How to ignore certain files when branching / checking out? - bazaar

Question

I'd like to compare a few files from the bazaar branch lp:ubuntu/nvidia-graphics-drivers. I'm mainly interested in the debian subdirectory inside that branch, but due to the binary blob in http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/oneiric/nvidia-graphics-drivers/oneiric/files, it takes ages to get just the text files. I've already downloaded 555MB and it's still counting.
Is it possible to retrieve a bazaar branch, including or excluding certain files by one of the following properties:
file size
file extension
file name (include only debian/ for example)
I do not need to push back any changes, nor do I need to view the history of a file. I just want to compare two files in the debian/ directory, files with the .in extension and files without.

Answer 1

As far as I'm aware, no. You're downloading the branch history, not just the individual files. And each file is an integral part of the branch's history.
On the bright side, you only have to check it out once. Unless those binary files change, they'll be skipped the next time you pull from Launchpad.
Depending on the branch's history, you may be able to cut down on the download size if you use a lightweight checkout (bzr checkout --lightweight). But of course, that may come back and bite you later, as it means you won't get a local copy of the branch, only the checked-out files. So it'll work much like SVN, where every operation has to go through the server. And as long as you don't need to look at the branch history, or commit your changes, that should serve you just fine, I believe.

Answer 2

I ended up doing some dirty grep-ing on the HTTP response since bzr info "$branch" and bzr ls -d "$branch" "$directory" did not provide enough information to me.
The below Bash script relies on the working of Launchpads front-end Loggerhead. It recursively downloads from a given URL. Currently, it ignores *.run files. Save it as bzrdl in a directory available from $PATH and run it with bzrdl http://launchpad.net/~ubuntu-branches/ubuntu/oneiric/nvidia-graphics-drivers/oneiric/files/head:/debian/. All files will be saved in the current directory, be sure that it's empty to avoid conflicts.
#!/bin/bash
max_retries=5
rooturl="$1"
if ! [[ $rooturl =~ /$ ]]; then
echo "Usage: ${0##*/} URL"
echo "URL must end with a slash. Example URL:"
echo "http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/oneiric/nvidia-graphics-drivers/oneiric/files/head:/"
exit 1
fi
tmpdir="$(mktemp -d)"
target="$(pwd)"
# used for holding HTTP response before extracting data
tmp="$(mktemp)"
# url_filter reads download URLs from stdin (piped)
url_filter() {
grep -v '\.run$'
}
get_files_from_dir() {
local slash=/
local dir="$1"
# to avoid name collision: a/b/c/ -> a.d/b.d/c.d/
local storedir="${dir//$slash/.d${slash}}"
mkdir -p "$tmpdir/$storedir" "$target/$dir"
local i subdir
for ((i=0; i<$max_retries; i++ )); do
if wget -O "$tmp" "$rooturl$dir"; then
# store file list
grep -F -B 1 '<img src="/static/images/ico_file_download.gif" alt="Download File" />' "$tmp" |\
grep '^<a' | cut -d '"' -f 2 | url_filter \
> "$tmpdir/$storedir/files"
IFS=$'\n'
for subdir in $(grep -F -B 1 '<img src="/static/images/ico_folder.gif" ' "$tmp" | \
grep -F '<a ' | rev | cut -d / -f 2 | rev); do
IFS=$' \t\n'
get_files_from_dir "$dir$subdir/"
done
return
fi
done
echo "Failed to download directory listing of: $dir" >> "$tmpdir/errors"
}
download_files() {
local slash=/
local dir="$1"
# to avoid name collision: a/b/c/ -> a.d/b.d/c.d/
local storedir="${dir//$slash/.d${slash}}"
local done=false
local subdir
cd "$tmpdir/$storedir"
for ((i=0; i<$max_retries; i++)); do
if wget -B "$rooturl$dir" -nc -i files -P "$target/$dir"; then
done=true
break
fi
done
$done || echo "Failed to download all files from $dir" >> "$tmpdir/errors"
for subdir in *.d; do
download_files "$dir${subdir%%.d}/"
done
}
get_files_from_dir ''
# make *.d expand to nothing if no directories are found
shopt -s nullglob
download_files ''
echo "TMP dir: $tmpdir"
echo "Errors : $(wc -l "$tmpdir/errors" 2>/dev/null | cut -d ' ' -f 2 || echo 0)"
The temporary directory and file is not removed afterwards, that must be done manually. Any errors (failures to download) will be written to $tmpdir/errors
It's confirmed to work with:
bzrdl http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/oneiric/nvidia-settings/oneiric/files/head:/debian/
Feel free to correct any mistakes or add improvements.

Answer 3

There is no way to selectively check out a specific directory from a Bazaar branch at the moment, although we do have plans to add such support in the future.
There is definitely too much traffic for the clone you are doing, considering the size of the branch. It's probably a bug in the client implementation.
Here on bzr 2.4 it is still quite slow but not too bad (60s):
localhost:/tmp% bzr branch http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/oneiric/nvidia-settings/oneiric
Most recent Ubuntu Oneiric version: 275.09.07-0ubuntu1
Packaging branch status: CURRENT
Branched 37 revision(s).
From the log:
[11866] 2011-07-31 00:56:57.007 INFO: Branched 37 revision(s).
56.786 Transferred: 5335kB (95.8kB/s r:5314kB w:21kB)