added support for accessing getLastError document.

new: mongoc_collection_get_last_error().
Documentation added.
Related to: https://jira.mongodb.org/browse/CDRIVER-295

Author: Maga Napanga

build/cmake/libmongoc-ssl.def

@@ -29,6 +29,7 @@ mongoc_collection_drop
 mongoc_collection_drop_index
 mongoc_collection_ensure_index
 mongoc_collection_find
+mongoc_collection_get_last_error
 mongoc_collection_get_name
 mongoc_collection_get_read_prefs
 mongoc_collection_get_write_concern

build/cmake/libmongoc.def

@@ -28,6 +28,7 @@ mongoc_collection_drop
 mongoc_collection_drop_index
 mongoc_collection_ensure_index
 mongoc_collection_find
+mongoc_collection_get_last_error
 mongoc_collection_get_name
 mongoc_collection_get_read_prefs
 mongoc_collection_get_write_concern

doc/mongoc_collection_get_last_error.txt

@@ -0,0 +1,46 @@
+mongoc_collection_get_last_error(3)
+=============================
+
+
+NAME
+----
+mongoc_collection_get_last_error - Returns getLastError document.
+
+
+SYNOPSIS
+--------
+[source,c]
+-----------------------
+bson_t *
+mongoc_collection_get_last_error (const mongoc_collection_t *collection);
+-----------------------
+
+
+DESCRIPTION
+-----------
+The _mongoc_collection_get_last_error()_ function shall return getLastError
+document, according to write_concern on last executed command for current
+collection instance.
+
+write_concern must be at least MONGOC_WRITE_CONCERN_W_DEFAULT (1) in
+last command execution for getLastError to be available.
+
+Last executed command must be any of:
+_mongoc_collection_insert()_
+_mongoc_collection_insert_bulk()_
+_mongoc_collection_update()_
+_mongoc_collection_delete()_
+_mongoc_collection_save()_
+_mongoc_collection_ensure_index()_
+
+
+RETURN VALUE
+------------
+A newly allocated bson_t getLastError document, that *must* be destroyed
+with _bson_destroy()_. Or NULL if no getLastError present.
+
+
+AUTHORS
+-------
+
+This page was written by MongoDB Inc.

doc/mongoc_symbols.txt

@@ -29,6 +29,7 @@ linkmongoc:mongoc_collection_drop[3] +
 linkmongoc:mongoc_collection_drop_index[3] +
 linkmongoc:mongoc_collection_ensure_index[3] +
 linkmongoc:mongoc_collection_find[3] +
+linkmongoc:mongoc_collection_get_last_error[3] +
 linkmongoc:mongoc_collection_get_name[3] +
 linkmongoc:mongoc_collection_get_read_prefs[3] +
 linkmongoc:mongoc_collection_get_write_concern[3] +

src/libmongoc.symbols

@@ -29,6 +29,7 @@ mongoc_collection_drop
 mongoc_collection_drop_index
 mongoc_collection_ensure_index
 mongoc_collection_find
+mongoc_collection_get_last_error
 mongoc_collection_get_name
 mongoc_collection_get_read_prefs
 mongoc_collection_get_write_concern

src/mongoc/mongoc-client-private.h

@@ -74,7 +74,7 @@ bool             _mongoc_client_recv          (mongoc_client_t              *cli
                                                mongoc_buffer_t              *buffer,
                                                uint32_t                      hint,
                                                bson_error_t                 *error);
-bool             _mongoc_client_recv_gle      (mongoc_client_t              *client,
+bool             _mongoc_client_recv_gle      (mongoc_collection_t          *collection,
                                                uint32_t                      hint,
                                                bson_error_t                 *error);
 uint32_t         _mongoc_client_stamp         (mongoc_client_t              *client,

src/mongoc/mongoc-client.c

@@ -554,10 +554,11 @@ _bson_to_error (const bson_t *b,
  */
 
 bool
-_mongoc_client_recv_gle (mongoc_client_t *client,
+_mongoc_client_recv_gle (mongoc_collection_t    *collection,
                          uint32_t    hint,
                          bson_error_t    *error)
 {
+   mongoc_client_t *client;
    mongoc_buffer_t buffer;
    mongoc_rpc_t rpc;
    bson_iter_t iter;
@@ -566,6 +567,8 @@ _mongoc_client_recv_gle (mongoc_client_t *client,
 
    ENTRY;
 
+   bson_return_val_if_fail (collection, false);
+   client = collection->client;
    bson_return_val_if_fail (client, false);
    bson_return_val_if_fail (hint, false);
 
@@ -594,9 +597,14 @@ _mongoc_client_recv_gle (mongoc_client_t *client,
 
    if (_mongoc_rpc_reply_get_first (&rpc.reply, &b)) {
       if (!bson_iter_init_find (&iter, &b, "ok") ||
-          !BSON_ITER_HOLDS_DOUBLE (&iter) ||
-          (bson_iter_double (&iter) == 0.0)) {
-         _bson_to_error (&b, error);
+          BSON_ITER_HOLDS_DOUBLE (&iter)) {
+        if (bson_iter_double (&iter) == 0.0) {
+          _bson_to_error (&b, error);
+        }
+        if (collection->gle) {
+          bson_destroy (collection->gle);
+        }
+        collection->gle = bson_copy (&b);
       }
       bson_destroy (&b);
    }

src/mongoc/mongoc-collection-private.h

@@ -40,6 +40,7 @@ struct _mongoc_collection_t
 
    mongoc_read_prefs_t    *read_prefs;
    mongoc_write_concern_t *write_concern;
+   bson_t *gle;
 };
 
 

src/mongoc/mongoc-collection.c

@@ -99,6 +99,8 @@ _mongoc_collection_new (mongoc_client_t              *client,
 
    _mongoc_buffer_init(&col->buffer, NULL, 0, NULL);
 
+   col->gle = NULL;
+
    RETURN(col);
 }
 
@@ -127,6 +129,10 @@ mongoc_collection_destroy (mongoc_collection_t *collection) /* IN */
 
    bson_return_if_fail(collection);
 
+   if (collection->gle) {
+      bson_destroy(collection->gle);
+   }
+
    _mongoc_buffer_destroy(&collection->buffer);
 
    if (collection->read_prefs) {
@@ -293,6 +299,10 @@ mongoc_collection_find (mongoc_collection_t       *collection, /* IN */
       read_prefs = collection->read_prefs;
    }
 
+   if (collection->gle) {
+      bson_destroy(collection->gle);
+   }
+
    return _mongoc_cursor_new(collection->client, collection->ns, flags, skip,
                              limit, batch_size, false, query, fields, read_prefs);
 }
@@ -344,6 +354,10 @@ mongoc_collection_command (mongoc_collection_t       *collection,
       read_prefs = collection->read_prefs;
    }
 
+   if (collection->gle) {
+      bson_destroy(collection->gle);
+   }
+
    return mongoc_client_command (collection->client, collection->db, flags,
                                  skip, limit, batch_size, query, fields, read_prefs);
 }
@@ -358,6 +372,10 @@ mongoc_collection_command_simple (mongoc_collection_t       *collection,
    BSON_ASSERT (collection);
    BSON_ASSERT (command);
 
+   if (collection->gle) {
+      bson_destroy(collection->gle);
+   }
+
    return mongoc_client_command_simple (collection->client, collection->db,
                                         command, read_prefs, reply, error);
 }
@@ -722,6 +740,11 @@ _mongoc_collection_insert_bulk_raw (mongoc_collection_t          *collection,
       bson_init_static (&reply_bson, reply.reply.documents,
                         reply.reply.documents_len);
 
+      if (collection->gle) {
+         bson_destroy (collection->gle);
+      }
+      collection->gle = bson_copy (&reply_bson);
+
       if (bson_iter_init_find (&reply_iter, &reply_bson, "err") &&
           BSON_ITER_HOLDS_UTF8 (&reply_iter)) {
          errmsg = bson_iter_utf8 (&reply_iter, NULL);
@@ -771,6 +794,7 @@ _mongoc_collection_insert_bulk_raw (mongoc_collection_t          *collection,
  *       not actually inserted on the MongoDB server or cluster.
  *
  * Side effects:
+ *       @collection->gle is setup, depending on write_concern->w value.
  *       @error may be set upon failure if non-NULL.
  *
  *--------------------------------------------------------------------------
@@ -856,6 +880,7 @@ mongoc_collection_insert_bulk (mongoc_collection_t           *collection,
  *       not actually inserted on the MongoDB server or cluster.
  *
  * Side effects:
+ *       @collection->gle is setup, depending on write_concern->w value.
  *       @error may be set upon failure if non-NULL.
  *
  *--------------------------------------------------------------------------
@@ -911,6 +936,7 @@ mongoc_collection_insert (mongoc_collection_t          *collection,
  *       true if successful; otherwise false and @error is set.
  *
  * Side effects:
+ *       @collection->gle is setup, depending on write_concern->w value.
  *       @error is setup upon failure.
  *
  *--------------------------------------------------------------------------
@@ -979,7 +1005,7 @@ mongoc_collection_update (mongoc_collection_t          *collection,
    }
 
    if (_mongoc_write_concern_has_gle (write_concern)) {
-      if (!_mongoc_client_recv_gle (collection->client, hint, error)) {
+      if (!_mongoc_client_recv_gle (collection, hint, error)) {
          RETURN(false);
       }
    }
@@ -1068,7 +1094,8 @@ mongoc_collection_save (mongoc_collection_t          *collection,
  *       function may return true even if it failed.
  *
  * Side effects:
- *       None.
+ *       @collection->gle is setup, depending on write_concern->w value.
+ *       @error is setup upon failure.
  *
  *--------------------------------------------------------------------------
  */
@@ -1109,7 +1136,7 @@ mongoc_collection_delete (mongoc_collection_t          *collection,
    }
 
    if (_mongoc_write_concern_has_gle(write_concern)) {
-      if (!_mongoc_client_recv_gle(collection->client, hint, error)) {
+      if (!_mongoc_client_recv_gle (collection, hint, error)) {
          return false;
       }
    }
@@ -1256,3 +1283,30 @@ mongoc_collection_get_name (mongoc_collection_t *collection)
 
    return collection->collection;
 }
+
+
+/*
+ *--------------------------------------------------------------------------
+ *
+ * mongoc_collection_get_last_error --
+ *
+ *       Returns getLastError document, according to write_concern on last
+ *       executed command for current collection instance.
+ *
+ * Returns:
+ *       A newly allocated bson_t getLastError document, that *must* be
+ *       destroyed with bson_destroy(). Or NULL if no getLastError present.
+ *
+ * Side effects:
+ *       None.
+ *
+ *--------------------------------------------------------------------------
+ */
+
+bson_t *
+mongoc_collection_get_last_error (const mongoc_collection_t *collection)
+{
+   bson_return_val_if_fail (collection, NULL);
+
+   return collection->gle ? bson_copy (collection->gle) : NULL;
+}

src/mongoc/mongoc-collection.h

@@ -114,6 +114,7 @@ const mongoc_write_concern_t *mongoc_collection_get_write_concern    (const mong
 void                          mongoc_collection_set_write_concern    (mongoc_collection_t           *collection,
                                                                       const mongoc_write_concern_t  *write_concern);
 const char                   *mongoc_collection_get_name             (mongoc_collection_t           *collection);
+bson_t                       *mongoc_collection_get_last_error       (const mongoc_collection_t *collection);
 char                         *mongoc_collection_keys_to_index_string (const bson_t                  *keys);