Add the experimental code using O_DIRECT in the read disk object and

it's disabled for now.

SVN-Revision: 2922

diff --git a/libarchive/archive_read_disk_posix.c b/libarchive/archive_read_disk_posix.c
index 3fe5cabb119a0f2470c1ab2cf5544dbb7f37f053..b302c090be6dbfa47cb570d185c11605bd766b1a 100644 (file)
--- a/libarchive/archive_read_disk_posix.c
+++ b/libarchive/archive_read_disk_posix.c
@@ -191,6 +191,7 @@ struct tree {
        struct stat              lst;
        struct stat              st;
        int                      descend;
+       int                      nlink;
 
        struct entry_sparse {
                int64_t          length;
@@ -651,22 +652,27 @@ _archive_read_data_block(struct archive *_a, const void **buff,
 
        /*
         * Open the current file.
-        * TODO: use O_DIRECT.
         */
        if (a->entry_fd < 0) {
+               int flags = O_RDONLY | O_BINARY;
+
+               /*
+                * Eliminate or reduce cache effects if we can.
+                *
+                * Carefully consider this to be enabled.
+                */
+#if defined(O_DIRECT) && 0/* Disabled for now */
+               if (t->current_filesystem->xfer_align != -1 &&
+                   t->nlink == 1)
+                       flags |= O_DIRECT;
+#endif
 #ifdef HAVE_OPENAT
                a->entry_fd = openat(tree_current_dir_fd(t),
-                   tree_current_access_path(t), O_RDONLY | O_BINARY);
-               if (a->entry_fd < 0) {
-                       archive_set_error(&a->archive, errno,
-                           "Couldn't open %s", tree_current_path(t));
-                       r = ARCHIVE_FAILED;
-                       goto abort_read_data;
-               }
+                   tree_current_access_path(t), flags);
 #else
                tree_enter_working_dir(t);
-               a->entry_fd = open(tree_current_access_path(t),
-                   O_RDONLY | O_BINARY);
+               a->entry_fd = open(tree_current_access_path(t), flags);
+#endif
                if (a->entry_fd < 0) {
                        archive_set_error(&a->archive, errno,
                            "Couldn't open %s", tree_current_path(t));
@@ -675,7 +681,6 @@ _archive_read_data_block(struct archive *_a, const void **buff,
                        goto abort_read_data;
                }
                tree_enter_initial_dir(t);
-#endif
        }
 
        /*
@@ -887,6 +892,7 @@ _archive_read_next_header2(struct archive *_a, struct archive_entry *entry)
        case ARCHIVE_WARN:
                a->entry_total = 0;
                if (archive_entry_filetype(entry) == AE_IFREG) {
+                       t->nlink = archive_entry_nlink(entry);
                        a->entry_remaining_bytes = archive_entry_size(entry);
                        a->entry_eof = (a->entry_remaining_bytes == 0)? 1: 0;
                        if (!a->entry_eof &&