* Allow an optional hash to be provided. This prevents redundant

fetches.
This commit is contained in:
Eelco Dolstra 2004-12-13 13:35:36 +00:00
parent 71926ee188
commit dca48aed34

View file

@ -1,35 +1,41 @@
#! @shell@ -e #! @shell@ -e
url=$1 url=$1
hash=$2
if test -z "$url"; then if test -z "$url"; then
echo "syntax: nix-prefetch-url URL" >&2 echo "syntax: nix-prefetch-url URL" >&2
exit 1 exit 1
fi fi
# !!! race # Determine the hash, unless it was given.
tmpPath1=@storedir@/nix-prefetch-url-$$ if test -z "$hash"; then
# Test whether we have write permission in the store. If not, fetch # !!! race
# to /tmp and don't copy to the store. This is a hack to make this tmpPath1=@storedir@/nix-prefetch-url-$$
# script at least work somewhat in setuid installations.
if ! touch $tmpPath1 2> /dev/null; then # Test whether we have write permission in the store. If not,
# fetch to /tmp and don't copy to the store. This is a hack to
# make this script at least work somewhat in setuid installations.
if ! touch $tmpPath1 2> /dev/null; then
echo "(cannot write to the store, result won't be cached)" >&2 echo "(cannot write to the store, result won't be cached)" >&2
dummyMode=1 dummyMode=1
tmpPath1=/tmp/nix-prefetch-url-$$ # !!! security? tmpPath1=/tmp/nix-prefetch-url-$$ # !!! security?
fi fi
# Perform the checkout. # Perform the checkout.
@curl@ --fail --location --max-redirs 20 "$url" > $tmpPath1 @curl@ --fail --location --max-redirs 20 "$url" > $tmpPath1
# Compute the hash. # Compute the hash.
hash=$(@bindir@/nix-hash --flat $tmpPath1) hash=$(@bindir@/nix-hash --flat $tmpPath1)
echo "hash is $hash" >&2 if ! test -n "$QUIET"; then echo "hash is $hash" >&2; fi
# Rename it so that the fetchurl builder can find it. # Rename it so that the fetchurl builder can find it.
if test "$dummyMode" != 1; then if test "$dummyMode" != 1; then
tmpPath2=@storedir@/nix-prefetch-url-$hash tmpPath2=@storedir@/nix-prefetch-url-$hash
test -e $tmpPath2 || mv $tmpPath1 $tmpPath2 # !!! race test -e $tmpPath2 || mv $tmpPath1 $tmpPath2 # !!! race
fi
fi fi
# Create a Nix expression that does a fetchurl. # Create a Nix expression that does a fetchurl.
@ -41,7 +47,7 @@ storeExpr=$( \
# Realise it. # Realise it.
finalPath=$(@bindir@/nix-store -qnB --force-realise $storeExpr) finalPath=$(@bindir@/nix-store -qnB --force-realise $storeExpr)
echo "path is $finalPath" >&2 if ! test -n "$QUIET"; then echo "path is $finalPath" >&2; fi
rm -rf $tmpPath1 $tmpPath2 || true rm -rf $tmpPath1 $tmpPath2 || true