Function UpdateAllMatchingDocuments

pg_documentdb/src/commands/update.c:1797–2211

* UpdateAllMatchingDocuments updates documents that match the query * and need to be updated based on the update document. Returns the * number of updated rows and matched documents for the query. */

 * number of updated rows and matched documents for the query.
 */
static UpdateAllMatchingDocsResult
UpdateAllMatchingDocuments(MongoCollection *collection,
						   UpdateOneParams *currentUpdate,
						   bool hasShardKeyValueFilter, int64 shardKeyHash,
						   ExprEvalState *schemaValidationExprEvalState,
						   bool *hasOnlyObjectIdFilter)
{
	const char *tableName = collection->tableName;
	bool isLocalShardQuery = false;
	bool setShardKeyValueFilter = false;
	if (collection->shardTableName[0] != '\0')
	{
		/* If we can push down to the local shard, then prefer that. */
		tableName = collection->shardTableName;
		isLocalShardQuery = true;
		NumBsonDocumentsUpdated = 0;
	}
	else if (!DefaultInlineWriteOperations)
	{
		setShardKeyValueFilter = true;
	}

	StringInfoData updateQuery;

	UpdateAllMatchingDocsResult result;
	memset(&result, 0, sizeof(UpdateAllMatchingDocsResult));

	SPI_connect();

	/* Here we need to create a document wrapper to preserve the type */
	pgbson *updateDoc = BsonValueToDocumentPgbson(currentUpdate->update);
	pgbson *arrayFilters = currentUpdate->arrayFilters == NULL ? NULL :
						   BsonValueToDocumentPgbson(currentUpdate->arrayFilters);

	/* Do these under the SPI Context so that they get deleted automatically at the end */
	bool queryHasNonIdFilters = false;

	/* TODO: if the _id is collation-sensitive, we will avoid filtering by _id */
	/* in the WHERE clause directly. */
	bool isIdFilterCollationAwareIgnore = false;
	pgbson *objectIdFilter = GetObjectIdFilterFromQueryDocumentValue(currentUpdate->query,
																	 &queryHasNonIdFilters,
																	 &
																	 isIdFilterCollationAwareIgnore);

	*hasOnlyObjectIdFilter = objectIdFilter != NULL && !queryHasNonIdFilters;

	const bson_value_t *variableSpec = currentUpdate->variableSpec;
	pgbson *variableSpecBson = NULL;
	if (queryHasNonIdFilters)
	{
		variableSpecBson = variableSpec != NULL &&
						   variableSpec->value_type == BSON_TYPE_DOCUMENT ?
						   PgbsonInitFromDocumentBsonValue(variableSpec) : NULL;
	}

	bool applyVariablSpec = variableSpecBson != NULL;