Binary-key trie with integer values¶

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-key trie with cdata values¶

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)

Functions¶

Trie.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.