Usage:
php_stream *stream = php_stream_fopen("/path/to/file", "r+b", NULL,
STREAM_OPEN_PERSISTENT | ENFORCE_SAFE_MODE | REPORT_ERRORS);
the filename and mode are combined to form the hash key for the persistent
list; they must be identical for this same stream to be returned again in the
next request.
Calling php_stream_close() on a persistent stream *will* close it, as is
usual with all persistent resources in PHP/ZE.
This is deliberately *not* exposed to user-space PHP at this time.
This breaks user-space filters (for the time being), and those
weird convert.* filters in ext/standard/filters.c
The filters stack has been separated into one chain for read and one chain
for write.
The user-space stream_filter_append() type functions currently only operate
on the read chain. They need extending to work with the write chain too.
