lix -

Age	Commit message (Collapse)	Author
2014-05-26	Use std::unordered_set	Eelco Dolstra

2014-05-15	nix-store --optimise: Remove bogus statistics	Eelco Dolstra

2014-05-15	Shortcut store files before lstat	Wout 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.
2014-05-14	Use the inodes given by readdir directly	Wout Mertens

2014-05-13	Preload linked hashes to speed up lookups	Wout 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.
2014-02-18	Add a flag ‘--check’ to verify build determinism	Eelco 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.
2013-11-14	Remove nix-setuid-helper	Eelco Dolstra
	AFAIK, nobody uses it, it's not maintained, and it has no tests.
2013-10-16	Retry all SQLite operations	Eelco Dolstra
	To deal with SQLITE_PROTOCOL, we also need to retry read-only operations.
2013-08-26	Fix typos, especially those that end up in the Nix manual	Ivan Kozik

2013-06-20	Don't keep "disabled" substituters running	Eelco 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.
2013-06-13	Allow hard links between the outputs of a derivation	Eelco Dolstra

2013-06-07	Process stderr from substituters while doing have/info queries	Eelco Dolstra

2013-06-07	Buffer reads from the substituter	Eelco Dolstra
	This greatly reduces the number of system calls.
2013-03-08	Revert "Prevent config.h from being clobbered"	Eelco Dolstra
	This reverts commit 28bba8c44f484eae38e8a15dcec73cfa999156f6.
2013-03-07	Prevent config.h from being clobbered	Eelco Dolstra

2013-02-27	Refactoring: 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.
2013-02-26	Security: Don't allow builders to change permissions on files they don't own	Eelco 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.
2013-01-03	Clear any immutable bits in the Nix store	Eelco Dolstra
	Doing this once makes subsequent operations like garbage collecting more efficient since we don't have to call makeMutable() first.
2012-12-20	nix-store -q --roots: Respect the gc-keep-outputs/gc-keep-derivations settings	Eelco 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.
2012-12-20	Yet another rewrite of the garbage collector	Eelco 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.
2012-11-09	Use vfork() instead of fork() if available	Eelco Dolstra
	Hopefully this reduces the chance of hitting ‘unable to fork: Cannot allocate memory’ errors. vfork() is used for everything except starting builders.
2012-10-03	Add a ‘--repair’ flag to nix-instantiate	Eelco Dolstra
	This allows repairing corrupted derivations and other source files.
2012-10-03	When repairing a derivation, check and repair the entire output closure	Eelco Dolstra
	If we find a corrupted path in the output closure, we rebuild the derivation that produced that particular path.
2012-10-02	Add a --repair flag to ‘nix-store -r’ to repair derivation outputs	Eelco 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.
2012-10-02	nix-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.
2012-10-02	Add 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.
2012-09-19	Support having /nix/store as a read-only bind mount	Eelco 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.
2012-09-13	Vacuum the SQLite DB after running the garbage collector	Eelco Dolstra

2012-08-27	Merge branch 'master' into no-manifests	Eelco Dolstra

2012-08-01	Count bytes freed deleting unused links	Eelco Dolstra

2012-08-01	Drop the block count in the garbage collector	Eelco Dolstra

2012-08-01	Report substituter errors to clients of the Nix daemon	Eelco Dolstra

2012-07-30	Refactor settings processing	Eelco Dolstra
	Put all Nix configuration flags in a Settings object.
2012-07-30	Remove unused variables	Eelco Dolstra

2012-07-26	Merge branch 'master' into no-manifests	Eelco Dolstra

2012-07-23	Garbage collect unused links in /nix/store/.links	Eelco 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.
2012-07-23	Automatically optimise the Nix store when a new path is added	Eelco Dolstra
	Auto-optimisation is enabled by default. It can be turned off by setting auto-optimise-store to false in nix.conf.
2012-07-23	optimiseStore(): Use a content-addressed file store in /nix/store/.links	Eelco 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.
2012-07-18	Use "#pragma once" to prevent repeated header file inclusion	Eelco Dolstra

2012-07-18	Merge branch 'master' into no-manifests	Eelco Dolstra

2012-07-17	Add 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.
2012-07-11	Replace hasSubstitutes() with querySubstitutablePaths()	Eelco Dolstra
	querySubstitutablePaths() takes a set of paths, so this greatly reduces daemon <-> client latency.
2012-07-11	Add 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).
2012-07-11	Rename queryValidPaths() to queryAllValidPaths()	Eelco Dolstra

2012-07-11	Implement querySubstitutablePathInfos() in the daemon	Eelco Dolstra
	Also removed querySubstitutablePathInfo().
2012-07-06	download-from-binary-cache: parallelise fetching of NAR info files	Eelco 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.
2012-06-27	nix-store -r: do substitutions in parallel	Eelco Dolstra
	I.e. when multiple non-derivation arguments are passed to ‘nix-store -r’ to be substituted, do them in parallel.
2012-05-29	Reserve some disk space for the garbage collector	Eelco Dolstra
	We can't open a SQLite database if the disk is full. Since this prevents the garbage collector from running when it's most needed, we reserve some dummy space that we can free just before doing a garbage collection. This actually revives some old code from the Berkeley DB days. Fixes #27.
2012-03-26	Make the garbage collector more concurrent	Eelco Dolstra
	Make the garbage collector more concurrent by deleting valid paths outside the region where we're holding the global GC lock. This should greatly reduce the time during which new builds are blocked, since the deletion accounts for the vast majority of the time spent in the GC. To ensure that this is safe, the valid paths are invalidated and renamed to some arbitrary path while we're holding the lock. This ensures that we when we finally delete the path, it's not a (newly) valid or locked path.
2011-12-16	* Sync with the trunk.	Eelco Dolstra