Creating a mix and max function - lua

I have a function which tells me if there is a crossover between sources (not allowed) between elements for two vendors. I won't go into how this is constructed as it will require a lot of explanation and I'm trying to keep this simple. All you need to know is that it takes two concatenated vendor names and returns true/false if they have no overlap or do (respectively).
E.g.
noCrossover["TescoSainsburys"] = true
Now, I want to find the best combination of stores to get a product A, without calling the source multiple times. For just two stores, this is easy (I have a table constructed earlier which contains vendors already):
vendorsCalled = {"Tesco", "Sainsburys"}
if noCrossover[vendorsCalled[1] .. vendorsCalled[2]] then
numProductsAgr = tescoProductA + sainsburysProductA
else
numProductsAgr = math.max(tescoProductA, sainsburysProductA)
end
However, as I increase the number of vendors, it gets more complex:
vendorsCalled = {"Tesco", "Sainsburys", Waitrose"}
if noCrossover[vendorsCalled[1] .. vendorsCalled[2]] and
noCrossover[vendorsCalled[1] .. vendorsCalled[3]] and
noCrossover[vendorsCalled[2] .. vendorsCalled[3]] then
numProductsAgr123 = tescoProductA + sainsburysProductA + waitroseProductA
else
numProductsAgr123 = 0
end
if noCrossover[vendorsCalled[1] .. vendorsCalled[2]] then
numProductsAgr12 = tescoProductA + sainsburysProductA
else
numProductsAgr12 = math.max(tescoProductA, sainsburysProductA)
end
if noCrossover[vendorsCalled[1] .. vendorsCalled[3]] then
numProductsAgr13 = tescoProductA + waitroseProductA
else
numProductsAgr13= math.max(tescoProductA, waitroseProductA)
end
if noCrossover[vendorsCalled[2] .. vendorsCalled[3]] then
numProductsAgr23 = sainsburysProductA + waitroseProductA
else
numProductsAgr23 = math.max(sainsburysProductA + waitroseProductA)
end
numResidencyMatchesAgr = math.max(numProductsAgr123 , numProductsAgr12 , numProductsAgr13 , numProductsAgr23 )
and it gets harder again with 4.
It's also worth noting that these are used in different places (1,2,3,4 stores) so I can use separate functions for each where I define how many stores are used.
I also need to be able to work out which vendors my final number steams from
Is there a better, more concise way of doing this to avoid needing to write out these log error prone scripts?

Related

Using Insert with a large multi-layered table using Lua

So I am working on a script for GTA5 and I need to transfer data over to a js script. However so I don't need to send multiple arrays to js I require a table, the template for the table should appear as below.
The issue I'm having at the moment is in the second section where I receive all vehicles and loop through each to add it to said 'vehicleTable'. I haven't been able to find the "table.insert" method used in a multilayered table
So far I've tried the following
table.insert(vehicleTable,vehicleTable[class][i][vehicleName])
This seems to store an 'object'(table)? so it does not show up when called in the latter for loop
Next,
vehicleTable = vehicleTable + vehicleTable[class][i][vehicleName]
This seemed like it was going nowhere as I either got a error or nothing happened.
Next,
table.insert(vehicleTable,class)
table.insert(vehicleTable[class],i)
table.insert(vehicleTable[class][i],vehicleName)
This one failed on the second line, I'm unsure why however it didn't even reach the next problem I saw later which would be the fact that line 3 had no way to specify the "Name" field.
Lastly the current one,
local test = {[class] = {[i]={["Name"]=vehicleName}}}
table.insert(vehicleTable,test)
It works without errors but ultimately it doesn't file it in the table instead it seems to create its own branch so object within the object.
And after about 3 hours of zero progress on this topic I turn to the stack overflow for assistance.
local vehicleTable = {
["Sports"] = {
[1] = {["Name"] = "ASS", ["Hash"] = "Asshole2"},
[2] = {["Name"] = "ASS2", ["Hash"] = "Asshole1"}
},
["Muscle"] = {
[1] = {["Name"] = "Sedi", ["Hash"] = "Sedina5"}
},
["Compacts"] = {
[1] = {["Name"] = "MuscleCar", ["Hash"] = "MCar2"}
},
["Sedan"] = {
[1] = {["Name"] = "Blowthing", ["Hash"] = "Blowthing887"}
}
}
local vehicles = GetAllVehicleModels();
for i=1, #vehicles do
local class = vehicleClasses[GetVehicleClassFromName(vehicles[i])]
local vehicleName = GetLabelText(GetDisplayNameFromVehicleModel(vehicles[i]))
print(vehicles[i].. " " .. class .. " " .. vehicleName)
local test = {[class] = {[i]={["Name"]=vehicleName}}}
table.insert(vehicleTable,test)
end
for k in pairs(vehicleTable) do
print(k)
-- for v in pairs(vehicleTable[k]) do
-- print(v .. " " .. #vehicleTable[k])
-- end
end
If there is not way to add to a library / table how would I go about sorting all this without needing to send a million (hash, name, etc...) requests to js?
Any recommendations or support would be much appreciated.
Aside the fact that you do not provide the definition of multiple functions and tables used in your code that would be necessary to provide a complete answere without making assumptions there are many misconceptions regarding very basic topics in Lua.
The most prominent is that you don't know how to use table.insert and what it can do. It will insert (append by default) a numeric field to a table. Given that you have non-numeric keys in your vehicleTable this doesn't make too much sense.
You also don't know how to use the + operator and that it does not make any sense to add a table and a string.
Most of your code seems to be the result of guess work and trial and error.
Instead of referring to the Lua manual so you know how to use table.insert and how to index tables properly you spend 3 hours trying all kinds of variations of your incorrect code.
Assuming a vehicle model is a table like {["Name"] = "MyCar", ["Hash"] = "MyCarHash"} you can add it to a vehicle class like so:
table.insert(vehicleTable["Sedan"], {["Name"] = "MyCar", ["Hash"] = "MyCarHash"})
This makes sense because vehicleTable.Sedan has numeric indices. And after that line it would contain 2 cars.
Read the manual. Then revisit your code and fix your errors.

LUA indexed table access via named constants

I am using LUA as embedded language on a µC project, so the ressources are limited. To save some cycles and memory I do always only indexed based table access (table[1]) instead og hash-based access (table.someMeaning = 1). This saves a lot of memory.
The clear drawback of this is approach are the magic numbers thrughtout the code.
A Cpp-like preprocessor would help here to replace the number with named-constants.
Is there a good way to achieve this?
A preprocessor in LUA itself, loading the script and editing the chunk and then loading it would be a variant, but I think this exhausts the ressources in the first place ...
So, I found a simple solution: write your own preprocessor in Lua!
It's probably the most easy thing to do.
First, define your symbols globally:
MySymbols = {
FIELD_1 = 1,
FIELD_2 = 2,
FIELD_3 = 3,
}
Then you write your preprocessing function, which basically just replace the strings from MySymbols by their value.
function Preprocess (FilenameIn, FilenameOut)
local FileIn = io.open(FilenameIn, "r")
local FileString = FileIn:read("*a")
for Name, Value in pairs(MySymbols) do
FileString = FileString:gsub(Name, Value)
end
FileIn:close()
local FileOut = io.open(FilenameOut, "w")
FileOut:write(FileString)
FileOut:close()
end
Then, if you try with this input file test.txt:
TEST FIELD_1
TEST FIELD_2
TEST FIELD_3
And call the following function:
Preprocess("test.txt", "test-out.lua")
You will get the fantastic output file:
TEST 1
TEST 2
TEST 3
I let you the joy to integrate it with your scripts/toolchain.
If you want to avoid attributing the number manually, you could just add a wonderful closure:
function MakeCounter ()
local Count = 0
return function ()
Count = Count + 1
return Count
end
end
NewField = MakeCounter()
MySymbols = {
FIELD_1 = NewField(),
FIELD_2 = NewField(),
FIELD_3 = NewField()
}

cyclomatic complexity is too high rubocop for method

This is code I have using in my project.
Please suggest some optimizations (I have refactored this code a lot but I can't think of any progress further to optimize it )
def convert_uuid_to_emails(user_payload)
return unless (user_payload[:target] == 'ticket' or user_payload[:target] == 'change')
action_data = user_payload[:actions]
action_data.each do |data|
is_add_project = data[:name] == 'add_fr_project'
is_task = data[:name] == 'add_fr_task'
next unless (is_add_project or is_task)
has_reporter_uuid = is_task && Va::Action::USER_TYPES.exclude?(data[:reporter_uuid])
user_uuids = data[:user_uuids] || []
user_uuids << data[:owner_uuid] if Va::Action::USER_TYPES.exclude?(data[:owner_uuid])
user_uuids << data[:reporter_uuid] if has_reporter_uuid
users_data = current_account.authorizations.includes(:user).where(uid: user_uuids).each_with_object({}) { |a, o| o[a.uid] = {uuid: a.uid, user_id: a.user.id, user_name: a.user.name} }
if Va::Action::USER_TYPES.include? data[:owner_uuid]
data['owner_details'] = {}
else
data['owner_details'] = users_data[data[:owner_uuid]]
users_data.delete(data[:owner_uuid])
end
data['reporter_details'] = has_reporter_uuid ? users_data[data[:reporter_uuid]] : {}
data['user_details'] = users_data.values
end
end
Note that Rubocop is complaining that your code is too hard to understand, not that it won't work correctly. The method is called convert_uuid_to_emails, but it doesn't just do that:
validates payload is one of two types
filters the items in the payload by two other types
determines the presence of various user roles in the input
shove all the found user UUIDs into an array
convert the UUIDs into users by looking them up
find them again in the array to enrich the various types of user details in the payload
This comes down to a big violation of the SRP (single responsibility principle), not to mention that it is a method that might surprise the caller with its unexpected list of side effects.
Obviously, all of these steps still need to be done, just not all in the same method.
Consider breaking these steps out into separate methods that you can compose into an enrich_payload_data method that works at a higher level of abstraction, keeping the details of how each part works local to each method. I would probably create a method that takes a UUID and converts it to a user, which can be called each time you need to look up a UUID to get the user details, as this doesn't appear to be role-specific.
The booleans is_task, is_add_project, and has_reporter_uuid are just intermediate variables that clutter up the code, and you probably won't need them if you break it down into smaller methods.

Mongoid caching or multiple requests accessing the Database

I have an application running on Rails 4 using MongoDB and mongoid to connect the Rails app with Mongodb.
Let me please paste in a few lines of my trouble maker code.
def generate_transaction_uuid
current_time = Time.now
julian_date = current_time.strftime("%j")
year = current_time.strftime("%Y")
date = current_time.strftime("%H")
channel_identifier = '1'
last_transaction_random_sequence = TransactionUuid.last.transaction_uuid[-5..-1]
if last_transaction_random_sequence.to_i == 99999
running_sequence_numbers = '00000'
else
current_sequence_number = (last_transaction_random_sequence.to_i + 1).to_s
running_sequence_numbers = '0' * (5 - (current_sequence_number).length) + current_sequence_number.to_s
end
uuid = year[-1] + julian_date[-3..-1] + date + channel_identifier + running_sequence_numbers
TransactionUuid.create(transaction_uuid: uuid)
uuid
end
The code above generates a transaction uuid. The logic ( the core part ) is generating the last 5 digits of the transaction id, the running sequence number. Currently the logic is to generate an id and store it in a table 'TransactionUuid'. When the next request arrives, the last stored uuid is queried from the table, the last 5 digits extracted out of that and the next sequence number is created. Its again inserted into the DB and the process goes on.
last_transaction_random_sequence = TransactionUuid.last.transaction_uuid[-5..-1]
if last_transaction_random_sequence.to_i == 99999
running_sequence_numbers = '00000'
else
current_sequence_number = (last_transaction_random_sequence.to_i + 1).to_s
running_sequence_numbers = '0' * (5 - (current_sequence_number).length) + current_sequence_number.to_s
end
This works fine in most cases and gives unique transaction ids for each Rails request. But on certain cases, this generates duplicate transaction Ids. Why exactly does that happen is quite unclear to me because from the code its quite evident that the transaction Ids generated are to be unique. Also, when i run the code manually it doesnt seem to be having a problem.
I inspected into the Rails logs to check if the problem is having two simultaneous requests accessing the database at the same time, which is possible. But from the Rails logs, it seems that even requests that have a difference of about 20seconds in between them seem to generate the same transaction id on certain instances. This is whats really confusing me. We use nginx-passenger to serve our requests.
What exactly might be the issue here, some kind of database caching that happens internally or some totally unrelated weird problem or may be even a bug in my code? Any kind of help on this would be much appreciated.

Using index value in method

In my Rails application, in a model, I am trying to use the loop index x in the following method, and I can't figure out how to get the value:
def set_winners ## loops over 4 quarters
1.upto(4) do |x|
qtr_[x]_winner.winner = 1
qtr_[x]_winner.save
end
end
I'm going to keep searching but any help would be greatly appreciated!
edit: So I guess I can't do that! Here is the original method I was trying to refactor in full by looping four times:
def set_winners
## set all 4 quarter's winning squares
home_qtr_1 = game.home_q1_score.to_s.split('').last.to_i
away_qtr_1 = game.away_q1_score.to_s.split('').last.to_i
qtr_1_winner = squares.where(xvalue:home_qtr_1, yvalue:away_qtr_1).first
qtr_1_winner.winner = 1
qtr_1_winner.save
home_qtr_2 = game.home_q2_score.to_s.split('').last.to_i
away_qtr_2 = game.away_q2_score.to_s.split('').last.to_i
qtr_2_winner = squares.where(xvalue:home_qtr_2, yvalue:away_qtr_2).first
qtr_2_winner.winner = 1
qtr_2_winner.save
home_qtr_3 = game.home_q3_score.to_s.split('').last.to_i
away_qtr_3 = game.away_q3_score.to_s.split('').last.to_i
qtr_3_winner = squares.where(xvalue:home_qtr_3, yvalue:away_qtr_3).first
qtr_3_winner.winner = 1
qtr_3_winner.save
home_qtr_4 = game.home_q4_score.to_s.split('').last.to_i
away_qtr_4 = game.away_q4_score.to_s.split('').last.to_i
qtr_4_winner = squares.where(xvalue:home_qtr_4, yvalue:away_qtr_4).first
qtr_4_winner.winner = 1
qtr_4_winner.save
end
Is there a better way to do this if it's bad practice to dynamically change attribute names?
It looks like you are trying to do a PHP-like trick in a language that doesn't support it, and where we recommend NOT doing it because it results in code that is very difficult to debug due to the dynamically named variables.
It looks like you want to generate a variable name using:
qtr_[x]_winner
to create something like:
qtr_1_winner
Instead, consider creating an array named qtr_winner containing your objects and access the elements like:
qtr_winner[1]
or
qtr_winner[2]
etc.
You could create a hash to do a similar thing:
qtr_winner = {}
qtr_winner[1] = 5
then later access it using qtr_winner[1] and get 5 back or
qtr_winner[1].winner = 1
The determination of whether to use a hash or an array is whether you need to walk the container, or need random access. If you are always indexing into it using a value, then it's probably a wash about which is faster.
Based on your edit, you don't need dynamic variables. The only thing that changes in your loop is game.home_qN_score, so that's what the focus of your refactoring should be. Given that, here's a viable solution:
1.upto(4) do |i|
home_qtr = game.send("home_q#{i}_score)".to_s.split('').last.to_i
away_qtr = game.send("away_q#{i}_score)".to_s.split('').last.to_i
winner = squares.where(xvalue:home_qtr, yvalue:away_qtr).first
winner.winner = 1
winner.save
end
Original answer:
If qtr_1_winner, etc. are instance methods, you can use Object#send to achieve what you want:
def set_winners ## loops over 4 quarters
1.upto(4) do |x|
send("qtr_#{x}_winner").winner = 1
send("qtr_#{x}_winner").save
end
end

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