Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

We can put the unsafe keyword as part of the function definition,
getting rid of the unsafe {} blocks in the functions themselves.

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

In this example we don't need the request buf.

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

The programs demonstrate handling requests with payloads larger than
4GiB which means they need to be written out to disk and so also
demonstrates the use of the file-system access mechanism.

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

The previous commit changed uwr_get_http_content_len() to return a u64
to allow for uploads larger than 4GiB, which now means this generates
compiler errors about type mismatches, expected usize got u64.

Cast the return value of uwr_get_http_content_len() to usize to match
that of TOTAL_RESPONSE_SENT.

(Making TOTAL_RESPONSE_SENT a u64 creates a larger trail of problems).

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

There is no need in this case to declare REQUEST_BUF as a global
variable. Declaring it local to uwr_request_handler() lets us get rid of
the unsafe code blocks.

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

Update the echo-request and upload-reflector examples for the new
uwr_http_add_header_content_type() and uwr_http_add_header_content_len()
functions.

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

When I renamed it from minimal to hello-world, it stopped being built
due to the make target name being the same as the directory name
(hello-world).

Rename the make target to rust-hello-world which also matches the naming
of the rest of the targets.

Fixes: 656c036 ("examples/rust: Add a minimal hello world rust example")
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>