lib/mongodb: generate native object ids for document without the field "_id"

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>

diff --git a/lib/mongodb/native_mongodb.nit b/lib/mongodb/native_mongodb.nit
index 0ee217d..6d6f2fe 100644 (file)
--- a/lib/mongodb/native_mongodb.nit
+++ b/lib/mongodb/native_mongodb.nit
@@ -103,11 +103,35 @@ extern class BSONError `{ bson_error_t * `}
        fun message: NativeString `{ return self->message; `}
 end
 
+# Wrapper for `bson_oid_t`.
+#
+# The `bson_oid_t` structure contains the 12-byte ObjectId notation defined by the
+# [BSON ObjectID specificiation](http://docs.mongodb.org/manual/reference/object-id/).
+#
+# ObjectId is a 12-byte BSON type, constructed using:
+# * a 4-byte value representing the seconds since the Unix epoch (in Big Endian)
+# * a 3-byte machine identifier
+# * a 2-byte process id (Big Endian), and
+# * a 3-byte counter (Big Endian), starting with a random value.
+extern class BSONObjectId `{ bson_oid_t * `}
+       # Object id.
+       fun id: String import NativeString.to_s_with_copy `{
+               char str[25];
+               bson_oid_to_string(self, str);
+               return NativeString_to_s_with_copy(str);
+       `}
+end
+
 redef class Sys
        # Last error raised by `monogdb::MongoClient`.
        #
        # See `MongoClient::last_error`.
        var last_mongoc_error: nullable BSONError = null
+
+       # Last auto generated id if any.
+       #
+       # See `MongoCollection::insert`.
+       var last_mongoc_id: nullable BSONObjectId = null is writable
 end
 
 # Wrapper for `char**`.
@@ -287,10 +311,16 @@ extern class NativeMongoCollection `{ mongoc_collection_t * `}
        # If no `_id` element is found in document, then a `bson_oid_t` will be
        # generated locally and added to the document.
        #
-       # You can retrieve a generated `_id` from `mongoc_collection_get_last_error()`.
-       fun insert(doc: NativeBSON): Bool import set_mongoc_error `{
+       # You can retrieve a generated `_id` from `sys.last_mongoc_id`.
+       fun insert(document: NativeBSON): Bool import set_mongoc_error, set_mongoc_last_id `{
+               bson_oid_t oid;
+               if(!bson_has_field(document, "_id")) {
+                       bson_oid_init (&oid, NULL);
+                       BSON_APPEND_OID (document, "_id", &oid);
+                       NativeMongoCollection_set_mongoc_last_id(self, &oid);
+               }
                bson_error_t error;
-               if(!mongoc_collection_insert(self, MONGOC_INSERT_NONE, doc, NULL, &error)) {
+               if(!mongoc_collection_insert(self, MONGOC_INSERT_NONE, document, NULL, &error)) {
                        NativeMongoCollection_set_mongoc_error(self, &error);
                        return false;
                }
@@ -302,7 +332,15 @@ extern class NativeMongoCollection `{ mongoc_collection_t * `}
        # This function shall save a document into the collection.
        # If the document has an `_id` field it will be updated.
        # Otherwise it will be inserted.
-       fun save(document: NativeBSON): Bool import set_mongoc_error `{
+       #
+       # You can retrieve a generated `_id` from `sys.last_mongoc_id`.
+       fun save(document: NativeBSON): Bool import set_mongoc_error, set_mongoc_last_id `{
+               bson_oid_t oid;
+               if(!bson_has_field(document, "_id")) {
+                       bson_oid_init (&oid, NULL);
+                       BSON_APPEND_OID (document, "_id", &oid);
+                       NativeMongoCollection_set_mongoc_last_id(self, &oid);
+               }
                bson_error_t error;
                if(!mongoc_collection_save(self, document, NULL, &error)) {
                        NativeMongoCollection_set_mongoc_error(self, &error);
@@ -443,6 +481,9 @@ extern class NativeMongoCollection `{ mongoc_collection_t * `}
        # This instance should not be used beyond this point!
        fun destroy `{ mongoc_collection_destroy(self); `}
 
+       # Utility method to set `Sys.last_mongoc_last_id`.
+       fun set_mongoc_last_id(id: BSONObjectId) do sys.last_mongoc_id = id
+
        # Utility method to set `Sys.last_mongoc_error`.
        fun set_mongoc_error(err: BSONError) do sys.last_mongoc_error = err
 end