Query-by-example in large-scale code repositories

A method for performing query-by-example, the method being performed in a system comprising a processor and a memory coupled with the processor, the method comprising:

• maintaining, by a query module executing on the system, a source code repository containing a plurality of source code files, wherein each of the plurality of source code files is associated with a corresponding source syntax structure generated based on said each of the plurality of source code files and representative of a syntactic structure of said each of the plurality of source code files;
• receiving, by the query module, a query snippet;
• generating, by the query module, a query syntax structure based on the query snippet, wherein the query syntax structure represents a syntactic structure of the query snippet;
• and
• identifying, by the query module, a first source code file from the plurality of source code files for being relevant to the query snippet by:
• extracting a source sub-structure from a first syntax structure associated with the first source code file for matching with a query sub-structure extracted from the query syntax structure,
• identifying a matching pattern contained in the source sub-structure and in the query sub-structure,
• calculating a matching ratio based on the matching pattern, the source sub-structure's size, and the query sub-structure's size, and
• assigning the matching ratio as a first similarity score upon a second determination that the matching ratio is above a predetermined matching threshold, and
• identifying the first source code file upon a first determination that the first similarity score is above a predetermined similarity threshold, wherein the being relevant to the query snippet is determined by a first relevance score which is calculated based on the query syntax structure and the first source code file's corresponding source syntax structure.

A non-transitory computer-readable storage medium that includes a set of instructions which, in response to execution by a processor, cause the processor to perform a method for performing query-by-example, the method being performed in a system comprising a processor and a memory coupled with the processor, the method comprising:

• maintaining, by a query module executing on the system, a source code repository containing a plurality of source code files, wherein each of the plurality of source code files is associated with a corresponding source syntax structure generated based on said each of the plurality of source code files and representative of a syntactic structure of said each of the plurality of source code files;
• receiving, by the query module, a query snippet;
• generating, by the query module, a query syntax structure based on the query snippet, wherein the query syntax structure represents a syntactic structure of the query snippet;
• and
• identifying, by the query module, a first source code file from the plurality of source code files for being relevant to the query snippet by:
• extracting a source sub-structure from a first syntax structure associated with the first source code file for matching with a query sub-structure extracted from the query syntax structure,
• identifying a matching pattern contained in the source sub-structure and in the query sub-structure,
• calculating a matching ratio based on the matching pattern, the source sub-structure's size, and the query sub-structure's size, and
• assigning the matching ratio as a first similarity score upon a second determination that the matching ratio is above a predetermined matching threshold, and identifying the first source code file upon a first determination that the first similarity score is above a predetermined similarity threshold, wherein the being relevant to the query snippet is determined by a first relevance score which is calculated based on the query syntax structure and the first source code file's corresponding source syntax structure.