Callers of normalize_timestamp() in the proxy server. For each module, each method listed indented 4 spaces are direct callers of normalize_timestamp(). Each subsequently indented method indicates the callers of that method. Those lines beginning with "*" indicate additional ways that method uses it.

proxy_normalize_timestamp_callers.txt

swift/proxy/controllers/base.py
    generate_request_headers() -- time.time()
        GETorHEAD_base()
    autocreate_account() -- time.time()

swift/proxy/controllers/account.py
    generate_request_headers() -- time.time()
        PUT()
        POST()
        DELETE()

swift/proxy/controllers/obj.py
    generate_request_headers() -- time.time()
        _backend_requests()
            POST(fast)
            PUT()
            DELETE()
    POST(fast) -- time.time()
    PUT() -- time.time() or req.headers['X-Timestamp']
        * comparison to swift_x_timestamp
        * normalize of swift_x_timestamp for versioning, value from x-timestamp response from GETorHEAD_base
    DELETE() -- time.time() or req.headers['X-Timestamp']

swift/proxy/controllers/container.py
    generate_request_headers() -- time.time()
        POST()
        _backend_requests()
            PUT()
            DELETE()