wireprotov2: client support for following content redirects
And with the server actually sending content redirects, it is finally
time to implement client support for following them!
When a redirect response is seen, we wait until all data for that
request has been received (it should be nearly immediate since no
data is expected to follow the redirect message). Then we use
a URL opener to make a request. We stuff that response into the
client handler and construct a new response object to track it.
When readdata() is called for servicing requests, we attempt to
read data from the first redirected response. During data reading,
data is processed similarly to as if it came from a frame payload.
The existing test for the functionality demonstrates the client
transparently following the redirect and obtaining the command
response data from an alternate URL!
There is still plenty of work to do here, including shoring up
testing. I'm not convinced things will work in the presence of
multiple redirect responses. And we don't yet implement support
for integrity verification or configuring server certificates
to validate the connection. But it's a start. And it should enable
us to start experimenting with "real" caches.
Differential Revision: https://phab.mercurial-scm.org/D4778
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 __future__ import print_function
> 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 __future__ import print_function
> 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, end=' ')
> 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, end=' ')
> 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 [(b'limit', b'\0\0\0\x02'), (b'segv', b'\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 + b"/.hg/store/00changelog.i", "wb").write(d)
> EOF
$ hg -R limit debugrevlogindex -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 debugrevlogindex -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
> from __future__ import print_function
> 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 + ':', end=' ')
> try:
> f()
> print('uncaught buffer overflow?')
> except ValueError as 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