From c6af346c9253e28f6d593f18f9bbc533c31c8b59 Mon Sep 17 00:00:00 2001
From: Jay Bosamiya <jaybosamiya@gmail.com>
Date: Sun, 26 Apr 2020 14:53:51 -0400
Subject: [PATCH] Introduces randomness to state order

---
 Cargo.lock  | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 Cargo.toml  |  1 +
 src/main.rs | 15 +++++++++++
 3 files changed, 87 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index f64c90e..1fab22d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -32,6 +32,12 @@ version = "1.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
 
+[[package]]
+name = "cfg-if"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
+
 [[package]]
 name = "clap"
 version = "2.33.0"
@@ -47,6 +53,17 @@ dependencies = [
  "vec_map",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7abc8dd8451921606d809ba32e95b6111925cd2906060d2dcc29c070220503eb"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
 [[package]]
 name = "hermit-abi"
 version = "0.1.10"
@@ -62,6 +79,53 @@ version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dea0c0405123bba743ee3f91f49b1c7cfb684eef0da0a50110f758ccf24cdff0"
 
+[[package]]
+name = "ppv-lite86"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "74490b50b9fbe561ac330df47c08f3f33073d2d00c150f719147d7c54522fa1b"
+
+[[package]]
+name = "rand"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
+dependencies = [
+ "getrandom",
+ "libc",
+ "rand_chacha",
+ "rand_core",
+ "rand_hc",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4c8ed856279c9737206bf725bf36935d8666ead7aa69b52be55af369d193402"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
+dependencies = [
+ "rand_core",
+]
+
 [[package]]
 name = "regex-automata"
 version = "0.1.9"
@@ -83,6 +147,7 @@ name = "regex2fat"
 version = "0.1.0"
 dependencies = [
  "clap",
+ "rand",
  "regex-automata",
 ]
 
@@ -113,6 +178,12 @@ version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
 
+[[package]]
+name = "wasi"
+version = "0.9.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
+
 [[package]]
 name = "winapi"
 version = "0.3.8"
diff --git a/Cargo.toml b/Cargo.toml
index 6a73ff9..574ad9b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,3 +13,4 @@ license = "Unlicense"
 [dependencies]
 regex-automata = "0.1"
 clap = "2.33"
+rand = "0.7.3"
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index 3a7b6fe..d84bd02 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,7 @@
 mod fat32;
 use clap::{App, Arg};
 use fat32::{StateFatMap, StatePosInfo, UFat};
+use rand::{thread_rng,seq::SliceRandom};
 use regex_automata::{dense, DFA};
 use std::collections::{HashMap, HashSet};
 use std::error::Error;
@@ -32,6 +33,7 @@ fn determine_state_positions<D: DFA>(
     // keep track of visited states
     let mut state_set = HashSet::new();
     state_vec.push(dfa.start_state());
+
     while let Some(&current_state) = state_vec.get(current_index) {
         // queue all unvisited states from current state
         for &next_byte in validlist {
@@ -40,6 +42,13 @@ fn determine_state_positions<D: DFA>(
                 state_vec.push(next_state);
             }
         }
+        current_index += 1;
+    }
+
+    state_vec.shuffle(&mut thread_rng());
+    current_index = 0;
+
+    while let Some(&current_state) = state_vec.get(current_index) {
         // relevant for size of directory (but mostly not because it's constant
         // and they're both the same)
         let size = if dfa.is_match_state(current_state) {
@@ -124,6 +133,12 @@ fn main() {
                 .long("anchor")
                 .help("Anchor regex at beginning (off by default)"),
         )
+        .arg(
+            Arg::with_name("randomize")
+                .short("r")
+                .long("randomize")
+                .help("Randomize cluster numbers for the states (off by default)"),
+        )
         .arg(
             Arg::with_name("pattern")
                 .required(true)