Fix: CDRIVER-4050: Set the correct uploadDate on GridFS files (#818)

* Fix: CDRIVER-4050: Set the correct uploadDate on GridFS files

Previously used the time from bson_get_monotonic_time(), which is
incorrect on most systems, as it is usually realtive to the system
uptime and is stored as microseconds, whereas uploadDate should be
stored as number of milliseconds since the Unix Epoch.

* Propagate failure from bson_gettimeofday

* Make get_real_time_ms a private API (for now)

* Fix inverted error case and tests on file uploadDate

* Fix test cases that check file uploadDate to use a more precise time

* Fix integer overflow in _mongoc_get_real_time_ms on MSVC

Author: vector-of-bool

src/libmongoc/src/mongoc/mongoc-gridfs-bucket-file.c

@@ -21,6 +21,7 @@
 #include "mongoc-stream-gridfs-download-private.h"
 #include "mongoc-stream-gridfs-upload-private.h"
 #include "mongoc-collection-private.h"
+#include "mongoc-util-private.h"
 
 /* Returns the minimum of two numbers */
 static size_t
@@ -369,7 +370,9 @@ _mongoc_gridfs_bucket_file_writev (mongoc_gridfs_bucket_file_t *file,
 #ifndef _WIN32
                  (char *)
 #endif
-                 iov[i].iov_base + written_this_iov,
+                       iov[i]
+                          .iov_base +
+                    written_this_iov,
                  to_write);
          file->in_buffer += to_write;
          written_this_iov += to_write;
@@ -420,11 +423,13 @@ _mongoc_gridfs_bucket_file_readv (mongoc_gridfs_bucket_file_t *file,
          to_read = _mongoc_min (bytes_available, space_available);
          memcpy (
 #ifndef _WIN32
-                 (char *)
+            (char *)
 #endif
-                 iov[i].iov_base + read_this_iov,
-                 file->buffer + file->bytes_read,
-                 to_read);
+                  iov[i]
+                     .iov_base +
+               read_this_iov,
+            file->buffer + file->bytes_read,
+            to_read);
          file->bytes_read += to_read;
          read_this_iov += to_read;
          total += to_read;
@@ -491,7 +496,7 @@ _mongoc_gridfs_bucket_file_save (mongoc_gridfs_bucket_file_t *file)
    BSON_APPEND_VALUE (&new_doc, "_id", file->file_id);
    BSON_APPEND_INT64 (&new_doc, "length", file->length);
    BSON_APPEND_INT32 (&new_doc, "chunkSize", file->chunk_size);
-   BSON_APPEND_DATE_TIME (&new_doc, "uploadDate", bson_get_monotonic_time ());
+   BSON_APPEND_DATE_TIME (&new_doc, "uploadDate", _mongoc_get_real_time_ms ());
    BSON_APPEND_UTF8 (&new_doc, "filename", file->filename);
    if (file->metadata) {
       BSON_APPEND_DOCUMENT (&new_doc, "metadata", file->metadata);

src/libmongoc/src/mongoc/mongoc-gridfs-file.c

@@ -33,6 +33,7 @@
 #include "mongoc-gridfs-file-page-private.h"
 #include "mongoc-iovec.h"
 #include "mongoc-trace-private.h"
+#include "mongoc-util-private.h"
 #include "mongoc-error.h"
 
 static bool
@@ -337,7 +338,7 @@ _mongoc_gridfs_file_new (mongoc_gridfs_t *gridfs, mongoc_gridfs_file_opt_t *opt)
    file->files_id.value_type = BSON_TYPE_OID;
    bson_oid_init (&file->files_id.value.v_oid, NULL);
 
-   file->upload_date = ((int64_t) time (NULL)) * 1000;
+   file->upload_date = _mongoc_get_real_time_ms ();
 
    if (opt->md5) {
       file->md5 = bson_strdup (opt->md5);

src/libmongoc/src/mongoc/mongoc-util-private.h

@@ -75,6 +75,10 @@ _mongoc_hex_md5 (const char *input);
 void
 _mongoc_usleep (int64_t usec);
 
+/* Get the current time as a number of milliseconds since the Unix Epoch. */
+int64_t
+_mongoc_get_real_time_ms (void);
+
 const char *
 _mongoc_get_command_name (const bson_t *command);
 

src/libmongoc/src/mongoc/mongoc-util.c

@@ -48,7 +48,7 @@ _mongoc_rand_simple (unsigned int *seed)
 
    err = rand_s (&ret);
    if (0 != err) {
-      MONGOC_ERROR ("rand_s failed: %s", strerror(err));
+      MONGOC_ERROR ("rand_s failed: %s", strerror (err));
    }
 
    return (int) ret;
@@ -100,6 +100,17 @@ _mongoc_usleep (int64_t usec)
 #endif
 }
 
+int64_t
+_mongoc_get_real_time_ms (void)
+{
+   struct timeval tv;
+   const bool rc = bson_gettimeofday (&tv);
+   if (rc != 0) {
+      return -1;
+   }
+   return tv.tv_sec * (int64_t) 1000 + tv.tv_usec / (int64_t) 1000;
+}
+
 
 const char *
 _mongoc_get_command_name (const bson_t *command)

src/libmongoc/tests/test-mongoc-gridfs.c

@@ -572,7 +572,7 @@ test_create_from_stream (void)
 
    mongoc_gridfs_drop (gridfs, &error);
 
-   start = ((int64_t) time (NULL)) * 1000;
+   start = _mongoc_get_real_time_ms ();
    stream =
       mongoc_stream_file_new_for_path (BINARY_DIR "/gridfs.dat", O_RDONLY, 0);
    ASSERT_OR_PRINT_ERRNO (stream, errno);
@@ -582,7 +582,7 @@ test_create_from_stream (void)
    ASSERT (file);
    ASSERT (mongoc_gridfs_file_save (file));
 
-   now = ((int64_t) time (NULL)) * 1000;
+   now = _mongoc_get_real_time_ms ();
 
    filter = tmp_bson (NULL);
    BSON_APPEND_VALUE (filter, "_id", mongoc_gridfs_file_get_id (file));