dnsjit.lib.trie - Prefix-tree data structure which addresses values by strings or byte arrays

       Jerry Lundström (DNS-OARC), Tomáš Křížek (CZ.NIC), Petr Špaček (ISC)

       Maintained by DNS-OARC

              https://www.dns-oarc.net/

       For issues and feature requests please use:

              https://github.com/DNS-OARC/dnsjit/issues

       For question and help please use:

              admin@dns-oarc.net

dnsjit                                                1.5.0                                   dnsjit.lib.trie(3)

       Prefix-tree  data  structure  that stores values indexed by strings or byte arrays, such as IP addresses.
       Values of size up to sizeof(size_t) can be stored directly, otherwise a pointer must be used.

   FunctionsTrie.new(ctype, binary, keylen)
              Create a new Trie that stores ctype values as data.  By default, keys are handled as strings.   To
              use  trie  with byte arrays, set binary to true.  Optionally, keylen may be specified as a default
              keylen for binary keys.  For string keys, their string length is used by default.

       Trie:log()
              Return the Log object to control logging of this instance or module.

       Trie:clear()
              Clear the trie instance (make it empty).

       Trie:weight()
              Return the number of keys in the trie.

       Trie:get_try(key, keylen)
              Search the trie and return nil of failure.

       Trie:get_ins(key, keylen)
              Search the trie and insert an empty node (with value set to 0) on failure.

       Trie:get_first()
              Return the first node (minimum).

       Trie:iter()
              Return a trie iterator.  It is only valid as long as the key-set remains unchanged.

       dnsjit.lib.trie - Prefix-tree data structure which addresses values by strings or byte arrays

dnsjit.lib.trie.node(3),dnsjit.lib.trie.iter(3)

Binary-keytriewithintegervalues
         local trie = require("dnsjit.lib.trie").new("uint64_t", true, 4)
         -- assume we have a bunch of dnsjit.core.object.ip packets to process
         for _, pkt in pairs(pkts) do
             local node = trie:get_ins(pkt.src)
             local value = node:get()  -- new nodes' values are initialized to 0
             node:set(value + 1)
         end
         -- iterate over unique IPs and print number of packets received from each
         local iter = trie:iter()
         local node = iter:node()
         local p = require("dnsjit.lib.ip")
         while node ~= nil do
             local ip_bytes = node:key()
             local npkts = tonumber(node:get())
             print(ip.tostring(ip_bytes).." sent "..npkts.." packets")
             iter:next()
             node = iter:node()
         end

   String-keytriewithcdatavalues
         local trie = require("dnsjit.lib.trie").new("core_object_t*")
         local obj1  -- assume this contains cdata of type core_object_t*
         local node = trie:get_ins("obj1")
         node:set(obj1)
         node = trie:get_try("obj1")
         assert(node:get() == obj1)