v01

thirdparty/Pangolin/include/pangolin/utils/threadedfilebuf.h

@@ -0,0 +1,97 @@
+/* This file is part of the Pangolin Project.
+ * http://github.com/stevenlovegrove/Pangolin
+ *
+ * Copyright (c) 2011 Steven Lovegrove
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#pragma once
+
+#include <iostream>
+#include <streambuf>
+#include <fstream>
+
+#include <pangolin/platform.h>
+#include <thread>
+#include <mutex>
+#include <condition_variable>
+
+#ifdef _LINUX_
+// On linux, using posix file i/o to allow sync writes.
+#define USE_POSIX_FILE_IO
+#endif
+
+namespace pangolin
+{
+
+class PANGOLIN_EXPORT threadedfilebuf : public std::streambuf
+{
+public:
+    ~threadedfilebuf();
+    threadedfilebuf();
+    threadedfilebuf(const std::string& filename, size_t buffer_size_bytes);
+    
+    void open(const std::string& filename, size_t buffer_size_bytes);
+    void close();
+    void force_close();
+    
+    void operator()();
+    
+protected:
+    void soft_close();
+
+    //! Override streambuf::xsputn for asynchronous write
+    std::streamsize xsputn(const char * s, std::streamsize n) override;
+
+    //! Override streambuf::overflow for asynchronous write
+    int overflow(int c) override;
+
+    std::streampos seekoff(
+        std::streamoff off, std::ios_base::seekdir way,
+        std::ios_base::openmode which = std::ios_base::in | std::ios_base::out
+    ) override;
+    
+#ifdef USE_POSIX_FILE_IO
+    int filenum = -1;
+#else
+    std::filebuf file;
+#endif
+
+    char* mem_buffer;
+    std::streamsize mem_size;
+    std::streamsize mem_max_size;
+    std::streamsize mem_start;
+    std::streamsize mem_end;
+
+    std::streampos input_pos;
+    
+    std::mutex update_mutex;
+    std::condition_variable cond_queued;
+    std::condition_variable cond_dequeued;
+    std::thread write_thread;
+
+    bool should_run;
+    bool is_pipe;
+};
+
+}