This commit enhances nxt_var_cache_value() to enable variable access
using string names, complementing the existing reference index method.
The modification ensures future compatibility with njs variable access.
This commit is to reimplement the variables with an unknown field
such as $header_{name} to make the parsing more generic,
it's a preparation for supporting response header variables.
When a variable is accessed in the Unit configuration, the value is cached.
This was useful prior to the URI rewrite feature, but now that the URI (more
precisely, the request target) can be rewritten, the contents of the variable
$uri (which contains the path part of the request target, and is decoded)
should not be cached anymore, or at least the cached value should be invalidated
after a URI rewrite.
Example:
{
"rewrite": "/prefix$uri",
"share": "$uri"
}
For a request line like GET /foo?bar=baz HTTP/1.1\r\n, the expected file
served in the response would be /prefix/foo, but due to the caching issue,
Unit currently serves /foo.
It's for the introduction of njs support.
For each option that supports native variable and JS template literals introduced next,
it's unified as template string.
No functional changes.
The casts are unnecessary, since memchr(3)'s argument is 'const void *'.
It might have been necessary in the times of K&R, where 'void *' didn't
exist. Nowadays, it's unnecessary, and _very_ unsafe, since casts can
hide all classes of bugs by silencing most compiler warnings.
The changes from nxt_memchr() to memchr(3) were scripted:
$ find src/ -type f \
| grep '\.[ch]$' \
| xargs sed -i 's/nxt_memchr/memchr/'
Reviewed-by: Andrew Clayton <a.clayton@nginx.com>
Signed-off-by: Alejandro Colomar <alx@nginx.com>
Since the "pass" option supports both strings and variables, a generic
nxt_var_t structure can be used in the configuration phase, and the "name"
field in actions is redundant.
No functional changes.
