add {read,write}_buf functions. closes #15

src/write_buf.cpp

@@ -0,0 +1,109 @@
+/*
+   The MIT License (MIT)
+
+   Copyright (c) 2014 Antonio SJ Musumeci <trapexit@spawn.link>
+
+   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.
+*/
+
+#include <string>
+
+#include <stdlib.h>
+#include <fuse.h>
+
+#include "config.hpp"
+#include "ugid.hpp"
+#include "fileinfo.hpp"
+#include "write.hpp"
+
+using std::string;
+
+static
+int
+_write_buf_controlfile(const string           controlfile,
+                       struct fuse_bufvec    *buf,
+                       struct fuse_file_info *fi)
+{
+  int rv;
+  size_t size;
+  struct fuse_bufvec dst;
+
+  size = fuse_buf_size(buf);
+  dst = FUSE_BUFVEC_INIT(size);
+  dst.buf->mem = malloc(size);
+
+  rv = fuse_buf_copy(&dst,buf,(fuse_buf_copy_flags)0);
+  if(rv < 0)
+    {
+      free(dst.buf->mem);
+      return rv;
+    }
+
+  rv = mergerfs::write::write(controlfile.c_str(),
+                              (const char*)dst.buf->mem,
+                              size,
+                              0,
+                              fi);
+  free(dst.buf->mem);
+
+  return rv;
+}
+
+static
+int
+_write_buf(const int           fd,
+           struct fuse_bufvec *buf,
+           const off_t         offset)
+{
+  size_t size = fuse_buf_size(buf);
+  struct fuse_bufvec dest = FUSE_BUFVEC_INIT(size);
+  const fuse_buf_copy_flags cpflags =
+    (fuse_buf_copy_flags)(FUSE_BUF_SPLICE_MOVE|FUSE_BUF_SPLICE_NONBLOCK);
+
+  dest.buf->flags = (fuse_buf_flags)(FUSE_BUF_IS_FD|FUSE_BUF_FD_SEEK);
+  dest.buf->fd    = fd;
+  dest.buf->pos   = offset;
+
+  return fuse_buf_copy(&dest,buf,cpflags);
+}
+
+namespace mergerfs
+{
+  namespace write_buf
+  {
+    int
+    write_buf(const char            *fusepath,
+              struct fuse_bufvec    *buf,
+              off_t                  offset,
+              struct fuse_file_info *fi)
+    {
+      const ugid::SetResetGuard  ugid;
+      const config::Config      &config = config::get();
+
+      if(fusepath == config.controlfile)
+        return _write_buf_controlfile(config.controlfile,
+                                      buf,
+                                      fi);
+
+      return _write_buf(((FileInfo*)fi->fh)->fd,
+                        buf,
+                        offset);
+    }
+  }
+}