# Functions for copying sources to the Nix store.
{ lib }:
# Tested in lib/tests/sources.sh
let
inherit (builtins)
hasContext
match
readDir
split
storeDir
tryEval
;
inherit (lib)
boolToString
filter
getAttr
isString
pathExists
readFile
;
/*
Returns the type of a path: regular (for file), symlink, or directory.
*/
pathType = path: getAttr (baseNameOf path) (readDir (dirOf path));
/*
Returns true if the path exists and is a directory, false otherwise.
*/
pathIsDirectory = path: if pathExists path then (pathType path) == "directory" else false;
/*
Returns true if the path exists and is a regular file, false otherwise.
*/
pathIsRegularFile = path: if pathExists path then (pathType path) == "regular" else false;
/*
A basic filter for `cleanSourceWith` that removes
directories of version control system, backup files (*~)
and some generated files.
*/
cleanSourceFilter = name: type: let baseName = baseNameOf (toString name); in ! (
# Filter out version control software files/directories
(baseName == ".git" || type == "directory" && (baseName == ".svn" || baseName == "CVS" || baseName == ".hg")) ||
# Filter out editor backup / swap files.
lib.hasSuffix "~" baseName ||
match "^\\.sw[a-z]$" baseName != null ||
match "^\\..*\\.sw[a-z]$" baseName != null ||
# Filter out generates files.
lib.hasSuffix ".o" baseName ||
lib.hasSuffix ".so" baseName ||
# Filter out nix-build result symlinks
(type == "symlink" && lib.hasPrefix "result" baseName) ||
# Filter out sockets and other types of files we can't have in the store.
(type == "unknown")
);
/*
Filters a source tree removing version control files and directories using cleanSourceFilter.
Example:
cleanSource ./.
*/
cleanSource = src: cleanSourceWith { filter = cleanSourceFilter; inherit src; };
/*
Like `builtins.filterSource`, except it will compose with itself,
allowing you to chain multiple calls together without any
intermediate copies being put in the nix store.
Example:
lib.cleanSourceWith {
filter = f;
src = lib.cleanSourceWith {
filter = g;
src = ./.;
};
}
# Succeeds!
builtins.filterSource f (builtins.filterSource g ./.)
# Fails!
*/
cleanSourceWith =
{
# A path or cleanSourceWith result to filter and/or rename.
src,
# Optional with default value: constant true (include everything)
# The function will be combined with the && operator such
# that src.filter is called lazily.
# For implementing a filter, see
# https://nixos.org/nix/manual/#builtin-filterSource
# Type: A function (path -> type -> bool)
filter ? _path: _type: true,
# Optional name to use as part of the store path.
# This defaults to `src.name` or otherwise `"source"`.
name ? null
}:
let
orig = toSourceAttributes src;
in fromSourceAttributes {
inherit (orig) origSrc;
filter = path: type: filter path type && orig.filter path type;
name = if name != null then name else orig.name;
};
/*
Add logging to a source, for troubleshooting the filtering behavior.
Type:
sources.trace :: sourceLike -> Source
*/
trace =
# Source to debug. The returned source will behave like this source, but also log its filter invocations.
src:
let
attrs = toSourceAttributes src;
in
fromSourceAttributes (
attrs // {
filter = path: type:
let
r = attrs.filter path type;
in
builtins.trace "${attrs.name}.filter ${path} = ${boolToString r}" r;
}
) // {
satisfiesSubpathInvariant = src ? satisfiesSubpathInvariant && src.satisfiesSubpathInvariant;
};
/*
Filter sources by a list of regular expressions.
Example: src = sourceByRegex ./my-subproject [".*\.py$" "^database.sql$"]
*/
sourceByRegex = src: regexes:
let
isFiltered = src ? _isLibCleanSourceWith;
origSrc = if isFiltered then src.origSrc else src;
in lib.cleanSourceWith {
filter = (path: type:
let relPath = lib.removePrefix (toString origSrc + "/") (toString path);
in lib.any (re: match re relPath != null) regexes);
inherit src;
};
/*
Get all files ending with the specified suffices from the given
source directory or its descendants, omitting files that do not match
any suffix. The result of the example below will include files like
`./dir/module.c` and `./dir/subdir/doc.xml` if present.
Type: sourceLike -> [String] -> Source
Example:
sourceFilesBySuffices ./. [ ".xml" ".c" ]
*/
sourceFilesBySuffices =
# Path or source containing the files to be returned
src:
# A list of file suffix strings
exts:
let filter = name: type:
let base = baseNameOf (toString name);
in type == "directory" || lib.any (ext: lib.hasSuffix ext base) exts;
in cleanSourceWith { inherit filter src; };
pathIsGitRepo = path: (tryEval (commitIdFromGitRepo path)).success;
/*
Get the commit id of a git repo.
Example: commitIdFromGitRepo <nixpkgs/.git>
*/
commitIdFromGitRepo =
let readCommitFromFile = file: path:
let fileName = toString path + "/" + file;
packedRefsName = toString path + "/packed-refs";
absolutePath = base: path:
if lib.hasPrefix "/" path
then path
else toString (/. + "${base}/${path}");
in if pathIsRegularFile path
# Resolve git worktrees. See gitrepository-layout(5)
then
let m = match "^gitdir: (.*)$" (lib.fileContents path);
in if m == null
then throw ("File contains no gitdir reference: " + path)
else
let gitDir = absolutePath (dirOf path) (lib.head m);
commonDir'' = if pathIsRegularFile "${gitDir}/commondir"
then lib.fileContents "${gitDir}/commondir"
else gitDir;
commonDir' = lib.removeSuffix "/" commonDir'';
commonDir = absolutePath gitDir commonDir';
refFile = lib.removePrefix "${commonDir}/" "${gitDir}/${file}";
in readCommitFromFile refFile commonDir
else if pathIsRegularFile fileName
# Sometimes git stores the commitId directly in the file but
# sometimes it stores something like: «ref: refs/heads/branch-name»
then
let fileContent = lib.fileContents fileName;
matchRef = match "^ref: (.*)$" fileContent;
in if matchRef == null
then fileContent
else readCommitFromFile (lib.head matchRef) path
else if pathIsRegularFile packedRefsName
# Sometimes, the file isn't there at all and has been packed away in the
# packed-refs file, so we have to grep through it:
then
let fileContent = readFile packedRefsName;
matchRef = match "([a-z0-9]+) ${file}";
isRef = s: isString s && (matchRef s) != null;
# there is a bug in libstdc++ leading to stackoverflow for long strings:
# https://github.com/NixOS/nix/issues/2147#issuecomment-659868795
refs = filter isRef (split "\n" fileContent);
in if refs == []
then throw ("Could not find " + file + " in " + packedRefsName)
else lib.head (matchRef (lib.head refs))
else throw ("Not a .git directory: " + path);
in readCommitFromFile "HEAD";
pathHasContext = builtins.hasContext or (lib.hasPrefix storeDir);
canCleanSource = src: src ? _isLibCleanSourceWith || !(pathHasContext (toString src));
# -------------------------------------------------------------------------- #
# Internal functions
#
# toSourceAttributes : sourceLike -> SourceAttrs
#
# Convert any source-like object into a simple, singular representation.
# We don't expose this representation in order to avoid having a fifth path-
# like class of objects in the wild.
# (Existing ones being: paths, strings, sources and x//{outPath})
# So instead of exposing internals, we build a library of combinator functions.
toSourceAttributes = src:
let
isFiltered = src ? _isLibCleanSourceWith;
in
{
# The original path
origSrc = if isFiltered then src.origSrc else src;
filter = if isFiltered then src.filter else _: _: true;
name = if isFiltered then src.name else "source";
};
# fromSourceAttributes : SourceAttrs -> Source
#
# Inverse of toSourceAttributes for Source objects.
fromSourceAttributes = { origSrc, filter, name }:
{
_isLibCleanSourceWith = true;
inherit origSrc filter name;
outPath = builtins.path { inherit filter name; path = origSrc; };
};
in {
inherit
pathType
pathIsDirectory
pathIsRegularFile
pathIsGitRepo
commitIdFromGitRepo
cleanSource
cleanSourceWith
cleanSourceFilter
pathHasContext
canCleanSource
sourceByRegex
sourceFilesBySuffices
trace
;
}