obsolete: don't use os.stat in repo.obsstore.__nonzero__ if it's static HTTP
If a repo is accessed via static HTTP, then we obviously can't use os.stat() to
just peek at the file size. Let's download the entire file to check its size.
Yes, this feels wasteful, but:
1. If we're cloning or pulling a repo from a static HTTP server, we need the
contents of the obsstore anyway.
2. Implementing statichttpvfs.stat() that uses HEAD will result in one more
request to a static-only HTTP server, which is already slow. Also parsing a
response to a HEAD request to construct os.stat_result is pretty hacky.
There's also a question of the remote server properly supporting HEAD method
and reporting at least file size.
3. Implementing statichttpvfs.stat() that uses GET is pretty much the same
thing as we do here, except we can't even cache the response easily, unlike
simply accessing obsstore._data, which is @propertycache'd.
Importing statichttprepo locally to avoid circular import.
See also: 4507bc001365 and commit message of f8f2ecdde4b5.
Differential Revision: https://phab.mercurial-scm.org/D12195
Test transaction safety
=======================
#testcases revlogv1 revlogv2 changelogv2
#if revlogv1
$ cat << EOF >> $HGRCPATH
> [experimental]
> revlogv2=no
> EOF
#endif
#if revlogv2
$ cat << EOF >> $HGRCPATH
> [experimental]
> revlogv2=enable-unstable-format-and-corrupt-my-data
> EOF
#endif
#if changelogv2
$ cat << EOF >> $HGRCPATH
> [format]
> exp-use-changelog-v2=enable-unstable-format-and-corrupt-my-data
> EOF
#endif
This test basic case to make sure external process do not see transaction
content until it is committed.
# TODO: also add an external reader accessing revlog files while they are written
# (instead of during transaction finalisation)
# TODO: also add stream clone and hardlink clone happening during these transaction.
setup
-----
synchronisation+output script using the following schedule:
[A1] "external" is started
[A2] "external" waits on EXT_UNLOCK
[A2] "external" + creates EXT_WAITING → unlocks [C1]
[B1] "hg commit/pull" is started
[B2] "hg commit/pull" is ready to be committed
[B3] "hg commit/pull" spawn "internal" using a pretxnclose hook (need [C4])
[C1] "internal" waits on EXT_WAITING (need [A2])
[C2] "internal" creates EXT_UNLOCK → unlocks [A2]
[C3] "internal" show the tipmost revision (inside of the transaction)
[C4] "internal" waits on EXT_DONE (need [A4])
[A3] "external" show the tipmost revision (outside of the transaction)
[A4] "external" creates EXT_DONE → unlocks [C4]
[C5] "internal" end of execution -> unlock [B3]
[B4] "hg commit/pull" transaction is committed on disk
$ mkdir sync
$ mkdir output
$ mkdir script
$ HG_TEST_FILE_EXT_WAITING=$TESTTMP/sync/ext_waiting
$ export HG_TEST_FILE_EXT_WAITING
$ HG_TEST_FILE_EXT_UNLOCK=$TESTTMP/sync/ext_unlock
$ export HG_TEST_FILE_EXT_UNLOCK
$ HG_TEST_FILE_EXT_DONE=$TESTTMP/sync/ext_done
$ export HG_TEST_FILE_EXT_DONE
$ cat << EOF > script/external.sh
> #!/bin/sh
> "$RUNTESTDIR/testlib/wait-on-file" 5 "$HG_TEST_FILE_EXT_UNLOCK" "$HG_TEST_FILE_EXT_WAITING"
> hg log --rev 'tip' -T 'external: {rev} {desc}\n' > "$TESTTMP/output/external.out"
> touch "$HG_TEST_FILE_EXT_DONE"
> EOF
$ cat << EOF > script/internal.sh
> #!/bin/sh
> "$RUNTESTDIR/testlib/wait-on-file" 5 "$HG_TEST_FILE_EXT_WAITING"
> touch "$HG_TEST_FILE_EXT_UNLOCK"
> hg log --rev 'tip' -T 'internal: {rev} {desc}\n' > "$TESTTMP/output/internal.out"
> "$RUNTESTDIR/testlib/wait-on-file" 5 "$HG_TEST_FILE_EXT_DONE"
> EOF
Automated commands:
$ make_one_commit() {
> rm -f $TESTTMP/sync/*
> rm -f $TESTTMP/output/*
> hg log --rev 'tip' -T 'pre-commit: {rev} {desc}\n'
> echo x >> a
> sh $TESTTMP/script/external.sh & hg commit -m "$1"
> cat $TESTTMP/output/external.out
> cat $TESTTMP/output/internal.out
> hg log --rev 'tip' -T 'post-tr: {rev} {desc}\n'
> }
$ make_one_pull() {
> rm -f $TESTTMP/sync/*
> rm -f $TESTTMP/output/*
> hg log --rev 'tip' -T 'pre-commit: {rev} {desc}\n'
> echo x >> a
> sh $TESTTMP/script/external.sh & hg pull ../other-repo/ --rev "$1" --force --quiet
> cat $TESTTMP/output/external.out
> cat $TESTTMP/output/internal.out
> hg log --rev 'tip' -T 'post-tr: {rev} {desc}\n'
> }
prepare a large source to which to pull from:
The source is large to unsure we don't use inline more after the pull
$ hg init other-repo
$ hg -R other-repo debugbuilddag .+500
prepare an empty repository where to make test:
$ hg init repo
$ cd repo
$ touch a
$ hg add a
prepare a small extension to controll inline size
$ mkdir $TESTTMP/ext
$ cat << EOF > $TESTTMP/ext/small_inline.py
> from mercurial import revlog
> revlog._maxinline = 64 * 100
> EOF
$ cat << EOF >> $HGRCPATH
> [extensions]
> small_inline=$TESTTMP/ext/small_inline.py
> [hooks]
> pretxnclose = sh $TESTTMP/script/internal.sh
> EOF
check this is true for the initial commit (inline → inline)
-----------------------------------------------------------
the repository should still be inline (for relevant format)
$ make_one_commit first
pre-commit: -1
external: -1
internal: 0 first
post-tr: 0 first
#if revlogv1
$ hg debugrevlog -c | grep inline
flags : inline
#endif
check this is true for extra commit (inline → inline)
-----------------------------------------------------
the repository should still be inline (for relevant format)
#if revlogv1
$ hg debugrevlog -c | grep inline
flags : inline
#endif
$ make_one_commit second
pre-commit: 0 first
external: 0 first
internal: 1 second
post-tr: 1 second
#if revlogv1
$ hg debugrevlog -c | grep inline
flags : inline
#endif
check this is true for a small pull (inline → inline)
-----------------------------------------------------
the repository should still be inline (for relevant format)
#if revlogv1
$ hg debugrevlog -c | grep inline
flags : inline
#endif
$ make_one_pull 3
pre-commit: 1 second
warning: repository is unrelated
external: 1 second
internal: 5 r3
post-tr: 5 r3
#if revlogv1
$ hg debugrevlog -c | grep inline
flags : inline
#endif
Make a large pull (inline → no-inline)
---------------------------------------
the repository should no longer be inline (for relevant format)
#if revlogv1
$ hg debugrevlog -c | grep inline
flags : inline
#endif
$ make_one_pull 400
pre-commit: 5 r3
external: 5 r3
internal: 402 r400
post-tr: 402 r400
#if revlogv1
$ hg debugrevlog -c | grep inline
[1]
#endif
check this is true for extra commit (no-inline → no-inline)
-----------------------------------------------------------
the repository should no longer be inline (for relevant format)
#if revlogv1
$ hg debugrevlog -c | grep inline
[1]
#endif
$ make_one_commit third
pre-commit: 402 r400
external: 402 r400
internal: 403 third
post-tr: 403 third
#if revlogv1
$ hg debugrevlog -c | grep inline
[1]
#endif
Make a pull (not-inline → no-inline)
-------------------------------------
the repository should no longer be inline (for relevant format)
#if revlogv1
$ hg debugrevlog -c | grep inline
[1]
#endif
$ make_one_pull tip
pre-commit: 403 third
external: 403 third
internal: 503 r500
post-tr: 503 r500
#if revlogv1
$ hg debugrevlog -c | grep inline
[1]
#endif