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path: root/src/libstore/local-store.hh
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2015-03-25addToStore(): Take explicit name argumentEelco Dolstra
2014-11-19Clean up temp roots in a more C++ wayEelco Dolstra
2014-09-01Add an 'optimiseStore' remote procedure call.Ludovic Courtès
2014-05-26Use std::unordered_setEelco Dolstra
2014-05-15nix-store --optimise: Remove bogus statisticsEelco Dolstra
2014-05-15Shortcut store files before lstatWout Mertens
readdir() already returns the inode numbers, so we don't need to call lstat to know if a file was already linked or not.
2014-05-14Use the inodes given by readdir directlyWout Mertens
2014-05-13Preload linked hashes to speed up lookupsWout Mertens
By preloading all inodes in the /nix/store/.links directory, we can quickly determine of a hardlinked file was already linked to the hashed links. This is tolerant of removing the .links directory, it will simply recalculate all hashes in the store.
2014-02-18Add a flag ‘--check’ to verify build determinismEelco Dolstra
The flag ‘--check’ to ‘nix-store -r’ or ‘nix-build’ will cause Nix to redo the build of a derivation whose output paths are already valid. If the new output differs from the original output, an error is printed. This makes it easier to test if a build is deterministic. (Obviously this cannot catch all sources of non-determinism, but it catches the most common one, namely the current time.) For example: $ nix-build '<nixpkgs>' -A patchelf ... $ nix-build '<nixpkgs>' -A patchelf --check error: derivation `/nix/store/1ipvxsdnbhl1rw6siz6x92s7sc8nwkkb-patchelf-0.6' may not be deterministic: hash mismatch in output `/nix/store/4pc1dmw5xkwmc6q3gdc9i5nbjl4dkjpp-patchelf-0.6.drv' The --check build fails if not all outputs are valid. Thus the first call to nix-build is necessary to ensure that all outputs are valid. The current outputs are left untouched: the new outputs are either put in a chroot or diverted to a different location in the store using hash rewriting.
2013-11-14Remove nix-setuid-helperEelco Dolstra
AFAIK, nobody uses it, it's not maintained, and it has no tests.
2013-10-16Retry all SQLite operationsEelco Dolstra
To deal with SQLITE_PROTOCOL, we also need to retry read-only operations.
2013-08-26Fix typos, especially those that end up in the Nix manualIvan Kozik
2013-06-20Don't keep "disabled" substituters runningEelco Dolstra
For instance, it's pointless to keep copy-from-other-stores running if there are no other stores, or download-using-manifests if there are no manifests. This also speeds things up because we don't send queries to those substituters.
2013-06-13Allow hard links between the outputs of a derivationEelco Dolstra
2013-06-07Process stderr from substituters while doing have/info queriesEelco Dolstra
2013-06-07Buffer reads from the substituterEelco Dolstra
This greatly reduces the number of system calls.
2013-03-08Revert "Prevent config.h from being clobbered"Eelco Dolstra
This reverts commit 28bba8c44f484eae38e8a15dcec73cfa999156f6.
2013-03-07Prevent config.h from being clobberedEelco Dolstra
2013-02-27Refactoring: Split off the non-recursive canonicalisePathMetaData()Eelco Dolstra
Also, change the file mode before changing the owner. This prevents a slight time window in which a setuid binary would be setuid root.
2013-02-26Security: Don't allow builders to change permissions on files they don't ownEelco Dolstra
It turns out that in multi-user Nix, a builder may be able to do ln /etc/shadow $out/foo Afterwards, canonicalisePathMetaData() will be applied to $out/foo, causing /etc/shadow's mode to be set to 444 (readable by everybody but writable by nobody). That's obviously Very Bad. Fortunately, this fails in NixOS's default configuration because /nix/store is a bind mount, so "ln" will fail with "Invalid cross-device link". It also fails if hard-link restrictions are enabled, so a workaround is: echo 1 > /proc/sys/fs/protected_hardlinks The solution is to check that all files in $out are owned by the build user. This means that innocuous operations like "ln ${pkgs.foo}/some-file $out/" are now rejected, but that already failed in chroot builds anyway.
2013-01-03Clear any immutable bits in the Nix storeEelco Dolstra
Doing this once makes subsequent operations like garbage collecting more efficient since we don't have to call makeMutable() first.
2012-12-20nix-store -q --roots: Respect the gc-keep-outputs/gc-keep-derivations settingsEelco Dolstra
So if a path is not garbage solely because it's reachable from a root due to the gc-keep-outputs or gc-keep-derivations settings, ‘nix-store -q --roots’ now shows that root.
2012-12-20Yet another rewrite of the garbage collectorEelco Dolstra
But this time it's *obviously* correct! No more segfaults due to infinite recursions for sure, etc. Also, move directories to /nix/store/trash instead of renaming them to /nix/store/bla-gc-<pid>. Then we can just delete /nix/store/trash at the end.
2012-11-09Use vfork() instead of fork() if availableEelco Dolstra
Hopefully this reduces the chance of hitting ‘unable to fork: Cannot allocate memory’ errors. vfork() is used for everything except starting builders.
2012-10-03Add a ‘--repair’ flag to nix-instantiateEelco Dolstra
This allows repairing corrupted derivations and other source files.
2012-10-03When repairing a derivation, check and repair the entire output closureEelco Dolstra
If we find a corrupted path in the output closure, we rebuild the derivation that produced that particular path.
2012-10-02Add a --repair flag to ‘nix-store -r’ to repair derivation outputsEelco Dolstra
With this flag, if any valid derivation output is missing or corrupt, it will be recreated by using a substitute if available, or by rebuilding the derivation. The latter may use hash rewriting if chroots are not available.
2012-10-02nix-store --verify: Add an option ‘--repair’ to repair all ↵Eelco Dolstra
missing/corrupt paths Also, return a non-zero exit code if errors remain after verifying/repairing.
2012-10-02Add operation ‘nix-store --repair-path’Eelco Dolstra
This operation allows fixing corrupted or accidentally deleted store paths by redownloading them using substituters, if available. Since the corrupted path cannot be replaced atomically, there is a very small time window (one system call) during which neither the old (corrupted) nor the new (repaired) contents are available. So repairing should be used with some care on critical packages like Glibc.
2012-09-19Support having /nix/store as a read-only bind mountEelco Dolstra
It turns out that the immutable bit doesn't work all that well. A better way is to make the entire Nix store a read-only bind mount, i.e. by doing $ mount --bind /nix/store /nix/store $ mount -o remount,ro,bind /nix/store (This would typically done in an early boot script, before anything from /nix/store is used.) Since Nix needs to be able to write to the Nix store, it now detects if /nix/store is a read-only bind mount and then makes it writable in a private mount namespace.
2012-09-13Vacuum the SQLite DB after running the garbage collectorEelco Dolstra
2012-08-27Merge branch 'master' into no-manifestsEelco Dolstra
2012-08-01Count bytes freed deleting unused linksEelco Dolstra
2012-08-01Drop the block count in the garbage collectorEelco Dolstra
2012-08-01Report substituter errors to clients of the Nix daemonEelco Dolstra
2012-07-30Refactor settings processingEelco Dolstra
Put all Nix configuration flags in a Settings object.
2012-07-30Remove unused variablesEelco Dolstra
2012-07-26Merge branch 'master' into no-manifestsEelco Dolstra
2012-07-23Garbage collect unused links in /nix/store/.linksEelco Dolstra
Incremental optimisation requires creating links in /nix/store/.links to all files in the store. However, this means that if we delete a store path, no files are actually deleted because links in /nix/store/.links still exists. So we need to check /nix/store/.links for files with a link count of 1 and delete them.
2012-07-23Automatically optimise the Nix store when a new path is addedEelco Dolstra
Auto-optimisation is enabled by default. It can be turned off by setting auto-optimise-store to false in nix.conf.
2012-07-23optimiseStore(): Use a content-addressed file store in /nix/store/.linksEelco Dolstra
optimiseStore() now creates persistent, content-addressed hard links in /nix/store/.links. For instance, if it encounters a file P with hash H, it will create a hard link P' = /nix/store/.link/<H> to P if P' doesn't already exist; if P' exist, then P is replaced by a hard link to P'. This is better than the previous in-memory map, because it had the tendency to unnecessarily replace hard links with a hard link to whatever happened to be the first file with a given hash it encountered. It also allows on-the-fly, incremental optimisation.
2012-07-18Use "#pragma once" to prevent repeated header file inclusionEelco Dolstra
2012-07-18Merge branch 'master' into no-manifestsEelco Dolstra
2012-07-17Add function queryPathFromHashPart()Eelco Dolstra
To implement binary caches efficiently, Hydra needs to be able to map the hash part of a store path (e.g. "gbg...zr7") to the full store path (e.g. "/nix/store/gbg...kzr7-subversion-1.7.5"). (The binary cache mechanism uses hash parts as a key for looking up store paths to ensure privacy.) However, doing a search in the Nix store for /nix/store/<hash>* is expensive since it requires reading the entire directory. queryPathFromHashPart() prevents this by doing a cheap database lookup.
2012-07-11Replace hasSubstitutes() with querySubstitutablePaths()Eelco Dolstra
querySubstitutablePaths() takes a set of paths, so this greatly reduces daemon <-> client latency.
2012-07-11Add a function queryValidPaths()Eelco Dolstra
queryValidPaths() combines multiple calls to isValidPath() in one. This matters when using the Nix daemon because it reduces latency. For instance, on "nix-env -qas \*" it reduces execution time from 5.7s to 4.7s (which is indistinguishable from the non-daemon case).
2012-07-11Rename queryValidPaths() to queryAllValidPaths()Eelco Dolstra
2012-07-11Implement querySubstitutablePathInfos() in the daemonEelco Dolstra
Also removed querySubstitutablePathInfo().
2012-07-06download-from-binary-cache: parallelise fetching of NAR info filesEelco Dolstra
Getting substitute information using the binary cache substituter has non-trivial latency overhead. A package or NixOS system configuration can have hundreds of dependencies, and in the worst case (when the local info cache is empty) we have to do a separate HTTP request for each of these. If the ping time to the server is t, getting N info files will take tN seconds; e.g., with a ping time of 0.1s to nixos.org, sequentially downloading 1000 info files (a typical NixOS config) will take at least 100 seconds. To fix this problem, the binary cache substituter can now perform requests in parallel. This required changing the substituter interface to support a function querySubstitutablePathInfos() that queries multiple paths at the same time, and rewriting queryMissing() to take advantage of parallelism. (Due to local caching, parallelising queryMissing() is sufficient for most use cases, since it's almost always called before building a derivation and thus fills the local info cache.) For example, parallelism speeds up querying all 1056 paths in a particular NixOS system configuration from 116s to 2.6s. It works so well because the eccentricity of the top-level derivation in the dependency graph is only 9. So we only need 10 round-trips (when using an unlimited number of parallel connections) to get everything. Currently we do a maximum of 150 parallel connections to the server. Thus it's important that the binary cache server (e.g. nixos.org) has a high connection limit. Alternatively we could use HTTP pipelining, but WWW::Curl doesn't support it and libcurl has a hard-coded limit of 5 requests per pipeline.
2012-06-27nix-store -r: do substitutions in parallelEelco Dolstra
I.e. when multiple non-derivation arguments are passed to ‘nix-store -r’ to be substituted, do them in parallel.