view tests/test-hgweb-annotate-whitespace.t @ 37631:2f626233859b

wireproto: implement batching on peer executor interface

This is a bit more complicated than non-batch requests because we
need to buffer sends until the last request arrives *and* we need
to support resolving futures as data arrives from the remote.

In a classical concurrent.futures executor model, the future
"starts" as soon as it is submitted. However, we have nothing to
start until the last command is submitted.

If we did nothing, calling result() would deadlock, since the future
hasn't "started." So in the case where we queue the command, we return
a special future type whose result() will trigger sendcommands().
This eliminates the deadlock potential. It also serves as a check
against callers who may be calling result() prematurely, as it will
prevent any subsequent callcommands() from working. This behavior
is slightly annoying and a bit restrictive. But it's the world
that half duplex connections forces on us.

In order to support streaming responses, we were previously using
a generator. But with a futures-based API, we're using futures
and not generators. So in order to get streaming, we need a
background thread to read data from the server.

The approach taken in this patch is to leverage the ThreadPoolExecutor
from concurrent.futures for managing a background thread. We create
an executor and future that resolves when all response data is
processed (or an error occurs). When exiting the context manager,
we wait on that background reading before returning.

I was hoping we could manually spin up a threading.Thread and this
would be simple. But I ran into a few deadlocks when implementing.
After looking at the source code to concurrent.futures, I figured
it would just be easier to use a ThreadPoolExecutor than implement
all the code needed to manually manage a thread.

To prove this works, a use of the batch API in discovery has been
updated.

Differential Revision: https://phab.mercurial-scm.org/D3269

#require serve

Create a repo with whitespace only changes

  $ hg init repo-with-whitespace
  $ cd repo-with-whitespace
  $ cat > foo << EOF
  > line 0
  > line 1
  > line 2
  > line 3
  > EOF
  $ hg -q commit -A -m 'commit 0'
  $ cat > foo << EOF
  > line 0
  > line 1 modified by 1
  > line 2
  > line 3
  > EOF
  $ hg commit -m 'commit 1'
  $ cat > foo << EOF
  > line 0
  > line 1 modified by 1
  >     line 2
  > line 3
  > EOF
  $ hg commit -m 'commit 2 (leading whitespace on line 2)'
  $ cat > foo << EOF
  > line 0
  > line 1 modified by 1
  >     line 2
  > EOF
Need to use printf to avoid check-code complaining about trailing whitespace.
  $ printf 'line 3    \n' >> foo
  $ hg commit -m 'commit 3 (trailing whitespace on line 3)'
  $ cat > foo << EOF
  > line  0
  > line 1 modified by 1
  >     line 2
  > EOF
  $ printf 'line 3    \n' >> foo
  $ hg commit -m 'commit 4 (intra whitespace on line 0)'
  $ cat > foo << EOF
  > line  0
  > 
  > line 1 modified by 1
  >     line 2
  > EOF
  $ printf 'line 3    \n' >> foo
  $ hg commit -m 'commit 5 (add blank line between line 0 and 1)'
  $ cat > foo << EOF
  > line  0
  > 
  > 
  > line 1 modified by 1
  >     line 2
  > EOF
  $ printf 'line 3    \n' >> foo
  $ hg commit -m 'commit 6 (add another blank line between line 0 and 1)'

  $ hg log -G -T '{rev}:{node|short} {desc}'
  @  6:9d1b2c7db017 commit 6 (add another blank line between line 0 and 1)
  |
  o  5:400ef1d40470 commit 5 (add blank line between line 0 and 1)
  |
  o  4:08adbe269f24 commit 4 (intra whitespace on line 0)
  |
  o  3:dcb62cfbfc9b commit 3 (trailing whitespace on line 3)
  |
  o  2:6bdb694e7b8c commit 2 (leading whitespace on line 2)
  |
  o  1:23e1e37387dc commit 1
  |
  o  0:b9c578134d72 commit 0
  

  $ hg serve -p $HGPORT -d --pid-file hg.pid
  $ cat hg.pid >> $DAEMON_PIDS
  $ hg serve --config annotate.ignorews=true -p $HGPORT1 -d --pid-file hg.pid
  $ cat hg.pid >> $DAEMON_PIDS
  $ cd ..

Annotate works

  $ get-with-headers.py --json $LOCALIP:$HGPORT 'json-annotate/9d1b2c7db017/foo'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 4 (intra whitespace on line 0)",
        "line": "line  0\n",
        "lineno": 1,
        "node": "08adbe269f24cf22d975eadeec16790c5b22f558",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 2 (leading whitespace on line 2)",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "6bdb694e7b8cebb68d5b6b27b4bcc2a49d62c602",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 3 (trailing whitespace on line 3)",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "dcb62cfbfc9b3ab995a5cbbaff6e1971c3e4f865",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }

annotate.ignorews=1 config option is honored

  $ get-with-headers.py --json $LOCALIP:$HGPORT1 'json-annotate/9d1b2c7db017/foo'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line  0\n",
        "lineno": 1,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }

ignorews=1 query string argument enables whitespace skipping

  $ get-with-headers.py --json $LOCALIP:$HGPORT 'json-annotate/9d1b2c7db017/foo?ignorews=1'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line  0\n",
        "lineno": 1,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }

ignorews=0 query string argument disables when config defaults to enabled

  $ get-with-headers.py --json $LOCALIP:$HGPORT1 'json-annotate/9d1b2c7db017/foo?ignorews=0'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 4 (intra whitespace on line 0)",
        "line": "line  0\n",
        "lineno": 1,
        "node": "08adbe269f24cf22d975eadeec16790c5b22f558",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 2 (leading whitespace on line 2)",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "6bdb694e7b8cebb68d5b6b27b4bcc2a49d62c602",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 3 (trailing whitespace on line 3)",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "dcb62cfbfc9b3ab995a5cbbaff6e1971c3e4f865",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }

ignorewsamount=1 query string enables whitespace amount skipping

  $ get-with-headers.py --json $LOCALIP:$HGPORT 'json-annotate/9d1b2c7db017/foo?ignorewsamount=1'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line  0\n",
        "lineno": 1,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 2 (leading whitespace on line 2)",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "6bdb694e7b8cebb68d5b6b27b4bcc2a49d62c602",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }

ignorewseol=1 query string enables whitespace end of line skipping

  $ get-with-headers.py --json $LOCALIP:$HGPORT 'json-annotate/9d1b2c7db017/foo?ignorewseol=1'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 4 (intra whitespace on line 0)",
        "line": "line  0\n",
        "lineno": 1,
        "node": "08adbe269f24cf22d975eadeec16790c5b22f558",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 2 (leading whitespace on line 2)",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "6bdb694e7b8cebb68d5b6b27b4bcc2a49d62c602",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }

ignoreblanklines=1 query string enables whitespace blank line skipping

  $ get-with-headers.py --json $LOCALIP:$HGPORT 'json-annotate/9d1b2c7db017/foo?ignoreblanklines=1'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 4 (intra whitespace on line 0)",
        "line": "line  0\n",
        "lineno": 1,
        "node": "08adbe269f24cf22d975eadeec16790c5b22f558",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 2 (leading whitespace on line 2)",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "6bdb694e7b8cebb68d5b6b27b4bcc2a49d62c602",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 3 (trailing whitespace on line 3)",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "dcb62cfbfc9b3ab995a5cbbaff6e1971c3e4f865",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }