1. 核心模块的配置解析
ngx_init_cycle的配置解析部分的目标是创建并初始化必须的核心模块的配置
ngx对配置上下文的定义是不确定类型，所以使用void *，在cycle->conf_ctx给所有模块留了配置接口，意味任何类型模块都可以将配置信息挂在cycle->conf_ctx
ngx对必须配置信息创建存储空间，并保证配置有效
如ngx_http_module虽然是核心模块，却没有必要指令（http指令非必要），所以ngx_http_module没有实现 create_conf 和 init_conf
cf 只有 ctx， module_type, cmd_type 属性会经常改变，其中 cf 描述一个解析指令的事件，cf->ctx 表示 解析后的指令信息 的输出挂载接口，cf->module_type 表示 限制输入指令信息的模块类型，cf->cmd_type 限制输入的指令类型
cycle->conf_ctx是一切配置信息的句柄
ngx_cycle_t *
ngx_init_cycle(ngx_cycle_t *old_cycle)
{
...
// 创建所有模块的配置接口
cycle->conf_ctx = ngx_pcalloc(pool, ngx_max_module * sizeof(void *));
if (cycle->conf_ctx == NULL) {
ngx_destroy_pool(pool);
return NULL;
}
...
// 创建必须使用的核心模块的配置存储空间
for (i = 0; ngx_modules[i]; i++) {
if (ngx_modules[i]->type != NGX_CORE_MODULE) {
continue;
}
module = ngx_modules[i]->ctx;
if (module->create_conf) {
rv = module->create_conf(cycle);
if (rv == NULL) {
ngx_destroy_pool(pool);
return NULL;
}
cycle->conf_ctx[ngx_modules[i]->index] = rv;
}
}
// 准备一个 conf 对象，用于解析 通过命令行输入的 指令
conf.temp_pool = ngx_create_pool(NGX_CYCLE_POOL_SIZE, log);
// ctx, module_type, cmd_type 会改变
// 下面的赋值表示，待会解析 core 类型模块的 Main 级别指令，将解析信息保存到 cycle->conf_ctx
conf.ctx = cycle->conf_ctx;
conf.cycle = cycle;
conf.pool = pool;
conf.log = log;
conf.module_type = NGX_CORE_MODULE;
conf.cmd_type = NGX_MAIN_CONF;
// 解析命令行输入的指令
if (ngx_conf_param(&conf) != NGX_CONF_OK) {
environ = senv;
ngx_destroy_cycle_pools(&conf);
return NULL;
}
// 解析配置文件输入的指令
if (ngx_conf_parse(&conf, &cycle->conf_file) != NGX_CONF_OK) {
environ = senv;
ngx_destroy_cycle_pools(&conf);
return NULL;
}
for (i = 0; ngx_modules[i]; i++) {
if (ngx_modules[i]->type != NGX_CORE_MODULE) {
continue;
}
module = ngx_modules[i]->ctx;
// 如果 用户没有设置必须配置 （在ngx_conf_param() ngx_conf_parse() ），则使用必须配置项使用默认值
if (module->init_conf) {
if (module->init_conf(cycle, cycle->conf_ctx[ngx_modules[i]->index])
== NGX_CONF_ERROR)
{
environ = senv;
ngx_destroy_cycle_pools(&conf);
return NULL;
}
}
}
char *
ngx_conf_parse(ngx_conf_t *cf, ngx_str_t *filename)
{
char *rv;
ngx_fd_t fd;
ngx_int_t rc;
ngx_buf_t buf;
ngx_conf_file_t *prev, conf_file;
enum {
parse_file = 0,
parse_block,
parse_param
} type;
#if (NGX_SUPPRESS_WARN)
fd = NGX_INVALID_FILE;
prev = NULL;
#endif
// 确定配置数据来源
if (filename) {
fd = ngx_open_file(filename->data, NGX_FILE_RDONLY, NGX_FILE_OPEN, 0);
if (fd == NGX_INVALID_FILE) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
ngx_open_file_n " \"%s\" failed",
filename->data);
return NGX_CONF_ERROR;
}
prev = cf->conf_file;
cf->conf_file = &conf_file;
if (ngx_fd_info(fd, &cf->conf_file->file.info) == -1) {
ngx_log_error(NGX_LOG_EMERG, cf->log, ngx_errno,
ngx_fd_info_n " \"%s\" failed", filename->data);
}
cf->conf_file->buffer = &buf;
buf.start = ngx_alloc(NGX_CONF_BUFFER, cf->log);
if (buf.start == NULL) {
goto failed;
}
buf.pos = buf.start;
buf.last = buf.start;
buf.end = buf.last + NGX_CONF_BUFFER;
buf.temporary = 1;
cf->conf_file->file.fd = fd;
cf->conf_file->file.name.len = filename->len;
cf->conf_file->file.name.data = filename->data;
cf->conf_file->file.offset = 0;
cf->conf_file->file.log = cf->log;
cf->conf_file->line = 1;
type = parse_file;
} else if (cf->conf_file->file.fd != NGX_INVALID_FILE) {
type = parse_block;
} else {
type = parse_param;
}
for ( ;; ) {
// 解析出 一个指令及其参数
rc = ngx_conf_read_token(cf);
/*
* ngx_conf_read_token() may return
*
* NGX_ERROR there is error
* NGX_OK the token terminated by ";" was found
* NGX_CONF_BLOCK_START the token terminated by "{" was found
* NGX_CONF_BLOCK_DONE the "}" was found
* NGX_CONF_FILE_DONE the configuration file is done
*/
if (rc == NGX_ERROR) {
goto done;
}
if (rc == NGX_CONF_BLOCK_DONE) {
if (type != parse_block) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "unexpected \"}\"");
goto failed;
}
goto done; // 递归解析命令块，返回递归
}
if (rc == NGX_CONF_FILE_DONE) {
if (type == parse_block) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"unexpected end of file, expecting \"}\"");
goto failed;
}
}
/* rc == NGX_OK || rc == NGX_CONF_BLOCK_START */
if (cf->handler) {
// 有些指令格式特别，如 http 模块的 type {...} 指令，所以ngx提供处理任意格式指令的接口
// 如果指令使用 handler处理，则意味不使用set处理
rv = (*cf->handler)(cf, NULL, cf->handler_conf);
if (rv == NGX_CONF_OK) {
continue;
}
if (rv == NGX_CONF_ERROR) {
goto failed;
}
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, rv);
goto failed;
}
// 固定格式的指令 处理
rc = ngx_conf_handler(cf, rc);
if (rc == NGX_ERROR) {
goto failed;
}
}
failed:
rc = NGX_ERROR;
done:
if (filename) {
if (cf->conf_file->buffer->start) {
ngx_free(cf->conf_file->buffer->start);
}
if (ngx_close_file(fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cf->log, ngx_errno,
ngx_close_file_n " %s failed",
filename->data);
return NGX_CONF_ERROR;
}
cf->conf_file = prev;
}
if (rc == NGX_ERROR) {
return NGX_CONF_ERROR;
}
return NGX_CONF_OK;
}
ngx_conf_read_token 读取配置数据并解析数据.
解析配置的方法是将数据分成三类，已解析（已经从该段数据中获得了 指令），已扫描（该段数据包含指令，但还没有找到该指令的结束符 ' ; '），已读取（文件数据的读缓存）。
也就将问题分成三个小问题：
如何处理无效数据
如何处理数据扫描
如何处理数据读取
从整个模块而言，ngx_conf_read_token最有用的输出是 将有效的 指令和参数 存放到 cf->args
static ngx_int_t
ngx_conf_read_token(ngx_conf_t *cf)
{
...
if (found) {
word = ngx_array_push(cf->args);
word->data = ngx_pnalloc(cf->pool, b->pos - start + 1);
for (dst = word->data, src = start, len = 0;
src < b->pos - 1;
len++)
{
...
*dst++ = *src++;
}
*dst = '\0';
}
ngx_conf_handler ：输入 指令及其参数， 检测指令是否合法，并执行指令
typedef struct {
void **main_conf;
void **srv_conf;
void **loc_conf;
} ngx_http_conf_ctx_t;
static ngx_int_t
ngx_conf_handler(ngx_conf_t *cf, ngx_int_t last)
{
char *rv;
void *conf, **confp;
ngx_uint_t i, multi;
ngx_str_t *name;
ngx_command_t *cmd;
// cf->args 是关键的输入，表示指令及其参数
name = cf->args->elts;
multi = 0;
for (i = 0; ngx_modules[i]; i++) {
/* look up the directive in the appropriate modules */
if (ngx_modules[i]->type != NGX_CONF_MODULE
&& ngx_modules[i]->type != cf->module_type)
{
continue;
}
cmd = ngx_modules[i]->commands;
if (cmd == NULL) {
continue;
}
for ( /* void */ ; cmd->name.len; cmd++) {
if (name->len != cmd->name.len) {
continue;
}
if (ngx_strcmp(name->data, cmd->name.data) != 0) {
continue;
}
/* is the directive's location right ? */
if (!(cmd->type & cf->cmd_type)) {
if (cmd->type & NGX_CONF_MULTI) {
multi = 1;
continue;
}
goto not_allowed;
}
if (!(cmd->type & NGX_CONF_BLOCK) && last != NGX_OK) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"directive \"%s\" is not terminated by \";\"",
name->data);
return NGX_ERROR;
/* is the directive's argument count right ? */
if (!(cmd->type & NGX_CONF_ANY)) {
if (cmd->type & NGX_CONF_FLAG) {
if (cf->args->nelts != 2) {
goto invalid;
}
} else if (cmd->type & NGX_CONF_1MORE) {
if (cf->args->nelts < 2) {
goto invalid;
}
} else if (cmd->type & NGX_CONF_2MORE) {
if (cf->args->nelts < 3) {
goto invalid;
}
} else if (cf->args->nelts > NGX_CONF_MAX_ARGS) {
goto invalid;
} else if (!(cmd->type & argument_number[cf->args->nelts - 1]))
{
goto invalid;
}
}
/* set up the directive's configuration context */
conf = NULL;
// 找到该指令对应的 配置存储空间
if (cmd->type & NGX_DIRECT_CONF) {
conf = ((void **) cf->ctx)[ngx_modules[i]->index];
} else if (cmd->type & NGX_MAIN_CONF) {
conf = &(((void **) cf->ctx)[ngx_modules[i]->index]);
} else if (cf->ctx) {
confp = *(void **) ((char *) cf->ctx + cmd->conf);
if (confp) {
conf = confp[ngx_modules[i]->ctx_index];
}
}
// cf主要提供 pool 和 log, cmd 通常无用，conf提供存储空间
rv = cmd->set(cf, cmd, conf);
if (rv == NGX_CONF_OK) {
return NGX_OK;
}
if (rv == NGX_CONF_ERROR) {
return NGX_ERROR;
}
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"\"%s\" directive %s", name->data, rv);
return NGX_ERROR;
}
}
if (multi == 0) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"unknown directive \"%s\"", name->data);
return NGX_ERROR;
}
not_allowed:
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"\"%s\" directive is not allowed here", name->data);
return NGX_ERROR;
invalid:
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid number of arguments in \"%s\" directive",
name->data);
return NGX_ERROR;
}
ngx_conf_handler中，这部分会让人看不懂，关键是cf->ctx会改变，涉及ngx配置内存结构
if (cmd->type & NGX_DIRECT_CONF) {
conf = ((void **) cf->ctx)[ngx_modules[i]->index];
} else if (cmd->type & NGX_MAIN_CONF) {
conf = &(((void **) cf->ctx)[ngx_modules[i]->index]);
} else if (cf->ctx) {
confp = *(void **) ((char *) cf->ctx + cmd->conf);
if (confp) {
conf = confp[ngx_modules[i]->ctx_index];
}
}
只有核心模块的cmd有NGX_DIRECT_CONF，这里的cf->ctx是 cycle->conf_ctx，因为cycle->conf_ctx是 void**，而cf->ctx是void*，所以需要转换类型
conf 是create_conf 创建的空间，NGX_DIRECT_CONF的命令是必须需要的，所以已经空间已经创建，可以直接使用
if (cmd->type & NGX_DIRECT_CONF) {
conf = ((void **) cf->ctx)[ngx_modules[i]->index];
是 NGX_MAIN_CONF 而不是 NGX_DIRECT_CONF 的命令 的 存储空间并没有预先创建，所以 conf 需要指向 挂载接口的地址，从而在 set回调中 创建空间，并设置挂载接口
这里的cf->ctx 也是 cycle->conf_ctx
} else if (cmd->type & NGX_MAIN_CONF) {
conf = &(((void **) cf->ctx)[ngx_modules[i]->index]);
这里是 非核心模块的解析，以http模块为例，cf->ctx指向 ngx_http_conf_ctx_t，(char *) cf->ctx + cmd->conf 得到 ngx_http_conf_ctx_t 下面某个成员的地址，而现在需要成员的值，所以需要转换成void **，再解引用，得到void *，获得 地址大小空间内的值。
因此 confp 指向 void*指针的数组，根据模块在本类模块的索引，得到改模块的 配置存储空间
} else if (cf->ctx) {
confp = *(void **) ((char *) cf->ctx + cmd->conf);
if (confp) {
conf = confp[ngx_modules[i]->ctx_index];
}
http核心模块
ngx_conf_handler中，若配置文件中使用了http { ...} 则会调用http的set回调 ngx_http_block
typedef struct {
void **main_conf;
void **srv_conf;
void **loc_conf;
} ngx_http_conf_ctx_t;
static char *
ngx_http_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
char *rv;
ngx_uint_t mi, m, s;
ngx_conf_t pcf;
ngx_http_module_t *module;
ngx_http_conf_ctx_t *ctx;
ngx_http_core_loc_conf_t *clcf;
ngx_http_core_srv_conf_t **cscfp;
ngx_http_core_main_conf_t *cmcf;
/* the main http context */
// http配置不一定使用，所以提前没有创建空间，而在指令set回调创建
ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_conf_ctx_t));
if (ctx == NULL) {
return NGX_CONF_ERROR;
}
*(ngx_http_conf_ctx_t **) conf = ctx;
/* count the number of the http modules and set up their indices */
ngx_http_max_module = 0;
for (m = 0; ngx_modules[m]; m++) {
if (ngx_modules[m]->type != NGX_HTTP_MODULE) {
continue;
}
ngx_modules[m]->ctx_index = ngx_http_max_module++;
}
/* the http main_conf context, it is the same in the all http contexts */
ctx->main_conf = ngx_pcalloc(cf->pool,
sizeof(void *) * ngx_http_max_module);
if (ctx->main_conf == NULL) {
return NGX_CONF_ERROR;
}
/*
* the http null srv_conf context, it is used to merge
* the server{}s' srv_conf's
*/
ctx->srv_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module);
if (ctx->srv_conf == NULL) {
return NGX_CONF_ERROR;
}
/*
* the http null loc_conf context, it is used to merge
* the server{}s' loc_conf's
*/
ctx->loc_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module);
if (ctx->loc_conf == NULL) {
return NGX_CONF_ERROR;
}
/*
* create the main_conf's, the null srv_conf's, and the null loc_conf's
* of the all http modules
*/
for (m = 0; ngx_modules[m]; m++) {
if (ngx_modules[m]->type != NGX_HTTP_MODULE) {
continue;
}
module = ngx_modules[m]->ctx;
mi = ngx_modules[m]->ctx_index;
if (module->create_main_conf) {
ctx->main_conf[mi] = module->create_main_conf(cf);
if (ctx->main_conf[mi] == NULL) {
return NGX_CONF_ERROR;
}
}
if (module->create_srv_conf) {
ctx->srv_conf[mi] = module->create_srv_conf(cf);
if (ctx->srv_conf[mi] == NULL) {
return NGX_CONF_ERROR;
}
}
if (module->create_loc_conf) {
ctx->loc_conf[mi] = module->create_loc_conf(cf);
if (ctx->loc_conf[mi] == NULL) {
return NGX_CONF_ERROR;
}
}
}
// 这里将 cf->ctx 指向 ngx_http_conf_ctx_t
pcf = *cf;
cf->ctx = ctx;
for (m = 0; ngx_modules[m]; m++) {
if (ngx_modules[m]->type != NGX_HTTP_MODULE) {
continue;
}
if (module->preconfiguration) {
if (module->preconfiguration(cf) != NGX_OK) {
return NGX_CONF_ERROR;
}
}
}
/* parse inside the http{} block */
cf->module_type = NGX_HTTP_MODULE;
cf->cmd_type = NGX_HTTP_MAIN_CONF;
rv = ngx_conf_parse(cf, NULL);
if (rv != NGX_CONF_OK) {
goto failed;
}
/*
* init http{} main_conf's, merge the server{}s' srv_conf's
* and its location{}s' loc_conf's
*/
cmcf = ctx->main_conf[ngx_http_core_module.ctx_index];
cscfp = cmcf->servers.elts;
for (m = 0; ngx_modules[m]; m++) {
if (ngx_modules[m]->type != NGX_HTTP_MODULE) {
continue;
}
module = ngx_modules[m]->ctx;
mi = ngx_modules[m]->ctx_index;
/* init http{} main_conf's */
if (module->init_main_conf) {
rv = module->init_main_conf(cf, ctx->main_conf[mi]);
if (rv != NGX_CONF_OK) {
goto failed;
}
}
rv = ngx_http_merge_servers(cf, cmcf, module, mi);
if (rv != NGX_CONF_OK) {
goto failed;
}
}
/* create location trees */
for (s = 0; s < cmcf->servers.nelts; s++) {
clcf = cscfp[s]->ctx->loc_conf[ngx_http_core_module.ctx_index];
if (ngx_http_init_locations(cf, cscfp[s], clcf) != NGX_OK) {
return NGX_CONF_ERROR;
}
if (ngx_http_init_static_location_trees(cf, clcf) != NGX_OK) {
return NGX_CONF_ERROR;
}
}
if (ngx_http_init_phases(cf, cmcf) != NGX_OK) {
return NGX_CONF_ERROR;
}
if (ngx_http_init_headers_in_hash(cf, cmcf) != NGX_OK) {
return NGX_CONF_ERROR;
}
for (m = 0; ngx_modules[m]; m++) {
if (ngx_modules[m]->type != NGX_HTTP_MODULE) {
continue;
}
module = ngx_modules[m]->ctx;
if (module->postconfiguration) {
if (module->postconfiguration(cf) != NGX_OK) {
return NGX_CONF_ERROR;
}
}
}
if (ngx_http_variables_init_vars(cf) != NGX_OK) {
return NGX_CONF_ERROR;
}
/*
* http{}'s cf->ctx was needed while the configuration merging
* and in postconfiguration process
*/
*cf = pcf;
if (ngx_http_init_phase_handlers(cf, cmcf) != NGX_OK) {
return NGX_CONF_ERROR;
}
/* optimize the lists of ports, addresses and server names */
if (ngx_http_optimize_servers(cf, cmcf, cmcf->ports) != NGX_OK) {
return NGX_CONF_ERROR;
}
return NGX_CONF_OK;
failed:
*cf = pcf;
return rv;
}
在 ngx_http_block 中使用新的配置挂载点
ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_conf_ctx_t));
...
cf->ctx = ctx;
ngx_http_core_module 的main_conf 为ngx_http_core_main_conf_t::servers 为 ngx_http_core_srv_conf_t类型的动态数组，即 为 http{..} 中的server {...}
cmcf = ctx->main_conf[ngx_http_core_module.ctx_index];
cscfp = cmcf->servers.elts;
通常该 执行 server {..} 指令了
static char *
ngx_http_core_server(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy)
{
char *rv;
void *mconf;
ngx_uint_t i;
ngx_conf_t pcf;
ngx_http_module_t *module;
struct sockaddr_in *sin;
ngx_http_conf_ctx_t *ctx, *http_ctx;
ngx_http_listen_opt_t lsopt;
ngx_http_core_srv_conf_t *cscf, **cscfp;
ngx_http_core_main_conf_t *cmcf;
// 可以发现每个指令块有一个 ngx_http_conf_ctx_t
ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_conf_ctx_t));
if (ctx == NULL) {
return NGX_CONF_ERROR;
}
// server下不能写 main级别的指令，所以 server 的 ctx->main_conf 指向http的ctx->main_conf
// 为配置继承做基础
http_ctx = cf->ctx;
ctx->main_conf = http_ctx->main_conf;
/* the server{}'s srv_conf */
ctx->srv_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module);
if (ctx->srv_conf == NULL) {
return NGX_CONF_ERROR;
}
/* the server{}'s loc_conf */
ctx->loc_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module);
if (ctx->loc_conf == NULL) {
return NGX_CONF_ERROR;
}
for (i = 0; ngx_modules[i]; i++) {
if (ngx_modules[i]->type != NGX_HTTP_MODULE) {
continue;
}
module = ngx_modules[i]->ctx;
if (module->create_srv_conf) {
mconf = module->create_srv_conf(cf);
if (mconf == NULL) {
return NGX_CONF_ERROR;
}
ctx->srv_conf[ngx_modules[i]->ctx_index] = mconf;
}
if (module->create_loc_conf) {
mconf = module->create_loc_conf(cf);
if (mconf == NULL) {
return NGX_CONF_ERROR;
}
ctx->loc_conf[ngx_modules[i]->ctx_index] = mconf;
}
if (module->create_loc_conf) {
mconf = module->create_loc_conf(cf);
if (mconf == NULL) {
return NGX_CONF_ERROR;
}
ctx->loc_conf[ngx_modules[i]->ctx_index] = mconf;
}
}
/* the server configuration context */
// ctx->srv_conf 是 server 块的 挂载点
cscf = ctx->srv_conf[ngx_http_core_module.ctx_index];
// cscf->ctx 指向 server块 挂载点 ngx_http_conf_ctx_t 类型
cscf->ctx = ctx;
// ctx->main_conf 指向 上层挂载点，这里是 http 块的，所以获得http级别的数组成员
cmcf = ctx->main_conf[ngx_http_core_module.ctx_index];
// 通过http块挂载点就能找到 下面所有的 server块中 ngx_http_core_moudle的 srv_conf，而 cscf->ctx = ctx; 所以能找到 server块中所有http模块的配置
cscfp = ngx_array_push(&cmcf->servers);
if (cscfp == NULL) {
return NGX_CONF_ERROR;
}
*cscfp = cscf;
/* parse inside server{} */
pcf = *cf;
cf->ctx = ctx; // 在server 块下 执行的 set回调，其 cf->ctx 指向 server块的 ngx_http_conf_ctx_t
cf->cmd_type = NGX_HTTP_SRV_CONF;
rv = ngx_conf_parse(cf, NULL);
*cf = pcf;
if (rv == NGX_CONF_OK && !cscf->listen) {
ngx_memzero(&lsopt, sizeof(ngx_http_listen_opt_t));
sin = &lsopt.u.sockaddr_in;
sin->sin_family = AF_INET;
#if (NGX_WIN32)
sin->sin_port = htons(80);
#else
sin->sin_port = htons((getuid() == 0) ? 80 : 8000);
#endif
sin->sin_addr.s_addr = INADDR_ANY;
lsopt.socklen = sizeof(struct sockaddr_in);
lsopt.backlog = NGX_LISTEN_BACKLOG;
lsopt.rcvbuf = -1;
lsopt.sndbuf = -1;
#if (NGX_HAVE_SETFIB)
lsopt.setfib = -1;
#endif
lsopt.wildcard = 1;
(void) ngx_sock_ntop(&lsopt.u.sockaddr, lsopt.addr,
NGX_SOCKADDR_STRLEN, 1);
if (ngx_http_add_listen(cf, cscf, &lsopt) != NGX_OK) {
return NGX_CONF_ERROR;
}
}
return rv;
}
ngx_http_core_server 最有效的信息 :
// 说明 ngx_http_conf_ctx_t 表示一个 配置块
ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_conf_ctx_t));
if (ctx == NULL) {
return NGX_CONF_ERROR;
}
http_ctx = cf->ctx;
// 子配置块 继承 父配置块 的基础
ctx->main_conf = http_ctx->main_conf;
// 说明如何能通过 ngx_http_core_module 的 srv_conf 找到 整个server {} 中所有的 http模块的配置信息
cscf = ctx->srv_conf[ngx_http_core_module.ctx_index];
cscf->ctx = ctx;
// 说明 如何通过 cycle->conf 如何找到某个 server{} 块的 配置信息
cmcf = ctx->main_conf[ngx_http_core_module.ctx_index];
cscfp = ngx_array_push(&cmcf->servers);
if (cscfp == NULL) {
return NGX_CONF_ERROR;
}
到location 指令
static char *
ngx_http_core_location(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy)
{
char *rv;
u_char *mod;
size_t len;
ngx_str_t *value, *name;
ngx_uint_t i;
ngx_conf_t save;
ngx_http_module_t *module;
ngx_http_conf_ctx_t *ctx, *pctx;
ngx_http_core_loc_conf_t *clcf, *pclcf;
ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_conf_ctx_t));
if (ctx == NULL) {
return NGX_CONF_ERROR;
}
// location的上级块，可能是 server，也可能是Location（嵌套location）
pctx = cf->ctx;
ctx->main_conf = pctx->main_conf;
ctx->srv_conf = pctx->srv_conf;
ctx->loc_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module);
if (ctx->loc_conf == NULL) {
return NGX_CONF_ERROR;
}
for (i = 0; ngx_modules[i]; i++) {
if (ngx_modules[i]->type != NGX_HTTP_MODULE) {
continue;
}
module = ngx_modules[i]->ctx;
if (module->create_loc_conf) {
ctx->loc_conf[ngx_modules[i]->ctx_index] =
module->create_loc_conf(cf);
if (ctx->loc_conf[ngx_modules[i]->ctx_index] == NULL) {
return NGX_CONF_ERROR;
}
}
}
// 如此就能通过 ngx_http_core_moudle的 loc_conf找到 相同配置块的所有 模块的 loc_conf
clcf = ctx->loc_conf[ngx_http_core_module.ctx_index];
clcf->loc_conf = ctx->loc_conf;
value = cf->args->elts;
// 因为 location 的 格式 为 location xxx {..}
if (cf->args->nelts == 3) {
len = value[1].len;
mod = value[1].data;
name = &value[2];
if (len == 1 && mod[0] == '=') {
clcf->name = *name;
clcf->exact_match = 1;
} else if (len == 2 && mod[0] == '^' && mod[1] == '~') {
clcf->name = *name;
clcf->noregex = 1;
} else if (len == 1 && mod[0] == '~') {
if (ngx_http_core_regex_location(cf, clcf, name, 0) != NGX_OK) {
return NGX_CONF_ERROR;
}
} else if (len == 2 && mod[0] == '~' && mod[1] == '*') {
if (ngx_http_core_regex_location(cf, clcf, name, 1) != NGX_OK) {
return NGX_CONF_ERROR;
}
} else {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid location modifier \"%V\"", &value[1]);
return NGX_CONF_ERROR;
}
} else {
name = &value[1];
if (name->data[0] == '=') {
clcf->name.len = name->len - 1;
clcf->name.data = name->data + 1;
clcf->exact_match = 1;
} else if (name->data[0] == '^' && name->data[1] == '~') {
clcf->name.len = name->len - 2;
clcf->name.data = name->data + 2;
clcf->noregex = 1;
} else if (name->data[0] == '~') {
name->len--;
name->data++;
if (name->data[0] == '*') {
name->len--;
name->data++;
if (name->data[0] == '*') {
name->len--;
name->data++;
if (ngx_http_core_regex_location(cf, clcf, name, 1) != NGX_OK) {
return NGX_CONF_ERROR;
}
} else {
if (ngx_http_core_regex_location(cf, clcf, name, 0) != NGX_OK) {
return NGX_CONF_ERROR;
}
}
} else {
clcf->name = *name;
if (name->data[0] == '@') {
clcf->named = 1;
}
}
}
// 上级块的 ngx_http_core_module 的 loc_conf
pclcf = pctx->loc_conf[ngx_http_core_module.ctx_index];
if (pclcf->name.len) {
/* nested location */
#if 0
clcf->prev_location = pclcf;
#endif
if (pclcf->exact_match) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"location \"%V\" cannot be inside "
"the exact location \"%V\"",
&clcf->name, &pclcf->name);
return NGX_CONF_ERROR;
}
if (pclcf->named) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"location \"%V\" cannot be inside "
"the named location \"%V\"",
&clcf->name, &pclcf->name);
return NGX_CONF_ERROR;
}
len = pclcf->name.len;
#if (NGX_PCRE)
if (clcf->regex == NULL
&& ngx_strncmp(clcf->name.data, pclcf->name.data, len) != 0)
#else
if (ngx_strncmp(clcf->name.data, pclcf->name.data, len) != 0)
#endif
{
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"location \"%V\" is outside location \"%V\"",
&clcf->name, &pclcf->name);
return NGX_CONF_ERROR;
}
}
// 将本块的 ngx_http_core_module 的 loc_conf 加入到 上级块的 ngx_http_core_module 的 loc_conf 的 locations队列的 队尾
if (ngx_http_add_location(cf, &pclcf->locations, clcf) != NGX_OK) {
return NGX_CONF_ERROR;
}
save = *cf;
cf->ctx = ctx; // 修改挂载点为 当前块
cf->cmd_type = NGX_HTTP_LOC_CONF;
rv = ngx_conf_parse(cf, NULL);
*cf = save;
return rv;
}
ngx_int_t
ngx_http_add_location(ngx_conf_t *cf, ngx_queue_t **locations,
ngx_http_core_loc_conf_t *clcf)
{
ngx_http_location_queue_t *lq;
if (*locations == NULL) {
*locations = ngx_palloc(cf->temp_pool,
sizeof(ngx_http_location_queue_t));
if (*locations == NULL) {
return NGX_ERROR;
}
ngx_queue_init(*locations);
}
lq = ngx_palloc(cf->temp_pool, sizeof(ngx_http_location_queue_t));
if (lq == NULL) {
return NGX_ERROR;
}
if (clcf->exact_match
#if (NGX_PCRE)
|| clcf->regex
#endif
|| clcf->named || clcf->noname)
{
lq->exact = clcf;
lq->inclusive = NULL;
} else {
lq->exact = NULL;
lq->inclusive = clcf;
}
lq->name = &clcf->name;
lq->file_name = cf->conf_file->file.name.data;
lq->line = cf->conf_file->line;
ngx_queue_init(&lq->list);
ngx_queue_insert_tail(*locations, &lq->queue);
return NGX_OK;
}
最后看 配置继承
http指令部分完成配置继承
/* parse inside the http{} block */
cf->module_type = NGX_HTTP_MODULE;
cf->cmd_type = NGX_HTTP_MAIN_CONF;
rv = ngx_conf_parse(cf, NULL);
if (rv != NGX_CONF_OK) {
goto failed;
}
// 到此构建完整个配置信息，开始merge
/*
* init http{} main_conf's, merge the server{}s' srv_conf's
* and its location{}s' loc_conf's
*/
cmcf = ctx->main_conf[ngx_http_core_module.ctx_index]; // http块的 ngx_http_core_module_t 的 main_conf
for (m = 0; ngx_modules[m]; m++) {
if (ngx_modules[m]->type != NGX_HTTP_MODULE) {
continue;
}
module = ngx_modules[m]->ctx; // 这个ngx_modules[m]->ctx是各个http模块关于配置上下文的回调方法，不是 上下文本身
mi = ngx_modules[m]->ctx_index; // 通过 这个索引才能找到真正的 配置上下文
/* init http{} main_conf's */
if (module->init_main_conf) {
rv = module->init_main_conf(cf, ctx->main_conf[mi]); //这里的ctx是 http块的
if (rv != NGX_CONF_OK) {
goto failed;
}
}
rv = ngx_http_merge_servers(cf, cmcf, module, mi);
if (rv != NGX_CONF_OK) {
goto failed;
}
}
// cf->ctx 是 http块的
// cmcf ： http块的 main_conf
// module : 要进行Merge的模块的 关于配置上下文的 操作方法
// ctx_index : 要进行merge的模块在同类模块的 index
static char *
ngx_http_merge_servers(ngx_conf_t *cf, ngx_http_core_main_conf_t *cmcf,
ngx_http_module_t *module, ngx_uint_t ctx_index)
{
char *rv;
ngx_uint_t s;
ngx_http_conf_ctx_t *ctx, saved;
ngx_http_core_loc_conf_t *clcf;
ngx_http_core_srv_conf_t **cscfp;
cscfp = cmcf->servers.elts; // 数组，元素为每个server 块 的 ngx_http_core_module_t 的srv_conf， 而 srv_conf->ctx 指向整个 server块，所以可以遍历整个server块的所有模块的配置上下文
ctx = (ngx_http_conf_ctx_t *) cf->ctx;
saved = *ctx;
rv = NGX_CONF_OK;
for (s = 0; s < cmcf->servers.nelts; s++) {
/* merge the server{}s' srv_conf's */
ctx->srv_conf = cscfp[s]->ctx->srv_conf;
if (module->merge_srv_conf) {
// http块 和 server 块 的 srv_conf 的merge
rv = module->merge_srv_conf(cf, saved.srv_conf[ctx_index],
cscfp[s]->ctx->srv_conf[ctx_index]);
if (rv != NGX_CONF_OK) {
goto failed;
}
}
if (module->merge_loc_conf) {
/* merge the server{}'s loc_conf */
ctx->loc_conf = cscfp[s]->ctx->loc_conf;
rv = module->merge_loc_conf(cf, saved.loc_conf[ctx_index],
cscfp[s]->ctx->loc_conf[ctx_index]);
if (rv != NGX_CONF_OK) {
goto failed;
}
/* merge the locations{}' loc_conf's */
// clcf->locations 队列记录 是 本块 下 的所有 loaction块
clcf = cscfp[s]->ctx->loc_conf[ngx_http_core_module.ctx_index];
rv = ngx_http_merge_locations(cf, clcf->locations,
cscfp[s]->ctx->loc_conf,
module, ctx_index);
if (rv != NGX_CONF_OK) {
goto failed;
}
}
}
failed:
*ctx = saved;
return rv;
}
// cf->ctx 是 http块的
// locations : 本块下所有的 location
// loc_conf : 本块的 loc_conf
// module ： 要进行 merge 的模块的 各种方法
static char *
ngx_http_merge_locations(ngx_conf_t *cf, ngx_queue_t *locations,
void **loc_conf, ngx_http_module_t *module, ngx_uint_t ctx_index)
{
char *rv;
ngx_queue_t *q;
ngx_http_conf_ctx_t *ctx, saved;
ngx_http_core_loc_conf_t *clcf;
ngx_http_location_queue_t *lq;
if (locations == NULL) {
return NGX_CONF_OK;
}
ctx = (ngx_http_conf_ctx_t *) cf->ctx;
saved = *ctx;
for (q = ngx_queue_head(locations);
q != ngx_queue_sentinel(locations);
q = ngx_queue_next(q))
{
lq = (ngx_http_location_queue_t *) q;
clcf = lq->exact ? lq->exact : lq->inclusive;
ctx->loc_conf = clcf->loc_conf;
// 参数顺序是 cf, 父块，子块
rv = module->merge_loc_conf(cf, loc_conf[ctx_index],
clcf->loc_conf[ctx_index]);
if (rv != NGX_CONF_OK) {
return rv;
}
rv = ngx_http_merge_locations(cf, clcf->locations, clcf->loc_conf,
module, ctx_index);
if (rv != NGX_CONF_OK) {
return rv;
}
}
*ctx = saved;
return NGX_CONF_OK;
}