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-rw-r--r--spec/util_smqueue_spec.lua55
-rw-r--r--teal-src/util/smqueue.tl107
-rw-r--r--util/smqueue.lua61
3 files changed, 223 insertions, 0 deletions
diff --git a/spec/util_smqueue_spec.lua b/spec/util_smqueue_spec.lua
new file mode 100644
index 00000000..991a656b
--- /dev/null
+++ b/spec/util_smqueue_spec.lua
@@ -0,0 +1,55 @@
+describe("util.smqueue", function()
+
+ local smqueue
+ setup(function() smqueue = require "util.smqueue"; end)
+
+ describe("#new()", function()
+ it("should work", function()
+ local q = smqueue.new(10);
+ assert.truthy(q);
+ end)
+ end)
+
+ describe("#push()", function()
+ it("should allow pushing many items", function()
+ local q = smqueue.new(10);
+ for i = 1, 20 do q:push(i); end
+ assert.equal(20, q:count_unacked());
+ end)
+ end)
+
+ describe("#resumable()", function()
+ it("returns true while the queue is small", function()
+ local q = smqueue.new(10);
+ for i = 1, 10 do q:push(i); end
+ assert.truthy(q:resumable());
+ q:push(11);
+ assert.falsy(q:resumable());
+ end)
+ end)
+
+ describe("#ack", function()
+ it("allows removing items", function()
+ local q = smqueue.new(10);
+ for i = 1, 10 do q:push(i); end
+ assert.same({ 1; 2; 3 }, q:ack(3));
+ assert.same({ 4; 5; 6 }, q:ack(6));
+ assert.falsy(q:ack(3), "can't go backwards")
+ assert.falsy(q:ack(100), "can't ack too many")
+ for i = 11, 20 do q:push(i); end
+ assert.same({ 11; 12 }, q:ack(12), "items are dropped");
+ end)
+ end)
+
+ describe("#resume", function()
+ it("iterates over current items", function()
+ local q = smqueue.new(10);
+ for i = 1, 12 do q:push(i); end
+ assert.same({ 3; 4; 5; 6 }, q:ack(6));
+ assert.truthy(q:resumable());
+ local resume = {}
+ for _, i in q:resume() do resume[i] = true end
+ assert.same({ [7] = true; [8] = true; [9] = true; [10] = true; [11] = true; [12] = true }, resume);
+ end)
+ end)
+end);
diff --git a/teal-src/util/smqueue.tl b/teal-src/util/smqueue.tl
new file mode 100644
index 00000000..0bbceb8e
--- /dev/null
+++ b/teal-src/util/smqueue.tl
@@ -0,0 +1,107 @@
+local queue = require "util.queue";
+
+local record lib
+ -- T would typically be util.stanza
+ record smqueue<T>
+ _queue : queue.queue<T>
+ _head : integer
+ _tail : integer
+
+ enum ack_errors
+ "tail"
+ "head"
+ "pop"
+ end
+ push : function (smqueue, T)
+ ack : function (smqueue, integer) : { T }, ack_errors
+ resumable : function (smqueue) : boolean
+ type consume_iter = function (smqueue<T>) : T
+ consume : function (smqueue<T>) : consume_iter
+
+ table : function (smqueue<T>) : { T }
+ end
+ new : function <T>(integer) : smqueue<T>
+end
+
+local type smqueue = lib.smqueue;
+
+function smqueue:push(v)
+ self._head = self._head + 1;
+ -- Wraps instead of errors
+ assert(self._queue:push(v));
+end
+
+function smqueue:ack(h : integer) : { any }, smqueue.ack_errors
+ if h < self._tail then
+ return nil, "tail";
+ elseif h > self._head then
+ return nil, "head";
+ end
+ -- TODO optimize? cache table fields
+ local acked = {};
+ self._tail = h;
+ local expect = self._head - self._tail;
+ while expect < self._queue:count() do
+ local v = self._queue:pop();
+ if not v then return nil, "pop"; end
+ table.insert(acked, v);
+ end
+ return acked;
+end
+
+function smqueue:count_unacked() : integer
+ return self._head - self._tail;
+end
+
+function smqueue:count_acked() : integer
+ return self._tail;
+end
+
+function smqueue:resumable() : boolean
+ return self._queue:count() >= (self._head - self._tail);
+end
+
+function smqueue:resume() : queue.queue.iterator, any, integer
+ return self._queue:items();
+end
+
+function smqueue:consume() : queue.queue.consume_iter
+ return self._queue:consume()
+end
+
+-- Compatibility wrapper, meant to look like a plain ol' array
+local record compat_mt
+ _queue : smqueue<any>
+end
+
+function compat_mt:__index(i : integer) : any
+ if i < self._queue._tail then return nil end
+ return self._queue._queue._items[(i + self._queue._tail) % self._queue._queue.size];
+end
+
+function compat_mt:__len() : integer
+ return self._queue:count_unacked()
+end
+
+function smqueue:table() : { any }
+ return setmetatable({ _queue = self }, compat_mt);
+end
+
+local function freeze(q : smqueue<any>) : { string:integer }
+ return { head = q._head, tail = q._tail }
+end
+
+local queue_mt = {
+ --
+ __name = "smqueue";
+ __index = smqueue;
+ __len = smqueue.count_unacked;
+ __freeze = freeze;
+}
+
+function lib.new<T>(size : integer) : queue.queue<T>
+ assert(size>0);
+ return setmetatable({ _head = 0; _tail = 0; _queue = queue.new(size, true) }, queue_mt);
+end
+
+return lib;
diff --git a/util/smqueue.lua b/util/smqueue.lua
new file mode 100644
index 00000000..d24c35ae
--- /dev/null
+++ b/util/smqueue.lua
@@ -0,0 +1,61 @@
+local queue = require("util.queue");
+
+local lib = { smqueue = {} }
+
+local smqueue = lib.smqueue;
+
+function smqueue:push(v)
+ self._head = self._head + 1;
+
+ assert(self._queue:push(v));
+end
+
+function smqueue:ack(h)
+ if h < self._tail then
+ return nil, "tail"
+ elseif h > self._head then
+ return nil, "head"
+ end
+
+ local acked = {};
+ self._tail = h;
+ local expect = self._head - self._tail;
+ while expect < self._queue:count() do
+ local v = self._queue:pop();
+ if not v then return nil, "pop" end
+ table.insert(acked, v);
+ end
+ return acked
+end
+
+function smqueue:count_unacked() return self._head - self._tail end
+
+function smqueue:count_acked() return self._tail end
+
+function smqueue:resumable() return self._queue:count() >= (self._head - self._tail) end
+
+function smqueue:resume() return self._queue:items() end
+
+function smqueue:consume() return self._queue:consume() end
+
+local compat_mt = {}
+
+function compat_mt:__index(i)
+ if i < self._queue._tail then return nil end
+ return self._queue._queue._items[(i + self._queue._tail) % self._queue._queue.size]
+end
+
+function compat_mt:__len() return self._queue:count_unacked() end
+
+function smqueue:table() return setmetatable({ _queue = self }, compat_mt) end
+
+local function freeze(q) return { head = q._head; tail = q._tail } end
+
+local queue_mt = { __name = "smqueue"; __index = smqueue; __len = smqueue.count_unacked; __freeze = freeze }
+
+function lib.new(size)
+ assert(size > 0);
+ return setmetatable({ _head = 0; _tail = 0; _queue = queue.new(size, true) }, queue_mt)
+end
+
+return lib