Initial source commit

minorGems/io/file/FileInputStream.h

@@ -0,0 +1,183 @@
+/*
+ * Modification History
+ *
+ * 2001-February-11		Jason Rohrer
+ * Created.
+ *
+ * 2001-April-12   Jason Rohrer
+ * Changed so that File is not destroyed when this stream is destroyed.
+ *
+ * 2001-April-29   Jason Rohrer
+ * Fixed a bug in the use of fread
+ * (num elements and element size swapped).
+ * Fixed a memory leak in the error message handling.
+ *
+ * 2006-November-23   Jason Rohrer
+ * Fixed a memory leak in error message handling.
+ *
+ * 2010-April-22   Jason Rohrer
+ * Added support for text mode.
+ */
+
+#include "minorGems/common.h"
+
+
+
+#ifndef FILE_INPUT_STREAM_CLASS_INCLUDED
+#define FILE_INPUT_STREAM_CLASS_INCLUDED
+
+#include "minorGems/io/InputStream.h"
+#include "File.h"
+
+#include <stdio.h>
+
+/**
+ * File implementation of an InputStream.
+ *
+ * @author Jason Rohrer
+ */ 
+class FileInputStream : public InputStream {
+
+	public:
+		
+		/**
+		 * Constructs an input stream.
+		 *
+		 * @param inFile the file to open for reading.
+		 *   If the file does not exist, all calls to read will fail.
+		 *   inFile is NOT destroyed when this class is destroyed.
+         * @param inTextMode true to open the file as text, false as binary.
+         *   Defaults to false.
+		 */
+		FileInputStream( File *inFile, char inTextMode = false );
+		
+		
+		/**
+		 * Destroys this stream and closes the file.
+		 */
+		~FileInputStream();
+		
+		
+		/**
+		 * Gets the file attached to this stream.
+		 *
+		 * @return the file used by this stream.
+		 *   Should not be modified or destroyed by caller until after
+		 *   this class is destroyed.
+		 */
+		File *getFile();
+		
+		
+		// implementst InputStream interface
+		virtual long read( unsigned char *inBuffer, long inNumBytes );
+		
+	private:
+		File *mFile;
+		
+		FILE *mUnderlyingFile;
+	};		
+
+
+
+
+inline FileInputStream::FileInputStream( File *inFile, char inTextMode ) 
+	: mFile( inFile ) {
+	
+	int fileNameLength;
+	
+	char *fileName = mFile->getFullFileName( &fileNameLength );
+	
+    if( inTextMode ) {
+        mUnderlyingFile = fopen( fileName, "r" );
+        }
+    else {
+        mUnderlyingFile = fopen( fileName, "rb" );
+        }
+    
+	
+	if( mUnderlyingFile == NULL ) {
+		// file open failed.
+		
+		char *stringBuffer = new char[ fileNameLength + 50 ];
+		sprintf( stringBuffer, "Opening file %s failed.", fileName );
+		setNewLastError( stringBuffer );
+		}
+		
+	delete [] fileName;	
+	}
+	
+
+
+inline FileInputStream::~FileInputStream() {
+	if( mUnderlyingFile != NULL ) {
+		fclose( mUnderlyingFile );
+		}
+	}
+
+
+	
+inline File *FileInputStream::getFile() {
+	return mFile;
+	}
+	
+	
+	
+inline long FileInputStream::read( 
+	unsigned char *inBuffer, long inNumBytes ) {
+	
+	if( mUnderlyingFile != NULL ) {
+	
+		long numRead = fread( inBuffer, 1, inNumBytes, mUnderlyingFile );
+
+		if( numRead < inNumBytes ) {
+
+			int fileNameLength;
+			char *fileName = mFile->getFullFileName( &fileNameLength );
+
+			if( feof( mUnderlyingFile ) ) {
+				// we reached the end of the file.
+				char *stringBuffer = new char[ fileNameLength + 50 ];
+				sprintf( stringBuffer, "Reached end of file %s on read.", 
+					fileName );
+				setNewLastError( stringBuffer );
+
+				delete [] fileName;
+				}
+			else {
+				// some other kind of error occured
+				char *stringBuffer = new char[ fileNameLength + 50 ];
+				sprintf( stringBuffer, "Reading from file %s failed.", 
+					fileName );
+				setNewLastError( stringBuffer );
+
+				delete [] fileName;
+				
+				if( numRead == 0 ) {
+					// a complete read failure
+					return -1;
+					}
+				}
+			}
+
+		return numRead;
+		}
+	else {
+		// file was not opened properly
+		
+		int fileNameLength;
+		char *fileName = mFile->getFullFileName( &fileNameLength );
+		char *stringBuffer = new char[ fileNameLength + 50 ];
+		sprintf( stringBuffer, 
+			"File %s was not opened properly before reading.", 
+			fileName );
+        delete [] fileName;
+        
+		setNewLastError( stringBuffer );
+		
+		return -1;
+		}
+	}
+
+	
+	
+#endif