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hashedassets 0.3.2

Copies files to filenames based on their contents

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 directories, one for the maps to live, one for the input files:

>>> system("mkdir maps/")
>>> system("mkdir -p input/subdir/2nd/")

We also create files that live in a sub- and subsubdirectories:

>>> write("input/foo.txt", "foo")
>>> write("input/subdir/bar.txt", "bar")
>>> write("input/subdir/2nd/baz.txt", "foofoofoo")

Simple usage

>>> system("hashedassets -v 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())
foo.txt: C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt
subdir/bar.txt: Ys23Ag_5IOWqZCw9QGaVDdHwH00.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]

If you specify a directory as source, all files and subdirectories will be processed:

>>> system("hashedassets -v maps/dirmap.txt input/ output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
cp 'input/subdir/2nd/baz.txt' 'output/NdbmnXyjdY2paFzlDw9aJzCKH9w.txt'
>>> system("rm output/NdbmnXyjdY2paFzlDw9aJzCKH9w.txt")

Output formats

We can easily do this with multiple formats:

Sed

This generates a sed script that does the replacements for us:

>>> system("hashedassets -v -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/foo\.txt/C-7Hteo_D9vJXQ3UfzxbwnXaijM\.txt/g
s/subdir\/bar\.txt/Ys23Ag_5IOWqZCw9QGaVDdHwH00\.txt/g
<BLANKLINE>

We should be able to use this with sed on this file:

>>> write("replaceme.html", "<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>

Note ‘.’ is not treated as wildcard, so the following does not work

>>> write("replaceme2.html", "<a href=fooAtxt>bar</a>")
>>> system("sed -f maps/map.sed replaceme2.html")
<a href=fooAtxt>bar</a>

JavaScript

>>> system("hashedassets -v -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 -v -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 -v -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"
});

SCSS

Sass (“Syntactically Awesome Stylesheets”) is a meta language on top of CSS.

>>> system("hashedassets -v -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 $path == "foo.txt" { #{$directive}: url("C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt"); }
    @else if $path == "subdir/bar.txt" { #{$directive}: url("Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt"); }
    @else {
      @warn "Did not find "#{$path}" in list of assets";
      #{$directive}: url($path);
    }
}

PHP

>>> system("hashedassets -v -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(
  "foo.txt" => "C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt",
  "subdir/bar.txt" => "Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt",
)

Options

Specifying the type with -t

The type of the map is guessed from the filename, but you can specify it as well:

>>> system("hashedassets -v -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 -v -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 -v -d md5 maps/md5map.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 -v --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/")

Don’t move anything with –map-only

If you specify ”–map-only”, the program will create a map but it won’t move any files. This is useful, if you want to use the hashed name as part of the path (”’http://static.example.com/aYs23A/subdir/bar.txt”’) that is dropped by the webserver during url rewriting.

>>> system("hashedassets -v --map-only maps/maponly.txt input/*.txt")
>>> print(open('maps/maponly.txt').read())
foo.txt: C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt
<BLANKLINE>

Don’t map anything with –identity

If you specify ”–identity” the program will create a map that maps every file to itself, similar to how the identity function is defined. You can use this if you want to disable hashedassets temporarily, but don’t want to alter your build script heavily:

>>> system("hashedassets -v --identity maps/identitymap.json input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/foo.txt'
mkdir -p output/subdir
cp 'input/subdir/bar.txt' 'output/subdir/bar.txt'
>>> print(open('maps/identitymap.json').read())
{
  "foo.txt": "foo.txt",
  "subdir/bar.txt": "subdir/bar.txt"
}

If you switch –identity off, all identity files get deleted:

>>> system("hashedassets -v maps/identitymap.json input/*.txt input/*/*.txt output/")
rm 'output/foo.txt'
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
rm 'output/subdir/bar.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
>>> print(open('maps/identitymap.json').read())
{
  "foo.txt": "C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt",
  "subdir/bar.txt": "Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt"
}
>>> system("rm -r output/subdir/")

Strip file extensions with –strip-extensions

If you want to strip the file extensions of the resulting hashed files, this option is for you! This is particularly useful in combination with the ”–map-only” option with the hashed name becoming part of the path of the url.

>>> system("hashedassets -v --strip-extensions maps/noextensions.json input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00'
>>> print(open('maps/noextensions.json').read())
{
  "foo.txt": "C-7Hteo_D9vJXQ3UfzxbwnXaijM",
  "subdir/bar.txt": "Ys23Ag_5IOWqZCw9QGaVDdHwH00"
}
>>> system("rm -r output/C-7Hteo_D9vJXQ3UfzxbwnXaijM output/Ys23Ag_5IOWqZCw9QGaVDdHwH00")

Verbose mode with -v

Usually the program does not print anything if it everything works as expected:

>>> system("hashedassets maps/map2.txt input/*.txt input/*/*.txt output/")

You can tell the program to log more information (using -v), optionally multiple times to see what’s going on inside:

>>> system("hashedassets -v maps/map3.txt input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'

Exclude files with –exclude

You can exclude dirs and files from being hashed, using the --exclude option, both using patterns and directories:

>>> system("hashedassets -v maps/xmap.txt --exclude input/*/2nd input/ output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'
>>> system("hashedassets -v maps/xmap2.txt --exclude input/subdir/ input/ output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
>>> system("hashedassets -v maps/xmap3.txt --exclude input/subdir/2nd/baz.txt input/ output/")
cp 'input/foo.txt' 'output/C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt'
cp 'input/subdir/bar.txt' 'output/Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt'

Relative paths with –reference

If you need all paths relative to a specific file or directory, --reference is your friend:

>>> system("hashedassets -v --keep-dirs --reference=output/subdir/style.css maps/refmap.txt input/ 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'
>>> print(open('maps/refmap.txt').read())
../foo.txt: ../C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt
bar.txt: Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt
2nd/baz.txt: 2nd/NdbmnXyjdY2paFzlDw9aJzCKH9w.txt

If we execute this again, there is no work to do:

>>> system("hashedassets -v --keep-dirs --reference=output/subdir/ maps/refmap.txt input/ output/")
>>> system("rm -r output/subdir/")

Advanced usage

Writing the map to stdout

>>> system("hashedassets --map-type=txt - input/*.txt input/*/*.txt output/")
foo.txt: C-7Hteo_D9vJXQ3UfzxbwnXaijM.txt
subdir/bar.txt: Ys23Ag_5IOWqZCw9QGaVDdHwH00.txt
<BLANKLINE>

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 -v maps/map.scss input/*.txt input/*/*.txt output/")
>>> system("hashedassets -v maps/map.php input/*.txt input/*/*.txt output/")
>>> system("hashedassets -v maps/map.js input/*.txt input/*/*.txt output/")
>>> system("hashedassets -v maps/map.json input/*.txt input/*/*.txt output/")
>>> system("hashedassets -v maps/map.sed input/*.txt input/*/*.txt output/")
>>> system("hashedassets -v maps/map.jsonp input/*.txt input/*/*.txt output/")
>>> system("hashedassets -v 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 -v maps/map.json input/*.txt input/*/*.txt output/")

If we change the file’s content, it will get a new name:

>>> write("input/foo.txt", "foofoo")

Then try again:

>>> system("hashedassets -v 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 -v 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")
>>> write("input/foo.txt", "foofoofoo")
>>> system("hashedassets -v maps/map.json input/*.txt input/*/*.txt output/")
cp 'input/foo.txt' 'output/NdbmnXyjdY2paFzlDw9aJzCKH9w.txt'

Using the same directory for SOURCE and DEST

This works as well:

>>> system("hashedassets -v maps/samedir.json input/*.txt input/")
cp 'input/foo.txt' 'input/NdbmnXyjdY2paFzlDw9aJzCKH9w.txt'

Even after the command is invoked a second time:

>>> system("hashedassets -v maps/samedir.json input/*.txt input/")

Notice, that the mapfile does not contain the self-reference:

>>> print(open("maps/samedir.json").read())
{
  "foo.txt": "NdbmnXyjdY2paFzlDw9aJzCKH9w.txt"
}
>>> write("input/foo.txt", "barbarbar")
>>> system("hashedassets -v maps/samedir.json input/*.txt input/")
rm 'input/NdbmnXyjdY2paFzlDw9aJzCKH9w.txt'
cp 'input/foo.txt' 'input/sWL19addVG2KRYJ02EDKXF4Oh8s.txt'
 
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hashedassets-0.3.2.tar.gz (md5) Source 2011-02-26 19KB
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