The reply to a /column_family/ GET request contains info about all
column families. Currently, all this info is stored in a single
string when replying, and this string may require a big allocation
when there are many column families.
To avoid that allocation, instead of a single string, use a
body_writer function, which writes chunks of the message content
to the output stream.
Fixes#7916
Signed-off-by: Wojciech Mitros <wojciech.mitros@scylladb.com>
Closes#7917
93613e20a3