internals: document CBOR utilization
I spoke with some people at Mozilla about CBOR and they advised me
that we should be careful about the subset of CBOR we use in order
to mitigate security, performance, and compatibility concerns.
This commit establishes a document that attempts to formalize our
use of CBOR.
Its main limitations are on what types are allowed. It explicitly
enumerates which types are supported. Notable missing features
include:
* Indefinite-length arrays and maps
* Text strings (bytes all the way)
* Floats
* Date/time types
* Big integers
* Use of indefinite-length byte strings for map keys, values in
containers.
If we have a need for any of these, we can have a discussion about
them when the time comes.
Differential Revision: https://phab.mercurial-scm.org/D4412
#require svn svn-bindings
$ cat >> $HGRCPATH <<EOF
> [extensions]
> convert =
> EOF
$ svnadmin create svn-repo
$ svnadmin load -q svn-repo < "$TESTDIR/svn/branches.svndump"
Convert trunk and branches
$ cat > branchmap <<EOF
> old3 newbranch
>
>
> EOF
$ hg convert --branchmap=branchmap --datesort -r 10 svn-repo A-hg
initializing destination A-hg repository
scanning source...
sorting...
converting...
10 init projA
9 hello
8 branch trunk, remove c and dir
7 change a
6 change b
5 move and update c
4 move and update c
3 change b again
2 move to old2
1 move back to old
0 last change to a
Test template keywords
$ hg -R A-hg log --template '{rev} {svnuuid}{svnpath}@{svnrev}\n'
10 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@10
9 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@9
8 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old2@8
7 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@7
6 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@6
5 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@6
4 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@5
3 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@4
2 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@3
1 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@2
0 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@1
Convert again
$ hg convert --branchmap=branchmap --datesort svn-repo A-hg
scanning source...
sorting...
converting...
0 branch trunk@1 into old3
$ cd A-hg
$ hg log -G --template 'branch={branches} {rev} {desc|firstline} files: {files}\n'
o branch=newbranch 11 branch trunk@1 into old3 files:
|
| o branch= 10 last change to a files: a
| |
| | o branch=old 9 move back to old files:
| | |
| | o branch=old2 8 move to old2 files:
| | |
| | o branch=old 7 change b again files: b
| | |
| o | branch= 6 move and update c files: b
| | |
| | o branch=old 5 move and update c files: c
| | |
| | o branch=old 4 change b files: b
| | |
| o | branch= 3 change a files: a
| | |
| | o branch=old 2 branch trunk, remove c and dir files: c
| |/
| o branch= 1 hello files: a b c dir/e
|/
o branch= 0 init projA files:
$ hg branches
newbranch 11:a6d7cc050ad1
default 10:6e2b33404495
old 9:1b494af68c0b
old2 8:5be40b8dcbf6 (inactive)
$ hg tags -q
tip
$ cd ..
Test hg failing to call itself
$ HG=foobar hg convert svn-repo B-hg 2>&1 | grep abort
abort: Mercurial failed to run itself, check hg executable is in PATH
Convert 'trunk' to branch other than 'default'
$ cat > branchmap <<EOF
> default hgtrunk
>
>
> EOF
$ hg convert --branchmap=branchmap --datesort -r 10 svn-repo C-hg
initializing destination C-hg repository
scanning source...
sorting...
converting...
10 init projA
9 hello
8 branch trunk, remove c and dir
7 change a
6 change b
5 move and update c
4 move and update c
3 change b again
2 move to old2
1 move back to old
0 last change to a
$ cd C-hg
$ hg branches --template '{branch}\n'
hgtrunk
old
old2
$ cd ..