- Enable NAG parsing

- Add the LargeFileStream interface to handle large file
- Debug parsing

8 files changed, 205 insertions, 71 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2381751..f493c30 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.10)
 project(pgnp)
 
 # Shared library
-add_library(pgnp SHARED src/PGN.cpp src/HalfMove.cpp)
+add_library(pgnp SHARED src/PGN.cpp src/HalfMove.cpp src/LargeFileStream.cpp)
 
 # Includes
 set(PGNP_INCLUDE_DIR ${CMAKE_CURRENT_BINARY_DIR}/includes) # For conveniance
@@ -10,6 +10,7 @@ set(PGNP_INCLUDE_DIR ${PGNP_INCLUDE_DIR} PARENT_SCOPE) # To be used by other pro
 file(MAKE_DIRECTORY ${PGNP_INCLUDE_DIR})
 configure_file(src/PGN.hpp ${PGNP_INCLUDE_DIR}/pgnp.hpp COPYONLY)
 configure_file(src/HalfMove.hpp ${PGNP_INCLUDE_DIR} COPYONLY)
+configure_file(src/LargeFileStream.hpp ${PGNP_INCLUDE_DIR} COPYONLY)
 
 include_directories(${PGNP_INCLUDE_DIR})
 
diff --git a/README.md b/README.md
index 99fbdb0..af417e3 100644
--- a/README.md
+++ b/README.md
@@ -4,8 +4,10 @@ PGNP is a Portable Game Notation (PGN) parser. More details about the
 PGN specification can be found [here](https://www.chessclub.com/help/PGN-spec).
 
 # Features
-- Basic PGN parsing (tags, move, comments, variations etc.)
+- Basic PGN parsing (tags, move, comments, variations, NAG, etc.)
 - Merged PGN files parsing (several games in one file)
+- Handle very large file (severals GB)
+- Very efficient
 
 # How to use it ?
 PGNP can be used as a shared library in your project.
diff --git a/src/HalfMove.cpp b/src/HalfMove.cpp
index 290587a..7e94ef9 100644
--- a/src/HalfMove.cpp
+++ b/src/HalfMove.cpp
@@ -19,8 +19,8 @@ std::string HalfMove::NestedDump(HalfMove *m, int indent) {
   ss << "  "
      << " Move=" << m->move << " Count=" << m->count << " Comment=\""
      << m->comment << "\""
-     << " IsBlack=" << m->isBlack << " Variations=" << m->variations.size()
-     << std::endl;
+     << " NAG=" << m->NAG << " IsBlack=" << m->isBlack
+     << " Variations=" << m->variations.size() << std::endl;
 
   for (auto *var : m->variations) {
     ss << NestedDump(var, indent + 1);
@@ -65,15 +65,15 @@ void HalfMove::Copy(HalfMove *copy) {
 }
 
 HalfMove *HalfMove::GetHalfMoveAt(int distance) {
-  HalfMove *tmp=this;
-  while(distance>0){
-    if(tmp==NULL){
+  HalfMove *tmp = this;
+  while (distance > 0) {
+    if (tmp == NULL) {
       throw HalfMoveOutOfRange();
     }
     distance--;
-    tmp=tmp->MainLine;
+    tmp = tmp->MainLine;
   }
-  return(tmp);
+  return (tmp);
 }
 
 } // namespace pgnp
\ No newline at end of file
diff --git a/src/HalfMove.hpp b/src/HalfMove.hpp
index e049571..8edea93 100644
--- a/src/HalfMove.hpp
+++ b/src/HalfMove.hpp
@@ -21,6 +21,7 @@ public:
   std::string move;
   /// @brief Comment associated to the move
   std::string comment;
+  std::string NAG;
   /// @brief Next HalfMove link to this line
   HalfMove *MainLine;
   /// @brief Next HalfMove links to variation of this line
diff --git a/src/LargeFileStream.cpp b/src/LargeFileStream.cpp
new file mode 100644
index 0000000..547415b
--- /dev/null
+++ b/src/LargeFileStream.cpp
@@ -0,0 +1,63 @@
+#include "LargeFileStream.hpp"
+
+namespace pgnp {
+using namespace std;
+
+LargeFileStream::LargeFileStream()
+    : chuck_count(-1), last_read_size(0), last_loc(0), use_string(false),
+      eof(false) {}
+
+void LargeFileStream::FromFile(std::string filepath) {
+  file.open(filepath);
+  ReadNextChunk();
+}
+
+void LargeFileStream::FromString(std::string content) {
+  use_string = true;
+  this->content = content;
+}
+
+void LargeFileStream::ReadNextChunk() {
+  chuck_count++;
+  file.read(buffer, BUFFER_SIZE);
+  last_read_size = file.gcount();
+}
+
+char LargeFileStream::operator[](long loc) {
+  // Perform various checks
+  if (eof) {
+    throw ReadToFar();
+  }
+  if (loc < last_loc) {
+    throw BackwardRead();
+  }
+  last_loc = loc; // Keep track
+
+  // Shortcut the operator for string content
+  if (use_string) {
+    if (loc >= content.size()) {
+      eof = true;
+    }
+    return ('?');
+  }
+
+  // Goto the right memory chuck
+  long loc_chunk_count = loc / BUFFER_SIZE;
+  while (chuck_count < loc_chunk_count) {
+    ReadNextChunk();
+  }
+  long offset = loc - (loc_chunk_count * BUFFER_SIZE);
+  
+  // Ensure for EOF
+  if (!file && offset >= last_read_size) {
+    eof = true;
+    return ('?');
+  }
+
+  // Return character
+  return buffer[offset];
+}
+
+bool LargeFileStream::IsEOF(long loc) { return (eof); }
+
+} // namespace pgnp
\ No newline at end of file
diff --git a/src/LargeFileStream.hpp b/src/LargeFileStream.hpp
new file mode 100644
index 0000000..6ac87e8
--- /dev/null
+++ b/src/LargeFileStream.hpp
@@ -0,0 +1,52 @@
+#define BUFFER_SIZE (1024 * 1024 / 2)
+
+#include <fstream>
+#include <iostream>
+#include <string>
+
+namespace pgnp {
+using namespace std;
+
+class LargeFileStream {
+  /// @brief File to load
+  ifstream file;
+  /// @brief In memory buffer
+  char buffer[BUFFER_SIZE];
+  /// @brief Number of chuck read minus 1
+  long chuck_count;
+  /// @brief Number of byte read during the last file access
+  long last_read_size;
+  /// @brief Keep track of the file offset (to prevent backward read)
+  long last_loc;
+  /// @brief Use a string as file content
+  std::string content;
+  /// @brief Use to shortcut some methods
+  bool use_string;
+  /// @brief End Of File ?
+  bool eof;
+
+  /// @brief Load the next chuck of data from disk to memory
+  void ReadNextChunk();
+
+public:
+  LargeFileStream();
+  void FromFile(std::string filepath);
+  /// @brief Emulate file access with a string
+  void FromString(std::string content);
+  /// @brief Allow array like access to the file
+  char operator[](long loc);
+  /// @brief Check if we reach the EOF
+  bool IsEOF(long loc);
+
+  // Various Exceptions
+  struct BackwardRead : public std::exception {
+    const char *what() const throw() {
+      return "LargeFileStream cannot read backward";
+    }
+  };
+  struct ReadToFar : public std::exception {
+    const char *what() const throw() { return "You reach the end of the file"; }
+  };
+};
+
+} // namespace pgnp
\ No newline at end of file
diff --git a/src/PGN.cpp b/src/PGN.cpp
index cd4bd96..953f225 100644
--- a/src/PGN.cpp
+++ b/src/PGN.cpp
@@ -7,7 +7,7 @@
 #define IS_DIGIT(c)                                                            \
   (c == '0' || c == '1' || c == '2' || c == '3' || c == '4' || c == '5' ||     \
    c == '6' || c == '7' || c == '8' || c == '9')
-#define IS_EOF(loc) ((loc) >= pgn_content.size())
+#define IS_EOF(loc) (pgn_content.IsEOF(loc))
 #define EOF_CHECK(loc)                                                         \
   {                                                                            \
     if (IS_EOF(loc))                                                           \
@@ -25,17 +25,10 @@ PGN::~PGN() {
 
 std::string PGN::GetResult() { return (result); }
 
-void PGN::FromFile(std::string filepath) {
-  std::ifstream inFile;
-  inFile.open(filepath);
-  std::stringstream strStream;
-  strStream << inFile.rdbuf();
-
-  this->pgn_content = strStream.str();
-}
+void PGN::FromFile(std::string filepath) { pgn_content.FromFile(filepath); }
 
 void PGN::FromString(std::string pgn_content) {
-  this->pgn_content = pgn_content;
+  this->pgn_content.FromString(pgn_content);
 }
 
 void PGN::ParseNextGame() {
@@ -46,20 +39,26 @@ void PGN::ParseNextGame() {
   result = "";
   tagkeys.clear();
   tags.clear();
-
   moves = new HalfMove();
+
+  // Search for new game
+  if (IS_EOF(LastGameEndLoc)) {
+    throw NoGameFound();
+  }
   int loc = NextNonBlank(LastGameEndLoc);
+
   if (IS_EOF(loc)) {
     throw NoGameFound();
   }
+
+  // Parse game
   while (!IS_EOF(loc)) {
     char c = pgn_content[loc];
     if (!IS_BLANK(c)) {
       if (c == '[') {
         loc = ParseNextTag(loc);
       } else if (IS_DIGIT(c)) {
-        loc = ParseHalfMove(loc, moves);
-        LastGameEndLoc = loc + 1; // Next game start 1 char after the last one
+        LastGameEndLoc = ParseHalfMove(loc, moves);
         break;
       } else if (c == '{') {
         loc = ParseComment(loc, moves);
@@ -68,6 +67,7 @@ void PGN::ParseNextGame() {
     }
     loc++;
   }
+
   if (result.size() <= 0) {
     throw InvalidGameResult();
   }
@@ -102,7 +102,7 @@ bool PGN::HasTag(std::string key) {
   return (std::find(tags.begin(), tags.end(), key) != tags.end());
 }
 
-int PGN::ParseComment(int loc, HalfMove *hm) {
+long PGN::ParseComment(long loc, HalfMove *hm) {
   // Goto next char
   loc = NextNonBlank(loc);
   EOF_CHECK(loc);
@@ -123,42 +123,39 @@ int PGN::ParseComment(int loc, HalfMove *hm) {
   return (loc);
 }
 
-int PGN::ParseHalfMove(int loc, HalfMove *hm) {
+long PGN::ParseHalfMove(long loc, HalfMove *hm) {
   // Goto next char
   loc = NextNonBlank(loc);
   EOF_CHECK(loc);
   char c = pgn_content[loc];
 
   // Check if we reach score entry (* or 1-0 or 0-1 or 1/2-1/2)
-  if (!IS_EOF(loc + 1)) {
-    char nc = pgn_content[loc + 1]; // Next c
-    if ((IS_DIGIT(c) && nc == '-') or (IS_DIGIT(c) && nc == '/') or c == '*') {
-      if (c == '*') {
-        result = "*";
-      } else if (nc == '-') {
-        if (c == '1') {
-          result = "1-0";
-          loc += 2;
-        } else {
-          result = "0-1";
-          loc += 2;
-        }
-      } else {
-        result = "1/2-1/2";
-        loc += 6;
-      }
-      return (loc);
-    }
+  if (c == '*') {
+    result = "*";
+    return (loc + 1);
   }
 
-  // Parse (move number
+  // Parse move number and check if end of game
   if (IS_DIGIT(c)) {
     std::string move_nb;
+    char first_digit = c;
     while (IS_DIGIT(c)) {
       move_nb += c;
       loc++;
       c = pgn_content[loc];
       EOF_CHECK(loc);
+      if (c == '/' || c == '-') {
+        if (c == '/') {
+          result = "1/2-1/2";
+          return (loc + 6);
+        } else if (first_digit == '1') {
+          result = "1-0";
+          return (loc + 2);
+        } else {
+          result = "0-1";
+          return (loc + 2);
+        }
+      }
     }
     hm->count = std::stoi(move_nb);
     loc++;
@@ -172,10 +169,6 @@ int PGN::ParseHalfMove(int loc, HalfMove *hm) {
     hm->isBlack = true;
   }
 
-  // Parse comment entries (various comment could appear during HalfMove
-  // parsing)
-  loc = ParseComment(loc, hm);
-
   // Parse the HalfMove
   loc = NextNonBlank(loc);
   EOF_CHECK(loc);
@@ -189,13 +182,21 @@ int PGN::ParseHalfMove(int loc, HalfMove *hm) {
   }
   hm->move = move;
 
-  // Parse comment
-  loc = ParseComment(loc, hm);
-
-  // Skip end of variation
-  if (c == ')') {
+  // Check for NAG
+  loc = NextNonBlank(loc);
+  EOF_CHECK(loc);
+  c = pgn_content[loc];
+  if (c == '$') {
+    hm->NAG += c;
     loc++;
-    return (loc);
+    EOF_CHECK(loc);
+    c = pgn_content[loc];
+    while (IS_DIGIT(c)) {
+      hm->NAG += c;
+      loc++;
+      EOF_CHECK(loc);
+      c = pgn_content[loc];
+    }
   }
 
   // Parse comment
@@ -209,10 +210,19 @@ int PGN::ParseHalfMove(int loc, HalfMove *hm) {
     loc = ParseHalfMove(loc, var);
     hm->variations.push_back(var);
     loc++; // Skip ')'
+    // Goto next var
+    loc = NextNonBlank(loc);
+    EOF_CHECK(loc);
+    c = pgn_content[loc];
   }
 
-  // Parse comment
-  loc = ParseComment(loc, hm);
+  // Skip end of variation
+  loc = NextNonBlank(loc);
+  EOF_CHECK(loc);
+  c = pgn_content[loc];
+  if (c == ')') {
+    return (loc);
+  }
 
   // Parse next HalfMove
   loc = NextNonBlank(loc);
@@ -231,10 +241,10 @@ int PGN::ParseHalfMove(int loc, HalfMove *hm) {
   return (loc);
 }
 
-int PGN::ParseNextTag(int start_loc) {
+long PGN::ParseNextTag(long start_loc) {
   // Parse key
   std::string key;
-  int keyloc = start_loc + 1;
+  long keyloc = start_loc + 1;
   EOF_CHECK(keyloc);
   char c = pgn_content[keyloc];
   while (!IS_BLANK(c)) {
@@ -246,7 +256,7 @@ int PGN::ParseNextTag(int start_loc) {
 
   // Parse value
   std::string value;
-  int valueloc = NextNonBlank(keyloc) + 1;
+  long valueloc = NextNonBlank(keyloc) + 1;
   EOF_CHECK(keyloc);
   c = pgn_content[valueloc];
   while (c != '"' or IS_EOF(valueloc)) {
@@ -294,14 +304,16 @@ std::string PGN::Dump() {
   return (ss.str());
 }
 
-int PGN::NextNonBlank(int loc) {
+long PGN::NextNonBlank(long loc) {
   char c = pgn_content[loc];
   while (IS_BLANK(c)) {
     loc++;
-    if (IS_EOF(loc))
+    if (IS_EOF(loc)) {
       return (loc);
+    }
     c = pgn_content[loc];
   }
+
   return (loc);
 }
 
diff --git a/src/PGN.hpp b/src/PGN.hpp
index c4e27d0..7e4d0e2 100644
--- a/src/PGN.hpp
+++ b/src/PGN.hpp
@@ -1,4 +1,5 @@
 #include "HalfMove.hpp"
+#include "LargeFileStream.hpp"
 #include <algorithm>
 #include <exception>
 #include <fstream>
@@ -17,9 +18,10 @@ private:
   /// @brief Contains the parsed PGN moves
   HalfMove *moves;
   /// @brief Contains the PGN data
-  std::string pgn_content;
-  /// @brief Contains the location of the end of the last parsed game (1 PGN file may have multiple games)
-  int LastGameEndLoc;
+  LargeFileStream pgn_content;
+  /// @brief Contains the location of the end of the last parsed game (1 PGN
+  /// file may have multiple games)
+  long LastGameEndLoc;
 
 public:
   PGN();
@@ -27,8 +29,9 @@ public:
   void FromFile(std::string);
   void FromString(std::string);
   /**
-   * Parse the next available game. Note that it raises a @a NoGameFound exception if no more game is available.
-   * A call to this method flush all the last parsed game data. Be careful.
+   * Parse the next available game. Note that it raises a @a NoGameFound
+   * exception if no more game is available. A call to this method flush all the
+   * last parsed game data. Be careful.
    */
   void ParseNextGame();
   /// @brief Check if PGN contains a specific tag
@@ -49,13 +52,13 @@ public:
 private:
   /// @brief Populate @a tags with by parsing the one starting at location in
   /// argument
-  int ParseNextTag(int);
+  long ParseNextTag(long);
   /// @brief Get the next non-blank char location starting from location in
   /// argument
-  int NextNonBlank(int);
+  long NextNonBlank(long);
   /// @brief Parse a HalfMove at a specific location into @a pgn_content
-  int ParseHalfMove(int, HalfMove *);
-  int ParseComment(int,HalfMove *);
+  long ParseHalfMove(long, HalfMove *);
+  long ParseComment(long, HalfMove *);
 };
 
 struct UnexpectedEOF : public std::exception {
@@ -76,7 +79,7 @@ struct NoGameFound : public std::exception {
 
 struct UnexpectedCharacter : public std::exception {
   std::string msg;
-  UnexpectedCharacter(char actual, char required, int loc) {
+  UnexpectedCharacter(char actual, char required, long loc) {
     std::stringstream ss;
     ss << "Expected \'" << required << "\' at location " << loc
        << " but read \'" << actual << "\'";