repository: define new interface for running commands
Today, the peer interface exposes methods for each command that can
be executed. In addition, there is an iterbatch() API that allows
commands to be issued in batches and provides an iterator over the
results. This is a glorified wrapper around the "batch" wire command.
Wire protocol version 2 supports nicer things (such as batching
any command and out-of-order replies). It will require a more
flexible API for executing commands.
This commit introduces a new peer interface for making command
requests. In the new world, you can't simply call a method on the
peer to execute a command: you need to obtain an object to be used
for executing commands. That object can be used to issue a single
command or it can batch multiple requests. In the case of full duplex
peers, the command may even be sent out over the wire immediately.
There are no per-command methods. Instead, there is a generic
method to call a command. The implementation can then perform domain
specific processing for specific commands. This includes passing
data via a specially named argument.
Arguments are also passed as a dictionary instead of using **kwargs.
While **kwargs is nicer to use, we've historically gotten into
trouble using it because there will inevitably be a conflict between
the name of an argument to a wire protocol command and an argument
we want to pass into a function.
Instead of a command returning a value, it returns a future which
will resolve to a value. This opens the door for out-of-order
response handling and concurrent response handling in the version
2 protocol.
Differential Revision: https://phab.mercurial-scm.org/D3267
revlog.parseindex must be able to parse the index file even if
an index entry is split between two 64k blocks. The ideal test
would be to create an index file with inline data where
64k < size < 64k + 64 (64k is the size of the read buffer, 64 is
the size of an index entry) and with an index entry starting right
before the 64k block boundary, and try to read it.
We approximate that by reducing the read buffer to 1 byte.
$ hg init a
$ cd a
$ echo abc > foo
$ hg add foo
$ hg commit -m 'add foo'
$ echo >> foo
$ hg commit -m 'change foo'
$ hg log -r 0:
changeset: 0:7c31755bf9b5
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
changeset: 1:26333235a41c
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: change foo
$ cat >> test.py << EOF
> from mercurial import changelog, vfs
> from mercurial.node import *
>
> class singlebyteread(object):
> def __init__(self, real):
> self.real = real
>
> def read(self, size=-1):
> if size == 65536:
> size = 1
> return self.real.read(size)
>
> def __getattr__(self, key):
> return getattr(self.real, key)
>
> def __enter__(self):
> self.real.__enter__()
> return self
>
> def __exit__(self, *args, **kwargs):
> return self.real.__exit__(*args, **kwargs)
>
> def opener(*args):
> o = vfs.vfs(*args)
> def wrapper(*a, **kwargs):
> f = o(*a, **kwargs)
> return singlebyteread(f)
> return wrapper
>
> cl = changelog.changelog(opener('.hg/store'))
> print len(cl), 'revisions:'
> for r in cl:
> print short(cl.node(r))
> EOF
$ $PYTHON test.py
2 revisions:
7c31755bf9b5
26333235a41c
$ cd ..
#if no-pure
Test SEGV caused by bad revision passed to reachableroots() (issue4775):
$ cd a
$ $PYTHON <<EOF
> from mercurial import changelog, vfs
> cl = changelog.changelog(vfs.vfs('.hg/store'))
> print 'good heads:'
> for head in [0, len(cl) - 1, -1]:
> print'%s: %r' % (head, cl.reachableroots(0, [head], [0]))
> print 'bad heads:'
> for head in [len(cl), 10000, -2, -10000, None]:
> print '%s:' % head,
> try:
> cl.reachableroots(0, [head], [0])
> print 'uncaught buffer overflow?'
> except (IndexError, TypeError) as inst:
> print inst
> print 'good roots:'
> for root in [0, len(cl) - 1, -1]:
> print '%s: %r' % (root, cl.reachableroots(root, [len(cl) - 1], [root]))
> print 'out-of-range roots are ignored:'
> for root in [len(cl), 10000, -2, -10000]:
> print '%s: %r' % (root, cl.reachableroots(root, [len(cl) - 1], [root]))
> print 'bad roots:'
> for root in [None]:
> print '%s:' % root,
> try:
> cl.reachableroots(root, [len(cl) - 1], [root])
> print 'uncaught error?'
> except TypeError as inst:
> print inst
> EOF
good heads:
0: [0]
1: [0]
-1: []
bad heads:
2: head out of range
10000: head out of range
-2: head out of range
-10000: head out of range
None: an integer is required
good roots:
0: [0]
1: [1]
-1: [-1]
out-of-range roots are ignored:
2: []
10000: []
-2: []
-10000: []
bad roots:
None: an integer is required
$ cd ..
Test corrupted p1/p2 fields that could cause SEGV at parsers.c:
$ mkdir invalidparent
$ cd invalidparent
$ hg clone --pull -q --config phases.publish=False ../a limit
$ hg clone --pull -q --config phases.publish=False ../a segv
$ rm -R limit/.hg/cache segv/.hg/cache
$ $PYTHON <<EOF
> data = open("limit/.hg/store/00changelog.i", "rb").read()
> for n, p in [('limit', '\0\0\0\x02'), ('segv', '\0\x01\0\0')]:
> # corrupt p1 at rev0 and p2 at rev1
> d = data[:24] + p + data[28:127 + 28] + p + data[127 + 32:]
> open(n + "/.hg/store/00changelog.i", "wb").write(d)
> EOF
$ hg -R limit debugindex -f1 -c
rev flag size link p1 p2 nodeid
0 0000 62 0 2 -1 7c31755bf9b5
1 0000 65 1 0 2 26333235a41c
$ hg -R limit debugdeltachain -c
rev chain# chainlen prev delta size rawsize chainsize ratio lindist extradist extraratio
0 1 1 -1 base 63 62 63 1.01613 63 0 0.00000
1 2 1 -1 base 66 65 66 1.01538 66 0 0.00000
$ hg -R segv debugindex -f1 -c
rev flag size link p1 p2 nodeid
0 0000 62 0 65536 -1 7c31755bf9b5
1 0000 65 1 0 65536 26333235a41c
$ hg -R segv debugdeltachain -c
rev chain# chainlen prev delta size rawsize chainsize ratio lindist extradist extraratio
0 1 1 -1 base 63 62 63 1.01613 63 0 0.00000
1 2 1 -1 base 66 65 66 1.01538 66 0 0.00000
$ cat <<EOF > test.py
> import sys
> from mercurial import changelog, vfs
> cl = changelog.changelog(vfs.vfs(sys.argv[1]))
> n0, n1 = cl.node(0), cl.node(1)
> ops = [
> ('reachableroots',
> lambda: cl.index.reachableroots2(0, [1], [0], False)),
> ('compute_phases_map_sets', lambda: cl.computephases([[0], []])),
> ('index_headrevs', lambda: cl.headrevs()),
> ('find_gca_candidates', lambda: cl.commonancestorsheads(n0, n1)),
> ('find_deepest', lambda: cl.ancestor(n0, n1)),
> ]
> for l, f in ops:
> print l + ':',
> try:
> f()
> print 'uncaught buffer overflow?'
> except ValueError, inst:
> print inst
> EOF
$ $PYTHON test.py limit/.hg/store
reachableroots: parent out of range
compute_phases_map_sets: parent out of range
index_headrevs: parent out of range
find_gca_candidates: parent out of range
find_deepest: parent out of range
$ $PYTHON test.py segv/.hg/store
reachableroots: parent out of range
compute_phases_map_sets: parent out of range
index_headrevs: parent out of range
find_gca_candidates: parent out of range
find_deepest: parent out of range
$ cd ..
#endif