1 files changed, 78 insertions, 0 deletions
diff --git a/src/database/engine/rrdenginelib.c b/src/database/engine/rrdenginelib.c
new file mode 100644
index 000000000..da880d3a3
--- /dev/null
+++ b/src/database/engine/rrdenginelib.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+#include "rrdengine.h"
+
+int check_file_properties(uv_file file, uint64_t *file_size, size_t min_size)
+{
+    int ret;
+    uv_fs_t req;
+    uv_stat_t* s;
+
+    ret = uv_fs_fstat(NULL, &req, file, NULL);
+    if (ret < 0) {
+        fatal("uv_fs_fstat: %s\n", uv_strerror(ret));
+    }
+    fatal_assert(req.result == 0);
+    s = req.ptr;
+    if (!(s->st_mode & S_IFREG)) {
+        netdata_log_error("Not a regular file.\n");
+        uv_fs_req_cleanup(&req);
+        return UV_EINVAL;
+    }
+    if (s->st_size < min_size) {
+        netdata_log_error("File length is too short.\n");
+        uv_fs_req_cleanup(&req);
+        return UV_EINVAL;
+    }
+    *file_size = s->st_size;
+    uv_fs_req_cleanup(&req);
+
+    return 0;
+}
+
+/**
+ * Open file for I/O.
+ *
+ * @param path The full path of the file.
+ * @param flags Same flags as the open() system call uses.
+ * @param file On success sets (*file) to be the uv_file that was opened.
+ * @param direct Tries to open a file in direct I/O mode when direct=1, falls back to buffered mode if not possible.
+ * @return Returns UV error number that is < 0 on failure. 0 on success.
+ */
+int open_file_for_io(char *path, int flags, uv_file *file, int direct)
+{
+    uv_fs_t req;
+    int fd = -1, current_flags;
+
+    fatal_assert(0 == direct || 1 == direct);
+    for ( ; direct >= 0 ; --direct) {
+#ifdef __APPLE__
+        /* Apple OS does not support O_DIRECT */
+        direct = 0;
+#endif
+        current_flags = flags;
+        if (direct) {
+            current_flags |= O_DIRECT;
+        }
+        fd = uv_fs_open(NULL, &req, path, current_flags, S_IRUSR | S_IWUSR, NULL);
+        if (fd < 0) {
+            if ((direct) && (UV_EINVAL == fd)) {
+                netdata_log_error("File \"%s\" does not support direct I/O, falling back to buffered I/O.", path);
+            } else {
+                netdata_log_error("Failed to open file \"%s\".", path);
+                --direct; /* break the loop */
+            }
+        } else {
+            fatal_assert(req.result >= 0);
+            *file = req.result;
+#ifdef __APPLE__
+            netdata_log_info("Disabling OS X caching for file \"%s\".", path);
+            fcntl(fd, F_NOCACHE, 1);
+#endif
+            --direct; /* break the loop */
+        }
+        uv_fs_req_cleanup(&req);
+    }
+
+    return fd;
+}
+