Redis store: Lua code: add debug logging, put comments

Author: derhuerst

stores/redis.js

@@ -22,14 +22,15 @@ const ATOMS = 'a'
 const READ_MATCHING_COLLECTION = `\
 local collections_prefix = ARGV[1];
 local rows_prefix = ARGV[2];
-local created_min = tonumber(ARGV[3]);
-local created_max = tonumber(ARGV[4]);
-local when_min = tonumber(ARGV[5]);
-local when_max = tonumber(ARGV[6]);
+local created_min = tonumber(ARGV[3]); -- UNIX epoch in seconds
+local created_max = tonumber(ARGV[4]); -- UNIX epoch in seconds
+local when_min = tonumber(ARGV[5]); -- UNIX epoch in milliseconds
+local when_max = tonumber(ARGV[6]); -- UNIX epoch in milliseconds
 
 local function read_collection (id)
 	local rows = {};
 
+	redis.log(redis.LOG_DEBUG, 'scanning for collection rows (rows_prefix: ' .. rows_prefix .. ')');
 	local cursor = "0";
 	while true do
 		-- todo: pass in collection rows prefix
@@ -43,22 +44,28 @@ local function read_collection (id)
 
 			if when >= when_min and when <= when_max
 			then
+				redis.log(redis.LOG_VERBOSE, 'collection row ' .. i .. ' matches');
 				local row = redis.call("get", key);
 				table.insert(rows, {i, row});
+			else
+				redis.log(redis.LOG_VERBOSE, 'collection row ' .. i .. ' doesn\\'t match (when: ' .. when .. ')');
 			end
 		end
 
 		if cursor == "0" then
+			redis.log(redis.LOG_VERBOSE, 'done scanning for collection rows');
 			break
 		end
 	end
 
 	return rows;
 end
 
+redis.log(redis.LOG_DEBUG, 'scanning for collections (collections_prefix: ' .. collections_prefix .. ')');
 local cursor = "0";
 while true do
 	-- todo: scan in reverse order to, when in doubt, get the latest collection
+	-- todo: COUNT 30 instead?
 	local res = redis.call("scan", cursor, "match", collections_prefix .. "*", "COUNT", 100);
 	cursor = res[1];
 
@@ -70,17 +77,24 @@ while true do
 		then
 			local col = redis.call("get", key);
 			local _, __, id, when, duration = string.find(col, "([^:]+):([^:]+):([^:]+)");
+			redis.log(redis.LOG_VERBOSE, 'id: ' .. id .. 'when: ' .. when .. ' duration: ' .. duration);
 			when = tonumber(when);
 			duration = tonumber(duration);
 
 			if when <= when_min and (when + duration) >= when_max
 			then
+				redis.log(redis.LOG_VERBOSE, 'collection ' .. id .. ' matches');
 				return read_collection(id);
+			else
+				redis.log(redis.LOG_VERBOSE, 'collection ' .. id .. ' doesn\\'t match (when: ' .. when .. ' duration: ' .. duration .. ')');
 			end
+		else
+			redis.log(redis.LOG_VERBOSE, 'collection ' .. id .. ' doesn\\'t match (created: ' .. created .. ')');
 		end
 	end
 
 	if cursor == "0" then
+		redis.log(redis.LOG_VERBOSE, 'done scanning for collections');
 		break
 	end
 end
@@ -90,9 +104,10 @@ return nil;
 
 const READ_MATCHING_ATOM = `\
 local prefix = ARGV[1];
-local created_min = tonumber(ARGV[2]);
-local created_max = tonumber(ARGV[3]);
+local created_min = tonumber(ARGV[2]); -- UNIX epoch in seconds
+local created_max = tonumber(ARGV[3]); -- UNIX epoch in seconds
 
+redis.log(redis.LOG_DEBUG, 'scanning for atoms (prefix: ' .. prefix .. ')');
 local cursor = "0";
 while true do
 	-- todo: scan in reverse order to, when in doubt, get the latest atom
@@ -107,10 +122,13 @@ while true do
 		then
 			local atom = redis.call("get", key);
 			return atom;
+		else
+			redis.log(redis.LOG_VERBOSE, 'atom doesn\\'t match (created: ' .. created .. ')');
 		end
 	end
 
 	if cursor == "0" then
+		redis.log(redis.LOG_VERBOSE, 'done scanning for atoms');
 		break
 	end
 end