feature: shdict:incr(): added the optional "init" argument to allow intializing nonexistent keys with an initial value.

Signed-off-by: Yichun Zhang (agentzh) <agentzh@gmail.com>

Author: doujiang24

lib/resty/core/shdict.lua

@@ -26,7 +26,8 @@ ffi.cdef[[
         int get_stale, int *is_stale);
 
     int ngx_http_lua_ffi_shdict_incr(void *zone, const unsigned char *key,
-        size_t key_len, double *value, char **err);
+        size_t key_len, double *value, char **err, int has_init, double init,
+        int *forcible);
 
     int ngx_http_lua_ffi_shdict_store(void *zone, int op,
         const unsigned char *key, size_t key_len, int value_type,
@@ -313,7 +314,7 @@ local function shdict_get_stale(zone, key)
 end
 
 
-local function shdict_incr(zone, key, value)
+local function shdict_incr(zone, key, value, init)
     zone = check_zone(zone)
 
     if key == nil then
@@ -337,13 +338,36 @@ local function shdict_incr(zone, key, value)
     end
     num_value[0] = value
 
+    local has_init
+
+    if init then
+        if type(init) ~= "number" then
+            init = tonumber(init)
+
+            if not init then
+                return error("init should be a number")
+            end
+        end
+
+        has_init = 1
+
+    else
+        has_init = 0
+        init = 0
+    end
+
     local rc = C.ngx_http_lua_ffi_shdict_incr(zone, key, key_len, num_value,
-                                             errmsg)
+                                              errmsg, has_init, init,
+                                              forcible)
     if rc ~= 0 then  -- ~= NGX_OK
         return nil, ffi_str(errmsg[0])
     end
 
-    return tonumber(num_value[0])
+    if has_init == 0 then
+        return tonumber(num_value[0])
+    end
+
+    return tonumber(num_value[0]), nil, forcible[0] == 1
 end
 
 

t/shdict.t

@@ -349,7 +349,7 @@ qr/\[TRACE   \d+ content_by_lua\(nginx\.conf:\d+\):12 loop\]/
             local val
             local dogs = ngx.shared.dogs
             -- local cd = ffi.cast("void *", dogs)
-            local ok, err, foricible = dogs:set("foo", 56)
+            local ok, err, forcible = dogs:set("foo", 56)
             if not ok then
                 ngx.say("failed to set: ", err)
                 return
@@ -867,7 +867,7 @@ failed to get stale: nil key
             local val, flags
             local dogs = ngx.shared.dogs
             local value, err = dogs:incr(nil, 32)
-            if not ok then
+            if not value then
                 ngx.say("failed to incr: ", err)
             end
         ';
@@ -915,3 +915,87 @@ qr/\[TRACE   \d+ content_by_lua\(nginx\.conf:\d+\):7 loop\]/
  -- NYI:
 stitch
 
+
+
+=== TEST 28: incr, value is not number
+--- http_config eval: $::HttpConfig
+--- config
+    location = /t {
+        content_by_lua_block {
+            local val, flags
+            local dogs = ngx.shared.dogs
+            local value, err = dogs:incr("foo", "bar")
+            if not value then
+                ngx.say("failed to incr: ", err)
+            end
+        }
+    }
+--- request
+GET /t
+--- error_code: 500
+--- response_body_like: 500
+--- error_log
+cannot convert 'nil' to 'double'
+--- no_error_log
+[alert]
+[crit]
+
+
+
+=== TEST 29: incr with init
+--- http_config eval: $::HttpConfig
+--- config
+    location = /t {
+        content_by_lua_block {
+            local val, flags
+            local dogs = ngx.shared.dogs
+            dogs:flush_all()
+
+            local value, err = dogs:incr("foo", 10)
+            if not value then
+                ngx.say("failed to incr: ", err)
+            end
+
+            local value, err, forcible = dogs:incr("foo", 10, 10)
+            if not value then
+                ngx.say("failed to incr: ", err)
+                return
+            end
+
+            ngx.say("incr ok, value: ", value, ", forcible: ", forcible)
+        }
+    }
+--- request
+GET /t
+--- response_body
+failed to incr: not found
+incr ok, value: 20, forcible: false
+--- no_error_log
+[error]
+[alert]
+[crit]
+
+
+
+=== TEST 30: incr, init is not number
+--- http_config eval: $::HttpConfig
+--- config
+    location = /t {
+        content_by_lua_block {
+            local val, flags
+            local dogs = ngx.shared.dogs
+            local value, err = dogs:incr("foo", 10, "bar")
+            if not ok then
+                ngx.say("failed to incr: ", err)
+            end
+        }
+    }
+--- request
+GET /t
+--- error_code: 500
+--- response_body_like: 500
+--- error_log
+init should be a number
+--- no_error_log
+[alert]
+[crit]