snihook/log.lua at master · luainkernel/snihook · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
local concat
concat = table.concat
local time
time = require("linux").time
local levels = {
  "EMERGENCY",
  "ALERT",
  "CRITICAL",
  "ERROR",
  "WARNING",
  "NOTICE",
  "INFO",
  "DEBUG"
}
for i = 1, #levels do
  levels[levels[i]] = i - 1
end
local sanitize
sanitize = function(part)
  local s = tostring(part)
  if s:find("[%z\1-\8\11\12\14-\31\127-\255]") then
    return s:gsub("[^ -~\t]", ".")
  else
    return s
  end
end
local prune_rate_state
prune_rate_state = function(state, now, window)
  if not (state and next(state)) then
    return
  end
  for k, v in pairs(state) do
    if (now - v.t0) >= (window * 10) then
      state[k] = nil
    end
  end
end
local can_log
can_log = function(self, lvl, line)
  local rl = self.rate_limit
  if not (rl) then
    return true
  end
  local now = time() / 1000000000
  local key = tostring(lvl) .. "\0" .. tostring(line)
  local ent = rl.state[key]
  if not (ent) then
    rl.state[key] = {
      t0 = now,
      n = 1
    }
    if rl.size > 2048 then
      prune_rate_state(rl.state, now, rl.window)
      rl.size = 0
      for _ in pairs(rl.state) do
        rl.size = rl.size + 1
      end
    else
      rl.size = rl.size + 1
    end
    return true
  end
  if (now - ent.t0) >= rl.window then
    ent.t0 = now
    ent.n = 1
    return true
  end
  if ent.n < rl.burst then
    ent.n = ent.n + 1
    return true
  end
  return false
end
local logger
logger = function(self, lvl, txt)
  if txt == nil then
    txt = levels[lvl + 1]
  end
  return function(...)
    if not (self.level < lvl) then
      local line = concat((function(...)
        local _accum_0 = { }
        local _len_0 = 1
        local _list_0 = {
          ...
        }
        for _index_0 = 1, #_list_0 do
          local part = _list_0[_index_0]
          _accum_0[_len_0] = sanitize(part)
          _len_0 = _len_0 + 1
        end
        return _accum_0
      end)(...), "\t")
      if not (can_log(self, lvl, line)) then
        return
      end
      return self.log(tostring(self.msg) .. " " .. tostring(txt) .. ": " .. tostring(line))
    end
  end
end
return function(level, msg, log, opts)
  if msg == nil then
    msg = ""
  end
  if log == nil then
    log = print
  end
  if opts == nil then
    opts = nil
  end
  if type(log) == "table" and not opts then
    opts = log
    log = print
  end
  opts = opts or { }
  local window = tonumber(opts.rate_limit_window) or 2
  local burst = tonumber(opts.rate_limit_burst) or 1
  local rate_limit = nil
  if window > 0 and burst > 0 then
    rate_limit = {
      window = window,
      burst = burst,
      state = { },
      size = 0
    }
  end
  local self = {
    log = log,
    msg = msg,
    rate_limit = rate_limit,
    level = tonumber(level) or levels[level]
  }
  for i, lvl in ipairs(levels) do
    self[lvl:lower()] = logger(self, i - 1)
  end
  return self
end