From 1b6e877724a25eeecaa24993fb8e55759c2f14f1 Mon Sep 17 00:00:00 2001
From: Tindy X <49061470+tindy2013@users.noreply.github.com>
Date: Sun, 1 Mar 2020 01:58:59 +0800
Subject: [PATCH] Enhancements

Add mutex lock to prevent reading and writing a cached file at the same time.
Optimize codes.
---
 src/misc.cpp   | 3 ++-
 src/misc.h     | 2 +-
 src/webget.cpp | 7 +++++++
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/misc.cpp b/src/misc.cpp
index 4967042..32e6103 100644
--- a/src/misc.cpp
+++ b/src/misc.cpp
@@ -711,10 +711,11 @@ std::string fileGet(const std::string &path, bool scope_limit)
         std::fseek(fp, 0, SEEK_END);
         long tot = std::ftell(fp);
         char *data = new char[tot + 1];
+        data[tot] = '\0';
         std::rewind(fp);
         std::fread(&data[0], 1, tot, fp);
         std::fclose(fp);
-        content.append(data, 0, tot);
+        content.assign(data, tot);
         delete[] data;
     }
 
diff --git a/src/misc.h b/src/misc.h
index 5388bb0..c8838d7 100644
--- a/src/misc.h
+++ b/src/misc.h
@@ -47,7 +47,7 @@ std::string getFormData(const std::string &raw_data);
 
 void sleep(int interval);
 bool regValid(const std::string &target);
-bool regFind(const std::string &src, const std::string &target);
+bool regFind(const std::string &src, const std::string &match);
 std::string regReplace(const std::string &src, const std::string &match, const std::string &rep);
 bool regMatch(const std::string &src, const std::string &match);
 std::string speedCalc(double speed);
diff --git a/src/webget.cpp b/src/webget.cpp
index b978c7d..7de3c8b 100644
--- a/src/webget.cpp
+++ b/src/webget.cpp
@@ -1,6 +1,7 @@
 #include <iostream>
 #include <unistd.h>
 #include <sys/stat.h>
+#include <mutex>
 
 #include <curl/curl.h>
 
@@ -17,6 +18,9 @@
 
 extern bool print_debug_info;
 
+typedef std::lock_guard<std::mutex> guarded_mutex;
+std::mutex cache_rw_lock;
+
 //std::string user_agent_str = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36";
 std::string user_agent_str = "subconverter/" + std::string(VERSION) + " cURL/" + std::string(LIBCURL_VERSION);
 
@@ -124,6 +128,7 @@ std::string webGet(std::string url, std::string proxy, std::string &response_hea
             if(difftime(now, mtime) <= cache_ttl) // within TTL
             {
                 writeLog(0, "CACHE HIT: '" + url + "', using local cache.");
+                guarded_mutex guard(cache_rw_lock);
                 response_headers = fileGet(path_header, true);
                 return fileGet(path, true);
             }
@@ -134,6 +139,7 @@ std::string webGet(std::string url, std::string proxy, std::string &response_hea
         content = curlGet(url, proxy, response_headers, return_code); // try to fetch data
         if(return_code == CURLE_OK) // success, save new cache
         {
+            guarded_mutex guard(cache_rw_lock);
             fileWrite(path, content, true);
             fileWrite(path_header, response_headers, true);
         }
@@ -142,6 +148,7 @@ std::string webGet(std::string url, std::string proxy, std::string &response_hea
             if(fileExist(path)) // failed, check if cache exist
             {
                 writeLog(0, "Fetch failed. Serving cached content."); // cache exist, serving cache
+                guarded_mutex guard(cache_rw_lock);
                 content = fileGet(path, true);
                 response_headers = fileGet(path_header, true);
             }