file: Open and close files

- Support OPEN_READ and OPEN_WRITE
- Update the design to accomidate for error checking
- Add lib/test.cpp containing basic functions that can be used for
  testing

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

design.txt

@@ -161,24 +161,27 @@ On-disk files: (lib/file.cpp)
 	enum OpenMode {
 		OPEN_READ,
 		OPEN_WRITE,
+		NOT_OPEN,
 	}
 
 - File:
 	class File {
 	private:
-		union {
-			ifstream in;
-			ofstream out;
-		} f;
+		ifstream in;
+		ofstream out;
+
 		unsigned int version;
 		OpenMode mode;
 		FileLocHint hint;
 		string filepath;
+
 	public:
 		File(string, FileLocHint);
+		~File();
 		const char *get_filepath();
 		bool exists();
 		bool open(OpenMode);
+		bool close();
 
 		const File &operator<<(File &);
 		const File &operator>>(File &);
@@ -198,6 +201,9 @@ On-disk files: (lib/file.cpp)
 			$HOME/.ocarina/
 			$HOME/.ocarina-debug/
 
+	File : ~File()
+		Close the file stream if it is open.
+
 	const char *get_filepath()
 		Return the full filepath to the file.
 
@@ -218,7 +224,11 @@ On-disk files: (lib/file.cpp)
 			- Write version information to the start of the file
 			- Return true
 
-		Return false if there are any errors opening the file.
+		Return false if the file is already open.
+		Return false if there are any other errors.
+
+	void File : close()
+		Close a file after IO.
 
 	File : operator<<()
 		Write data to the file.

design/file.txt

@@ -42,24 +42,27 @@ On-disk files: (lib/file.cpp)
 	enum OpenMode {
 		OPEN_READ,
 		OPEN_WRITE,
+		NOT_OPEN,
 	}
 
 - File:
 	class File {
 	private:
-		union {
-			ifstream in;
-			ofstream out;
-		} f;
+		ifstream in;
+		ofstream out;
+
 		unsigned int version;
 		OpenMode mode;
 		FileLocHint hint;
 		string filepath;
+
 	public:
 		File(string, FileLocHint);
+		~File();
 		const char *get_filepath();
 		bool exists();
 		bool open(OpenMode);
+		bool close();
 
 		const File &operator<<(File &);
 		const File &operator>>(File &);
@@ -79,6 +82,9 @@ On-disk files: (lib/file.cpp)
 			$HOME/.ocarina/
 			$HOME/.ocarina-debug/
 
+	File : ~File()
+		Close the file stream if it is open.
+
 	const char *get_filepath()
 		Return the full filepath to the file.
 
@@ -99,7 +105,11 @@ On-disk files: (lib/file.cpp)
 			- Write version information to the start of the file
 			- Return true
 
-		Return false if there are any errors opening the file.
+		Return false if the file is already open.
+		Return false if there are any other errors.
+
+	void File : close()
+		Close a file after IO.
 
 	File : operator<<()
 		Write data to the file.

include/file.h

@@ -4,22 +4,42 @@
 #ifndef OCARINA_FILE_H
 #define OCARINA_FILE_H
 
+#include <fstream>
 #include <string>
 
+#define FILE_VERSION 0
+
 enum FileLocHint {
 	FILE_TYPE_CONFIG,
 	FILE_TYPE_DATA,
 	FILE_TYPE_LEGACY,
 };
 
+enum OpenMode {
+	OPEN_READ,
+	OPEN_WRITE,
+	NOT_OPEN,
+};
+
 class File {
 private:
+	std::fstream stream;
+	OpenMode mode;
 	FileLocHint hint;
 	std::string filepath;
+	unsigned int version;
+
+	void find_dir(std::string &);
+	bool open_read();
+	bool open_write();
 
 public:
 	File(std::string, FileLocHint);
+	~File();
 	const char *get_filepath();
+	bool exists();
+	bool open(OpenMode);
+	bool close();
 };
 
 #endif /* OCARINA_FILE_H */

include/test.h

@@ -0,0 +1,9 @@
+#ifndef OCARINA_TEST_H
+#define OCARINA_TEST_H
+#ifdef CONFIG_TEST
+
+void rm_test_config();
+void rm_test_data();
+
+#endif /* CONFIG_TEST */
+#endif /* OCARINA_TEST_H */

lib/Sconscript

@@ -7,4 +7,7 @@ if CONFIG.FILE:
 	CONFIG.package("glib-2.0")
 	build += [ env.Object("file.cpp") ]
 
+if CONFIG.TEST:
+	build += [ env.Object("test.cpp") ]
+
 Return("build")

lib/file.cpp

@@ -2,6 +2,7 @@
  * Copyright 2013 (c) Bryan Schumaker.
  */
 #include <file.h>
+#include <print.h>
 
 #include <glib.h>
 
@@ -13,37 +14,118 @@
 #define OCARINA_DIR "ocarina"
 #endif
 
+void File :: find_dir(std::string &res)
+{
+	switch (hint) {
+	case FILE_TYPE_CONFIG:
+		res = g_get_user_config_dir();
+		break;
+	case FILE_TYPE_DATA:
+		res = g_get_user_data_dir();
+		break;
+	case FILE_TYPE_LEGACY:
+		res = g_get_home_dir();
+	}
+
+	res += "/";
+	switch (hint) {
+	case FILE_TYPE_CONFIG:
+	case FILE_TYPE_DATA:
+		res += OCARINA_DIR;
+		break;
+	case FILE_TYPE_LEGACY:
+		res += ".";
+		res += OCARINA_DIR;
+	}
+}
+
 File :: File(std::string path, FileLocHint file_hint)
-      : hint(file_hint)
+      : mode(NOT_OPEN), hint(file_hint), version(FILE_VERSION)
 {
 	std::string dir;
 
-	switch (file_hint) {
-	case FILE_TYPE_CONFIG:
-		dir = g_get_user_config_dir();
-		break;
-	case FILE_TYPE_DATA:
-		dir = g_get_user_data_dir();
-		break;
-	case FILE_TYPE_LEGACY:
-		dir = g_get_home_dir();
-	}
-
-	dir += "/";
-	switch (file_hint) {
-	case FILE_TYPE_CONFIG:
-	case FILE_TYPE_DATA:
-		dir += OCARINA_DIR;
-		break;
-	case FILE_TYPE_LEGACY:
-		dir += ".";
-		dir += OCARINA_DIR;
-	}
-
+	find_dir(dir);
 	filepath = dir + "/" + path;
 }
 
+File :: ~File()
+{
+	close();
+}
+
 const char *File :: get_filepath()
 {
 	return filepath.c_str();
 }
+
+bool File :: exists()
+{
+	return g_file_test(filepath.c_str(), G_FILE_TEST_EXISTS);
+}
+
+bool File :: open_read()
+{
+	if (!exists()) {
+		dprint("ERROR: File does not exist (%s)\n", filepath.c_str());
+		return false;
+	}
+
+	stream.open(filepath.c_str(), std::fstream::in);
+	if (stream.fail()) {
+		dprint("ERROR: Could not open file for reading (%s)\n", filepath.c_str());
+		return false;
+	}
+
+	mode = OPEN_READ;
+	stream >> version;
+	return stream.good();
+}
+
+bool File :: open_write()
+{
+	std::string dir;
+	if (hint == FILE_TYPE_LEGACY) {
+		dprint("ERROR: Cannot write to legacy files (%s)\n", filepath.c_str());
+		return false;
+	}
+
+	find_dir(dir);
+	if (g_mkdir_with_parents(dir.c_str(), 0755) != 0) {
+		dprint("ERROR: Could not make directory (%s)\n", dir.c_str());
+		return false;
+	}
+
+	stream.open(filepath.c_str(), std::fstream::out);
+	if (stream.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();
+}
+
+bool File :: open(OpenMode m)
+{
+	if (mode != NOT_OPEN) {
+		dprint("ERROR: File is already open (%s)\n", filepath.c_str());
+		return false;
+	}
+
+	if (m == NOT_OPEN) {
+		dprint("ERROR: NOT_OPEN is not a legal OpenMode (%s)\n", filepath.c_str());
+		return false;
+	} else if (m == OPEN_READ)
+		return open_read();
+	else /* m == OPEN_WRITE */
+		return open_write();
+}
+
+bool File :: close()
+{
+	if (mode != NOT_OPEN)
+		stream.close();
+	mode = NOT_OPEN;
+	return stream.good();
+}

lib/test.cpp

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2013 (c) Bryan Schumaker.
+ */
+#include <test.h>
+
+#include <string>
+#include <glib.h>
+#include <stdlib.h>
+
+/* A bit hackish, but it works... */
+static void rm_dir(const char *dir)
+{
+	std::string cmd = "rm -frv ";
+	cmd += dir;
+	cmd += "/ocarina-test";
+	system(cmd.c_str());
+}
+
+void rm_test_config()
+{
+	rm_dir(g_get_user_config_dir());
+}
+
+void rm_test_data()
+{
+	rm_dir(g_get_user_data_dir());
+}

tests/file/Sconscript

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

tests/file/open-debug.good

@@ -0,0 +1,22 @@
+removed ‘/home/anna/.local/share/ocarina-test/test.4’
+removed ‘/home/anna/.local/share/ocarina-test/test.3’
+removed directory: ‘/home/anna/.local/share/ocarina-test’
+
+ERROR: NOT_OPEN is not a legal OpenMode (/home/anna/.local/share/ocarina-test/test.0)
+Test 0: Passed
+
+ERROR: File does not exist (/home/anna/.local/share/ocarina-test/test.1)
+Test 1: Passed
+
+ERROR: Cannot write to legacy files (/home/anna/.ocarina-test/test.2)
+Test 2: Passed
+
+Test 3a: Passed
+ERROR: File is already open (/home/anna/.local/share/ocarina-test/test.3)
+Test 3b: Passed
+
+Test 4a: Passed
+Test 4b: Passed
+Test 4c: Passed
+
+Test 5: Passed

tests/file/open.cpp

@@ -0,0 +1,106 @@
+/*
+ * Test opening files under various conditions
+ */
+#include <file.h>
+#include <test.h>
+#include <print.h>
+
+static int test_result(const char *num, bool res, bool expected)
+{
+	print("Test %s: ", num);
+	if (res == expected) {
+		print("Passed\n");
+		return 0;
+	} else {
+		print("Failed\n");
+		return 1;
+	}
+}
+
+static int test_error(const char *num, FileLocHint hint, OpenMode mode)
+{
+	std::string f = "test.";
+	f += num;
+
+	File file(f.c_str(), hint);
+	print("\n");
+	return test_result(num, file.open(mode), false);
+}
+
+/*
+ * Attempt to open a file with mode == NOT_OPEN
+ */
+int test_0()
+{
+	return test_error("0", FILE_TYPE_DATA, NOT_OPEN);
+}
+
+/*
+ * Attempt to open a file that doesn't exist for reading
+ */
+int test_1()
+{
+	return test_error("1", FILE_TYPE_DATA, OPEN_READ);
+}
+
+/*
+ * Attempt to open a legacy file for writing
+ */
+int test_2()
+{
+	return test_error("2", FILE_TYPE_LEGACY, OPEN_WRITE);
+}
+
+/*
+ * Write to a file, then open it for reading WITHOUT closing first
+ */
+int test_3()
+{
+	File file("test.3", FILE_TYPE_DATA);
+
+	printf("\n");
+	if (test_result("3a", file.open(OPEN_WRITE), true) != 0)
+		return 1;
+	return test_result("3b", file.open(OPEN_READ), false);
+}
+
+/*
+ * Write to a file, close it, then open it again for reading
+ */
+int test_4()
+{
+	File file("test.4", FILE_TYPE_DATA);
+
+	printf("\n");
+	if (test_result("4a", file.open(OPEN_WRITE), true) != 0)
+		return 1;
+	if (test_result("4b", file.close(), true) != 0)
+		return 1;
+	return test_result("4c", file.open(OPEN_READ), true);
+}
+
+/*
+ * Attempt to close a file that was never opened
+ */
+int test_5()
+{
+	File file("test.5", FILE_TYPE_DATA);
+
+	print("\n");
+	return test_result("5", file.close(), true);
+}
+
+int main(int argc, char **argv)
+{
+	int failed = 0;
+	rm_test_data();
+
+	failed += test_0();
+	failed += test_1();
+	failed += test_2();
+	failed += test_3();
+	failed += test_4();
+	failed += test_5();
+
+	return failed;
+}

tests/file/open.good

@@ -0,0 +1,18 @@
+removed ‘/home/anna/.local/share/ocarina-test/test.4’
+removed ‘/home/anna/.local/share/ocarina-test/test.3’
+removed directory: ‘/home/anna/.local/share/ocarina-test’
+
+Test 0: Passed
+
+Test 1: Passed
+
+Test 2: Passed
+
+Test 3a: Passed
+Test 3b: Passed
+
+Test 4a: Passed
+Test 4b: Passed
+Test 4c: Passed
+
+Test 5: Passed