feature: implemented the shdict:lindex method

Author: tokers

lib/resty/core/shdict.lua

@@ -30,6 +30,7 @@ local ngx_lua_ffi_shdict_set_expire
 local ngx_lua_ffi_shdict_capacity
 local ngx_lua_ffi_shdict_free_space
 local ngx_lua_ffi_shdict_udata_to_zone
+local ngx_lua_ffi_shdict_lindex
 
 
 if subsystem == 'http' then
@@ -60,6 +61,10 @@ int ngx_http_lua_ffi_shdict_set_expire(void *zone,
 size_t ngx_http_lua_ffi_shdict_capacity(void *zone);
 
 void *ngx_http_lua_ffi_shdict_udata_to_zone(void *zone_udata);
+
+int ngx_http_lua_ffi_shdict_lindex(void *zone, const unsigned char *key,
+    size_t key_len, int *value_type, unsigned char **str_value_buf,
+    size_t *str_value_len, double *num_value, int index, char **errmsg);
     ]]
 
     ngx_lua_ffi_shdict_get = C.ngx_http_lua_ffi_shdict_get
@@ -71,6 +76,7 @@ void *ngx_http_lua_ffi_shdict_udata_to_zone(void *zone_udata);
     ngx_lua_ffi_shdict_capacity = C.ngx_http_lua_ffi_shdict_capacity
     ngx_lua_ffi_shdict_udata_to_zone =
         C.ngx_http_lua_ffi_shdict_udata_to_zone
+    ngx_lua_ffi_shdict_lindex = C.ngx_http_lua_ffi_shdict_lindex
 
     if not pcall(function ()
         return C.ngx_http_lua_ffi_shdict_free_space
@@ -588,6 +594,77 @@ local function shdict_free_space(zone)
 end
 
 
+local function shdict_lindex(zone, key, index)
+    zone = check_zone(zone)
+
+    if key == nil then
+        return nil, "nil key"
+    end
+
+    if type(key) ~= "string" then
+        key = tostring(key)
+    end
+
+    local key_len = #key
+    if key_len == 0 then
+        return nil, "empty key"
+    end
+
+    if key_len > 65535 then
+        return nil, "key too long"
+    end
+
+    if type(index) ~= "number" then
+        return nil, "bad index"
+    end
+
+    local size = get_string_buf_size()
+    local buf = get_string_buf(size)
+    str_value_buf[0] = buf
+    local value_len = get_size_ptr()
+    value_len[0] = size
+
+    local rc = ngx_lua_ffi_shdict_lindex(zone, key, key_len, value_type,
+                                         str_value_buf, value_len,
+                                         num_value, index, errmsg)
+
+    if rc ~= 0 then
+        if errmsg[0] then
+            return nil, ffi_str(errmsg[0])
+        end
+
+        error("failed to index the key")
+    end
+
+    local typ = value_type[0]
+
+    if typ == 0 then -- LUA_TNIL
+        return nil
+    end
+
+    local val
+
+    if typ == 4 then -- LUA_TSTRING
+        if str_value_buf[0] ~= buf then
+            buf = str_value_buf[0]
+            val = ffi_str(buf, value_len[0])
+            C.free(buf)
+
+        else
+            val = ffi_str(buf, value_len[0])
+        end
+
+    elseif typ == 3 then -- LUA_TNUMBER
+        val = tonumber(num_value[0])
+
+    else
+        error("unknown value type: " .. typ)
+    end
+
+    return val
+end
+
+
 if ngx_shared then
     local _, dict = next(ngx_shared, nil)
     if dict then
@@ -609,6 +686,7 @@ if ngx_shared then
                 mt.expire = shdict_expire
                 mt.capacity = shdict_capacity
                 mt.free_space = shdict_free_space
+                mt.lindex = shdict_lindex
             end
         end
     end

t/shdict.t

@@ -1620,3 +1620,192 @@ ok
 [error]
 [alert]
 [crit]
+
+
+
+=== TEST 51: lindex index argument is not a number
+--- config
+    location = /t {
+            content_by_lua_block {
+                local dogs = ngx.shared.dogs
+                dogs:flush_all()
+                local ok, err = dogs:lindex("corgi", nil)
+                ngx.say("ok: ", ok, " err: ", err)
+            }
+    }
+--- request
+GET /t
+--- response_body
+ok: nil err: bad index
+--- no_error_log
+[error]
+[alert]
+[crit]
+
+
+
+=== TEST 52: lindex value is not a list
+--- config
+    location = /t {
+            content_by_lua_block {
+                local dogs = ngx.shared.dogs
+                dogs:flush_all()
+                local ok, err = dogs:set("corgi", "cute")
+                if not ok then
+                    ngx.say("dogs:set() error: ", err)
+                    return
+                end
+
+                local ok, err = dogs:lindex("corgi", -1)
+                ngx.say("ok: ", ok, " err: ", err)
+            }
+    }
+--- request
+GET /t
+--- response_body
+ok: nil err: value not a list
+--- no_error_log
+[error]
+[alert]
+[crit]
+
+
+
+=== TEST 53: lindex value is nil
+--- config
+    location = /t {
+            content_by_lua_block {
+                local dogs = ngx.shared.dogs
+                dogs:flush_all()
+                local ok, err = dogs:lindex("corgi", -1)
+                ngx.say("ok: ", ok, " err: ", err)
+            }
+    }
+--- request
+GET /t
+--- response_body
+ok: nil err: nil
+--- no_error_log
+[error]
+[alert]
+[crit]
+
+
+
+=== TEST 54: lindex negative index
+--- config
+    location = /t {
+            content_by_lua_block {
+                local dogs = ngx.shared.dogs
+                dogs:flush_all()
+                local value = { 2147, 483647, "meat", "bone" }
+                for i = 1, #value do
+                    local ok, err = dogs:lpush("corgi", value[i])
+                    if not ok then
+                        ngx.say("dogs:lpush() error: ", err)
+                        return
+                    end
+                end
+
+                -- bone meat 483647 2147
+
+                for i = -1, -(#value), -1 do
+                    local val, err = dogs:lindex("corgi", i)
+                    if err ~= nil then
+                        ngx.say("index: ", i, " error: ", err)
+                        return
+                    end
+
+                    ngx.say("index: ", i, " value: ", val)
+                end
+            }
+    }
+--- request
+GET /t
+--- response_body
+index: -1 value: 2147
+index: -2 value: 483647
+index: -3 value: meat
+index: -4 value: bone
+--- no_error_log
+[error]
+[alert]
+[crit]
+
+
+
+=== TEST 55: lindex non-negative index
+--- config
+    location = /t {
+            content_by_lua_block {
+                local dogs = ngx.shared.dogs
+                dogs:flush_all()
+                local value = { 2147, 483647, "meat", "bone" }
+                for i = 1, #value do
+                    local ok, err = dogs:lpush("corgi", value[i])
+                    if not ok then
+                        ngx.say("dogs:lpush() error: ", err)
+                        return
+                    end
+                end
+
+                -- bone meat 483647 2147
+
+                for i = 0, #value - 1 do
+                    local val, err = dogs:lindex("corgi", i)
+                    if err ~= nil then
+                        ngx.say("index: ", i, " error: ", err)
+                        return
+                    end
+
+                    ngx.say("index: ", i, " value: ", val)
+                end
+            }
+    }
+--- request
+GET /t
+--- response_body
+index: 0 value: bone
+index: 1 value: meat
+index: 2 value: 483647
+index: 3 value: 2147
+--- no_error_log
+[error]
+[alert]
+[crit]
+
+
+
+=== TEST 56: lindex index out of bound
+--- config
+    location = /t {
+            content_by_lua_block {
+                local dogs = ngx.shared.dogs
+                dogs:flush_all()
+                local value = { 2147, 483647, "meat", "bone" }
+                for i = 1, #value do
+                    local ok, err = dogs:lpush("corgi", value[i])
+                    if not ok then
+                        ngx.say("dogs:lpush() error: ", err)
+                        return
+                    end
+                end
+
+                -- bone meat 483647 2147
+
+                local val, err = dogs:lindex("corgi", -5)
+                ngx.say("val: ", val, " err: ", err)
+
+                local val, err = dogs:lindex("corgi", 4)
+                ngx.say("val: ", val, " err: ", err)
+            }
+    }
+--- request
+GET /t
+--- response_body
+val: nil err: nil
+val: nil err: nil
+--- no_error_log
+[error]
+[alert]
+[crit]