From ed2a6b3ce80bf35b3171e1ae263afd1f53aff781 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Mon, 2 Sep 2019 08:23:38 -0400
Subject: [PATCH] Card: Make querying functions const member functions where
 applicable

These don't modify member state, so they can be made const .
---
 include/kabufuda/Card.hpp |  8 ++++----
 lib/kabufuda/Card.cpp     | 15 +++++++++------
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/include/kabufuda/Card.hpp b/include/kabufuda/Card.hpp
index 6b913db..5a56a51 100644
--- a/include/kabufuda/Card.hpp
+++ b/include/kabufuda/Card.hpp
@@ -204,7 +204,7 @@ public:
    *
    * @return Gets the name of the given file.
    */
-  const char* getFilename(const FileHandle& fh);
+  const char* getFilename(const FileHandle& fh) const;
 
   /**
    * @brief deleteFile
@@ -269,7 +269,7 @@ public:
    *
    * @return The offset or -1 if an invalid handle is passed.
    */
-  int32_t tell(const FileHandle& fh);
+  int32_t tell(const FileHandle& fh) const;
 
   /**
    * @brief setPublic
@@ -425,7 +425,7 @@ public:
    * @param checksum The checksum of the system header.
    * @param inverse  The inverse checksum of the system header.
    */
-  void getChecksum(uint16_t& checksum, uint16_t& inverse);
+  void getChecksum(uint16_t& checksum, uint16_t& inverse) const;
 
   /**
    * @brief Retrieves the available storage and directory space.
@@ -433,7 +433,7 @@ public:
    * @param bytesNotUsed Number of free bytes out.
    * @param filesNotUsed Number of free files out.
    */
-  void getFreeBlocks(int32_t& bytesNotUsed, int32_t& filesNotUsed);
+  void getFreeBlocks(int32_t& bytesNotUsed, int32_t& filesNotUsed) const;
 
   /**
    * @brief Formats the memory card and assigns a new serial.
diff --git a/lib/kabufuda/Card.cpp b/lib/kabufuda/Card.cpp
index f517df8..63f1cf8 100644
--- a/lib/kabufuda/Card.cpp
+++ b/lib/kabufuda/Card.cpp
@@ -246,10 +246,13 @@ FileHandle Card::nextFile(const FileHandle& cur) {
   return FileHandle(m_dirs[m_currentDir].indexForFile(next));
 }
 
-const char* Card::getFilename(const FileHandle& fh) {
-  File* f = _fileFromHandle(fh);
-  if (!f)
+const char* Card::getFilename(const FileHandle& fh) const {
+  const File* const f = _fileFromHandle(fh);
+
+  if (f == nullptr) {
     return nullptr;
+  }
+
   return f->m_filename;
 }
 
@@ -454,7 +457,7 @@ void Card::seek(FileHandle& fh, int32_t pos, SeekOrigin whence) {
   }
 }
 
-int32_t Card::tell(const FileHandle& fh) { return fh.offset; }
+int32_t Card::tell(const FileHandle& fh) const { return fh.offset; }
 
 void Card::setPublic(const FileHandle& fh, bool pub) {
   File* file = _fileFromHandle(fh);
@@ -755,12 +758,12 @@ void Card::getSerial(uint64_t& serial) {
   m_ch._swapEndian();
 }
 
-void Card::getChecksum(uint16_t& checksum, uint16_t& inverse) {
+void Card::getChecksum(uint16_t& checksum, uint16_t& inverse) const {
   checksum = m_ch.m_checksum;
   inverse = m_ch.m_checksumInv;
 }
 
-void Card::getFreeBlocks(int32_t& bytesNotUsed, int32_t& filesNotUsed) {
+void Card::getFreeBlocks(int32_t& bytesNotUsed, int32_t& filesNotUsed) const {
   bytesNotUsed = m_bats[m_currentBat].numFreeBlocks() * 0x2000;
   filesNotUsed = m_dirs[m_currentDir].numFreeFiles();
 }