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base repository: NixOS/nix
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  • 3 commits
  • 2 files changed
  • 2 contributors

Commits on Aug 17, 2018

  1. fetchGit: use a better caching scheme 

    The current usage technically works by putting multiple different
repos in to the same git directory. However, it is very slow as
Git tries very hard to find common commits between the two
repositories. If the two repositories are large (like Nixpkgs and
another long-running project,) it is maddeningly slow.

This change busts the cache for existing deployments, but users
will be promptly repaid in per-repository performance.
    @graham-at-target
    graham-at-target committed Aug 17, 2018
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    02098d2 View commit details

Commits on Nov 20, 2018

  1. Merge branch 'better-git-cache' of https://github.com/graham-at-targe… 

    …t/nix
    @edolstra
    edolstra committed Nov 20, 2018
    1
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    3f4de91 View commit details

  2. fetchGit: Drop unnecessary localRef

    @edolstra
    edolstra committed Nov 20, 2018
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    4aee93d View commit details
Showing with 9 additions and 7 deletions.
  1. +7 −5 src/libexpr/primops/fetchGit.cc
  2. +2 −2 tests/fetchGit.sh
12 changes: 7 additions & 5 deletions src/libexpr/primops/fetchGit.cc
View file
Original file line number Diff line number Diff line change
@@ -3,6 +3,7 @@
#include "download.hh"
#include "store-api.hh"
#include "pathlocks.hh"
#include "hash.hh"

#include <sys/time.h>

@@ -84,15 +85,16 @@ GitInfo exportGit(ref<Store> store, const std::string & uri,
if (rev != "" && !std::regex_match(rev, revRegex))
throw Error("invalid Git revision '%s'", rev);

Path cacheDir = getCacheDir() + "/nix/git";
deletePath(getCacheDir() + "/nix/git");

Path cacheDir = getCacheDir() + "/nix/gitv2/" + hashString(htSHA256, uri).to_string(Base32, false);

if (!pathExists(cacheDir)) {
createDirs(dirOf(cacheDir));
runProgram("git", true, { "init", "--bare", cacheDir });
}

std::string localRef = hashString(htSHA256, fmt("%s-%s", uri, *ref)).to_string(Base32, false);

Path localRefFile = cacheDir + "/refs/heads/" + localRef;
Path localRefFile = cacheDir + "/refs/heads/" + *ref;

bool doFetch;
time_t now = time(0);
@@ -122,7 +124,7 @@ GitInfo exportGit(ref<Store> store, const std::string & uri,

// FIXME: git stderr messes up our progress indicator, so
// we're using --quiet for now. Should process its stderr.
runProgram("git", true, { "-C", cacheDir, "fetch", "--quiet", "--force", "--", uri, *ref + ":" + localRef });
runProgram("git", true, { "-C", cacheDir, "fetch", "--quiet", "--force", "--", uri, fmt("%s:%s", *ref, *ref) });

struct timeval times[2];
times[0].tv_sec = now;
4 changes: 2 additions & 2 deletions tests/fetchGit.sh
View file
Original file line number Diff line number Diff line change
@@ -9,7 +9,7 @@ clearStore

repo=$TEST_ROOT/git

rm -rf $repo ${repo}-tmp $TEST_HOME/.cache/nix/git
rm -rf $repo ${repo}-tmp $TEST_HOME/.cache/nix/gitv2

git init $repo
git -C $repo config user.email "foobar@example.com"
@@ -129,7 +129,7 @@ path5=$(nix eval --raw "(builtins.fetchGit { url = $repo; ref = \"dev\"; }).outP


# Nuke the cache
rm -rf $TEST_HOME/.cache/nix/git
rm -rf $TEST_HOME/.cache/nix/gitv2

# Try again, but without 'git' on PATH
NIX=$(command -v nix)