Add util::freespace to check for free space on a path. (with tests)

Originally committed to SVN as r5346.

aegisub/libaegisub/common/util.cpp

@@ -19,10 +19,12 @@
 /// @ingroup libaegisub
 
 #ifndef LAGI_PRE
-#include <stdio.h>
+#include <sys/param.h>
-#include <stdlib.h>
+#include <sys/mount.h>
 
 #include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
 
 #include <climits>
 #include <locale>
@@ -41,6 +43,7 @@ void str_lower(std::string &str) {
 	}
 }
 
+
 int strtoi(std::string &str) {
 	long l = strtol(str.c_str(), NULL, 10);
 
@@ -50,5 +53,24 @@ int strtoi(std::string &str) {
 	return (int)l;
 }
 
+
+uint64_t freespace(std::string &path, PathType type) {
+	struct statfs fs;
+	std::string check(path);
+
+	if (type == TypeFile)
+		check.assign(DirName(path));
+
+	acs::CheckDirRead(check);
+
+	if ((statfs(check.c_str(), &fs)) == 0) {
+		return fs.f_bsize * fs.f_bavail;
+	} else {
+		/// @todo We need a collective set of exceptions for ENOTDIR, EIO etc.
+		throw("Failed getting free space");
+	}
+}
+
+
 	} // namespace util
 } // namespace agi

aegisub/libaegisub/include/libaegisub/util.h

@@ -32,6 +32,13 @@
 namespace agi {
 	namespace util {
 
+
+	/// Whether the path is a file or directory.
+	enum PathType {
+		TypeFile,		///< File
+		TypeDir			///< Directory
+	};
+
 	// Calculate midpoint from a list of Integers
 	template<typename T> inline T mid(T a, T b, T c) { return std::max(a, std::min(b, c)); }
 
@@ -56,6 +63,11 @@ namespace agi {
 	// @param str Input string
 	int strtoi(std::string &str);
 
+	/// Check for amount of free space on a Path.
+	// @param path[in] Path to check
+	// @param type     PathType (default is TypeDir)
+	uint64_t freespace(std::string &path, PathType type=TypeDir);
+
 	struct delete_ptr {
 		template<class T>
 		void operator()(T* ptr) const {

aegisub/libaegisub/lagi_pre.h

@@ -10,6 +10,8 @@
 #include <stdint.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <sys/param.h>
+#include <sys/mount.h>
 #ifdef HAVE_SYS_TIME_H
 #  include <sys/time.h>
 #else

aegisub/tests/libaegisub_util.cpp

@@ -97,6 +97,28 @@ TEST_F(lagi_util, UtilstrtoiValidString) {
 	EXPECT_EQ(i, 24);
 }
 
+TEST_F(lagi_util, UtilfreespaceFile) {
+	std::string path("./data/somefile");
+	EXPECT_NO_THROW(util::freespace(path, util::TypeFile));
+	EXPECT_ANY_THROW(util::freespace(path));
+
+}
+
+TEST_F(lagi_util, UtilfreespaceDir) {
+	std::string path("./data");
+	EXPECT_NO_THROW(util::freespace(path));
+}
+
+TEST_F(lagi_util, UtilfreespaceNoAccess) {
+	std::string path("./data/dir_access_denied");
+	EXPECT_THROW(util::freespace(path), acs::AcsAccess);
+}
+
+TEST_F(lagi_util, UtilfreespaceInvalid) {
+	std::string path("/nonexistent");
+	EXPECT_ANY_THROW(util::freespace(path));
+}
+