nginx源码琐碎

来源：互联网发布：tpo模考软件mac版下载编辑：程序博客网时间：2024/06/05 21:28

推荐两个测试工具（适用于nginx 网络方面的测试）：

ectproxy(王晓哲)：https://github.com/chaoslawful/etcproxy

mockeagain(章亦春)：https://github.com/agentzh/mockeagain

都是国人写的。

nginx源代码地址：http://trac.nginx.org/nginx/browser

nginx-core-progress:

nginx-core-p

ngx_http_upstream_t中几个函数指针的作用：

create_request ：创建请求时调用（对请求的内容进行处理）
reinit_request ：重新请求
process_header：响应请求时调用。（处理response的内容）

abort_request ：放弃请求
finalize_request ：完成请求

1. 在ngx_http_request_t结构中包含upstream

2.upstream相关结构：

当前upstream各个节点为链表结构

struct ngx_http_upstream_rr_peers_s {
ngx_uint_t single; /* unsigned single:1; */
ngx_uint_t number;
ngx_uint_t last_cached;

/* ngx_mutex_t *mutex; */
ngx_connection_t **cached;

ngx_str_t *name;

ngx_http_upstream_rr_peers_t *next;

ngx_http_upstream_rr_peer_t peer[1];
};

typedef struct {
ngx_http_upstream_rr_peers_t *peers;
ngx_uint_t current;
uintptr_t *tried;
uintptr_t data;
} ngx_http_upstream_rr_peer_data_t;

typedef struct {
ngx_http_upstream_init_pt init_upstream;
ngx_http_upstream_init_peer_pt init;

//目前为ngx_http_upstream_rr_peers_t
void *data;
} ngx_http_upstream_peer_t;

struct ngx_http_upstream_srv_conf_s {

ngx_http_upstream_peer_t peer;
void **srv_conf;

ngx_array_t *servers; /* ngx_http_upstream_server_t */

ngx_uint_t flags;
ngx_str_t host;
u_char *file_name;
ngx_uint_t line;
in_port_t port;
in_port_t default_port;
};

typedef struct {

//当前站点upstream配置信息
ngx_http_upstream_srv_conf_t *upstream;

ngx_msec_t connect_timeout;
ngx_msec_t send_timeout;
ngx_msec_t read_timeout;
ngx_msec_t timeout;

size_t send_lowat;
size_t buffer_size;

size_t busy_buffers_size;
size_t max_temp_file_size;
size_t temp_file_write_size;

size_t busy_buffers_size_conf;
size_t max_temp_file_size_conf;
size_t temp_file_write_size_conf;

ngx_bufs_t bufs;

ngx_uint_t ignore_headers;
ngx_uint_t next_upstream;
ngx_uint_t store_access;
ngx_flag_t buffering;
ngx_flag_t pass_request_headers;
ngx_flag_t pass_request_body;

ngx_flag_t ignore_client_abort;
ngx_flag_t intercept_errors;
ngx_flag_t cyclic_temp_file;

ngx_path_t *temp_path;

ngx_hash_t hide_headers_hash;
ngx_array_t *hide_headers;
ngx_array_t *pass_headers;

ngx_addr_t *local;

#if (NGX_HTTP_CACHE)
ngx_shm_zone_t *cache;

ngx_uint_t cache_min_uses;
ngx_uint_t cache_use_stale;
ngx_uint_t cache_methods;

ngx_array_t *cache_valid;
ngx_array_t *cache_bypass;
ngx_array_t *no_cache;
#endif

ngx_array_t *store_lengths;
ngx_array_t *store_values;

signed store:2;
unsigned intercept_404:1;
unsigned change_buffering:1;

#if (NGX_HTTP_SSL)
ngx_ssl_t *ssl;
ngx_flag_t ssl_session_reuse;
#endif

ngx_str_t module;
} ngx_http_upstream_conf_t;

struct ngx_http_upstream_s {
ngx_http_upstream_handler_pt read_event_handler;
ngx_http_upstream_handler_pt write_event_handler;

ngx_peer_connection_t peer;

ngx_event_pipe_t *pipe;

ngx_chain_t *request_bufs;

ngx_output_chain_ctx_t output;
ngx_chain_writer_ctx_t writer;

//upstream配置信息
ngx_http_upstream_conf_t *conf;

ngx_http_upstream_headers_in_t headers_in;

ngx_http_upstream_resolved_t *resolved;

ngx_buf_t buffer;
off_t length;

ngx_chain_t *out_bufs;
ngx_chain_t *busy_bufs;
ngx_chain_t *free_bufs;

ngx_int_t (*input_filter_init)(void *data);
ngx_int_t (*input_filter)(void *data, ssize_t bytes);
void *input_filter_ctx;

#if (NGX_HTTP_CACHE)
ngx_int_t (*create_key)(ngx_http_request_t *r);
#endif
ngx_int_t (*create_request)(ngx_http_request_t *r);
ngx_int_t (*reinit_request)(ngx_http_request_t *r);
ngx_int_t (*process_header)(ngx_http_request_t *r);
void (*abort_request)(ngx_http_request_t *r);
void (*finalize_request)(ngx_http_request_t *r,
ngx_int_t rc);
ngx_int_t (*rewrite_redirect)(ngx_http_request_t *r,
ngx_table_elt_t *h, size_t prefix);

ngx_msec_t timeout;

ngx_http_upstream_state_t *state;

ngx_str_t method;
ngx_str_t schema;
ngx_str_t uri;

ngx_http_cleanup_pt *cleanup;

unsigned store:1;
unsigned cacheable:1;
unsigned accel:1;
unsigned ssl:1;
#if (NGX_HTTP_CACHE)
unsigned cache_status:3;
#endif

unsigned buffering:1;
unsigned keepalive:1;

unsigned request_sent:1;
unsigned header_sent:1;
};

ngx_http.c文件中的ngx_http_block函数功能：

1.初始化各http模块的配置信息

2 对main_conf,srv_conf,loc_conf进行赋值。

main_conf：用于处理所有配置信息的函数指针。

srv_conf：用于处理server中的配置信息的函数指针。

loc_conf：用于处理server中的配置信息的函数指针。

3.合并配置文件中http{} 的main conf，server {}的 src config以及loc config（ngx_http文件中ngx_http_merge_servers）

4.建立location和upstream等的映射。

ngx_http_conf_get_module_main_conf，ngx_http_conf_get_module_src_conf ，ngx_http_conf_get_module_loc_conf用于获取各个模块相应的配置信息。

在ngx_http_request这个核心文件里，找到ngx_http_init_request函数，在该函数里，可以看到：

r->main_conf = cscf->ctx->main_conf;
r->srv_conf = cscf->ctx->srv_conf;
r->loc_conf = cscf->ctx->loc_conf;

以上cscf为对应server的配置信息，r为request指针

请求流程（在ngx_http_request文件里）：

ngx_http_init_request=>ngx_http_process_request_headers（header处理完毕后）=>ngx_http_process_request=> ngx_http_handler=>ngx_http_core_run_phases（核心模块的处理）

在http redis模块的ngx_http_redis_merge_loc_conf函数里可以获取到该模块所要用到的upstream。