| Constant |
Description |
| HTTP_OPTION_NOCACHE |
This instructs the server to not return a cached copy of
the resource. When connected to an HTTP 1.0 or earlier server,
this directive may be ignored. |
| HTTP_OPTION_KEEPALIVE |
This instructs the server to maintain a persistent
connection between requests. This can improve performance
because it eliminates the need to establish a separate
connection for each resource that is requested. |
| HTTP_OPTION_REDIRECT |
This option specifies the client should automatically
handle resource redirection. If the server indicates that the
requested resource has moved to a new location, the client will
close the current connection and request the resource from the
new location. Note that it is possible that the redirected
resource will be located on a different server. |
| HTTP_OPTION_ERRORDATA |
This option specifies the client should return the
content of an error response from the server, rather than
returning an error code. Note that this option will disable
automatic resource redirection, and should not be used with
HTTP_OPTION_REDIRECT. |
| HTTP_OPTION_NOUSERAGENT |
This option specifies the client should not include a
User-Agent header with any requests made during the session. The
user agent is a string which is used to identify the client
application to the server. |
| HTTP_OPTION_TUNNEL |
This option specifies that a tunneled TCP connection and/or
port-forwarding is being used to establish the connection to
the server. This changes the behavior of the client with
regards to internal checks of the destination IP address and
remote port number, default capability selection and how the
connection is established. |
| HTTP_OPTION_TRUSTEDSITE |
This option specifies the server is trusted. The
server certificate will not be validated and the connection
will always be permitted. This option only affects connections
using either the SSL or TLS protocols. |
| HTTP_OPTION_SECURE |
This option specifies the client should attempt to
establish a secure connection with the server. Note that the
server must support secure connections using either the SSL or
TLS protocol. The client will default to using TLS 1.2 or later
for secure connections. |
| HTTP_OPTION_SECURE_FALLBACK |
This option specifies the client should permit the use
of less secure cipher suites for compatibility with legacy
servers. If this option is specified, the client will allow
connections using TLS 1.0 and cipher suites that use RC4, MD5
and SHA1. |
| HTTP_OPTION_PREFER_IPV6 |
This option specifies the client should prefer the use of
IPv6 if the server hostname can be resolved to both an IPv6 and
IPv4 address. This option is ignored if the local system does
not have IPv6 enabled, or when the hostname can only be resolved
to an IPv4 address. If the server hostname can only be resolved
to an IPv6 address, the client will attempt to establish a
connection using IPv6 regardless if this option has been
specified. |
| HTTP_OPTION_FREETHREAD |
This option specifies the handle returned by this
function may be used by any thread, and is not limited to the
thread which created it. The application is responsible for
ensuring that access to the handle is synchronized across
multiple threads. |
| HTTP_OPTION_HIRES_TIMER |
This option specifies the elapsed time for data
transfers should be returned in milliseconds instead of seconds.
This will return more accurate transfer times for smaller
amounts of data over fast network connections. |