nixpkgs/lib/sources.nix
Robert Hensing 9a2180fa0b lib.cleanSourceWith: Allow name to be set, optional filter, doc
This change is API-compatible and hash-compatible with the previous
version.

At first I considered to write a rename function too, but adding
it name to cleanSourceWith was a no-brainer for ease of use. It
turns out that a rename function isn't any more useful than
cleanSourceWith.
To avoid having to write the identity predicate when renaming,
the filter is now optional.

builtins.path is supported since Nix 2.0 which is required by nixpkgs
2019-09-03 10:36:57 +02:00

138 lines
5.6 KiB
Nix

# Functions for copying sources to the Nix store.
{ lib }:
rec {
# Returns the type of a path: regular (for file), symlink, or directory
pathType = p: with builtins; getAttr (baseNameOf p) (readDir (dirOf p));
# Returns true if the path exists and is a directory, false otherwise
pathIsDirectory = p: if builtins.pathExists p then (pathType p) == "directory" else false;
# Bring in a path as a source, filtering out all Subversion and CVS
# directories, as well as backup 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 ||
builtins.match "^\\.sw[a-z]$" baseName != null ||
builtins.match "^\\..*\\.sw[a-z]$" 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)
);
# Filters a source tree removing version control files and directories using cleanSourceWith
#
# 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.
#
# lib.cleanSourceWith {
# filter = f;
# src = lib.cleanSourceWith {
# filter = g;
# src = ./.;
# };
# }
# # Succeeds!
#
# builtins.filterSource f (builtins.filterSource g ./.)
# # Fails!
#
# Parameters:
#
# src: A path or cleanSourceWith result to filter and/or rename.
#
# filter: A function (path -> type -> bool)
# 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
#
# name: Optional name to use as part of the store path.
# This defaults `src.name` or otherwise `baseNameOf src`.
# We recommend setting `name` whenever `src` is syntactically `./.`.
# Otherwise, you depend on `./.`'s name in the parent directory,
# which can cause inconsistent names, defeating caching.
#
cleanSourceWith = { filter ? _path: _type: true, src, name ? null }:
let
isFiltered = src ? _isLibCleanSourceWith;
origSrc = if isFiltered then src.origSrc else src;
filter' = if isFiltered then name: type: filter name type && src.filter name type else filter;
name' = if name != null then name else if isFiltered then src.name else baseNameOf src;
in {
inherit origSrc;
filter = filter';
outPath = builtins.path { filter = filter'; path = origSrc; name = name'; };
_isLibCleanSourceWith = true;
name = name';
};
# Filter sources by a list of regular expressions.
#
# E.g. `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: builtins.match re relPath != null) regexes);
inherit src;
};
# Get all files ending with the specified suffices from the given
# directory or its descendants. E.g. `sourceFilesBySuffices ./dir
# [".xml" ".c"]'.
sourceFilesBySuffices = path: 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 = path; };
# Get the commit id of a git repo
# Example: commitIdFromGitRepo <nixpkgs/.git>
commitIdFromGitRepo =
let readCommitFromFile = file: path:
with builtins;
let fileName = toString path + "/" + file;
packedRefsName = toString path + "/packed-refs";
in if lib.pathExists fileName
then
let fileContent = lib.fileContents fileName;
# Sometimes git stores the commitId directly in the file but
# sometimes it stores something like: «ref: refs/heads/branch-name»
matchRef = match "^ref: (.*)$" fileContent;
in if matchRef == null
then fileContent
else readCommitFromFile (lib.head matchRef) path
# 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:
else if lib.pathExists packedRefsName
then
let fileContent = readFile packedRefsName;
matchRef = match (".*\n([^\n ]*) " + file + "\n.*") fileContent;
in if matchRef == null
then throw ("Could not find " + file + " in " + packedRefsName)
else lib.head matchRef
else throw ("Not a .git directory: " + path);
in readCommitFromFile "HEAD";
pathHasContext = builtins.hasContext or (lib.hasPrefix builtins.storeDir);
canCleanSource = src: src ? _isLibCleanSourceWith || !(pathHasContext (toString src));
}