util.signal: Add support for signalfd(2) on Linux
signalfd allows handling signal events using the same method as sockets,
via file descriptors. Thus all signal dispatch can go through the same
main event loop as everything else, removing need for thread-scary
signal handling where execution would just jump to the signal handler
regardless of the state of Lua, and needing to keep track of Lua
states/threads.
local cache = require "util.cache";
describe("util.cache", function()
describe("#new()", function()
it("should work", function()
do
local c = cache.new(1);
assert.is_not_nil(c);
assert.has_error(function ()
cache.new(0);
end);
assert.has_error(function ()
cache.new(-1);
end);
assert.has_error(function ()
cache.new("foo");
end);
end
local c = cache.new(5);
local function expect_kv(key, value, actual_key, actual_value)
assert.are.equal(key, actual_key, "key incorrect");
assert.are.equal(value, actual_value, "value incorrect");
end
expect_kv(nil, nil, c:head());
expect_kv(nil, nil, c:tail());
assert.are.equal(c:count(), 0);
c:set("one", 1)
assert.are.equal(c:count(), 1);
expect_kv("one", 1, c:head());
expect_kv("one", 1, c:tail());
c:set("two", 2)
expect_kv("two", 2, c:head());
expect_kv("one", 1, c:tail());
c:set("three", 3)
expect_kv("three", 3, c:head());
expect_kv("one", 1, c:tail());
c:set("four", 4)
c:set("five", 5);
assert.are.equal(c:count(), 5);
expect_kv("five", 5, c:head());
expect_kv("one", 1, c:tail());
c:set("foo", nil);
assert.are.equal(c:count(), 5);
expect_kv("five", 5, c:head());
expect_kv("one", 1, c:tail());
assert.are.equal(c:get("one"), 1);
expect_kv("five", 5, c:head());
expect_kv("one", 1, c:tail());
assert.are.equal(c:get("two"), 2);
assert.are.equal(c:get("three"), 3);
assert.are.equal(c:get("four"), 4);
assert.are.equal(c:get("five"), 5);
assert.are.equal(c:get("foo"), nil);
assert.are.equal(c:get("bar"), nil);
c:set("six", 6);
assert.are.equal(c:count(), 5);
expect_kv("six", 6, c:head());
expect_kv("two", 2, c:tail());
assert.are.equal(c:get("one"), nil);
assert.are.equal(c:get("two"), 2);
assert.are.equal(c:get("three"), 3);
assert.are.equal(c:get("four"), 4);
assert.are.equal(c:get("five"), 5);
assert.are.equal(c:get("six"), 6);
c:set("three", nil);
assert.are.equal(c:count(), 4);
assert.are.equal(c:get("one"), nil);
assert.are.equal(c:get("two"), 2);
assert.are.equal(c:get("three"), nil);
assert.are.equal(c:get("four"), 4);
assert.are.equal(c:get("five"), 5);
assert.are.equal(c:get("six"), 6);
c:set("seven", 7);
assert.are.equal(c:count(), 5);
assert.are.equal(c:get("one"), nil);
assert.are.equal(c:get("two"), 2);
assert.are.equal(c:get("three"), nil);
assert.are.equal(c:get("four"), 4);
assert.are.equal(c:get("five"), 5);
assert.are.equal(c:get("six"), 6);
assert.are.equal(c:get("seven"), 7);
c:set("eight", 8);
assert.are.equal(c:count(), 5);
assert.are.equal(c:get("one"), nil);
assert.are.equal(c:get("two"), nil);
assert.are.equal(c:get("three"), nil);
assert.are.equal(c:get("four"), 4);
assert.are.equal(c:get("five"), 5);
assert.are.equal(c:get("six"), 6);
assert.are.equal(c:get("seven"), 7);
assert.are.equal(c:get("eight"), 8);
c:set("four", 4);
assert.are.equal(c:count(), 5);
assert.are.equal(c:get("one"), nil);
assert.are.equal(c:get("two"), nil);
assert.are.equal(c:get("three"), nil);
assert.are.equal(c:get("four"), 4);
assert.are.equal(c:get("five"), 5);
assert.are.equal(c:get("six"), 6);
assert.are.equal(c:get("seven"), 7);
assert.are.equal(c:get("eight"), 8);
c:set("nine", 9);
assert.are.equal(c:count(), 5);
assert.are.equal(c:get("one"), nil);
assert.are.equal(c:get("two"), nil);
assert.are.equal(c:get("three"), nil);
assert.are.equal(c:get("four"), 4);
assert.are.equal(c:get("five"), nil);
assert.are.equal(c:get("six"), 6);
assert.are.equal(c:get("seven"), 7);
assert.are.equal(c:get("eight"), 8);
assert.are.equal(c:get("nine"), 9);
do
local keys = { "nine", "four", "eight", "seven", "six" };
local values = { 9, 4, 8, 7, 6 };
local i = 0;
for k, v in c:items() do
i = i + 1;
assert.are.equal(k, keys[i]);
assert.are.equal(v, values[i]);
end
assert.are.equal(i, 5);
c:set("four", "2+2");
assert.are.equal(c:count(), 5);
assert.are.equal(c:get("one"), nil);
assert.are.equal(c:get("two"), nil);
assert.are.equal(c:get("three"), nil);
assert.are.equal(c:get("four"), "2+2");
assert.are.equal(c:get("five"), nil);
assert.are.equal(c:get("six"), 6);
assert.are.equal(c:get("seven"), 7);
assert.are.equal(c:get("eight"), 8);
assert.are.equal(c:get("nine"), 9);
end
do
local keys = { "four", "nine", "eight", "seven", "six" };
local values = { "2+2", 9, 8, 7, 6 };
local i = 0;
for k, v in c:items() do
i = i + 1;
assert.are.equal(k, keys[i]);
assert.are.equal(v, values[i]);
end
assert.are.equal(i, 5);
c:set("foo", nil);
assert.are.equal(c:count(), 5);
assert.are.equal(c:get("one"), nil);
assert.are.equal(c:get("two"), nil);
assert.are.equal(c:get("three"), nil);
assert.are.equal(c:get("four"), "2+2");
assert.are.equal(c:get("five"), nil);
assert.are.equal(c:get("six"), 6);
assert.are.equal(c:get("seven"), 7);
assert.are.equal(c:get("eight"), 8);
assert.are.equal(c:get("nine"), 9);
end
do
local keys = { "four", "nine", "eight", "seven", "six" };
local values = { "2+2", 9, 8, 7, 6 };
local i = 0;
for k, v in c:items() do
i = i + 1;
assert.are.equal(k, keys[i]);
assert.are.equal(v, values[i]);
end
assert.are.equal(i, 5);
c:set("four", nil);
assert.are.equal(c:get("one"), nil);
assert.are.equal(c:get("two"), nil);
assert.are.equal(c:get("three"), nil);
assert.are.equal(c:get("four"), nil);
assert.are.equal(c:get("five"), nil);
assert.are.equal(c:get("six"), 6);
assert.are.equal(c:get("seven"), 7);
assert.are.equal(c:get("eight"), 8);
assert.are.equal(c:get("nine"), 9);
end
do
local keys = { "nine", "eight", "seven", "six" };
local values = { 9, 8, 7, 6 };
local i = 0;
for k, v in c:items() do
i = i + 1;
assert.are.equal(k, keys[i]);
assert.are.equal(v, values[i]);
end
assert.are.equal(i, 4);
end
do
local evicted_key, evicted_value;
local c2 = cache.new(3, function (_key, _value)
evicted_key, evicted_value = _key, _value;
end);
local function set(k, v, should_evict_key, should_evict_value)
evicted_key, evicted_value = nil, nil;
c2:set(k, v);
assert.are.equal(evicted_key, should_evict_key);
assert.are.equal(evicted_value, should_evict_value);
end
set("a", 1)
set("a", 1)
set("a", 1)
set("a", 1)
set("a", 1)
set("b", 2)
set("c", 3)
set("b", 2)
set("d", 4, "a", 1)
set("e", 5, "c", 3)
end
do
local evicted_key, evicted_value;
local c3 = cache.new(1, function (_key, _value)
evicted_key, evicted_value = _key, _value;
if _key == "a" then
-- Sanity check for what we're evicting
assert.are.equal(_key, "a");
assert.are.equal(_value, 1);
-- We're going to block eviction of this key/value, so set to nil...
evicted_key, evicted_value = nil, nil;
-- Returning false to block eviction
return false
end
end);
local function set(k, v, should_evict_key, should_evict_value)
evicted_key, evicted_value = nil, nil;
local ret = c3:set(k, v);
assert.are.equal(evicted_key, should_evict_key);
assert.are.equal(evicted_value, should_evict_value);
return ret;
end
set("a", 1)
set("a", 1)
set("a", 1)
set("a", 1)
set("a", 1)
-- Our on_evict prevents "a" from being evicted, causing this to fail...
assert.are.equal(set("b", 2), false, "Failed to prevent eviction, or signal result");
expect_kv("a", 1, c3:head());
expect_kv("a", 1, c3:tail());
-- Check the final state is what we expect
assert.are.equal(c3:get("a"), 1);
assert.are.equal(c3:get("b"), nil);
assert.are.equal(c3:count(), 1);
end
local c4 = cache.new(3, false);
assert.are.equal(c4:set("a", 1), true);
assert.are.equal(c4:set("a", 1), true);
assert.are.equal(c4:set("a", 1), true);
assert.are.equal(c4:set("a", 1), true);
assert.are.equal(c4:set("b", 2), true);
assert.are.equal(c4:set("c", 3), true);
assert.are.equal(c4:set("d", 4), false);
assert.are.equal(c4:set("d", 4), false);
assert.are.equal(c4:set("d", 4), false);
expect_kv("c", 3, c4:head());
expect_kv("a", 1, c4:tail());
local c5 = cache.new(3, function (k, v) --luacheck: ignore 212/v
if k == "a" then
return nil;
elseif k == "b" then
return true;
end
return false;
end);
assert.are.equal(c5:set("a", 1), true);
assert.are.equal(c5:set("a", 1), true);
assert.are.equal(c5:set("a", 1), true);
assert.are.equal(c5:set("a", 1), true);
assert.are.equal(c5:set("b", 2), true);
assert.are.equal(c5:set("c", 3), true);
assert.are.equal(c5:set("d", 4), true); -- "a" evicted (cb returned nil)
assert.are.equal(c5:set("d", 4), true); -- nop
assert.are.equal(c5:set("d", 4), true); -- nop
assert.are.equal(c5:set("e", 5), true); -- "b" evicted (cb returned true)
assert.are.equal(c5:set("f", 6), false); -- "c" won't evict (cb returned false)
expect_kv("e", 5, c5:head());
expect_kv("c", 3, c5:tail());
end);
it(":table works", function ()
local t = cache.new(3):table();
assert.is.table(t);
t["a"] = "1";
assert.are.equal(t["a"], "1");
t["b"] = "2";
assert.are.equal(t["b"], "2");
t["c"] = "3";
assert.are.equal(t["c"], "3");
t["d"] = "4";
assert.are.equal(t["d"], "4");
assert.are.equal(t["a"], nil);
local i = spy.new(function () end);
for k, v in pairs(t) do
i(k,v)
end
assert.spy(i).was_called();
assert.spy(i).was_called_with("b", "2");
assert.spy(i).was_called_with("c", "3");
assert.spy(i).was_called_with("d", "4");
end);
local function vs(t)
local vs_ = {};
for v in t:values() do
vs_[#vs_+1] = v;
end
return vs_;
end
it(":values works", function ()
local t = cache.new(3);
t:set("k1", "v1");
t:set("k2", "v2");
assert.same({"v2", "v1"}, vs(t));
t:set("k3", "v3");
assert.same({"v3", "v2", "v1"}, vs(t));
t:set("k4", "v4");
assert.same({"v4", "v3", "v2"}, vs(t));
end);
it(":resize works", function ()
local c = cache.new(5);
for i = 1, 5 do
c:set(("k%d"):format(i), ("v%d"):format(i));
end
assert.same({"v5", "v4", "v3", "v2", "v1"}, vs(c));
assert.has_error(function ()
c:resize(-1);
end);
assert.has_error(function ()
c:resize(0);
end);
assert.has_error(function ()
c:resize("foo");
end);
c:resize(3);
assert.same({"v5", "v4", "v3"}, vs(c));
end);
it("eviction stuff", function ()
local c = cache.new(4, function(_k,_v,c)
if c.size < 10 then
c:resize(c.size*2);
end
end)
for i = 1,20 do
c:set(i,i)
end
assert.equal(16, c.size);
assert.is_nil(c:get(1))
assert.is_nil(c:get(4))
assert.equal(5, c:get(5))
assert.equal(20, c:get(20))
c:resize(4)
assert.equal(20, c:get(20))
assert.equal(17, c:get(17))
assert.is_nil(c:get(10))
end)
end);
end);