set variables that are going to
be ignored if the variable name was not used elsewhere before.
Usually this mean that there is no `var()` sample fetch for the
variable in question within the configuration.
---
doc/lua-api/index.rst | 18 +++++++++++++++---
reg-tests/lua/set_var.lua | 13 +++++++++++++
reg-tests/lua/set_var.vtc | 24 +++++++++++++++++++++++-
src/hlua.c | 30 ++++++++++++++++++++++++------
4 files changed, 75 insertions(+), 10 deletions(-)
diff --git a/doc/lua-api/index.rst b/doc/lua-api/index.rst
index f3e5cb786..3d8282cdb 100644
--- a/doc/lua-api/index.rst
+++ b/doc/lua-api/index.rst
@@ -1710,7 +1710,7 @@ TXN class
:param class_txn txn: The class txn object containing the data.
:param opaque data: The data which is stored in the transaction.
-.. js:function:: TXN.set_var(TXN, var, value)
+.. js:function:: TXN.set_var(TXN, var, value[, ifexist])
Converts a Lua type in a HAProxy type and store it in a variable <var>.
@@ -1718,6 +1718,10 @@ TXN class
:param string var: The variable name according with the HAProxy variable
syntax.
:param type value: The value associated to the variable. The type can be
string or
integer.
+ :param boolean ifexist: If this parameter is set to a truthy value the
variable
+ will only be set if it was defined elsewhere (i.e.
used
+ within the configuration). It is highly recommended
to
+ always set this to true.
.. js:function:: TXN.unset_var(TXN, var)
@@ -2513,7 +2517,7 @@ AppletHTTP class
:param opaque data: The data which is stored in the transaction.
:see: :js:func:`AppletHTTP.get_priv`
-.. js:function:: AppletHTTP.set_var(applet, var, value)
+.. js:function:: AppletHTTP.set_var(applet, var, value[, ifexist])
Converts a Lua type in a HAProxy type and store it in a variable <var>.
@@ -2521,6 +2525,10 @@ AppletHTTP class
:param string var: The variable name according with the HAProxy variable
syntax.
:param type value: The value associated to the variable. The type ca be
string or
integer.
+ :param boolean ifexist: If this parameter is set to a truthy value the
variable
+ will only be set if it was defined elsewhere (i.e.
used
+ within the configuration). It is highly recommended
to
+ always set this to true.
:see: :js:func:`AppletHTTP.unset_var`
:see: :js:func:`AppletHTTP.get_var`
@@ -2624,7 +2632,7 @@ AppletTCP class
:param opaque data: The data which is stored in the transaction.
:see: :js:func:`AppletTCP.get_priv`
-.. js:function:: AppletTCP.set_var(applet, var, value)
+.. js:function:: AppletTCP.set_var(applet, var, value[, ifexist])
Converts a Lua type in a HAProxy type and stores it in a variable <var>.
@@ -2632,6 +2640,10 @@ AppletTCP class
:param string var: The variable name according with the HAProxy variable
syntax.
:param type value: The value associated to the variable. The type can be
string or
integer.
+ :param boolean ifexist: If this parameter is set to a truthy value the
variable
+ will only be set if it was defined elsewhere (i.e.
used
+ within the configuration). It is highly recommended
to
+ always set this to true.
:see: :js:func:`AppletTCP.unset_var`
:see: :js:func:`AppletTCP.get_var`
diff --git a/reg-tests/lua/set_var.lua b/reg-tests/lua/set_var.lua
index 78d1fd495..f4d5e7af4 100644
--- a/reg-tests/lua/set_var.lua
+++ b/reg-tests/lua/set_var.lua
@@ -10,3 +10,16 @@ core.register_service("set_var", "http", function(applet)
applet:start_response()
applet:send("")
end)
+
+core.register_service("set_var_ifexist", "http", function(applet)
+ local var_name = applet.headers["var"][0]
+ local result = applet:set_var(var_name, "value", true)
+ if result then
+ applet:set_status(202)
+ else
+ applet:set_status(400)
+ end
+ applet:add_header("echo", applet:get_var(var_name) or "(nil)")
+ applet:start_response()
+ applet:send("")
+end)
diff --git a/reg-tests/lua/set_var.vtc b/reg-tests/lua/set_var.vtc
index 2f1ba4ee9..5d37fcb88 100644
--- a/reg-tests/lua/set_var.vtc
+++ b/reg-tests/lua/set_var.vtc
@@ -13,11 +13,20 @@ haproxy h1 -conf {
bind "fd@${fe1}"
http-request use-service lua.set_var
+
+ frontend fe2
+ mode http
+ ${no-htx} option http-use-htx
+ bind "fd@${fe2}"
+
+ http-request set-header Dummy %[var(txn.fe2_foo)]
+
+ http-request use-service lua.set_var_ifexist
} -start
client c0 -connect ${h1_fe1_sock} {
txreq -url "/" \
- -hdr "Var: txn.foo"
+ -hdr "Var: txn.fe1_foo"
rxresp
expect resp.status == 202
expect resp.http.echo == "value"
@@ -27,3 +36,16 @@ client c0 -connect ${h1_fe1_sock} {
expect resp.status == 400
expect resp.http.echo == "(nil)"
} -run
+
+client c1 -connect ${h1_fe2_sock} {
+ txreq -url "/" \
+ -hdr "Var: txn.fe2_foo"
+ rxresp
+ expect resp.status == 202
+ expect resp.http.echo == "value"
+ txreq -url "/" \
+ -hdr "Var: txn.fe2_bar"
+ rxresp
+ expect resp.status == 400
+ expect resp.http.echo == "(nil)"
+} -run
diff --git a/src/hlua.c b/src/hlua.c
index 0ce57c7ed..f0d7e0f9e 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -3475,7 +3475,8 @@ __LJMP static int hlua_applet_tcp_set_var(lua_State *L)
size_t len;
struct sample smp;
- MAY_LJMP(check_args(L, 3, "set_var"));
+ if (lua_gettop(L) < 3 || lua_gettop(L) > 4)
+ WILL_LJMP(luaL_error(L, "'set_var' needs between 3 and 4
arguments"));
/* It is useles to retrieve the stream, but this function
* runs only in a stream context.
@@ -3489,7 +3490,12 @@ __LJMP static int hlua_applet_tcp_set_var(lua_State *L)
/* Store the sample in a variable. */
smp_set_owner(&smp, s->be, s->sess, s, 0);
- lua_pushboolean(L, vars_set_by_name(name, len, &smp) != 0);
+
+ if (lua_gettop(L) == 4 && lua_toboolean(L, 4))
+ lua_pushboolean(L, vars_set_by_name_ifexist(name, len, &smp) !=
0);
+ else
+ lua_pushboolean(L, vars_set_by_name(name, len, &smp) != 0);
+
return 1;
}
@@ -3953,7 +3959,8 @@ __LJMP static int hlua_applet_http_set_var(lua_State *L)
size_t len;
struct sample smp;
- MAY_LJMP(check_args(L, 3, "set_var"));
+ if (lua_gettop(L) < 3 || lua_gettop(L) > 4)
+ WILL_LJMP(luaL_error(L, "'set_var' needs between 3 and 4
arguments"));
/* It is useles to retrieve the stream, but this function
* runs only in a stream context.
@@ -3967,7 +3974,12 @@ __LJMP static int hlua_applet_http_set_var(lua_State *L)
/* Store the sample in a variable. */
smp_set_owner(&smp, s->be, s->sess, s, 0);
- lua_pushboolean(L, vars_set_by_name(name, len, &smp) != 0);
+
+ if (lua_gettop(L) == 4 && lua_toboolean(L, 4))
+ lua_pushboolean(L, vars_set_by_name_ifexist(name, len, &smp) !=
0);
+ else
+ lua_pushboolean(L, vars_set_by_name(name, len, &smp) != 0);
+
return 1;
}
@@ -5040,7 +5052,8 @@ __LJMP static int hlua_set_var(lua_State *L)
size_t len;
struct sample smp;
- MAY_LJMP(check_args(L, 3, "set_var"));
+ if (lua_gettop(L) < 3 || lua_gettop(L) > 4)
+ WILL_LJMP(luaL_error(L, "'set_var' needs between 3 and 4
arguments"));
/* It is useles to retrieve the stream, but this function
* runs only in a stream context.
@@ -5053,7 +5066,12 @@ __LJMP static int hlua_set_var(lua_State *L)
/* Store the sample in a variable. */
smp_set_owner(&smp, htxn->p, htxn->s->sess, htxn->s, htxn->dir &
SMP_OPT_DIR);
- lua_pushboolean(L, vars_set_by_name(name, len, &smp) != 0);
+
+ if (lua_gettop(L) == 4 && lua_toboolean(L, 4))
+ lua_pushboolean(L, vars_set_by_name_ifexist(name, len, &smp) !=
0);
+ else
+ lua_pushboolean(L, vars_set_by_name(name, len, &smp) != 0);
+
return 1;
}
--
2.26.2
