MINOR: lua: fetches and converters can return an empty string in place of nil

In some cases we don't want to known if a fetch or converter
fails. We just want a valid string. After this patch, we
have two sets of fetches and two sets of converters. There are:
txn.f, txn.sf, txn.c, txn.sc. The version prefixed by 's' always
returns strings for any type, and returns an empty string in the
error case or when the data are not available. This is particularly
useful when manipulating headers or cookies.

diff --git a/include/types/hlua.h b/include/types/hlua.h
index eea91361807b4d6812af93ff0105ba4c35ff792a..88a8b8d2e9b4afe332e20faa30c716e5237c39a4 100644 (file)
--- a/include/types/hlua.h
+++ b/include/types/hlua.h
@@ -95,6 +95,14 @@ struct hlua_txn {
        void *l7;
 };
 
+/* This struc is used with sample fetches and sample converters. */
+struct hlua_smp {
+       struct session *s;
+       struct proxy *p;
+       void *l7;
+       int stringsafe;
+};
+
 /* This struct is used as a closure argument associated
  * with dynamic sample-fetch created fucntions. This contains
  * a pointer to the original sample_fetch struct. It is used

diff --git a/src/hlua.c b/src/hlua.c
index 25e1a2b019308e329de08b4497a59e9421116cda..9a6bd33b0338614dbc9baff9474bf84af983ab11 100644 (file)
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -118,6 +118,7 @@ static int hlua_arg2lua(lua_State *L, const struct arg *arg);
 static int hlua_lua2arg(lua_State *L, int ud, struct arg *arg);
 __LJMP static int hlua_lua2arg_check(lua_State *L, int first, struct arg *argp, unsigned int mask);
 static int hlua_smp2lua(lua_State *L, struct sample *smp);
+static int hlua_smp2lua_str(lua_State *L, struct sample *smp);
 static int hlua_lua2smp(lua_State *L, int ud, struct sample *smp);
 
 /* Used to check an Lua function type in the stack. It creates and
@@ -414,6 +415,57 @@ static int hlua_smp2lua(lua_State *L, struct sample *smp)
        return 1;
 }
 
+/* the following functions are used to convert a struct sample
+ * in Lua strings. This is useful to convert the return of the
+ * fetchs or converters.
+ */
+static int hlua_smp2lua_str(lua_State *L, struct sample *smp)
+{
+       switch (smp->type) {
+
+       case SMP_T_BIN:
+       case SMP_T_STR:
+               lua_pushlstring(L, smp->data.str.str, smp->data.str.len);
+               break;
+
+       case SMP_T_METH:
+               switch (smp->data.meth.meth) {
+               case HTTP_METH_OPTIONS: lua_pushstring(L, "OPTIONS"); break;
+               case HTTP_METH_GET:     lua_pushstring(L, "GET");     break;
+               case HTTP_METH_HEAD:    lua_pushstring(L, "HEAD");    break;
+               case HTTP_METH_POST:    lua_pushstring(L, "POST");    break;
+               case HTTP_METH_PUT:     lua_pushstring(L, "PUT");     break;
+               case HTTP_METH_DELETE:  lua_pushstring(L, "DELETE");  break;
+               case HTTP_METH_TRACE:   lua_pushstring(L, "TRACE");   break;
+               case HTTP_METH_CONNECT: lua_pushstring(L, "CONNECT"); break;
+               case HTTP_METH_OTHER:
+                       lua_pushlstring(L, smp->data.meth.str.str, smp->data.meth.str.len);
+                       break;
+               default:
+                       lua_pushstring(L, "");
+                       break;
+               }
+               break;
+
+       case SMP_T_SINT:
+       case SMP_T_BOOL:
+       case SMP_T_UINT:
+       case SMP_T_IPV4:
+       case SMP_T_IPV6:
+       case SMP_T_ADDR: /* This type is never used to qualify a sample. */
+               if (sample_casts[smp->type][SMP_T_STR] &&
+                   sample_casts[smp->type][SMP_T_STR](smp))
+                       lua_pushlstring(L, smp->data.str.str, smp->data.str.len);
+               else
+                       lua_pushstring(L, "");
+               break;
+       default:
+               lua_pushstring(L, "");
+               break;
+       }
+       return 1;
+}
+
 /* the following functions are used to convert an Lua type in a
  * struct sample. This is useful to provide data from a converter
  * to the LUA code.
@@ -2477,17 +2529,17 @@ __LJMP static int hlua_channel_get_out_len(lua_State *L)
 /* Returns a struct hlua_session if the stack entry "ud" is
  * a class session, otherwise it throws an error.
  */
-__LJMP static struct hlua_txn *hlua_checkfetches(lua_State *L, int ud)
+__LJMP static struct hlua_smp *hlua_checkfetches(lua_State *L, int ud)
 {
-       return (struct hlua_txn *)MAY_LJMP(hlua_checkudata(L, ud, class_fetches_ref));
+       return (struct hlua_smp *)MAY_LJMP(hlua_checkudata(L, ud, class_fetches_ref));
 }
 
 /* This function creates and push in the stack a fetch object according
  * with a current TXN.
  */
-static int hlua_fetches_new(lua_State *L, struct hlua_txn *txn)
+static int hlua_fetches_new(lua_State *L, struct hlua_txn *txn, int stringsafe)
 {
-       struct hlua_txn *hs;
+       struct hlua_smp *hs;
 
        /* Check stack size. */
        if (!lua_checkstack(L, 3))
@@ -2498,12 +2550,13 @@ static int hlua_fetches_new(lua_State *L, struct hlua_txn *txn)
         * transaction object.
         */
        lua_newtable(L);
-       hs = lua_newuserdata(L, sizeof(struct hlua_txn));
+       hs = lua_newuserdata(L, sizeof(struct hlua_smp));
        lua_rawseti(L, -2, 0);
 
        hs->s = txn->s;
        hs->p = txn->p;
        hs->l7 = txn->l7;
+       hs->stringsafe = stringsafe;
 
        /* Pop a class sesison metatable and affect it to the userdata. */
        lua_rawgeti(L, LUA_REGISTRYINDEX, class_fetches_ref);
@@ -2520,7 +2573,7 @@ static int hlua_fetches_new(lua_State *L, struct hlua_txn *txn)
  */
 __LJMP static int hlua_run_sample_fetch(lua_State *L)
 {
-       struct hlua_txn *s;
+       struct hlua_smp *s;
        struct hlua_sample_fetch *f;
        struct arg args[ARGM_NBARGS + 1];
        int i;
@@ -2554,12 +2607,18 @@ __LJMP static int hlua_run_sample_fetch(lua_State *L)
 
        /* Run the sample fetch process. */
        if (!f->f->process(s->p, s->s, s->l7, 0, args, &smp, f->f->kw, f->f->private)) {
-               lua_pushnil(L);
+               if (s->stringsafe)
+                       lua_pushstring(L, "");
+               else
+                       lua_pushnil(L);
                return 1;
        }
 
        /* Convert the returned sample in lua value. */
-       hlua_smp2lua(L, &smp);
+       if (s->stringsafe)
+               hlua_smp2lua_str(L, &smp);
+       else
+               hlua_smp2lua(L, &smp);
        return 1;
 }
 
@@ -2574,17 +2633,17 @@ __LJMP static int hlua_run_sample_fetch(lua_State *L)
 /* Returns a struct hlua_session if the stack entry "ud" is
  * a class session, otherwise it throws an error.
  */
-__LJMP static struct hlua_txn *hlua_checkconverters(lua_State *L, int ud)
+__LJMP static struct hlua_smp *hlua_checkconverters(lua_State *L, int ud)
 {
-       return (struct hlua_txn *)MAY_LJMP(hlua_checkudata(L, ud, class_converters_ref));
+       return (struct hlua_smp *)MAY_LJMP(hlua_checkudata(L, ud, class_converters_ref));
 }
 
 /* This function creates and push in the stack a Converters object
  * according with a current TXN.
  */
-static int hlua_converters_new(lua_State *L, struct hlua_txn *txn)
+static int hlua_converters_new(lua_State *L, struct hlua_txn *txn, int stringsafe)
 {
-       struct hlua_txn *hs;
+       struct hlua_smp *hs;
 
        /* Check stack size. */
        if (!lua_checkstack(L, 3))
@@ -2601,6 +2660,7 @@ static int hlua_converters_new(lua_State *L, struct hlua_txn *txn)
        hs->s = txn->s;
        hs->p = txn->p;
        hs->l7 = txn->l7;
+       hs->stringsafe = stringsafe;
 
        /* Pop a class session metatable and affect it to the table. */
        lua_rawgeti(L, LUA_REGISTRYINDEX, class_converters_ref);
@@ -2617,7 +2677,7 @@ static int hlua_converters_new(lua_State *L, struct hlua_txn *txn)
  */
 __LJMP static int hlua_run_sample_conv(lua_State *L)
 {
-       struct hlua_txn *txn;
+       struct hlua_smp *sc;
        struct sample_conv *conv;
        struct arg args[ARGM_NBARGS + 1];
        int i;
@@ -2627,7 +2687,7 @@ __LJMP static int hlua_run_sample_conv(lua_State *L)
        conv = (struct sample_conv *)lua_touserdata(L, lua_upvalueindex(1));
 
        /* Get traditionnal arguments. */
-       txn = MAY_LJMP(hlua_checkconverters(L, 1));
+       sc = MAY_LJMP(hlua_checkconverters(L, 1));
 
        /* Get extra arguments. */
        for (i = 0; i < lua_gettop(L) - 2; i++) {
@@ -2665,14 +2725,20 @@ __LJMP static int hlua_run_sample_conv(lua_State *L)
        }
 
        /* Run the sample conversion process. */
-       if (!conv->process(txn->s, args, &smp, conv->private)) {
-               lua_pushnil(L);
+       if (!conv->process(sc->s, args, &smp, conv->private)) {
+               if (sc->stringsafe)
+                       lua_pushstring(L, "");
+               else
+                       lua_pushnil(L);
                return 1;
        }
 
        /* Convert the returned sample in lua value. */
-       hlua_smp2lua(L, &smp);
-       return 1;
+       if (sc->stringsafe)
+               hlua_smp2lua_str(L, &smp);
+       else
+               hlua_smp2lua(L, &smp);
+        return 1;
 }
 
 /*
@@ -2759,13 +2825,25 @@ static int hlua_txn_new(lua_State *L, struct session *s, struct proxy *p, void *
 
        /* Create the "f" field that contains a list of fetches. */
        lua_pushstring(L, "f");
-       if (!hlua_fetches_new(L, hs))
+       if (!hlua_fetches_new(L, hs, 0))
+               return 0;
+       lua_settable(L, -3);
+
+       /* Create the "sf" field that contains a list of stringsafe fetches. */
+       lua_pushstring(L, "sf");
+       if (!hlua_fetches_new(L, hs, 1))
                return 0;
        lua_settable(L, -3);
 
        /* Create the "c" field that contains a list of converters. */
        lua_pushstring(L, "c");
-       if (!hlua_converters_new(L, hs))
+       if (!hlua_converters_new(L, hs, 0))
+               return 0;
+       lua_settable(L, -3);
+
+       /* Create the "sc" field that contains a list of stringsafe converters. */
+       lua_pushstring(L, "sc");
+       if (!hlua_converters_new(L, hs, 1))
                return 0;
        lua_settable(L, -3);