Monkey-patch botocore to improve performance on large API requests

patch_boto.py

# Monkeypatch botocore.awsrequest.AWSRequest.body to improve performance by caching result.
# Usage: import this file once, at some point before making boto3 requests
# See https://github.com/boto/botocore/issues/1561

import six
from botocore.awsrequest import AWSRequest


# Monkeypatch AWSRequest.body to improve performance by caching result.
# - AWSRequest.body is accessed multiple times during request signing.
#   (See also https://github.com/boto/botocore/pull/1478.)
# - AWSPreparedRequest.prepare_body uses urlencode, which is lengthy on large strings
#   (specifically quote_plus/quote_from_bytes).
# - The botocore 1.12.3 AWSRequest.body implementation needlessly runs prepare_body
#   twice in a row (because AWSPreparedRequest.__init__ also calls prepare_body).
def request_body(self):
    if not hasattr(self, "_cached_body") or self.data != self._cached_body_data:
        body = self.prepare().body
        if isinstance(body, six.text_type):
            body = body.encode('utf-8')
        # Note: if self.data is mutable (e.g., POST data dict), this could conceivably
        # miss changes to the data and return a stale body. As a practical matter,
        # though, the only botocore code that modifies AWSRequest.data after creation is
        # auth.SigV4QueryAuth, which might replace a data dict with an empty string.
        # (So there's no need to implement more robust--and expensive--caching here.)
        self._cached_body_data = self.data
        self._cached_body = body
    return self._cached_body


setattr(AWSRequest, "body", property(request_body))