1 hostip.c explained
2 ==================
3
4 The main COMPILE-TIME DEFINES to keep in mind when reading the host*.c
5 source file are these:
6
7 CURLRES_IPV6 - this host has getaddrinfo() and family, and thus we use
8 that. The host may not be able to resolve IPv6, but we don't really have to
9 take that into account. Hosts that aren't IPv6-enabled have CURLRES_IPV4
10 defined.
11
12 CURLRES_ARES - is defined if libcurl is built to use c-ares for asynchronous
13 name resolves. This can be Windows or *nix.
14
15 CURLRES_THREADED - is defined if libcurl is built to use threading for
16 asynchronous name resolves. The name resolve will be done in a new thread,
17 and the supported asynch API will be the same as for ares-builds. This is
18 the default under (native) Windows.
19
20 If any of the two previous are defined, CURLRES_ASYNCH is defined too. If
21 libcurl is not built to use an asynchronous resolver, CURLRES_SYNCH is
22 defined.
23
24 The host*.c sources files are split up like this:
25
26 hostip.c      - method-independent resolver functions and utility functions
27 hostasyn.c    - functions for asynchronous name resolves
28 hostsyn.c     - functions for synchronous name resolves
29 asyn-ares.c   - functions for asynchronous name resolves using c-ares
30 asyn-thread.c - functions for asynchronous name resolves using threads
31 hostip4.c     - ipv4-specific functions
32 hostip6.c     - ipv6-specific functions
33
34 The hostip.h is the single united header file for all this. It defines the
35 CURLRES_* defines based on the config*.h and curl_setup.h defines.
36