Copies files to filenames based on their contents
Project description
A command line tool that copies files to filenames based on their contents. It also writes a map of what was renamed to what, so you can find your files.
Main purpose of this is that you can add a far future Expires header to your components. Using hash based filenames is a lot better than using your $VCS revision number, because users only need to download files that didn’t change.
Creating some source files
For this demo, we’ll create a few files that will be used throughout the whole process:
>>> system("mkdir maps/")
>>> system("mkdir input/")
>>> with open("input/foo.txt", "w") as file:
... file.write("foo")
We also create files that live in a sub- and subsubdirectories:
>>> system("mkdir input/subdir/")
>>> with open("input/subdir/bar.txt", "w") as writeme:
... writeme.write("bar")
>>> system("mkdir input/subdir/2nd/")
>>> with open("input/subdir/2nd/baz.txt", "w") as writeme:
... writeme.write("foofoofoo")
Simple usage
>>> system("hashedassets maps/map.txt input/*.txt input/*/*.txt output/")
mkdir 'output'
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
>>> system("ls maps/")
map.txt
>>> print open("maps/map.txt").read()
subdir/bar.txt: Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt
foo.txt: C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt
<BLANKLINE>
>>> system("ls output/")
C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt
Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt
Modification time is also preserved:
>>> old_stat = os.stat("input/foo.txt")
>>> new_stat = os.stat("output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt")
>>> [(getattr(old_stat, prop) == getattr(new_stat, prop))
... for prop in ('st_mtime', 'st_atime', 'st_ino',)]
[True, True, False]
We can easily do this with multiple formats:
JavaScript
>>> system("hashedassets -n my_callback maps/map.js input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
>>> print open("maps/map.js").read()
var my_callback = {
"foo.txt": "C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt",
"subdir/bar.txt": "Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt"
};
JSON
>>> system("hashedassets -n my_callback maps/map.json input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
>>> print open("maps/map.json").read()
{
"foo.txt": "C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt",
"subdir/bar.txt": "Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt"
}
JSONP
>>> system("hashedassets -n my_callback maps/map.jsonp input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
>>> print open("maps/map.jsonp").read()
my_callback({
"foo.txt": "C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt",
"subdir/bar.txt": "Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt"
});
Sass
Sass is a meta language on top of CSS.
>>> system("hashedassets -n my_callback maps/map.scss input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
>>> print open("maps/map.scss").read()
@mixin my_callback($directive, $path) {
@if $path == "subdir/bar.txt" { #{$directive}: url("Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt"); }
@else if $path == "foo.txt" { #{$directive}: url("C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt"); }
@else {
@warn "Did not find "#{$path}" in list of assets";
#{$directive}: url($path);
}
}
PHP
>>> system("hashedassets -n my_callback maps/map.php input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
>>> print open("maps/map.php").read()
$my_callback = array(
"subdir/bar.txt" => "Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt",
"foo.txt" => "C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt",
)
Sed
We can also generate a sed script that does the replacements for us:
>>> system("hashedassets -n my_callback maps/map.sed input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
>>> print open("maps/map.sed").read()
s/subdir\/bar\.txt/Ys23Ag_5IOWqZCw9QGaVDdHwH00\.txt/g
s/foo\.txt/C-7Hteo_D9vJXQ3UfzxbwnXaijM\.txt/g
<BLANKLINE>
We should also be able to use this directly with sed
>>> with open("replaceme.html", "w") as writeme:
... writeme.write('<a href=foo.txt>bar</a>')
The script is then applied like this:
>>> system("sed -f maps/map.sed replaceme.html")
<a href=C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt>bar</a>
However, ‘.’ is not treated as wildcard, so the following does not work
>>> with open("replaceme2.html", "w") as writeme:
... writeme.write('<a href=fooAtxt>bar</a>')
>>> system("sed -f maps/map.sed replaceme2.html")
<a href=fooAtxt>bar</a>
Specifying the type with -t
The type of the map is guessed from the filename, but you can specify it as well:
>>> system("hashedassets -t js cantguessmaptype input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
Specifying the length of the filename with -l
>>> system("hashedassets -l 10 maps/shortmap.json input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IO.txt'
>>> system("rm output/C-7Hteo_D9.txt output/Ys23Ag_5IO.txt")
Specifying the digest with -d
Hashedassets uses sha1 by default to hash the input files. You can change that with the -d command line parameter, e.g. by specifying -d md5 to use the md5 digest method.
>>> system("hashedassets -d md5 maps/shortmap.json input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/rL0Y20zC-Fzt72VPzMSk2A.txt'
cp 'input/subdir/bar.txt' 'output/N7UdGUp1E-RbVvZSTy1R8g.txt'
>>> system("rm output/rL0Y20zC-Fzt72VPzMSk2A.txt output/N7UdGUp1E-RbVvZSTy1R8g.txt")
Keep the directory structure with –keep-dirs
By default hashedassets copies all output files into the root level of the output dir. You can turn this off, with the ‘’–keep-dirs’’ option:
>>> system("hashedassets --keep-dirs maps/preserve.json input/*.txt input/*/*.txt input/*/*/*.txt output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
mkdir -p output/subdir
cp 'input/subdir/bar.txt' 'output/subdir/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
mkdir -p output/subdir/2nd
cp 'input/subdir/2nd/baz.txt' 'output/subdir/2nd/NdbmnXyjdY2paFzlDw9aJzCKH9w.txt'
>>> system("rm -r output/subdir/")
Verbose mode with -v
If we tell the command to be quiet, it does not print what it is doing:
>>> system("hashedassets -q maps/map2.txt input/*.txt input/*/*.txt output/")
If we tell the command to be more verbose, it logs more information:
>>> system("hashedassets -vvv maps/map3.txt input/*.txt input/*/*.txt output/")
Debug level set to 10
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
Re-using a map
The program reads in maps it created in a prior run to only copy files that haven’t changed since. So, the following commands do not copy any files:
>>> system("hashedassets maps/map.scss input/*.txt input/*/*.txt output/")
>>> system("hashedassets maps/map.php input/*.txt input/*/*.txt output/")
>>> system("hashedassets maps/map.js input/*.txt input/*/*.txt output/")
>>> system("hashedassets maps/map.json input/*.txt input/*/*.txt output/")
>>> system("hashedassets maps/map.sed input/*.txt input/*/*.txt output/")
>>> system("hashedassets maps/map.jsonp input/*.txt input/*/*.txt output/")
>>> system("hashedassets maps/map.txt input/*.txt input/*/*.txt output/")
If we touch one of the input files in between, the file will be read but not copied because the hashsum is the same:
>>> system('touch -t200504072214.12 input/foo.txt')
>>> system("hashedassets maps/map.json input/*.txt input/*/*.txt output/")
If we change the file’s content, it will get a new name:
>>> with open("input/foo.txt", "w") as writeme:
... writeme.write("foofoo")
>>> system("hashedassets maps/map.json input/*.txt input/*/*.txt output/")
rm 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/foo.txt' 'output/QIDaFD7KLKQh0l5O6b8exdew3b0.txt'
If you then list the files in the directory, note that the old file ‘’output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt’’ is gone:
>>> system("ls output/")
QIDaFD7KLKQh0l5O6b8exdew3b0.txt
Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt
If we remove one of the created files, it gets recreated:
>>> system("rm output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt")
>>> system("hashedassets maps/map.json input/*.txt input/*/*.txt output/")
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
>>> system("ls output/")
QIDaFD7KLKQh0l5O6b8exdew3b0.txt
Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt
If a file that is about to be removed because the original content changed, it isn’t recreated:
>>> system("rm output/QIDaFD7KLKQh0l5O6b8exdew3b0.txt")
>>> with open("input/foo.txt", "w") as writeme:
... writeme.write("foofoofoo")
>>> system("hashedassets maps/map.json input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/NdbmnXyjdY2paFzlDw9aJzCKH9w.txt'
Error handling
If try to use the software with no arguments the user is reminded to specify at least the mapfile, the source and the destination directory:
>>> system("hashedassets", external=True)
Usage: hashedassets [ options ] MAPFILE SOURCE [...] DEST
<BLANKLINE>
hashedassets: error: You need to specify at least MAPFILE SOURCE and DEST
If the user specifies the –help option, detailed usage information is shown:
>>> system("hashedassets --help", external=True)
Usage: hashedassets [ options ] MAPFILE SOURCE [...] DEST
<BLANKLINE>
Version: ...
<BLANKLINE>
Options:
--version show program's version number and exit
-h, --help show this help message and exit
-v, --verbose increase verbosity level
-q, --quiet don't print status messages to stdout
-n MAPNAME, --map-name=MAPNAME
name of the map [default: hashedassets]
-t MAPTYPE, --map-type=MAPTYPE
type of the map. one of scss, php, js, json, sed,
jsonp, txt [default: guessed from MAPFILE]
-l LENGTH, --digest-length=LENGTH
length of the generated filenames (without extension)
[default: 27]
-d HASHFUN, --digest=HASHFUN
hash function to use. One of sha1, md5 [default: sha1]
-k, --keep-dirs Mirror SOURCE dir structure to DEST [default: false]
