feat(shm/ffi) expose kv and metrics write operations to Lua

This commit also changes shm-related FFI functions from returning
NGX_DECLINED to returning NGX_ABORT, when the necessary conditions for
their completion are not satisfied.

src/common/lua/ngx_wasm_lua_ffi.c

@@ -260,27 +260,22 @@ ngx_http_wasm_ffi_set_host_properties_handlers(ngx_http_request_t *r,
 
 
 ngx_int_t
-ngx_wa_ffi_shm_get_zones(ngx_wa_ffi_shm_get_zones_handler_pt handler)
+ngx_wa_ffi_shm_setup_zones(ngx_wa_ffi_shm_setup_zones_handler_pt setup_handler)
 {
     ngx_uint_t             i;
-    ngx_cycle_t           *cycle = (ngx_cycle_t *) ngx_cycle;
-    ngx_array_t           *shms = ngx_wasmx_shms(cycle);
+    ngx_array_t           *shms = ngx_wasmx_shms((ngx_cycle_t *) ngx_cycle);
     ngx_wa_shm_t          *shm;
     ngx_wa_shm_mapping_t  *mappings;
 
-    if (!handler) {
-        return NGX_ERROR;
-    }
-
-    if (!shms) {
-        return NGX_DECLINED;
+    if (setup_handler == NULL || shms == NULL) {
+        return NGX_ABORT;
     }
 
     mappings = shms->elts;
 
     for (i = 0; i < shms->nelts; i++) {
         shm = mappings[i].zone->data;
-        handler(shm);
+        setup_handler(shm);
     }
 
     return NGX_OK;
@@ -289,78 +284,161 @@ ngx_wa_ffi_shm_get_zones(ngx_wa_ffi_shm_get_zones_handler_pt handler)
 
 static void
 shm_kv_retrieve_keys(ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel,
-                     ngx_int_t *total, ngx_int_t limit, ngx_str_t **keys)
+                     ngx_uint_t start,  ngx_uint_t limit, ngx_uint_t *total,
+                     ngx_str_t **keys)
 {
     ngx_wa_shm_kv_node_t *n = (ngx_wa_shm_kv_node_t *) node;
 
-    if (!node || node == sentinel || (limit > 0 && *total == limit)) {
+    if (limit > 0 && (*total - start) == limit) {
         return;
     }
 
-    if (keys) {
-        keys[*total] = &n->key.str;
+    if (keys && *total >= start) {
+        keys[(*total - start)] = &n->key.str;
     }
 
     (*total)++;
 
-    shm_kv_retrieve_keys(node->right, sentinel, total, limit, keys);
-    shm_kv_retrieve_keys(node->left, sentinel, total, limit, keys);
+    if (node->left != sentinel) {
+        shm_kv_retrieve_keys(node->left, sentinel, start, limit, total, keys);
+    }
+
+    if (node->right != sentinel) {
+        shm_kv_retrieve_keys(node->right, sentinel, start, limit, total, keys);
+    }
 }
 
 
 ngx_int_t
-ngx_wa_ffi_shm_get_keys(ngx_wa_shm_t *shm, ngx_uint_t n, ngx_str_t **keys)
+ngx_wa_ffi_shm_get_keys(ngx_wa_shm_t *shm, ngx_uint_t start, ngx_uint_t max,
+                        ngx_str_t **keys, ngx_uint_t *total)
 {
-    ngx_int_t         total = 0;
     ngx_wa_shm_kv_t  *kv;
 
-    if (!shm || shm->type == NGX_WASM_SHM_TYPE_QUEUE) {
-        return NGX_ERROR;
+    if (shm == NULL || shm->type == NGX_WASM_SHM_TYPE_QUEUE) {
+        return NGX_ABORT;
     }
 
     kv = shm->data;
 
+    if (kv->nelts <= start) {
+        return NGX_ABORT;
+    }
+
     ngx_shmtx_lock(&shm->shpool->mutex);
 
-    shm_kv_retrieve_keys(kv->rbtree.root, kv->rbtree.sentinel, &total, n, keys);
+    if (kv->rbtree.root != kv->rbtree.sentinel) {
+        shm_kv_retrieve_keys(kv->rbtree.root, kv->rbtree.sentinel, start, max,
+                             total, keys);
+    }
 
     ngx_shmtx_unlock(&shm->shpool->mutex);
 
-    return total;
+    *total = *total - start;
+
+    return NGX_OK;
 }
 
 
 ngx_int_t
 ngx_wa_ffi_shm_get_kv_value(ngx_wa_shm_t *shm, ngx_str_t *k, ngx_str_t **v,
                             uint32_t *cas)
 {
-    if (!shm || !k || !v || !cas) {
-        return NGX_ERROR;
+    if (shm == NULL || k == NULL || v == NULL || cas == NULL) {
+        return NGX_ABORT;
     }
 
     return ngx_wa_shm_kv_get_locked(shm, k, NULL, v, cas);
 }
 
 
 ngx_int_t
-ngx_wa_ffi_shm_get_metric(ngx_str_t *name,
-                          u_char *m_buf, size_t mbs,
-                          u_char *h_buf, size_t hbs)
+ngx_wa_ffi_shm_set_kv_value(ngx_wa_shm_t *shm, ngx_str_t *k, ngx_str_t *v,
+                            uint32_t cas, ngx_int_t *written)
+{
+    if (shm == NULL || k == NULL || v == NULL || written == NULL) {
+        return NGX_ABORT;
+    }
+
+    return ngx_wa_shm_kv_set_locked(shm, k, v, cas, written);
+}
+
+
+ngx_int_t
+ngx_wa_ffi_shm_define_metric(ngx_str_t *name, ngx_wa_metric_type_e type)
 {
     uint32_t           metric_id;
-    ngx_wa_metrics_t  *metrics;
+    ngx_int_t          rc;
+    ngx_str_t          prefixed_name;
+    ngx_wa_metrics_t  *metrics = ngx_wasmx_metrics((ngx_cycle_t *) ngx_cycle);
+
+    if (name == NULL || metrics == NULL) {
+        return NGX_ABORT;
+    }
+
+    u_char             buf[metrics->config.max_metric_name_length];
+
+    prefixed_name.data = buf;
+    prefixed_name.len = ngx_sprintf(buf, "lua.%V", name) - buf;
+
+    rc = ngx_wa_metrics_define(metrics, &prefixed_name, type, &metric_id);
+    if (rc != NGX_OK) {
+        return rc;
+    }
+
+    return metric_id;
+}
+
+
+ngx_int_t
+ngx_wa_ffi_shm_increment_metric(uint32_t metric_id, ngx_uint_t value)
+{
+    ngx_wa_metrics_t  *metrics = ngx_wasmx_metrics((ngx_cycle_t *) ngx_cycle);
+
+    if (metrics == NULL) {
+        return NGX_ABORT;
+    }
+
+    return ngx_wa_metrics_increment(metrics, metric_id, value);
+}
+
+
+ngx_int_t
+ngx_wa_ffi_shm_record_metric(uint32_t metric_id, ngx_uint_t value)
+{
+    ngx_wa_metrics_t  *metrics = ngx_wasmx_metrics((ngx_cycle_t *) ngx_cycle);
+
+    if (metrics == NULL) {
+        return NGX_ABORT;
+    }
+
+    return ngx_wa_metrics_record(metrics, metric_id, value);
+}
+
+
+ngx_int_t
+ngx_wa_ffi_shm_get_metric(uint32_t metric_id, ngx_str_t *name,
+                          u_char *m_buf, size_t mbs, u_char *h_buf, size_t hbs)
+{
+    ngx_wa_metrics_t  *metrics = ngx_wasmx_metrics((ngx_cycle_t *) ngx_cycle);
     ngx_wa_metric_t   *m;
 
-    if (!name || !m_buf || !h_buf) {
-        return NGX_ERROR;
+    if ((name == NULL && !metric_id)
+        || m_buf == NULL || mbs < NGX_WA_METRICS_ONE_SLOT_METRIC_SIZE
+        || h_buf == NULL || hbs < NGX_WA_METRICS_MAX_HISTOGRAM_SIZE
+        || metrics == NULL)
+    {
+        return NGX_ABORT;
     }
 
-    metrics = ngx_wasmx_metrics((ngx_cycle_t *) ngx_cycle);
-    metric_id = ngx_crc32_long(name->data, name->len);
     m = (ngx_wa_metric_t *) m_buf;
+    ngx_wa_metrics_histogram_set_buffer(m, h_buf, hbs);
 
-    ngx_wa_metrics_set_histogram_buffer(m, h_buf, hbs);
+    if (metric_id) {
+        return ngx_wa_metrics_get(metrics, metric_id, m);
+    }
 
-    return ngx_wa_metrics_get(metrics, metric_id, m);
+    return ngx_wa_metrics_get(metrics,
+                              ngx_crc32_long(name->data, name->len), m);
 }
 #endif

src/common/lua/ngx_wasm_lua_ffi.h

@@ -24,7 +24,7 @@ typedef struct {
 } ngx_wasm_ffi_filter_t;
 
 
-typedef void (*ngx_wa_ffi_shm_get_zones_handler_pt)(ngx_wa_shm_t *shm);
+typedef void (*ngx_wa_ffi_shm_setup_zones_handler_pt)(ngx_wa_shm_t *shm);
 
 
 ngx_int_t ngx_http_wasm_ffi_plan_new(ngx_wavm_t *vm,
@@ -46,13 +46,22 @@ ngx_int_t ngx_http_wasm_ffi_set_host_properties_handlers(ngx_http_request_t *r,
 #endif
 
 
-ngx_int_t ngx_wa_ffi_shm_get_zones(ngx_wa_ffi_shm_get_zones_handler_pt handler);
-ngx_int_t ngx_wa_ffi_shm_get_keys(ngx_wa_shm_t *shm, ngx_uint_t n,
-    ngx_str_t **keys);
+ngx_int_t ngx_wa_ffi_shm_setup_zones(
+    ngx_wa_ffi_shm_setup_zones_handler_pt handler);
+ngx_int_t ngx_wa_ffi_shm_get_keys(ngx_wa_shm_t *shm, ngx_uint_t start,
+    ngx_uint_t n, ngx_str_t **keys, ngx_uint_t *total);
 ngx_int_t ngx_wa_ffi_shm_get_kv_value(ngx_wa_shm_t *shm, ngx_str_t *k,
     ngx_str_t **v, uint32_t *cas);
-ngx_int_t ngx_wa_ffi_shm_get_metric(ngx_str_t *k, u_char *m_buf, size_t mbs,
-                                    u_char *h_buf, size_t hbs);
+ngx_int_t ngx_wa_ffi_shm_set_kv_value(ngx_wa_shm_t *shm, ngx_str_t *k,
+    ngx_str_t *v, uint32_t cas, ngx_int_t *written);
+
+
+ngx_int_t ngx_wa_ffi_shm_define_metric(ngx_str_t *name,
+    ngx_wa_metric_type_e type);
+ngx_int_t ngx_wa_ffi_shm_increment_metric(uint32_t metric_id, ngx_uint_t value);
+ngx_int_t ngx_wa_ffi_shm_record_metric(uint32_t metric_id, ngx_uint_t value);
+ngx_int_t ngx_wa_ffi_shm_get_metric(uint32_t metric_id, ngx_str_t *name,
+    u_char *m_buf, size_t mbs, u_char *h_buf, size_t hbs);
 
 
 ngx_int_t

src/common/metrics/ngx_wa_metrics.h

@@ -99,7 +99,7 @@ void ngx_wa_metrics_histogram_get(ngx_wa_metrics_t *metrics, ngx_wa_metric_t *m,
 
 
 static ngx_inline ngx_wa_metrics_histogram_t *
-ngx_wa_metrics_set_histogram_buffer(ngx_wa_metric_t *m, u_char *b, size_t s)
+ngx_wa_metrics_histogram_set_buffer(ngx_wa_metric_t *m, u_char *b, size_t s)
 {
     m->slots[0].histogram = (ngx_wa_metrics_histogram_t *) b;
     m->slots[0].histogram->n_bins = (s - sizeof(ngx_wa_metrics_histogram_t))
@@ -109,4 +109,5 @@ ngx_wa_metrics_set_histogram_buffer(ngx_wa_metric_t *m, u_char *b, size_t s)
     return m->slots[0].histogram;
 }
 
+
 #endif /* _NGX_WA_METRICS_H_INCLUDED_ */

src/common/proxy_wasm/ngx_proxy_wasm_host.c

@@ -1679,7 +1679,7 @@ ngx_proxy_wasm_hfuncs_get_metric(ngx_wavm_instance_t *instance,
     ret_value = NGX_WAVM_HOST_LIFT(instance, args[1].of.i32, ngx_uint_t);
 
     m = (ngx_wa_metric_t *) m_buf;
-    ngx_wa_metrics_set_histogram_buffer(m, h_buf, sizeof(h_buf));
+    ngx_wa_metrics_histogram_set_buffer(m, h_buf, sizeof(h_buf));
 
     rc = ngx_wa_metrics_get(metrics, metric_id, m);
     if (rc == NGX_OK && m->type != NGX_WA_METRIC_HISTOGRAM) {

t/04-openresty/ffi/shm/001-get_zones.t → t/04-openresty/ffi/shm/001-setup_zones.t

@@ -12,25 +12,28 @@ run_tests();
 
 __DATA__
 
-=== TEST 1: shm - get_zones()
-get_zones() is silently called when resty.wasmx.shm module is loaded.
+=== TEST 1: shm - setup_zones()
+setup_zones() is silently called when resty.wasmx.shm module is loaded.
 
 --- valgrind
 --- load_nginx_modules: ngx_http_echo_module
---- wasm_modules: hostcalls
---- shm_kv: kv1 1m
---- shm_queue: q1 1m
+--- main_config
+    wasm {
+        shm_kv kv1 1m;
+        shm_queue q1 1m;
+    }
+
 --- config
     location /t {
         access_by_lua_block {
             local shm = require "resty.wasmx.shm"
 
-            assert(shm.kv1 ~= nil)
-            assert(shm.q1 ~= nil)
-            assert(shm.metrics ~= nil)
-        }
+            assert(shm.kv1)
+            assert(shm.q1)
+            assert(shm.metrics)
 
-        echo ok;
+            ngx.say("ok")
+        }
     }
 --- response_body
 ok
@@ -43,32 +46,30 @@ ok
 
 
 
-=== TEST 2: shm - get_zones(), no zones
+=== TEST 2: shm - setup_zones(), no zones
 --- valgrind
---- load_nginx_modules: ngx_http_echo_module
 --- config
     location /t {
         access_by_lua_block {
             local shm = require "resty.wasmx.shm"
 
             assert(shm.metrics == nil)
-        }
 
-        echo ok;
+            ngx.say("ok")
+        }
     }
 --- response_body
 ok
---- error_log eval
-qr/\[info\] .*? no shm zones found/,
 --- no_error_log
 [error]
 [crit]
 [emerg]
 [alert]
+[stub]
 
 
 
-=== TEST 3: shm - get_zones(), bad pointer
+=== TEST 3: shm - setup_zones(), bad pointer
 A call with a bad pointer is simply ignored.
 
 --- valgrind
@@ -82,12 +83,12 @@ A call with a bad pointer is simply ignored.
             ffi.cdef [[
                 typedef struct ngx_wa_shm_t  ngx_wa_shm_t;
 
-                typedef void (*ngx_wa_ffi_shm_get_zones_handler_pt)(ngx_wa_shm_t *shm);
+                typedef void (*ngx_wa_ffi_shm_setup_zones_handler_pt)(ngx_wa_shm_t *shm);
 
-                int ngx_wa_ffi_shm_get_zones(ngx_wa_ffi_shm_get_zones_handler_pt handler);
+                int ngx_wa_ffi_shm_setup_zones(ngx_wa_ffi_shm_setup_zones_handler_pt handler);
             ]]
 
-            C.ngx_wa_ffi_shm_get_zones(nil)
+            C.ngx_wa_ffi_shm_setup_zones(nil)
         }
 
         echo ok;