File

The file contents.

If non-empty, indicates that the named file should already exist, and the content here is to be inserted into that file at a defined insertion point. This feature allows a code generator to extend the output produced by another code generator. The original generator may provide insertion points by placing special annotations in the file that look like: @@protoc_insertion_point(NAME) The annotation can have arbitrary text before and after it on the line, which allows it to be placed in a comment. NAME should be replaced with an identifier naming the point -- this is what other generators will use as the insertion_point. Code inserted at this point will be placed immediately above the line containing the insertion point (thus multiple insertions to the same point will come out in the order they were added). The double-@ is intended to make it unlikely that the generated code could contain things that look like insertion points by accident. For example, the C++ code generator places the following line in the .pb.h files that it generates: // @@protoc_insertion_point(namespace_scope) This line appears within the scope of the file's package namespace, but outside of any particular class. Another plugin can then specify the insertion_point "namespace_scope" to generate additional classes or other declarations that should be placed in this scope. Note that if the line containing the insertion point begins with whitespace, the same whitespace will be added to every line of the inserted text. This is useful for languages like Python, where indentation matters. In these languages, the insertion point comment should be indented the same amount as any inserted code will need to be in order to work correctly in that context. The code generator that generates the initial file and the one which inserts into it must both run as part of a single invocation of protoc. Code generators are executed in the order in which they appear on the command line. If |insertion_point| is present, |name| must also be present.

The file name, relative to the output directory. The name must not contain "." or ".." components and must be relative, not be absolute (so, the file cannot lie outside the output directory). "/" must be used as the path separator, not "&92;". If the name is omitted, the content will be appended to the previous file. This allows the generator to break large files into small chunks, and allows the generated text to be streamed back to protoc so that large files need not reside completely in memory at one time. Note that as of this writing protoc does not optimize for this -- it will read the entire CodeGeneratorResponse before writing files to disk.