Curl_cftype
连接接口定义
struct Curl_cftype {
const char *name; /* name of the filter type */
int flags; /* flags of filter type */
int log_level; /* log level for such filters */
Curl_cft_destroy_this *destroy; /* destroy resources of this cf */
Curl_cft_connect *do_connect; /* establish connection */
Curl_cft_close *do_close; /* close conn */
Curl_cft_get_host *get_host; /* host filter talks to */
Curl_cft_adjust_pollset *adjust_pollset; /* adjust transfer poll set */
Curl_cft_data_pending *has_data_pending;/* conn has data pending */
Curl_cft_send *do_send; /* send data */
Curl_cft_recv *do_recv; /* receive data */
Curl_cft_cntrl *cntrl; /* events/control */
Curl_cft_conn_is_alive *is_alive; /* FALSE if conn is dead, Jim! */
Curl_cft_conn_keep_alive *keep_alive; /* try to keep it alive */
Curl_cft_query *query; /* query filter chain */
};
初始化Curl_cftype类型数组
数组定义为struct Curl_cftype *cf_types
static struct Curl_cftype *cf_types[] = {
&Curl_cft_tcp,
&Curl_cft_udp,
&Curl_cft_unix,
&Curl_cft_tcp_accept,
&Curl_cft_happy_eyeballs,
&Curl_cft_setup,
#ifdef USE_NGHTTP2
&Curl_cft_nghttp2,
#endif
#ifdef USE_SSL
&Curl_cft_ssl,
#ifndef CURL_DISABLE_PROXY
&Curl_cft_ssl_proxy,
#endif
#endif
#if !defined(CURL_DISABLE_PROXY)
#if !defined(CURL_DISABLE_HTTP)
&Curl_cft_h1_proxy,
#ifdef USE_NGHTTP2
&Curl_cft_h2_proxy,
#endif
&Curl_cft_http_proxy,
#endif /* !CURL_DISABLE_HTTP */
&Curl_cft_haproxy,
&Curl_cft_socks_proxy,
#endif /* !CURL_DISABLE_PROXY */
#ifdef ENABLE_QUIC
&Curl_cft_http3,
#endif
#if !defined(CURL_DISABLE_HTTP) && !defined(USE_HYPER)
&Curl_cft_http_connect,
#endif
NULL,
};
Curl_cfilter
连接处理链
struct Curl_cfilter {
const struct Curl_cftype *cft; /* the type providing implementation */
struct Curl_cfilter *next; /* next filter in chain */
void *ctx; /* filter type specific settings */
struct connectdata *conn; /* the connection this filter belongs to */
int sockindex; /* the index the filter is installed at */
BIT(connected); /* != 0 iff this filter is connected */
};
transport_provider
定义如下
struct transport_provider {
int transport;
cf_ip_connect_create *cf_create;
};
初始化代码为
struct transport_provider transport_providers[] = {
{
TRNSPRT_TCP, Curl_cf_tcp_create },
#ifdef ENABLE_QUIC
{
TRNSPRT_QUIC, Curl_cf_quic_create },
#endif
#ifndef CURL_DISABLE_TFTP
{
TRNSPRT_UDP, Curl_cf_udp_create },
#endif
#ifdef USE_UNIX_SOCKETS
{
TRNSPRT_UNIX, Curl_cf_unix_create },
#endif
};