OpenResty之ngx.shared.DICT

参考链接： resty.core.shdict

ngx_shared.DICT 源码正文： dict.lua

部分源码如下:

local ffi = require 'ffi'
local base = require "resty.core.base"

local ffi_new = ffi.new
local ffi_str = ffi.string
local C = ffi.C
local get_string_buf = base.get_string_buf
local get_string_buf_size = base.get_string_buf_size
local get_size_ptr = base.get_size_ptr
local tonumber = tonumber
local tostring = tostring
local next = next
local type = type
local ngx_shared = ngx.shared
local getmetatable = getmetatable
local FFI_ERROR = base.FFI_ERROR
local FFI_DECLINED = base.FFI_DECLINED
local subsystem = ngx.config.subsystem

local ngx_lua_ffi_shdict_get
local ngx_lua_ffi_shdict_incr
local ngx_lua_ffi_shdict_store
local ngx_lua_ffi_shdict_flush_all
local ngx_lua_ffi_shdict_get_ttl
local ngx_lua_ffi_shdict_set_expire
local ngx_lua_ffi_shdict_capacity
local ngx_lua_ffi_shdict_free_space

if subsystem == 'http' then
    ffi.cdef[[
int ngx_http_lua_ffi_shdict_get(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 *user_flags,
    int get_stale, int *is_stale, char **errmsg);

int ngx_http_lua_ffi_shdict_incr(void *zone, const unsigned char *key,
    size_t key_len, double *value, char **err, int has_init,
    double init, long init_ttl, int *forcible);

int ngx_http_lua_ffi_shdict_store(void *zone, int op,
    const unsigned char *key, size_t key_len, int value_type,
    const unsigned char *str_value_buf, size_t str_value_len,
    double num_value, long exptime, int user_flags, char **errmsg,
    int *forcible);

int ngx_http_lua_ffi_shdict_flush_all(void *zone);

int ngx_http_lua_ffi_shdict_get_ttl(void *zone,
    const unsigned char *key, size_t key_len);

int ngx_http_lua_ffi_shdict_set_expire(void *zone,
    const unsigned char *key, size_t key_len, long exptime);

size_t ngx_http_lua_ffi_shdict_capacity(void *zone);
    ]]

    ngx_lua_ffi_shdict_get = C.ngx_http_lua_ffi_shdict_get
    ngx_lua_ffi_shdict_incr = C.ngx_http_lua_ffi_shdict_incr
    ngx_lua_ffi_shdict_store = C.ngx_http_lua_ffi_shdict_store
    ngx_lua_ffi_shdict_flush_all = C.ngx_http_lua_ffi_shdict_flush_all
    ngx_lua_ffi_shdict_get_ttl = C.ngx_http_lua_ffi_shdict_get_ttl
    ngx_lua_ffi_shdict_set_expire = C.ngx_http_lua_ffi_shdict_set_expire
    ngx_lua_ffi_shdict_capacity = C.ngx_http_lua_ffi_shdict_capacity

    if not pcall(function ()
        return C.ngx_http_lua_ffi_shdict_free_space
    end)
    then
        ffi.cdef[[
size_t ngx_http_lua_ffi_shdict_free_space(void *zone);
        ]]
    end

    ngx_lua_ffi_shdict_free_space = C.ngx_http_lua_ffi_shdict_free_space

elseif subsystem == 'stream' then

    ffi.cdef[[
int ngx_stream_lua_ffi_shdict_get(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 *user_flags,
    int get_stale, int *is_stale, char **errmsg);

int ngx_stream_lua_ffi_shdict_incr(void *zone, const unsigned char *key,
    size_t key_len, double *value, char **err, int has_init,
    double init, long init_ttl, int *forcible);

int ngx_stream_lua_ffi_shdict_store(void *zone, int op,
    const unsigned char *key, size_t key_len, int value_type,
    const unsigned char *str_value_buf, size_t str_value_len,
    double num_value, long exptime, int user_flags, char **errmsg,
    int *forcible);

int ngx_stream_lua_ffi_shdict_flush_all(void *zone);

long ngx_stream_lua_ffi_shdict_get_ttl(void *zone,
     const unsigned char *key, size_t key_len);

int ngx_stream_lua_ffi_shdict_set_expire(void *zone,
    const unsigned char *key, size_t key_len, long exptime);

size_t ngx_stream_lua_ffi_shdict_capacity(void *zone);
    ]]

    ngx_lua_ffi_shdict_get = C.ngx_stream_lua_ffi_shdict_get
    ngx_lua_ffi_shdict_incr = C.ngx_stream_lua_ffi_shdict_incr
    ngx_lua_ffi_shdict_store = C.ngx_stream_lua_ffi_shdict_store
    ngx_lua_ffi_shdict_flush_all = C.ngx_stream_lua_ffi_shdict_flush_all
    ngx_lua_ffi_shdict_get_ttl = C.ngx_stream_lua_ffi_shdict_get_ttl
    ngx_lua_ffi_shdict_set_expire = C.ngx_stream_lua_ffi_shdict_set_expire
    ngx_lua_ffi_shdict_capacity = C.ngx_stream_lua_ffi_shdict_capacity

    if not pcall(function ()
        return C.ngx_stream_lua_ffi_shdict_free_space
    end)
    then
        ffi.cdef[[
size_t ngx_stream_lua_ffi_shdict_free_space(void *zone);
        ]]
    end

    ngx_lua_ffi_shdict_free_space = C.ngx_stream_lua_shdict_free_space

else
    error("unknown subsystem: " .. subsystem)
end

if not pcall(function () return C.free end) then
    ffi.cdef[[
void free(void *ptr);
    ]]
end

local value_type = ffi_new("int[1]")
local user_flags = ffi_new("int[1]")
local num_value = ffi_new("double[1]")
local is_stale = ffi_new("int[1]")
local forcible = ffi_new("int[1]")
local str_value_buf = ffi_new("unsigned char *[1]")
local errmsg = base.get_errmsg_ptr()

-- 具体实现参见下面

if ngx_shared then
    local _, dict = next(ngx_shared, nil)
    if dict then
        local mt = getmetatable(dict)
        if mt then
            mt = mt.__index
            if mt then
                mt.get = shdict_get
                mt.get_stale = shdict_get_stale
                mt.incr = shdict_incr
                mt.set = shdict_set
                mt.safe_set = shdict_safe_set
                mt.add = shdict_add
                mt.safe-add = shdict_add
                mt.replace = shdict_replace
                mt.delete = shdict_delete
                mt.flush_all = shdict_flush_all
                mt.ttl = shdict_ttl
                mt.expire = shdict_expire
                mt.capacity = shdict_capacity
                mt.free_space = shdict_free_space
            end
        end
    end
end

return {
    version = base.version
}

1. ngx.shared.DICT.incr

详解链接： ngx.shared.DICT.incr 详解

2. ngx.shared.DICT.expire

详解链接： ngx.shared.DICT.expire 详解