some progress on historical scanning

persistence.lua

@@ -0,0 +1,168 @@
+local on_load, load_dataset, new_dataset, get_dataset_key, get_snapshot, save_snapshot, get_item_record, save_item_record
+local encode_median_list, decode_median_list, serialize, deserialize, deserializing_iterator
+
+local DATABASE_VERSION = 0
+
+aux_database = {}
+
+function on_load()
+	perform_migration(aux_database)
+    aux_database.version = DATABASE_VERSION
+end
+
+function get_dataset_key()
+	local realm = GetCVar('realmName')
+	local zone = GetMinimapZoneText()
+	local faction
+	if zone == 'Gadgetzan' or zone == 'Everlook' or zone == 'Booty Bay' then
+		faction = 'Neutral'
+	else
+		faction = UnitFactionGroup('player')
+	end
+	return realm..'|'..faction
+end
+
+function new_dataset()
+    return {
+        snapshot = '',
+        scan_data = '',
+        item_data = {},
+    }
+end
+
+function load_dataset()
+    local dataset_key = get_dataset_key()
+    aux_database[dataset_key] = aux_database[dataset_key] or new_dataset()
+    return aux_database[dataset_key]
+end
+
+function get_snapshot()
+    local dataset = load_dataset()
+    local signatures = deserialize(dataset.snapshot, '#')
+    local snapshot = Aux.util.set()
+    snapshot.add_all(signatures)
+    return snapshot
+end
+
+function save_snapshot(snapshot)
+	local dataset = load_dataset()
+    dataset.snapshot = serialize(snapshot.values(), '#')
+end
+
+--function load_scan_data()
+--
+--end
+--
+--function store_scan_data()
+--
+--end
+
+function get_item_record(item_key)
+    local dataset = load_dataset()
+
+    if dataset.item_data[item_key] then
+        local serialized_record = dataset.item_data[item_key]
+        local count, accumulated_price, encoded_price_list = unpack(deserialize(serialized_record, '|'))
+        local price_list = decode_median_list(encoded_price_list)
+
+        return {
+            count = count,
+            accumulated_price = accumulated_price,
+            price_list = price_list
+        }
+    end
+end
+
+function save_item_record(item_key, record)
+    local dataset = load_dataset()
+
+    local encoded_price_list = encode_median_list(record.price_list)
+    local serialized_record = serialize({record.count, record.acumulated_price, encoded_price_list}, '|')
+
+    dataset.item_data[item_key] = serialized_record
+end
+
+--    AuctionConfig.data[auctKey][itemKey] = string.format("%s|%s", iData.data, hist);
+--    AuctionConfig.info[itemKey] = string.format("%s|%s", iData.category, iData.name);
+--    Auctioneer.Storage.SetHistMed(auctKey, itemKey, Auctioneer.Statistic.GetMedian(iData.buyoutPricesHistoryList))
+
+function encode_median_list(list)
+    local encoded_list = ''
+    local function extend(last, n)
+        if n == 1 then
+            encoded_list = encoded_list == '' and last or string.format('%s:%d', encoded_list, last)
+        elseif n > 1 then
+            encoded_list = encoded_list == '' and string.format('%dx%d', last, n) or string.format('%s:%dx%d', encoded_list, last, n)
+        end
+    end
+    local n = 0
+    local last = 0
+    for i, price in pairs(list) do
+        if i == 1 then
+            last = price
+        elseif price ~= last then
+            extend(last, n)
+            last = price
+            n = 0
+        end
+        n = n + 1
+    end
+    extend(last, n)
+    return encoded_list
+end
+
+function decode_median_list(str)
+    local array = {}
+    for x, c in string.gfind(str, '([^%:]*)(%:?)') do
+        local _, _, y, n = strfind(x, '(%d*)x(%d*)')
+        if y == nil then
+            tinsert(array, tonumber(x))
+        else
+            for i = 1,n do
+                tinsert(array, tonumber(y))
+            end
+        end
+        if c == '' then break end
+    end
+    return array
+end
+
+function serialize(data, separator)
+    local data_string = ''
+    for i, datum in ipairs(data) do
+        data_string = data_string..(i == 1 and separator or '')..datum
+    end
+    return data_string
+end
+
+function deserialize(data_string, separator)
+    local data = {}
+    while true do
+        local start_index, _ = strfind(data_string, separator, 1, true)
+        if start_index then
+            local datum = string.sub(data_string, 1, start_index - 1)
+            tinsert(data, datum)
+            data_string = string.sub(data_string, start_index + 1, strlen(data_string))
+        else
+            return data
+        end
+    end
+end
+
+function deserializing_iterator(data_string, separator)
+    return function()
+        local start_index, _ = strfind(data_string, separator, 1, true)
+        if start_index then
+            local datum = string.sub(data_string, 1, start_index - 1)
+            data_string = string.sub(data_string, start_index, strlen(data_string))
+            return datum
+        end
+    end
+end
+
+Aux.persistence = {
+    get_item_record = get_item_record,
+    save_item_record = save_item_record,
+    get_snapshot = get_snapshot,
+    save_snapshot = save_snapshot,
+}