[PATCH v3 12/12] Static: multiple paths in the "index" option

[Alejandro Colomar]

This adds support for multiple paths in the "index" option.
An example:

{
	"share": "/srv/www/stat/static/$uri",
	"index": [
		"$method.html",
		"alt.html"
	]
}

When <example.com/foo/bar/> is requested,
</srv/www/data/static/foo/bar/GET.html> will be served if it
exists; otherwise, </srv/www/data/static/foo/bar/alt.html> will be
served.

===

test_static.py:

Use an array instead of a string for "index".  Add a nonexisting
file name to the beginning of the array to make sure that the next
file is being served.

Signed-off-by: Alejandro Colomar <alx.manpages at gmail.com>
Cc: Nginx Unit <unit at nginx.org>
Cc: "Valentin V. Bartenev" <vbart at nginx.com>
Cc: Zhidao HONG <z.hong at f5.com>
Cc: Igor Sysoev <igor at sysoev.ru>
Cc: Oisin Canty <o.canty at f5.com>
---
 docs/changes.xml          |  6 ++++++
 src/nxt_conf_validation.c |  2 +-
 src/nxt_http_static.c     | 31 ++++++++++++++++++++++---------
 test/test_static.py       |  2 +-
 4 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/docs/changes.xml b/docs/changes.xml
index 8931165..7b0f6a7 100644
--- a/docs/changes.xml
+++ b/docs/changes.xml
@@ -18,6 +18,12 @@
          date="" time=""
          packager="Andrei Belov <defan at nginx.com>">
 
+<change type="feature">
+<para>
+multiple paths in the "index" option.
+</para>
+</change>
+
 <change type="feature">
 <para>
 variables support in the "index" option.
diff --git a/src/nxt_conf_validation.c b/src/nxt_conf_validation.c
index 6236720..ede5bf1 100644
--- a/src/nxt_conf_validation.c
+++ b/src/nxt_conf_validation.c
@@ -647,7 +647,7 @@ static nxt_conf_vldt_object_t  nxt_conf_vldt_share_action_members[] = {
         .validator  = nxt_conf_vldt_share,
     }, {
         .name       = nxt_string("index"),
-        .type       = NXT_CONF_VLDT_STRING,
+        .type       = NXT_CONF_VLDT_STRING | NXT_CONF_VLDT_ARRAY,
         .flags      = NXT_CONF_VLDT_VAR,
     }, {
         .name       = nxt_string("types"),
diff --git a/src/nxt_http_static.c b/src/nxt_http_static.c
index 16744f2..91bf26e 100644
--- a/src/nxt_http_static.c
+++ b/src/nxt_http_static.c
@@ -18,8 +18,9 @@ typedef struct {
 
 typedef struct {
     nxt_uint_t                  nshares;
+    nxt_uint_t                  nindices;
     nxt_http_static_share_t     *shares;
-    nxt_var_t                   *index;
+    nxt_var_t                   **indices;
 #if (NXT_HAVE_OPENAT2)
     nxt_var_t                   *chroot;
     nxt_uint_t                  resolve;
@@ -36,6 +37,7 @@ typedef struct {
     nxt_str_t                   chroot;
 #endif
     uint32_t                    share_idx;
+    uint32_t                    index_idx;
     uint8_t                     need_body;  /* 1 bit */
 } nxt_http_static_ctx_t;
 
@@ -123,14 +125,23 @@ nxt_http_static_init(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
         nxt_conf_set_string_dup(acf->index, mp, &default_index);
     }
 
-    nxt_conf_get_string(acf->index, &str);
-
-    var = nxt_var_compile(&str, mp, 1);
-    if (nxt_slow_path(var == NULL)) {
+    conf->nindices = nxt_conf_array_elements_count(acf->index);
+    conf->indices = nxt_mp_zget(mp, sizeof(*conf->indices) * conf->nindices);
+    if (nxt_slow_path(conf->indices == NULL)) {
         return NXT_ERROR;
     }
 
-    conf->index = var;
+    for (i = 0; i < conf->nindices; i++) {
+        cv = nxt_conf_get_array_element(acf->index, i);
+        nxt_conf_get_string(cv, &str);
+
+        var = nxt_var_compile(&str, mp, 1);
+        if (nxt_slow_path(var == NULL)) {
+            return NXT_ERROR;
+        }
+
+        conf->indices[i] = var;
+    }
 
 #if (NXT_HAVE_OPENAT2)
     if (acf->chroot.length > 0) {
@@ -235,6 +246,7 @@ nxt_http_static_iterate(nxt_task_t *task, nxt_http_request_t *r,
     nxt_http_static_ctx_t *ctx)
 {
     nxt_int_t                ret;
+    nxt_var_t                *index;
     nxt_http_static_conf_t   *conf;
     nxt_http_static_share_t  *share;
     nxt_bool_t               shr_is_const, idx_is_const;
@@ -242,6 +254,7 @@ nxt_http_static_iterate(nxt_task_t *task, nxt_http_request_t *r,
     conf = ctx->action->u.conf;
 
     share = &conf->shares[ctx->share_idx];
+    index = conf->indices[ctx->index_idx];
 
 #if (NXT_DEBUG)
     nxt_str_t  shr;
@@ -268,7 +281,7 @@ nxt_http_static_iterate(nxt_task_t *task, nxt_http_request_t *r,
 #endif /* NXT_DEBUG */
 
     shr_is_const = share->is_const;
-    idx_is_const = nxt_var_is_const(conf->index);
+    idx_is_const = nxt_var_is_const(index);
 
     if (!shr_is_const || !idx_is_const) {
         ret = nxt_var_query_init(&r->var_query, r, r->mem_pool);
@@ -279,10 +292,10 @@ nxt_http_static_iterate(nxt_task_t *task, nxt_http_request_t *r,
     }
 
     if (idx_is_const) {
-        nxt_var_raw(conf->index, &ctx->index);
+        nxt_var_raw(index, &ctx->index);
 
     } else {
-        nxt_var_query(task, r->var_query, conf->index, &ctx->index);
+        nxt_var_query(task, r->var_query, index, &ctx->index);
     }
 
     if (shr_is_const) {
diff --git a/test/test_static.py b/test/test_static.py
index 2190901..7fe40b6 100644
--- a/test/test_static.py
+++ b/test/test_static.py
@@ -34,7 +34,7 @@ class TestStatic(TestApplicationProto):
                     {
                         "action": {
                             "share": option.temp_dir + "/assets$uri",
-                            "index": "$host.html"
+                            "index": ["idontexist", "$host.html"]
                         }
                     }
                 ],
-- 
2.34.1