file: Implement reading and writing

- Inherit from fstream to gain access to << and >> operators.
- Make the file version accessable to the outside world.

Signed-off-by: Bryan Schumaker <bjschuma@gmail.com>

design.txt

@@ -165,11 +165,8 @@ On-disk files: (lib/file.cpp)
 	}
 
 - File:
-	class File {
+	class File : std::fstream {
 	private:
-		ifstream in;
-		ofstream out;
-
 		unsigned int version;
 		OpenMode mode;
 		FileLocHint hint;
@@ -179,18 +176,16 @@ On-disk files: (lib/file.cpp)
 		File(string, FileLocHint);
 		~File();
 		const char *get_filepath();
+		const unsigned int get_version();
 		bool exists();
 		bool open(OpenMode);
 		bool close();
-
-		const File &operator<<(File &);
-		const File &operator>>(File &);
-		void getline(string &);
+		string getline();
 	}
 
 - File format:
 	File << FILE_VERSION << endl;
-	File << <OTHER_DATA> << endl;
+	File << <OTHER_DATA>;
 
 - API:
 	File : File(string filepath, FileLocHint hint)
@@ -207,6 +202,9 @@ On-disk files: (lib/file.cpp)
 	const char *get_filepath()
 		Return the full filepath to the file.
 
+	const unsigned int get_version()
+		Return the file version number.
+
 	bool File : exists()
 		Return true if the file exists in the filesystem.
 		Return false otherwise.
@@ -227,17 +225,13 @@ On-disk files: (lib/file.cpp)
 		Return false if the file is already open.
 		Return false if there are any other errors.
 
-	void File : close()
+	bool File : close()
 		Close a file after IO.
 
-	File : operator<<()
-		Write data to the file.
-
-	File : operator>>()
-		Read data from the file.
-
-	File : getline(string);
-		Read an entire line from the file, strip whitespace on either end
+	string File : getline();
+		Read an entire line from the file and return it to the caller.
+		In theory a return value optimization will occur so returning
+		a string by value won't be a problem.
 
 
 

design/file.txt

@@ -46,11 +46,8 @@ On-disk files: (lib/file.cpp)
 	}
 
 - File:
-	class File {
+	class File : std::fstream {
 	private:
-		ifstream in;
-		ofstream out;
-
 		unsigned int version;
 		OpenMode mode;
 		FileLocHint hint;
@@ -60,18 +57,16 @@ On-disk files: (lib/file.cpp)
 		File(string, FileLocHint);
 		~File();
 		const char *get_filepath();
+		const unsigned int get_version();
 		bool exists();
 		bool open(OpenMode);
 		bool close();
-
-		const File &operator<<(File &);
-		const File &operator>>(File &);
-		void getline(string &);
+		string getline();
 	}
 
 - File format:
 	File << FILE_VERSION << endl;
-	File << <OTHER_DATA> << endl;
+	File << <OTHER_DATA>;
 
 - API:
 	File : File(string filepath, FileLocHint hint)
@@ -88,6 +83,9 @@ On-disk files: (lib/file.cpp)
 	const char *get_filepath()
 		Return the full filepath to the file.
 
+	const unsigned int get_version()
+		Return the file version number.
+
 	bool File : exists()
 		Return true if the file exists in the filesystem.
 		Return false otherwise.
@@ -108,14 +106,10 @@ On-disk files: (lib/file.cpp)
 		Return false if the file is already open.
 		Return false if there are any other errors.
 
-	void File : close()
+	bool File : close()
 		Close a file after IO.
 
-	File : operator<<()
-		Write data to the file.
-
-	File : operator>>()
-		Read data from the file.
-
-	File : getline(string);
-		Read an entire line from the file, strip whitespace on either end
+	string File : getline();
+		Read an entire line from the file and return it to the caller.
+		In theory a return value optimization will occur so returning
+		a string by value won't be a problem.

include/file.h

@@ -21,9 +21,8 @@ enum OpenMode {
 	NOT_OPEN,
 };
 
-class File {
+class File : public std::fstream {
 private:
-	std::fstream stream;
 	OpenMode mode;
 	FileLocHint hint;
 	std::string filepath;
@@ -37,9 +36,11 @@ public:
 	File(std::string, FileLocHint);
 	~File();
 	const char *get_filepath();
+	const unsigned int get_version();
 	bool exists();
 	bool open(OpenMode);
 	bool close();
+	std::string getline();
 };
 
 #endif /* OCARINA_FILE_H */

lib/file.cpp

@@ -40,7 +40,7 @@ void File :: find_dir(std::string &res)
 }
 
 File :: File(std::string path, FileLocHint file_hint)
-      : mode(NOT_OPEN), hint(file_hint), version(FILE_VERSION)
+      : mode(NOT_OPEN), hint(file_hint)
 {
 	std::string dir;
 
@@ -58,6 +58,11 @@ const char *File :: get_filepath()
 	return filepath.c_str();
 }
 
+const unsigned int File :: get_version()
+{
+	return version;
+}
+
 bool File :: exists()
 {
 	return g_file_test(filepath.c_str(), G_FILE_TEST_EXISTS);
@@ -70,15 +75,16 @@ bool File :: open_read()
 		return false;
 	}
 
-	stream.open(filepath.c_str(), std::fstream::in);
-	if (stream.fail()) {
+	std::fstream::open(filepath.c_str(), std::fstream::in);
+	if (std::fstream::fail()) {
 		dprint("ERROR: Could not open file for reading (%s)\n", filepath.c_str());
 		return false;
 	}
 
 	mode = OPEN_READ;
-	stream >> version;
-	return stream.good();
+	std::fstream::operator>>(version);
+	getline();
+	return std::fstream::good();
 }
 
 bool File :: open_write()
@@ -95,15 +101,15 @@ bool File :: open_write()
 		return false;
 	}
 
-	stream.open(filepath.c_str(), std::fstream::out);
-	if (stream.fail()) {
+	std::fstream::open(filepath.c_str(), std::fstream::out);
+	if (std::fstream::fail()) {
 		dprint("ERROR: Could not open file for writing (%s)\n", filepath.c_str());
 		return false;
 	}
 
 	mode = OPEN_WRITE;
-	stream << version << std::endl;
-	return stream.good();
+	std::fstream::operator<<(FILE_VERSION) << std::endl;
+	return std::fstream::good();
 }
 
 bool File :: open(OpenMode m)
@@ -125,7 +131,14 @@ bool File :: open(OpenMode m)
 bool File :: close()
 {
 	if (mode != NOT_OPEN)
-		stream.close();
+		std::fstream::close();
 	mode = NOT_OPEN;
-	return stream.good();
+	return std::fstream::good();
+}
+
+std::string File :: getline()
+{
+	std::string res;
+	std::getline(*static_cast<std::fstream *>(this), res);
+	return res;
 }

tests/file/Sconscript

@@ -5,3 +5,4 @@ CONFIG.FILE = True
 
 Test("file", "compile.cpp")
 Test("file", "open.cpp")
+Test("file", "io.cpp")

tests/file/io-debug.good

@@ -0,0 +1,7 @@
+Writing data to file: /home/anna/.local/share/ocarina-test/test.io
+Closing file
+Reading file
+File version is: 0
+	Hello, World!
+	This is a multi-line file =)
+	a: 1, b: 2, c: 3, d: 4, e: 5

tests/file/io.cpp

@@ -0,0 +1,50 @@
+/*
+ * Test reading and writing to files
+ */
+#include <file.h>
+#include <test.h>
+#include <print.h>
+
+int main(int argc, char **argv)
+{
+	int a, b, c, d, e;
+	File file("test.io", FILE_TYPE_DATA);
+
+	rm_test_data();
+
+	print("Writing data to file: %s\n", file.get_filepath());
+	if (!file.open(OPEN_WRITE))
+		return 1;
+
+	file << "Hello, World!" << std::endl;
+	file << "This is a multi-line file =)" << std::endl;
+	file << "1 2 3 4 5" << std::endl;
+
+	print("Closing file\n");
+	if (!file.close())
+		return 1;
+
+	print("Reading file\n");
+	if (!file.open(OPEN_READ))
+		return 1;
+
+	print("File version is: %u\n", file.get_version());
+
+	print("\t%s\n", file.getline().c_str());
+	if (!file.good())
+		return 1;
+
+	print("\t%s\n", file.getline().c_str());
+	if (!file.good())
+		return 1;
+
+	file >> a >> b >> c >> d >> e;
+	if (!file.good())
+		return 1;
+	print("\ta: %d, b: %d, c: %d, d: %d, e: %d\n", a, b, c, d, e);
+
+	if (!file.close())
+		return 1;
+
+	return 0;
+}

tests/file/io.good

@@ -0,0 +1,7 @@
+Writing data to file: /home/anna/.local/share/ocarina-test/test.io
+Closing file
+Reading file
+File version is: 0
+	Hello, World!
+	This is a multi-line file =)
+	a: 1, b: 2, c: 3, d: 4, e: 5