1 files changed, 63 insertions, 0 deletions
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