1 files changed, 58 insertions, 0 deletions
diff --git a/src/mongo/util/logfile.h b/src/mongo/util/logfile.h
new file mode 100644
index 00000000000..e41ecc2f6ec
--- /dev/null
+++ b/src/mongo/util/logfile.h
@@ -0,0 +1,58 @@
+// @file logfile.h simple file log writing / journaling
+
+/**
+*    Copyright (C) 2010 10gen Inc.
+*
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+namespace mongo {
+
+    class LogFile {
+    public:
+        /** create the file and open.  must not already exist.
+            throws UserAssertion on i/o error
+        */
+        LogFile(string name, bool readwrite = false);
+
+        /** closes */
+        ~LogFile();
+
+        /** append to file.  does not return until sync'd.  uses direct i/o when possible.
+            throws UserAssertion on an i/o error
+            note direct i/o may have alignment requirements
+        */
+        void synchronousAppend(const void *buf, size_t len);
+
+        /** write at specified offset. must be aligned.  noreturn until physically written. thread safe */
+        void writeAt(unsigned long long offset, const void *_bug, size_t _len);
+
+        void readAt(unsigned long long offset, void *_buf, size_t _len);
+
+        const string _name;
+
+        void truncate(); // Removes extra data after current position
+
+    private:
+#if defined(_WIN32)
+        typedef HANDLE fd_type;
+#else
+        typedef int fd_type;
+#endif
+        fd_type _fd;
+        bool _direct; // are we using direct I/O
+    };
+
+}