comparison mercurial/debugcommands.py @ 37290:cc5a040fe150

wireproto: syntax for encoding CBOR into frames

We just vendored a library for encoding and decoding the CBOR
data format. While the intent of that vendor was to support state
files, CBOR is really a nice data format. It is extensible and
compact.

I've been feeling dirty inventing my own data formats for
frame payloads. While custom formats can always beat out a generic
format, there is a cost to be paid in terms of implementation,
comprehension, etc. CBOR is compact enough that I'm not too
worried about efficiency loss. I think the benefits of using
a standardized format outweigh rolling our own formats. So
I plan to make heavy use of CBOR in the wire protocol going
forward.

This commit introduces support for encoding CBOR data in frame
payloads to our function to make a frame from a human string.
We do need to employ some low-level Python code in order to
evaluate a string as a Python expression. But other than that,
this should hopefully be pretty straightforward.

Unit tests for this function have been added.

Differential Revision: https://phab.mercurial-scm.org/D2948

37289:5fadc63ac99f

    ``stream-flags`` and ``flags`` are a ``|`` delimited list of flag
    components. Each component (and there can be just one) can be an integer
    or a flag name for stream flags or frame flags, respectively. Values are
    resolved to integers and then bitwise OR'd together.

    ``payload`` is is evaluated as a Python byte string literal.
    """
    opts = pycompat.byteskwargs(opts)

    if opts['localssh'] and not repo:
        raise error.Abort(_('--localssh requires a repository'))

37290:cc5a040fe150

    ``stream-flags`` and ``flags`` are a ``|`` delimited list of flag
    components. Each component (and there can be just one) can be an integer
    or a flag name for stream flags or frame flags, respectively. Values are
    resolved to integers and then bitwise OR'd together.

    ``payload`` represents the raw frame payload. If it begins with
    ``cbor:``, the following string is evaluated as Python code and the
    resulting object is fed into a CBOR encoder. Otherwise it is interpreted
    as a Python byte string literal.
    """
    opts = pycompat.byteskwargs(opts)

    if opts['localssh'] and not repo:
        raise error.Abort(_('--localssh requires a repository'))