hostip.c explained | |
================== | |
The main COMPILE-TIME DEFINES to keep in mind when reading the host*.c | |
source file are these: | |
CURLRES_IPV6 - this host has getaddrinfo() and family, and thus we use | |
that. The host may not be able to resolve IPv6, but we don't really have to | |
take that into account. Hosts that aren't IPv6-enabled have CURLRES_IPV4 | |
defined. | |
CURLRES_ARES - is defined if libcurl is built to use c-ares for asynchronous | |
name resolves. This can be Windows or *nix. | |
CURLRES_THREADED - is defined if libcurl is built to use threading for | |
asynchronous name resolves. The name resolve will be done in a new thread, | |
and the supported asynch API will be the same as for ares-builds. This is | |
the default under (native) Windows. | |
If any of the two previous are defined, CURLRES_ASYNCH is defined too. If | |
libcurl is not built to use an asynchronous resolver, CURLRES_SYNCH is | |
defined. | |
The host*.c sources files are split up like this: | |
hostip.c - method-independent resolver functions and utility functions | |
hostasyn.c - functions for asynchronous name resolves | |
hostsyn.c - functions for synchronous name resolves | |
asyn-ares.c - functions for asynchronous name resolves using c-ares | |
asyn-thread.c - functions for asynchronous name resolves using threads | |
hostip4.c - IPv4 specific functions | |
hostip6.c - IPv6 specific functions | |
The hostip.h is the single united header file for all this. It defines the | |
CURLRES_* defines based on the config*.h and curl_setup.h defines. |