Optimize fuse_fs_read. (#145)

Redundant copy when only op.read is available removed.

diff --git a/lib/fuse.c b/lib/fuse.c
index ab5a593e85fff9bbc29d993dfd9e5b1691707c6b..d08bc49fd350dbe7ff1c59c710acc0dbd8036244 100644 (file)
--- a/lib/fuse.c
+++ b/lib/fuse.c
@@ -1734,19 +1734,43 @@ int fuse_fs_read_buf(struct fuse_fs *fs, const char *path,
 int fuse_fs_read(struct fuse_fs *fs, const char *path, char *mem, size_t size,
                 off_t off, struct fuse_file_info *fi)
 {
-       int res;
-       struct fuse_bufvec *buf = NULL;
+       fuse_get_context()->private_data = fs->user_data;
+       if (fs->op.read || fs->op.read_buf) {
+               int res;
 
-       res = fuse_fs_read_buf(fs, path, &buf, size, off, fi);
-       if (res == 0) {
-               struct fuse_bufvec dst = FUSE_BUFVEC_INIT(size);
+               if (fs->debug)
+                       fprintf(stderr,
+                               "read[%llu] %zu bytes from %llu flags: 0x%x\n",
+                               (unsigned long long) fi->fh,
+                               size, (unsigned long long) off, fi->flags);
 
-               dst.buf[0].mem = mem;
-               res = fuse_buf_copy(&dst, buf, 0);
-       }
-       fuse_free_buf(buf);
+               if (fs->op.read_buf) {
+                       struct fuse_bufvec *buf = NULL;
 
-       return res;
+                       res = fs->op.read_buf(path, &buf, size, off, fi);
+                       if (res == 0) {
+                               struct fuse_bufvec dst = FUSE_BUFVEC_INIT(size);
+
+                               dst.buf[0].mem = mem;
+                               res = fuse_buf_copy(&dst, buf, 0);
+                       }
+                       fuse_free_buf(buf);
+               } else {
+                       res = fs->op.read(path, mem, size, off, fi);
+               }
+
+               if (fs->debug && res >= 0)
+                       fprintf(stderr, "   read[%llu] %u bytes from %llu\n",
+                               (unsigned long long) fi->fh,
+                               res,
+                               (unsigned long long) off);
+               if (res >= 0 && res > (int) size)
+                       fprintf(stderr, "fuse: read too many bytes\n");
+
+               return res;
+       } else {
+               return -ENOSYS;
+       }
 }
 
 int fuse_fs_write_buf(struct fuse_fs *fs, const char *path,