[ostree] pull: Merge metadata and content fetch phases

[Colin Walters <walters src gnome org>]

commit 4e51701bea3458bac654e89c3f2c1b5702e3db7e
Author: Colin Walters <walters verbum org>
Date:   Thu Oct 4 15:29:39 2012 -0400

    pull: Merge metadata and content fetch phases
    
    This is a notable speedup when the metadata scanner is working, and we
    don't have a lot of traffic; we can pull down data at the same time.

 src/ostree/ostree-pull.c |  238 ++++++++++++++++------------------------------
 1 files changed, 84 insertions(+), 154 deletions(-)
---
diff --git a/src/ostree/ostree-pull.c b/src/ostree/ostree-pull.c
index af06bdb..247fa49 100644
--- a/src/ostree/ostree-pull.c
+++ b/src/ostree/ostree-pull.c
@@ -90,27 +90,25 @@ typedef struct {
   OstreeFetcher *fetcher;
   SoupURI      *base_uri;
 
-  GHashTable   *file_checksums_to_fetch;
-
   GMainLoop    *loop;
   GCancellable *cancellable;
 
-  /* Used in meta fetch phase */
-  gboolean      fetching_metadata;
+  gboolean      metadata_scan_active;
   volatile gint n_scanned_metadata;
+  volatile gint n_requested_metadata;
+  volatile gint n_requested_content;
   guint         n_fetched_metadata;
   guint         outstanding_uri_requests;
 
   GThread      *metadata_scan_thread;
   OtWorkerQueue  *metadata_objects_to_scan;
   GHashTable   *scanned_metadata; /* Maps object name to itself */
+  GHashTable   *requested_content; /* Maps object name to itself */
   
-  /* Used in content fetch phase */
   guint         n_fetched_content;
   guint         outstanding_filemeta_requests;
   guint         outstanding_filecontent_requests;
   guint         outstanding_checksum_requests;
-  GHashTable   *loose_files;
 
   GError      **async_error;
   gboolean      caught_error;
@@ -119,6 +117,17 @@ typedef struct {
   guint         last_padding;
 } OtPullData;
 
+typedef struct {
+  OtPullData *pull_data;
+
+  gboolean fetching_content;
+
+  GFile *meta_path;
+  GFile *content_path;
+
+  char *checksum;
+} OtFetchOneContentItemData;
+
 static SoupURI *
 suburi_new (SoupURI   *base,
             const char *first,
@@ -178,24 +187,16 @@ uri_fetch_update_status (gpointer user_data)
  
   status = g_string_new ("");
 
-  if (pull_data->fetching_metadata)
-    {
-      g_string_append_printf (status, "Metadata phase: %u fetched, %u scanned; ",
-                              g_atomic_int_get (&pull_data->n_fetched_metadata),
-                              g_atomic_int_get (&pull_data->n_scanned_metadata));
-    }
-
-  if (pull_data->loose_files != NULL)
-    g_string_append_printf (status, "%u loose files to fetch: ",
-                            g_hash_table_size (pull_data->loose_files)
-                            + pull_data->outstanding_filemeta_requests
-                            + pull_data->outstanding_filecontent_requests);
+  g_string_append_printf (status, "%u/%u metadata %u/%u content fetched; ",
+                          g_atomic_int_get (&pull_data->n_fetched_metadata),
+                          g_atomic_int_get (&pull_data->n_requested_metadata),
+                          pull_data->n_fetched_content,
+                          g_atomic_int_get (&pull_data->n_requested_content));
 
   if (pull_data->outstanding_checksum_requests > 0)
     g_string_append_printf (status, "Calculating %u checksums; ",
                             pull_data->outstanding_checksum_requests);
 
-
   fetcher_status = ostree_fetcher_query_state_text (pull_data->fetcher);
   g_string_append (status, fetcher_status);
   if (status->len > pull_data->last_padding)
@@ -239,11 +240,11 @@ static void
 check_outstanding_requests_handle_error (OtPullData          *pull_data,
                                          GError              *error)
 {
-  if (pull_data->outstanding_uri_requests == 0 &&
+  if (!pull_data->metadata_scan_active &&
+      pull_data->outstanding_uri_requests == 0 &&
       pull_data->outstanding_filemeta_requests == 0 &&
       pull_data->outstanding_filecontent_requests == 0 &&
-      pull_data->outstanding_checksum_requests == 0 &&
-      (pull_data->loose_files == NULL || g_hash_table_size (pull_data->loose_files) == 0))
+      pull_data->outstanding_checksum_requests == 0)
     g_main_loop_quit (pull_data->loop);
   throw_async_error (pull_data, error);
 }
@@ -361,6 +362,9 @@ fetch_uri_contents_utf8 (OtPullData  *pull_data,
 }
 
 static gboolean
+idle_queue_content_request (gpointer user_data);
+
+static gboolean
 scan_dirtree_object (OtPullData   *pull_data,
                      const char   *checksum,
                      int           recursion_depth,
@@ -369,6 +373,7 @@ scan_dirtree_object (OtPullData   *pull_data,
 {
   gboolean ret = FALSE;
   int i, n;
+  gboolean compressed = pull_data->remote_mode == OSTREE_REPO_MODE_ARCHIVE_Z;
   ot_lvariant GVariant *tree = NULL;
   ot_lvariant GVariant *files_variant = NULL;
   ot_lvariant GVariant *dirs_variant = NULL;
@@ -393,18 +398,39 @@ scan_dirtree_object (OtPullData   *pull_data,
   for (i = 0; i < n; i++)
     {
       const char *filename;
+      gboolean file_is_stored;
+      OtFetchOneContentItemData *idle_fetch_data;
       ot_lvariant GVariant *csum = NULL;
+      ot_lfree char *file_checksum;
 
       g_variant_get_child (files_variant, i, "(&s ay)", &filename, &csum);
 
       if (!ot_util_filename_validate (filename, error))
         goto out;
 
-      {
-        char *duped_key = ostree_checksum_from_bytes_v (csum);
-        g_hash_table_replace (pull_data->file_checksums_to_fetch,
-                              duped_key, duped_key);
-      }
+      file_checksum = ostree_checksum_from_bytes_v (csum);
+
+      if (!ostree_repo_has_object (pull_data->repo, OSTREE_OBJECT_TYPE_FILE, file_checksum,
+                                   &file_is_stored, cancellable, error))
+        goto out;
+
+      if (!file_is_stored && !g_hash_table_lookup (pull_data->requested_content, file_checksum))
+        {
+          char *duped_checksum;
+
+          idle_fetch_data = g_new0 (OtFetchOneContentItemData, 1);
+          idle_fetch_data->pull_data = pull_data;
+          idle_fetch_data->checksum = file_checksum;
+          idle_fetch_data->fetching_content = compressed;
+          file_checksum = NULL; /* Transfer ownership */
+
+          duped_checksum = g_strdup (idle_fetch_data->checksum);
+          g_hash_table_insert (pull_data->requested_content, duped_checksum, duped_checksum);
+
+          g_atomic_int_inc (&pull_data->n_requested_content);
+          ot_worker_queue_hold (pull_data->metadata_objects_to_scan);
+          g_main_context_invoke (NULL, idle_queue_content_request, idle_fetch_data);
+        }
     }
       
   n = g_variant_n_children (dirs_variant);
@@ -466,17 +492,6 @@ fetch_ref_contents (OtPullData    *pull_data,
   return ret;
 }
 
-typedef struct {
-  OtPullData *pull_data;
-
-  gboolean fetching_content;
-
-  GFile *meta_path;
-  GFile *content_path;
-
-  char *checksum;
-} OtFetchOneContentItemData;
-
 static void
 destroy_fetch_one_content_item_data (OtFetchOneContentItemData *data)
 {
@@ -569,9 +584,6 @@ content_fetch_on_checksum_complete (GObject        *object,
 }
 
 static void
-enqueue_loose_meta_requests (OtPullData   *pull_data);
-
-static void
 content_fetch_on_complete (GObject        *object,
                            GAsyncResult   *result,
                            gpointer        user_data) 
@@ -682,115 +694,35 @@ content_fetch_on_complete (GObject        *object,
   if (was_content_fetch)
     data->pull_data->outstanding_filecontent_requests--;
   else
-    {
-      data->pull_data->outstanding_filemeta_requests--;
-      enqueue_loose_meta_requests (data->pull_data);
-    }
+    data->pull_data->outstanding_filemeta_requests--;
   check_outstanding_requests_handle_error (data->pull_data, local_error);
 }
 
-static void
-enqueue_loose_meta_requests (OtPullData *pull_data)
-{
-  GHashTableIter hash_iter;
-  gpointer key, value;
-  GCancellable *cancellable = NULL;
-
-  g_hash_table_iter_init (&hash_iter, pull_data->loose_files);
-  while (g_hash_table_iter_next (&hash_iter, &key, &value))
-    {
-      const char *checksum = key;
-      ot_lfree char *objpath = NULL;
-      SoupURI *obj_uri = NULL;
-      OtFetchOneContentItemData *one_item_data;
-      gboolean compressed = pull_data->remote_mode == OSTREE_REPO_MODE_ARCHIVE_Z;
-          
-      one_item_data = g_new0 (OtFetchOneContentItemData, 1);
-      one_item_data->pull_data = pull_data;
-      one_item_data->checksum = g_strdup (checksum);
-      one_item_data->fetching_content = compressed;
-          
-      objpath = ostree_get_relative_object_path (checksum, OSTREE_OBJECT_TYPE_FILE, compressed);
-      obj_uri = suburi_new (pull_data->base_uri, objpath, NULL);
-
-      ostree_fetcher_request_uri_async (pull_data->fetcher, obj_uri, cancellable,
-                                        content_fetch_on_complete, one_item_data);
-      soup_uri_free (obj_uri);
-
-      if (compressed)
-        pull_data->outstanding_filecontent_requests++;
-      else
-        pull_data->outstanding_filemeta_requests++;
-      g_hash_table_iter_remove (&hash_iter);
-
-      /* Don't let too many requests queue up; when we're fetching
-       * files we need to process the actual content.
-       */
-      if (pull_data->outstanding_filemeta_requests > 20)
-        break;
-    }
-}
-
 static gboolean
-fetch_content (OtPullData           *pull_data,
-               GCancellable         *cancellable,
-               GError              **error)
+idle_queue_content_request (gpointer user_data)
 {
-  gboolean ret = FALSE;
-  GHashTableIter hash_iter;
-  gpointer key, value;
-  ot_lobj GFile *temp_path = NULL;
-  ot_lobj GFile *content_temp_path = NULL;
-  ot_lhash GHashTable *loose_files = NULL;
-  SoupURI *content_uri = NULL;
-  guint n_objects_to_fetch = 0;
-
-  loose_files = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
-  
-  g_hash_table_iter_init (&hash_iter, pull_data->file_checksums_to_fetch);
-  while (g_hash_table_iter_next (&hash_iter, &key, &value))
-    {
-      const char *checksum = key;
-      gboolean is_stored;
-
-      if (!ostree_repo_has_object (pull_data->repo, OSTREE_OBJECT_TYPE_FILE, checksum, &is_stored,
-                                   cancellable, error))
-        goto out;
+  OtFetchOneContentItemData *data = user_data;
+  OtPullData *pull_data = data->pull_data;
+  const char *checksum = data->checksum;
+  ot_lfree char *objpath = NULL;
+  SoupURI *obj_uri = NULL;
+  gboolean compressed = pull_data->remote_mode == OSTREE_REPO_MODE_ARCHIVE_Z;
+          
+  objpath = ostree_get_relative_object_path (checksum, OSTREE_OBJECT_TYPE_FILE, compressed);
+  obj_uri = suburi_new (pull_data->base_uri, objpath, NULL);
 
-      if (!is_stored)
-        {
-          char *key = g_strdup (checksum);
-          g_hash_table_insert (loose_files, key, key);
-          n_objects_to_fetch++;
-        }
-    }
+  ostree_fetcher_request_uri_async (pull_data->fetcher, obj_uri, pull_data->cancellable,
+                                    content_fetch_on_complete, data);
+  soup_uri_free (obj_uri);
 
-  if (n_objects_to_fetch > 0)
-    g_print ("%u content objects to fetch\n", n_objects_to_fetch);
+  if (compressed)
+    pull_data->outstanding_filecontent_requests++;
+  else
+    pull_data->outstanding_filemeta_requests++;
 
-  if (g_hash_table_size (loose_files) > 0)
-    g_print ("Fetching %u loose objects\n",
-             g_hash_table_size (loose_files));
-  
-  pull_data->loose_files = loose_files;
+  ot_worker_queue_release (pull_data->metadata_objects_to_scan);
   
-  if (g_hash_table_size (loose_files) > 0)
-    {
-      enqueue_loose_meta_requests (pull_data);
-
-      if (!run_mainloop_monitor_fetcher (pull_data))
-        goto out;
-    }
-
-  ret = TRUE;
- out:
-  if (content_uri)
-    soup_uri_free (content_uri);
-  if (temp_path)
-    (void) ot_gfile_unlink (temp_path, NULL, NULL);
-  if (content_temp_path)
-    (void) ot_gfile_unlink (content_temp_path, NULL, NULL);
-  return ret;
+  return FALSE;
 }
 
 typedef struct {
@@ -969,6 +901,7 @@ scan_one_metadata_object (OtPullData         *pull_data,
       
   if (!is_stored)
     {
+      g_atomic_int_inc (&pull_data->n_requested_metadata);
       queue_metadata_object_fetch (pull_data, object);
     }
   else
@@ -1071,8 +1004,10 @@ static void
 on_metadata_worker_idle (gpointer user_data)
 {
   OtPullData *pull_data = user_data;
+
+  pull_data->metadata_scan_active = FALSE;
   
-  g_main_loop_quit (pull_data->loop);
+  check_outstanding_requests_handle_error (pull_data, NULL);
 }
 
 static gboolean
@@ -1085,7 +1020,6 @@ idle_start_worker (gpointer user_data)
   return FALSE;
 }
 
-
 static gboolean
 parse_ref_summary (const char    *contents,
                    GHashTable   **out_refs,
@@ -1253,10 +1187,11 @@ ostree_builtin_pull (int argc, char **argv, GFile *repo_path, GError **error)
   pull_data->loop = g_main_loop_new (NULL, FALSE);
 
   pull_data->repo = repo;
-  pull_data->file_checksums_to_fetch = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
 
   pull_data->scanned_metadata = g_hash_table_new_full (ostree_hash_object_name, g_variant_equal,
                                                        (GDestroyNotify)g_variant_unref, NULL);
+  pull_data->requested_content = g_hash_table_new_full (g_str_hash, g_str_equal,
+                                                        (GDestroyNotify)g_free, NULL);
 
   if (argc < 2)
     {
@@ -1386,9 +1321,7 @@ ostree_builtin_pull (int argc, char **argv, GFile *repo_path, GError **error)
   if (!ostree_repo_prepare_transaction (pull_data->repo, NULL, error))
     goto out;
 
-  pull_data->fetching_metadata = TRUE;
-
-  g_print ("Analyzing objects needed...\n");
+  pull_data->metadata_scan_active = TRUE;
 
   pull_data->metadata_objects_to_scan = ot_worker_queue_new ("metadatascan",
                                                              scan_one_metadata_object_dispatch,
@@ -1434,15 +1367,12 @@ ostree_builtin_pull (int argc, char **argv, GFile *repo_path, GError **error)
 
   g_idle_add (idle_start_worker, pull_data);
 
-  /* Handle queued metadata requests here */
+  /* Start metadata thread, which kicks off further metadata requests
+   * as well as content fetches.
+   */
   if (!run_mainloop_monitor_fetcher (pull_data))
     goto out;
 
-  pull_data->fetching_metadata = FALSE;
-
-  if (!fetch_content (pull_data, cancellable, error))
-    goto out;
-
   if (!ostree_repo_commit_transaction (pull_data->repo, cancellable, error))
     goto out;
 
@@ -1488,7 +1418,7 @@ ostree_builtin_pull (int argc, char **argv, GFile *repo_path, GError **error)
     soup_uri_free (pull_data->base_uri);
   g_clear_pointer (&pull_data->metadata_objects_to_scan, (GDestroyNotify) ot_worker_queue_unref);
   g_clear_pointer (&pull_data->scanned_metadata, (GDestroyNotify) g_hash_table_unref);
-  g_clear_pointer (&pull_data->file_checksums_to_fetch, (GDestroyNotify) g_hash_table_unref);
+  g_clear_pointer (&pull_data->requested_content, (GDestroyNotify) g_hash_table_unref);
   g_clear_pointer (&remote_config, (GDestroyNotify) g_key_file_unref);
   if (summary_uri)
     soup_uri_free (summary_uri);