Syncing file with reference to another one

I have the following situation: file2 on remote host and file1 on localhost. file1 and file2 are mostly the same. Simply running rsync remotehost:file2 file2 will actually transfer the entire file. But I would like to use the factt that I have local file1 that is mostly similar to file2. I.e. how

Syncing file with reference to another one

I have the following situation: file2 on remote host and file1 on localhost. file1 and file2 are mostly the same. Simply running rsync remotehost:file2 file2 will actually transfer the entire file. But I would like to use the factt that I have local file1 that is mostly similar to file2. I.e. how