view tests/test-eol-hook.t @ 37054:40206e227412

wireproto: define and implement protocol for issuing requests

The existing HTTP and SSH wire protocols suffer from a host of flaws
and shortcomings. I've been wanting to rewrite the protocol for a while
now. Supporting partial clone - which will require new wire protocol
commands and capabilities - and other advanced server functionality
will be much easier if we start from a clean slate and don't have
to be constrained by limitations of the existing wire protocol.

This commit starts to introduce a new data exchange format for
use over the wire protocol.

The new protocol is built on top of "frames," which are atomic
units of metadata + data. Frames will make it easier to implement
proxies and other mechanisms that want to inspect data without
having to maintain state. The existing frame metadata is very
minimal and it will evolve heavily. (We will eventually support
things like concurrent requests, out-of-order responses,
compression, side-channels for status updates, etc. Some of
these will require additions to the frame header.)

Another benefit of frames is that all reads are of a fixed size.
A reader works by consuming a frame header, extracting the payload
length, then reading that many bytes. No lookahead, buffering, or
memory reallocations are needed.

The new protocol attempts to be transport agnostic. I want all that's
required to use the new protocol to be a pair of unidirectional,
half-duplex pipes. (Yes, we will eventually make use of full-duplex
pipes, but that's for another commit.) Notably, when the SSH
transport switches to this new protocol, stderr will be unused.
This is by design: the lack of stderr on HTTP harms protocol
behavior there. By shoehorning everything into a pair of pipes,
we can have more consistent behavior across transports.

We currently only define the client side parts of the new protocol,
specifically the bits for requesting that a command run. This keeps
the new code and feature small and somewhat easy to review.

We add support to `hg debugwireproto` for writing frames into
HTTP request bodies. Our tests that issue commands to the new
HTTP endpoint have been updated to transmit frames. The server
bits haven't been touched to consume the frames yet. This will
occur in the next commit...

Astute readers may notice that the command name is transmitted in
both the HTTP request URL and the command request frame. This is
partially a kludge from me initially implementing the frame-based
protocol for SSH first. But it is also a feature: I intend to
eventually support issuing multiple commands per HTTP request. This
will allow us to replace the abomination that is the "batch" wire
protocol command with a protocol-level mechanism for performing
multi-dispatch. Because I want the frame-based protocol to be
as similar as possible across transports, I'd rather we (redundantly)
include the command name in the frame than differ behavior between
transports that have out-of-band routing information (like HTTP)
readily available.

Differential Revision: https://phab.mercurial-scm.org/D2851

Test the EOL hook

  $ hg init main
  $ cat > main/.hg/hgrc <<EOF
  > [hooks]
  > pretxnchangegroup = python:hgext.eol.hook
  > EOF
  $ hg clone main fork
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd fork

Create repo
  $ cat > .hgeol <<EOF
  > [patterns]
  > mixed.txt = BIN
  > crlf.txt = CRLF
  > **.txt = native
  > EOF
  $ hg add .hgeol
  $ hg commit -m 'Commit .hgeol'

  $ printf "first\nsecond\nthird\n" > a.txt
  $ hg add a.txt
  $ hg commit -m 'LF a.txt'
  $ hg push ../main
  pushing to ../main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files

  $ printf "first\r\nsecond\r\nthird\n" > a.txt
  $ hg commit -m 'CRLF a.txt'
  $ hg push ../main
  pushing to ../main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  error: pretxnchangegroup hook failed: end-of-line check failed:
    a.txt in a8ee6548cd86 should not have CRLF line endings
  transaction abort!
  rollback completed
  abort: end-of-line check failed:
    a.txt in a8ee6548cd86 should not have CRLF line endings
  [255]

  $ printf "first\nsecond\nthird\n" > a.txt
  $ hg commit -m 'LF a.txt (fixed)'
  $ hg push ../main
  pushing to ../main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files

  $ printf "first\nsecond\nthird\n" > crlf.txt
  $ hg add crlf.txt
  $ hg commit -m 'LF crlf.txt'
  $ hg push ../main
  pushing to ../main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  error: pretxnchangegroup hook failed: end-of-line check failed:
    crlf.txt in 004ba2132725 should not have LF line endings
  transaction abort!
  rollback completed
  abort: end-of-line check failed:
    crlf.txt in 004ba2132725 should not have LF line endings
  [255]

  $ printf "first\r\nsecond\r\nthird\r\n" > crlf.txt
  $ hg commit -m 'CRLF crlf.txt (fixed)'
  $ hg push ../main
  pushing to ../main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files

  $ printf "first\r\nsecond" > b.txt
  $ hg add b.txt
  $ hg commit -m 'CRLF b.txt'
  $ hg push ../main
  pushing to ../main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  error: pretxnchangegroup hook failed: end-of-line check failed:
    b.txt in fbcf9b1025f5 should not have CRLF line endings
  transaction abort!
  rollback completed
  abort: end-of-line check failed:
    b.txt in fbcf9b1025f5 should not have CRLF line endings
  [255]

  $ hg up -r -2
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ printf "some\nother\nfile" > c.txt
  $ hg add c.txt
  $ hg commit -m "LF c.txt, b.txt doesn't exist here"
  created new head
  $ hg push -f ../main
  pushing to ../main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  error: pretxnchangegroup hook failed: end-of-line check failed:
    b.txt in fbcf9b1025f5 should not have CRLF line endings
  transaction abort!
  rollback completed
  abort: end-of-line check failed:
    b.txt in fbcf9b1025f5 should not have CRLF line endings
  [255]

Test checkheadshook alias

  $ cat > ../main/.hg/hgrc <<EOF
  > [hooks]
  > pretxnchangegroup = python:hgext.eol.checkheadshook
  > EOF
  $ hg push -f ../main
  pushing to ../main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  error: pretxnchangegroup hook failed: end-of-line check failed:
    b.txt in fbcf9b1025f5 should not have CRLF line endings
  transaction abort!
  rollback completed
  abort: end-of-line check failed:
    b.txt in fbcf9b1025f5 should not have CRLF line endings
  [255]

We can fix the head and push again

  $ hg up 6
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ printf "first\nsecond" > b.txt
  $ hg ci -m "remove CRLF from b.txt"
  $ hg push -f ../main
  pushing to ../main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 2 files (+1 heads)
  $ hg -R ../main rollback
  repository tip rolled back to revision 5 (undo push)

Test it still fails with checkallhook

  $ cat > ../main/.hg/hgrc <<EOF
  > [hooks]
  > pretxnchangegroup = python:hgext.eol.checkallhook
  > EOF
  $ hg push -f ../main
  pushing to ../main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 2 files (+1 heads)
  error: pretxnchangegroup hook failed: end-of-line check failed:
    b.txt in fbcf9b1025f5 should not have CRLF line endings
  transaction abort!
  rollback completed
  abort: end-of-line check failed:
    b.txt in fbcf9b1025f5 should not have CRLF line endings
  [255]

But we can push the clean head

  $ hg push -r7 -f ../main
  pushing to ../main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files

Test multiple files/revisions output

  $ printf "another\r\nbad\r\none" > d.txt
  $ hg add d.txt
  $ hg ci -m "add d.txt"
  $ hg push -f ../main
  pushing to ../main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 2 files (+1 heads)
  error: pretxnchangegroup hook failed: end-of-line check failed:
    b.txt in fbcf9b1025f5 should not have CRLF line endings
    d.txt in a7040e68714f should not have CRLF line endings
  transaction abort!
  rollback completed
  abort: end-of-line check failed:
    b.txt in fbcf9b1025f5 should not have CRLF line endings
    d.txt in a7040e68714f should not have CRLF line endings
  [255]

  $ cd ..