Make some methods const (#2614)

Found via cppcheck --inconclusive.

src/curl.cpp

@@ -1089,7 +1089,7 @@ bool S3fsCurl::SetIPResolveType(const char* value)
     return true;
 }
 
-int S3fsCurl::MapPutErrorResponse(int result)
+int S3fsCurl::MapPutErrorResponse(int result) const
 {
     if(result != 0){
         return result;

src/curl.h

@@ -254,7 +254,7 @@ class S3fsCurl
         int MultipartUploadCopyPartSetup(const char* from, const char* to, int part_num, const std::string& upload_id, const headers_t& meta);
         bool MultipartUploadContentPartComplete();
         bool MultipartUploadCopyPartComplete();
-        int MapPutErrorResponse(int result);
+        int MapPutErrorResponse(int result) const;
 
     public:
         // class methods

src/fdcache_page.cpp

@@ -1000,7 +1000,7 @@ void PageList::Dump() const
 // If it is a bad area in the previous case, it will be reported as an error.
 // If the latter case does not match, it will be reported as a warning.
 // 
-bool PageList::CompareSparseFile(int fd, size_t file_size, fdpage_list_t& err_area_list, fdpage_list_t& warn_area_list)
+bool PageList::CompareSparseFile(int fd, size_t file_size, fdpage_list_t& err_area_list, fdpage_list_t& warn_area_list) const
 {
     err_area_list.clear();
     warn_area_list.clear();

src/fdcache_page.h

@@ -125,7 +125,7 @@ class PageList
         bool Compress();
         bool Deserialize(CacheFileStat& file, ino_t inode);
         void Dump() const;
-        bool CompareSparseFile(int fd, size_t file_size, fdpage_list_t& err_area_list, fdpage_list_t& warn_area_list);
+        bool CompareSparseFile(int fd, size_t file_size, fdpage_list_t& err_area_list, fdpage_list_t& warn_area_list) const;
 };
 
 #endif // S3FS_FDCACHE_PAGE_H_

src/fdcache_untreated.cpp

@@ -27,7 +27,7 @@
 //------------------------------------------------
 // UntreatedParts methods
 //------------------------------------------------
-bool UntreatedParts::empty()
+bool UntreatedParts::empty() const
 {
     const std::lock_guard<std::mutex> lock(untreated_list_lock);
     return untreated_list.empty();

src/fdcache_untreated.h

@@ -48,7 +48,7 @@ class UntreatedParts
         UntreatedParts& operator=(const UntreatedParts&) = delete;
         UntreatedParts& operator=(UntreatedParts&&) = delete;
 
-        bool empty();
+        bool empty() const;
 
         bool AddPart(off_t start, off_t size);
         bool GetLastUpdatedPart(off_t& start, off_t& size, off_t max_size, off_t min_size = MIN_MULTIPART_SIZE) const { return RowGetPart(start, size, max_size, min_size, true); }

src/s3fs_cred.cpp

@@ -1039,7 +1039,7 @@ bool S3fsCred::InitialS3fsCredentials()
 //-------------------------------------------------------------------
 // Methods : for IAM
 //-------------------------------------------------------------------
-bool S3fsCred::ParseIAMCredentialResponse(const char* response, iamcredmap_t& keyval)
+bool S3fsCred::ParseIAMCredentialResponse(const char* response, iamcredmap_t& keyval) const
 {
     if(!response){
       return false;

src/s3fs_cred.h

@@ -148,7 +148,7 @@ class S3fsCred
         bool ReadAwsCredentialFile(const std::string &filename) REQUIRES(S3fsCred::token_lock);
 
         bool InitialS3fsCredentials() REQUIRES(S3fsCred::token_lock);
-        bool ParseIAMCredentialResponse(const char* response, iamcredmap_t& keyval);
+        bool ParseIAMCredentialResponse(const char* response, iamcredmap_t& keyval) const;
 
         bool GetIAMCredentialsURL(std::string& url, bool check_iam_role) REQUIRES(S3fsCred::token_lock);
         bool LoadIAMCredentials() REQUIRES(S3fsCred::token_lock);

src/s3fs_logger.cpp

@@ -234,7 +234,7 @@ S3fsLog::s3fs_log_level S3fsLog::LowSetLogLevel(s3fs_log_level level)
     return old;
 }
 
-S3fsLog::s3fs_log_level S3fsLog::LowBumpupLogLevel()
+S3fsLog::s3fs_log_level S3fsLog::LowBumpupLogLevel() const
 {
     if(S3fsLog::pSingleton != this){
         S3FS_PRN_ERR("This object is not as same as S3fsLog::pSingleton.");

src/s3fs_logger.h

@@ -67,7 +67,7 @@ class S3fsLog
         bool LowLoadEnv();
         bool LowSetLogfile(const char* pfile);
         s3fs_log_level LowSetLogLevel(s3fs_log_level level);
-        s3fs_log_level LowBumpupLogLevel();
+        s3fs_log_level LowBumpupLogLevel() const;
 
     public:
         static bool IsS3fsLogLevel(s3fs_log_level level);