968 lines
41 KiB
Nix
968 lines
41 KiB
Nix
{
|
|
lib ? import ../.,
|
|
}:
|
|
let
|
|
|
|
inherit (builtins)
|
|
isAttrs
|
|
isPath
|
|
isString
|
|
nixVersion
|
|
pathExists
|
|
readDir
|
|
split
|
|
trace
|
|
typeOf
|
|
fetchGit
|
|
;
|
|
|
|
inherit (lib.attrsets)
|
|
attrNames
|
|
attrValues
|
|
mapAttrs
|
|
mapAttrsToList
|
|
optionalAttrs
|
|
zipAttrsWith
|
|
;
|
|
|
|
inherit (lib.filesystem)
|
|
pathType
|
|
;
|
|
|
|
inherit (lib.lists)
|
|
all
|
|
commonPrefix
|
|
concatLists
|
|
elemAt
|
|
filter
|
|
findFirst
|
|
findFirstIndex
|
|
foldl'
|
|
head
|
|
length
|
|
sublist
|
|
tail
|
|
;
|
|
|
|
inherit (lib.path)
|
|
append
|
|
splitRoot
|
|
hasStorePathPrefix
|
|
splitStorePath
|
|
;
|
|
|
|
inherit (lib.path.subpath)
|
|
components
|
|
join
|
|
;
|
|
|
|
inherit (lib.strings)
|
|
isStringLike
|
|
concatStringsSep
|
|
substring
|
|
stringLength
|
|
hasSuffix
|
|
versionAtLeast
|
|
;
|
|
|
|
inherit (lib.trivial)
|
|
inPureEvalMode
|
|
;
|
|
in
|
|
# Rare case of justified usage of rec:
|
|
# - This file is internal, so the return value doesn't matter, no need to make things overridable
|
|
# - The functions depend on each other
|
|
# - We want to expose all of these functions for easy testing
|
|
rec {
|
|
|
|
# If you change the internal representation, make sure to:
|
|
# - Increment this version
|
|
# - Add an additional migration function below
|
|
# - Update the description of the internal representation in ./README.md
|
|
_currentVersion = 3;
|
|
|
|
# Migrations between versions. The 0th element converts from v0 to v1, and so on
|
|
migrations = [
|
|
# Convert v0 into v1: Add the _internalBase{Root,Components} attributes
|
|
(
|
|
filesetV0:
|
|
let
|
|
parts = splitRoot filesetV0._internalBase;
|
|
in
|
|
filesetV0
|
|
// {
|
|
_internalVersion = 1;
|
|
_internalBaseRoot = parts.root;
|
|
_internalBaseComponents = components parts.subpath;
|
|
}
|
|
)
|
|
|
|
# Convert v1 into v2: filesetTree's can now also omit attributes to signal paths not being included
|
|
(
|
|
filesetV1:
|
|
# This change is backwards compatible (but not forwards compatible, so we still need a new version)
|
|
filesetV1
|
|
// {
|
|
_internalVersion = 2;
|
|
}
|
|
)
|
|
|
|
# Convert v2 into v3: filesetTree's now have a representation for an empty file set without a base path
|
|
(
|
|
filesetV2:
|
|
filesetV2
|
|
// {
|
|
# All v1 file sets are not the new empty file set
|
|
_internalIsEmptyWithoutBase = false;
|
|
_internalVersion = 3;
|
|
}
|
|
)
|
|
];
|
|
|
|
_noEvalMessage = ''
|
|
lib.fileset: Directly evaluating a file set is not supported.
|
|
To turn it into a usable source, use `lib.fileset.toSource`.
|
|
To pretty-print the contents, use `lib.fileset.trace` or `lib.fileset.traceVal`.'';
|
|
|
|
# The empty file set without a base path
|
|
_emptyWithoutBase = {
|
|
_type = "fileset";
|
|
|
|
_internalVersion = _currentVersion;
|
|
|
|
# The one and only!
|
|
_internalIsEmptyWithoutBase = true;
|
|
|
|
# Due to alphabetical ordering, this is evaluated last,
|
|
# which makes the nix repl output nicer than if it would be ordered first.
|
|
# It also allows evaluating it strictly up to this error, which could be useful
|
|
_noEval = throw _noEvalMessage;
|
|
};
|
|
|
|
# Create a fileset, see ./README.md#fileset
|
|
# Type: path -> filesetTree -> fileset
|
|
_create =
|
|
base: tree:
|
|
let
|
|
# Decompose the base into its components
|
|
# See ../path/README.md for why we're not just using `toString`
|
|
parts = splitRoot base;
|
|
in
|
|
{
|
|
_type = "fileset";
|
|
|
|
_internalVersion = _currentVersion;
|
|
|
|
_internalIsEmptyWithoutBase = false;
|
|
_internalBase = base;
|
|
_internalBaseRoot = parts.root;
|
|
_internalBaseComponents = components parts.subpath;
|
|
_internalTree = tree;
|
|
|
|
# Due to alphabetical ordering, this is evaluated last,
|
|
# which makes the nix repl output nicer than if it would be ordered first.
|
|
# It also allows evaluating it strictly up to this error, which could be useful
|
|
_noEval = throw _noEvalMessage;
|
|
};
|
|
|
|
# Coerce a value to a fileset, erroring when the value cannot be coerced.
|
|
# The string gives the context for error messages.
|
|
# Type: String -> (fileset | Path) -> fileset
|
|
_coerce =
|
|
context: value:
|
|
if value._type or "" == "fileset" then
|
|
if value._internalVersion > _currentVersion then
|
|
throw ''
|
|
${context} is a file set created from a future version of the file set library with a different internal representation:
|
|
- Internal version of the file set: ${toString value._internalVersion}
|
|
- Internal version of the library: ${toString _currentVersion}
|
|
Make sure to update your Nixpkgs to have a newer version of `lib.fileset`.''
|
|
else if value._internalVersion < _currentVersion then
|
|
let
|
|
# Get all the migration functions necessary to convert from the old to the current version
|
|
migrationsToApply = sublist value._internalVersion (
|
|
_currentVersion - value._internalVersion
|
|
) migrations;
|
|
in
|
|
foldl' (value: migration: migration value) value migrationsToApply
|
|
else
|
|
value
|
|
else if !isPath value then
|
|
if value ? _isLibCleanSourceWith then
|
|
throw ''
|
|
${context} is a `lib.sources`-based value, but it should be a file set or a path instead.
|
|
To convert a `lib.sources`-based value to a file set you can use `lib.fileset.fromSource`.
|
|
Note that this only works for sources created from paths.''
|
|
else if isStringLike value then
|
|
throw ''
|
|
${context} ("${toString value}") is a string-like value, but it should be a file set or a path instead.
|
|
Paths represented as strings are not supported by `lib.fileset`, use `lib.sources` or derivations instead.''
|
|
else
|
|
throw ''${context} is of type ${typeOf value}, but it should be a file set or a path instead.''
|
|
else if !pathExists value then
|
|
throw ''
|
|
${context} (${toString value}) is a path that does not exist.
|
|
To create a file set from a path that may not exist, use `lib.fileset.maybeMissing`.''
|
|
else
|
|
_singleton value;
|
|
|
|
# Coerce many values to filesets, erroring when any value cannot be coerced,
|
|
# or if the filesystem root of the values doesn't match.
|
|
# Type: String -> [ { context :: String, value :: fileset | Path } ] -> [ fileset ]
|
|
_coerceMany =
|
|
functionContext: list:
|
|
let
|
|
filesets = map ({ context, value }: _coerce "${functionContext}: ${context}" value) list;
|
|
|
|
# Find the first value with a base, there may be none!
|
|
firstWithBase = findFirst (fileset: !fileset._internalIsEmptyWithoutBase) null filesets;
|
|
# This value is only accessed if first != null
|
|
firstBaseRoot = firstWithBase._internalBaseRoot;
|
|
|
|
# Finds the first element with a filesystem root different than the first element, if any
|
|
differentIndex = findFirstIndex (
|
|
fileset:
|
|
# The empty value without a base doesn't have a base path
|
|
!fileset._internalIsEmptyWithoutBase && firstBaseRoot != fileset._internalBaseRoot
|
|
) null filesets;
|
|
in
|
|
# Only evaluates `differentIndex` if there are any elements with a base
|
|
if firstWithBase != null && differentIndex != null then
|
|
throw ''
|
|
${functionContext}: Filesystem roots are not the same:
|
|
${(head list).context}: Filesystem root is "${toString firstBaseRoot}"
|
|
${(elemAt list differentIndex).context}: Filesystem root is "${toString (elemAt filesets differentIndex)._internalBaseRoot}"
|
|
Different filesystem roots are not supported.''
|
|
else
|
|
filesets;
|
|
|
|
# Create a file set from a path.
|
|
# Type: Path -> fileset
|
|
_singleton =
|
|
path:
|
|
let
|
|
type = pathType path;
|
|
in
|
|
if type == "directory" then
|
|
_create path type
|
|
else
|
|
# This turns a file path ./default.nix into a fileset with
|
|
# - _internalBase: ./.
|
|
# - _internalTree: {
|
|
# "default.nix" = <type>;
|
|
# }
|
|
# See ./README.md#single-files
|
|
_create (dirOf path) {
|
|
${baseNameOf path} = type;
|
|
};
|
|
|
|
# Expand a directory representation to an equivalent one in attribute set form.
|
|
# All directory entries are included in the result.
|
|
# Type: Path -> filesetTree -> { <name> = filesetTree; }
|
|
_directoryEntries =
|
|
path: value:
|
|
if value == "directory" then
|
|
readDir path
|
|
else
|
|
# Set all entries not present to null
|
|
mapAttrs (name: value: null) (readDir path) // value;
|
|
|
|
/*
|
|
A normalisation of a filesetTree suitable filtering with `builtins.path`:
|
|
- Replace all directories that have no files with `null`.
|
|
This removes directories that would be empty
|
|
- Replace all directories with all files with `"directory"`.
|
|
This speeds up the source filter function
|
|
|
|
Note that this function is strict, it evaluates the entire tree
|
|
|
|
Type: Path -> filesetTree -> filesetTree
|
|
*/
|
|
_normaliseTreeFilter =
|
|
path: tree:
|
|
if tree == "directory" || isAttrs tree then
|
|
let
|
|
entries = _directoryEntries path tree;
|
|
normalisedSubtrees = mapAttrs (name: _normaliseTreeFilter (path + "/${name}")) entries;
|
|
subtreeValues = attrValues normalisedSubtrees;
|
|
in
|
|
# This triggers either when all files in a directory are filtered out
|
|
# Or when the directory doesn't contain any files at all
|
|
if all isNull subtreeValues then
|
|
null
|
|
# Triggers when we have the same as a `readDir path`, so we can turn it back into an equivalent "directory".
|
|
else if all isString subtreeValues then
|
|
"directory"
|
|
else
|
|
normalisedSubtrees
|
|
else
|
|
tree;
|
|
|
|
/*
|
|
A minimal normalisation of a filesetTree, intended for pretty-printing:
|
|
- If all children of a path are recursively included or empty directories, the path itself is also recursively included
|
|
- If all children of a path are fully excluded or empty directories, the path itself is an empty directory
|
|
- Other empty directories are represented with the special "emptyDir" string
|
|
While these could be replaced with `null`, that would take another mapAttrs
|
|
|
|
Note that this function is partially lazy.
|
|
|
|
Type: Path -> filesetTree -> filesetTree (with "emptyDir"'s)
|
|
*/
|
|
_normaliseTreeMinimal =
|
|
path: tree:
|
|
if tree == "directory" || isAttrs tree then
|
|
let
|
|
entries = _directoryEntries path tree;
|
|
normalisedSubtrees = mapAttrs (name: _normaliseTreeMinimal (path + "/${name}")) entries;
|
|
subtreeValues = attrValues normalisedSubtrees;
|
|
in
|
|
# If there are no entries, or all entries are empty directories, return "emptyDir".
|
|
# After this branch we know that there's at least one file
|
|
if all (value: value == "emptyDir") subtreeValues then
|
|
"emptyDir"
|
|
|
|
# If all subtrees are fully included or empty directories
|
|
# (both of which are coincidentally represented as strings), return "directory".
|
|
# This takes advantage of the fact that empty directories can be represented as included directories.
|
|
# Note that the tree == "directory" check allows avoiding recursion
|
|
else if tree == "directory" || all (value: isString value) subtreeValues then
|
|
"directory"
|
|
|
|
# If all subtrees are fully excluded or empty directories, return null.
|
|
# This takes advantage of the fact that empty directories can be represented as excluded directories
|
|
else if all (value: isNull value || value == "emptyDir") subtreeValues then
|
|
null
|
|
|
|
# Mix of included and excluded entries
|
|
else
|
|
normalisedSubtrees
|
|
else
|
|
tree;
|
|
|
|
# Trace a filesetTree in a pretty way when the resulting value is evaluated.
|
|
# This can handle both normal filesetTree's, and ones returned from _normaliseTreeMinimal
|
|
# Type: Path -> filesetTree (with "emptyDir"'s) -> Null
|
|
_printMinimalTree =
|
|
base: tree:
|
|
let
|
|
treeSuffix =
|
|
tree:
|
|
if isAttrs tree then
|
|
""
|
|
else if tree == "directory" then
|
|
" (all files in directory)"
|
|
else
|
|
# This does "leak" the file type strings of the internal representation,
|
|
# but this is the main reason these file type strings even are in the representation!
|
|
# TODO: Consider removing that information from the internal representation for performance.
|
|
# The file types can still be printed by querying them only during tracing
|
|
" (${tree})";
|
|
|
|
# Only for attribute set trees
|
|
traceTreeAttrs =
|
|
prevLine: indent: tree:
|
|
foldl' (
|
|
prevLine: name:
|
|
let
|
|
subtree = tree.${name};
|
|
|
|
# Evaluating this prints the line for this subtree
|
|
thisLine = trace "${indent}- ${name}${treeSuffix subtree}" prevLine;
|
|
in
|
|
if subtree == null || subtree == "emptyDir" then
|
|
# Don't print anything at all if this subtree is empty
|
|
prevLine
|
|
else if isAttrs subtree then
|
|
# A directory with explicit entries
|
|
# Do print this node, but also recurse
|
|
traceTreeAttrs thisLine "${indent} " subtree
|
|
else
|
|
# Either a file, or a recursively included directory
|
|
# Do print this node but no further recursion needed
|
|
thisLine
|
|
) prevLine (attrNames tree);
|
|
|
|
# Evaluating this will print the first line
|
|
firstLine =
|
|
if tree == null || tree == "emptyDir" then
|
|
trace "(empty)" null
|
|
else
|
|
trace "${toString base}${treeSuffix tree}" null;
|
|
in
|
|
if isAttrs tree then traceTreeAttrs firstLine "" tree else firstLine;
|
|
|
|
# Pretty-print a file set in a pretty way when the resulting value is evaluated
|
|
# Type: fileset -> Null
|
|
_printFileset =
|
|
fileset:
|
|
if fileset._internalIsEmptyWithoutBase then
|
|
trace "(empty)" null
|
|
else
|
|
_printMinimalTree fileset._internalBase (
|
|
_normaliseTreeMinimal fileset._internalBase fileset._internalTree
|
|
);
|
|
|
|
# Turn a fileset into a source filter function suitable for `builtins.path`
|
|
# Only directories recursively containing at least one files are recursed into
|
|
# Type: fileset -> (String -> String -> Bool)
|
|
_toSourceFilter =
|
|
fileset:
|
|
let
|
|
# Simplify the tree, necessary to make sure all empty directories are null
|
|
# which has the effect that they aren't included in the result
|
|
tree = _normaliseTreeFilter fileset._internalBase fileset._internalTree;
|
|
|
|
# The base path as a string with a single trailing slash
|
|
baseString =
|
|
if fileset._internalBaseComponents == [ ] then
|
|
# Need to handle the filesystem root specially
|
|
"/"
|
|
else
|
|
"/" + concatStringsSep "/" fileset._internalBaseComponents + "/";
|
|
|
|
baseLength = stringLength baseString;
|
|
|
|
# Check whether a list of path components under the base path exists in the tree.
|
|
# This function is called often, so it should be fast.
|
|
# Type: [ String ] -> Bool
|
|
inTree =
|
|
components:
|
|
let
|
|
recurse =
|
|
index: localTree:
|
|
if isAttrs localTree then
|
|
# We have an attribute set, meaning this is a directory with at least one file
|
|
if index >= length components then
|
|
# The path may have no more components though, meaning the filter is running on the directory itself,
|
|
# so we always include it, again because there's at least one file in it.
|
|
true
|
|
else
|
|
# If we do have more components, the filter runs on some entry inside this directory, so we need to recurse
|
|
# We do +2 because builtins.split is an interleaved list of the inbetweens and the matches
|
|
recurse (index + 2) localTree.${elemAt components index}
|
|
else
|
|
# If it's not an attribute set it can only be either null (in which case it's not included)
|
|
# or a string ("directory" or "regular", etc.) in which case it's included
|
|
localTree != null;
|
|
in
|
|
recurse 0 tree;
|
|
|
|
# Filter suited when there's no files
|
|
empty = _: _: false;
|
|
|
|
# Filter suited when there's some files
|
|
# This can't be used for when there's no files, because the base directory is always included
|
|
nonEmpty =
|
|
path: type:
|
|
let
|
|
# Add a slash to the path string, turning "/foo" to "/foo/",
|
|
# making sure to not have any false prefix matches below.
|
|
# Note that this would produce "//" for "/",
|
|
# but builtins.path doesn't call the filter function on the `path` argument itself,
|
|
# meaning this function can never receive "/" as an argument
|
|
pathSlash = path + "/";
|
|
in
|
|
(
|
|
# Same as `hasPrefix pathSlash baseString`, but more efficient.
|
|
# With base /foo/bar we need to include /foo:
|
|
# hasPrefix "/foo/" "/foo/bar/"
|
|
if substring 0 (stringLength pathSlash) baseString == pathSlash then
|
|
true
|
|
# Same as `! hasPrefix baseString pathSlash`, but more efficient.
|
|
# With base /foo/bar we need to exclude /baz
|
|
# ! hasPrefix "/baz/" "/foo/bar/"
|
|
else if substring 0 baseLength pathSlash != baseString then
|
|
false
|
|
else
|
|
# Same as `removePrefix baseString path`, but more efficient.
|
|
# From the above code we know that hasPrefix baseString pathSlash holds, so this is safe.
|
|
# We don't use pathSlash here because we only needed the trailing slash for the prefix matching.
|
|
# With base /foo and path /foo/bar/baz this gives
|
|
# inTree (split "/" (removePrefix "/foo/" "/foo/bar/baz"))
|
|
# == inTree (split "/" "bar/baz")
|
|
# == inTree [ "bar" "baz" ]
|
|
inTree (split "/" (substring baseLength (-1) path))
|
|
)
|
|
# This is a way have an additional check in case the above is true without any significant performance cost
|
|
&& (
|
|
# This relies on the fact that Nix only distinguishes path types "directory", "regular", "symlink" and "unknown",
|
|
# so everything except "unknown" is allowed, seems reasonable to rely on that
|
|
type != "unknown"
|
|
|| throw ''
|
|
lib.fileset.toSource: `fileset` contains a file that cannot be added to the store: ${path}
|
|
This file is neither a regular file nor a symlink, the only file types supported by the Nix store.
|
|
Therefore the file set cannot be added to the Nix store as is. Make sure to not include that file to avoid this error.''
|
|
);
|
|
in
|
|
# Special case because the code below assumes that the _internalBase is always included in the result
|
|
# which shouldn't be done when we have no files at all in the base
|
|
# This also forces the tree before returning the filter, leads to earlier error messages
|
|
if fileset._internalIsEmptyWithoutBase || tree == null then empty else nonEmpty;
|
|
|
|
# Turn a builtins.filterSource-based source filter on a root path into a file set
|
|
# containing only files included by the filter.
|
|
# The filter is lazily called as necessary to determine whether paths are included
|
|
# Type: Path -> (String -> String -> Bool) -> fileset
|
|
_fromSourceFilter =
|
|
root: sourceFilter:
|
|
let
|
|
# During the recursion we need to track both:
|
|
# - The path value such that we can safely call `readDir` on it
|
|
# - The path string value such that we can correctly call the `filter` with it
|
|
#
|
|
# While we could just recurse with the path value,
|
|
# this would then require converting it to a path string for every path,
|
|
# which is a fairly expensive operation
|
|
|
|
# Create a file set from a directory entry
|
|
fromDirEntry =
|
|
path: pathString: type:
|
|
# The filter needs to run on the path as a string
|
|
if !sourceFilter pathString type then
|
|
null
|
|
else if type == "directory" then
|
|
fromDir path pathString
|
|
else
|
|
type;
|
|
|
|
# Create a file set from a directory
|
|
fromDir =
|
|
path: pathString:
|
|
mapAttrs
|
|
# This looks a bit funny, but we need both the path-based and the path string-based values
|
|
(name: fromDirEntry (path + "/${name}") (pathString + "/${name}"))
|
|
# We need to readDir on the path value, because reading on a path string
|
|
# would be unspecified if there are multiple filesystem roots
|
|
(readDir path);
|
|
|
|
rootPathType = pathType root;
|
|
|
|
# We need to convert the path to a string to imitate what builtins.path calls the filter function with.
|
|
# We don't want to rely on `toString` for this though because it's not very well defined, see ../path/README.md
|
|
# So instead we use `lib.path.splitRoot` to safely deconstruct the path into its filesystem root and subpath
|
|
# We don't need the filesystem root though, builtins.path doesn't expose that in any way to the filter.
|
|
# So we only need the components, which we then turn into a string as one would expect.
|
|
rootString = "/" + concatStringsSep "/" (components (splitRoot root).subpath);
|
|
in
|
|
if rootPathType == "directory" then
|
|
# We imitate builtins.path not calling the filter on the root path
|
|
_create root (fromDir root rootString)
|
|
else
|
|
# Direct files are always included by builtins.path without calling the filter
|
|
# But we need to lift up the base path to its parent to satisfy the base path invariant
|
|
_create (dirOf root) {
|
|
${baseNameOf root} = rootPathType;
|
|
};
|
|
|
|
# Turns a file set into the list of file paths it includes.
|
|
# Type: fileset -> [ Path ]
|
|
_toList =
|
|
fileset:
|
|
let
|
|
recurse =
|
|
path: tree:
|
|
if isAttrs tree then
|
|
concatLists (mapAttrsToList (name: value: recurse (path + "/${name}") value) tree)
|
|
else if tree == "directory" then
|
|
recurse path (readDir path)
|
|
else if tree == null then
|
|
[ ]
|
|
else
|
|
[ path ];
|
|
in
|
|
if fileset._internalIsEmptyWithoutBase then
|
|
[ ]
|
|
else
|
|
recurse fileset._internalBase fileset._internalTree;
|
|
|
|
# Transforms the filesetTree of a file set to a shorter base path, e.g.
|
|
# _shortenTreeBase [ "foo" ] (_create /foo/bar null)
|
|
# => { bar = null; }
|
|
_shortenTreeBase =
|
|
targetBaseComponents: fileset:
|
|
let
|
|
recurse =
|
|
index:
|
|
# If we haven't reached the required depth yet
|
|
if index < length fileset._internalBaseComponents then
|
|
# Create an attribute set and recurse as the value, this can be lazily evaluated this way
|
|
{ ${elemAt fileset._internalBaseComponents index} = recurse (index + 1); }
|
|
else
|
|
# Otherwise we reached the appropriate depth, here's the original tree
|
|
fileset._internalTree;
|
|
in
|
|
recurse (length targetBaseComponents);
|
|
|
|
# Transforms the filesetTree of a file set to a longer base path, e.g.
|
|
# _lengthenTreeBase [ "foo" "bar" ] (_create /foo { bar.baz = "regular"; })
|
|
# => { baz = "regular"; }
|
|
_lengthenTreeBase =
|
|
targetBaseComponents: fileset:
|
|
let
|
|
recurse =
|
|
index: tree:
|
|
# If the filesetTree is an attribute set and we haven't reached the required depth yet
|
|
if isAttrs tree && index < length targetBaseComponents then
|
|
# Recurse with the tree under the right component (which might not exist)
|
|
recurse (index + 1) (tree.${elemAt targetBaseComponents index} or null)
|
|
else
|
|
# For all values here we can just return the tree itself:
|
|
# tree == null -> the result is also null, everything is excluded
|
|
# tree == "directory" -> the result is also "directory",
|
|
# because the base path is always a directory and everything is included
|
|
# isAttrs tree -> the result is `tree`
|
|
# because we don't need to recurse any more since `index == length longestBaseComponents`
|
|
tree;
|
|
in
|
|
recurse (length fileset._internalBaseComponents) fileset._internalTree;
|
|
|
|
# Computes the union of a list of filesets.
|
|
# The filesets must already be coerced and validated to be in the same filesystem root
|
|
# Type: [ Fileset ] -> Fileset
|
|
_unionMany =
|
|
filesets:
|
|
let
|
|
# All filesets that have a base, aka not the ones that are the empty value without a base
|
|
filesetsWithBase = filter (fileset: !fileset._internalIsEmptyWithoutBase) filesets;
|
|
|
|
# The first fileset that has a base.
|
|
# This value is only accessed if there are at all.
|
|
firstWithBase = head filesetsWithBase;
|
|
|
|
# To be able to union filesetTree's together, they need to have the same base path.
|
|
# Base paths can be unioned by taking their common prefix,
|
|
# e.g. such that `union /foo/bar /foo/baz` has the base path `/foo`
|
|
|
|
# A list of path components common to all base paths.
|
|
# Note that commonPrefix can only be fully evaluated,
|
|
# so this cannot cause a stack overflow due to a build-up of unevaluated thunks.
|
|
commonBaseComponents =
|
|
foldl' (components: el: commonPrefix components el._internalBaseComponents)
|
|
firstWithBase._internalBaseComponents
|
|
# We could also not do the `tail` here to avoid a list allocation,
|
|
# but then we'd have to pay for a potentially expensive
|
|
# but unnecessary `commonPrefix` call
|
|
(tail filesetsWithBase);
|
|
|
|
# The common base path assembled from a filesystem root and the common components
|
|
commonBase = append firstWithBase._internalBaseRoot (join commonBaseComponents);
|
|
|
|
# A list of filesetTree's that all have the same base path
|
|
# This is achieved by nesting the trees into the components they have over the common base path
|
|
# E.g. `union /foo/bar /foo/baz` has the base path /foo
|
|
# So the tree under `/foo/bar` gets nested under `{ bar = ...; ... }`,
|
|
# while the tree under `/foo/baz` gets nested under `{ baz = ...; ... }`
|
|
# Therefore allowing combined operations over them.
|
|
trees = map (_shortenTreeBase commonBaseComponents) filesetsWithBase;
|
|
|
|
# Folds all trees together into a single one using _unionTree
|
|
# We do not use a fold here because it would cause a thunk build-up
|
|
# which could cause a stack overflow for a large number of trees
|
|
resultTree = _unionTrees trees;
|
|
in
|
|
# If there's no values with a base, we have no files
|
|
if filesetsWithBase == [ ] then _emptyWithoutBase else _create commonBase resultTree;
|
|
|
|
# The union of multiple filesetTree's with the same base path.
|
|
# Later elements are only evaluated if necessary.
|
|
# Type: [ filesetTree ] -> filesetTree
|
|
_unionTrees =
|
|
trees:
|
|
let
|
|
stringIndex = findFirstIndex isString null trees;
|
|
withoutNull = filter (tree: tree != null) trees;
|
|
in
|
|
if stringIndex != null then
|
|
# If there's a string, it's always a fully included tree (dir or file),
|
|
# no need to look at other elements
|
|
elemAt trees stringIndex
|
|
else if withoutNull == [ ] then
|
|
# If all trees are null, then the resulting tree is also null
|
|
null
|
|
else
|
|
# The non-null elements have to be attribute sets representing partial trees
|
|
# We need to recurse into those
|
|
zipAttrsWith (name: _unionTrees) withoutNull;
|
|
|
|
# Computes the intersection of a list of filesets.
|
|
# The filesets must already be coerced and validated to be in the same filesystem root
|
|
# Type: Fileset -> Fileset -> Fileset
|
|
_intersection =
|
|
fileset1: fileset2:
|
|
let
|
|
# The common base components prefix, e.g.
|
|
# (/foo/bar, /foo/bar/baz) -> /foo/bar
|
|
# (/foo/bar, /foo/baz) -> /foo
|
|
commonBaseComponentsLength =
|
|
# TODO: Have a `lib.lists.commonPrefixLength` function such that we don't need the list allocation from commonPrefix here
|
|
length (commonPrefix fileset1._internalBaseComponents fileset2._internalBaseComponents);
|
|
|
|
# To be able to intersect filesetTree's together, they need to have the same base path.
|
|
# Base paths can be intersected by taking the longest one (if any)
|
|
|
|
# The fileset with the longest base, if any, e.g.
|
|
# (/foo/bar, /foo/bar/baz) -> /foo/bar/baz
|
|
# (/foo/bar, /foo/baz) -> null
|
|
longestBaseFileset =
|
|
if commonBaseComponentsLength == length fileset1._internalBaseComponents then
|
|
# The common prefix is the same as the first path, so the second path is equal or longer
|
|
fileset2
|
|
else if commonBaseComponentsLength == length fileset2._internalBaseComponents then
|
|
# The common prefix is the same as the second path, so the first path is longer
|
|
fileset1
|
|
else
|
|
# The common prefix is neither the first nor the second path
|
|
# This means there's no overlap between the two sets
|
|
null;
|
|
|
|
# Whether the result should be the empty value without a base
|
|
resultIsEmptyWithoutBase =
|
|
# If either fileset is the empty fileset without a base, the intersection is too
|
|
fileset1._internalIsEmptyWithoutBase
|
|
|| fileset2._internalIsEmptyWithoutBase
|
|
# If there is no overlap between the base paths
|
|
|| longestBaseFileset == null;
|
|
|
|
# Lengthen each fileset's tree to the longest base prefix
|
|
tree1 = _lengthenTreeBase longestBaseFileset._internalBaseComponents fileset1;
|
|
tree2 = _lengthenTreeBase longestBaseFileset._internalBaseComponents fileset2;
|
|
|
|
# With two filesetTree's with the same base, we can compute their intersection
|
|
resultTree = _intersectTree tree1 tree2;
|
|
in
|
|
if resultIsEmptyWithoutBase then
|
|
_emptyWithoutBase
|
|
else
|
|
_create longestBaseFileset._internalBase resultTree;
|
|
|
|
# The intersection of two filesetTree's with the same base path
|
|
# The second element is only evaluated as much as necessary.
|
|
# Type: filesetTree -> filesetTree -> filesetTree
|
|
_intersectTree =
|
|
lhs: rhs:
|
|
if isAttrs lhs && isAttrs rhs then
|
|
# Both sides are attribute sets, we can recurse for the attributes existing on both sides
|
|
mapAttrs (name: _intersectTree lhs.${name}) (builtins.intersectAttrs lhs rhs)
|
|
else if lhs == null || isString rhs then
|
|
# If the lhs is null, the result should also be null
|
|
# And if the rhs is the identity element
|
|
# (a string, aka it includes everything), then it's also the lhs
|
|
lhs
|
|
else
|
|
# In all other cases it's the rhs
|
|
rhs;
|
|
|
|
# Compute the set difference between two file sets.
|
|
# The filesets must already be coerced and validated to be in the same filesystem root.
|
|
# Type: Fileset -> Fileset -> Fileset
|
|
_difference =
|
|
positive: negative:
|
|
let
|
|
# The common base components prefix, e.g.
|
|
# (/foo/bar, /foo/bar/baz) -> /foo/bar
|
|
# (/foo/bar, /foo/baz) -> /foo
|
|
commonBaseComponentsLength =
|
|
# TODO: Have a `lib.lists.commonPrefixLength` function such that we don't need the list allocation from commonPrefix here
|
|
length (commonPrefix positive._internalBaseComponents negative._internalBaseComponents);
|
|
|
|
# We need filesetTree's with the same base to be able to compute the difference between them
|
|
# This here is the filesetTree from the negative file set, but for a base path that matches the positive file set.
|
|
# Examples:
|
|
# For `difference /foo /foo/bar`, `negativeTreeWithPositiveBase = { bar = "directory"; }`
|
|
# because under the base path of `/foo`, only `bar` from the negative file set is included
|
|
# For `difference /foo/bar /foo`, `negativeTreeWithPositiveBase = "directory"`
|
|
# because under the base path of `/foo/bar`, everything from the negative file set is included
|
|
# For `difference /foo /bar`, `negativeTreeWithPositiveBase = null`
|
|
# because under the base path of `/foo`, nothing from the negative file set is included
|
|
negativeTreeWithPositiveBase =
|
|
if commonBaseComponentsLength == length positive._internalBaseComponents then
|
|
# The common prefix is the same as the positive base path, so the second path is equal or longer.
|
|
# We need to _shorten_ the negative filesetTree to the same base path as the positive one
|
|
# E.g. for `difference /foo /foo/bar` the common prefix is /foo, equal to the positive file set's base
|
|
# So we need to shorten the base of the tree for the negative argument from /foo/bar to just /foo
|
|
_shortenTreeBase positive._internalBaseComponents negative
|
|
else if commonBaseComponentsLength == length negative._internalBaseComponents then
|
|
# The common prefix is the same as the negative base path, so the first path is longer.
|
|
# We need to lengthen the negative filesetTree to the same base path as the positive one.
|
|
# E.g. for `difference /foo/bar /foo` the common prefix is /foo, equal to the negative file set's base
|
|
# So we need to lengthen the base of the tree for the negative argument from /foo to /foo/bar
|
|
_lengthenTreeBase positive._internalBaseComponents negative
|
|
else
|
|
# The common prefix is neither the first nor the second path.
|
|
# This means there's no overlap between the two file sets,
|
|
# and nothing from the negative argument should get removed from the positive one
|
|
# E.g for `difference /foo /bar`, we remove nothing to get the same as `/foo`
|
|
null;
|
|
|
|
resultingTree =
|
|
_differenceTree positive._internalBase positive._internalTree
|
|
negativeTreeWithPositiveBase;
|
|
in
|
|
# If the first file set is empty, we can never have any files in the result
|
|
if positive._internalIsEmptyWithoutBase then
|
|
_emptyWithoutBase
|
|
# If the second file set is empty, nothing gets removed, so the result is just the first file set
|
|
else if negative._internalIsEmptyWithoutBase then
|
|
positive
|
|
else
|
|
# We use the positive file set base for the result,
|
|
# because only files from the positive side may be included,
|
|
# which is what base path is for
|
|
_create positive._internalBase resultingTree;
|
|
|
|
# Computes the set difference of two filesetTree's
|
|
# Type: Path -> filesetTree -> filesetTree
|
|
_differenceTree =
|
|
path: lhs: rhs:
|
|
# If the lhs doesn't have any files, or the right hand side includes all files
|
|
if lhs == null || isString rhs then
|
|
# The result will always be empty
|
|
null
|
|
# If the right hand side has no files
|
|
else if rhs == null then
|
|
# The result is always the left hand side, because nothing gets removed
|
|
lhs
|
|
else
|
|
# Otherwise we always have two attribute sets to recurse into
|
|
mapAttrs (name: lhsValue: _differenceTree (path + "/${name}") lhsValue (rhs.${name} or null)) (
|
|
_directoryEntries path lhs
|
|
);
|
|
|
|
# Filters all files in a path based on a predicate
|
|
# Type: ({ name, type, ... } -> Bool) -> Path -> FileSet
|
|
_fileFilter =
|
|
predicate: root:
|
|
let
|
|
# Check the predicate for a single file
|
|
# Type: String -> String -> filesetTree
|
|
fromFile =
|
|
name: type:
|
|
if
|
|
predicate {
|
|
inherit name type;
|
|
hasExt = ext: hasSuffix ".${ext}" name;
|
|
|
|
# To ensure forwards compatibility with more arguments being added in the future,
|
|
# adding an attribute which can't be deconstructed :)
|
|
"lib.fileset.fileFilter: The predicate function passed as the first argument must be able to handle extra attributes for future compatibility. If you're using `{ name, file, hasExt }:`, use `{ name, file, hasExt, ... }:` instead." =
|
|
null;
|
|
}
|
|
then
|
|
type
|
|
else
|
|
null;
|
|
|
|
# Check the predicate for all files in a directory
|
|
# Type: Path -> filesetTree
|
|
fromDir =
|
|
path:
|
|
mapAttrs (
|
|
name: type: if type == "directory" then fromDir (path + "/${name}") else fromFile name type
|
|
) (readDir path);
|
|
|
|
rootType = pathType root;
|
|
in
|
|
if rootType == "directory" then
|
|
_create root (fromDir root)
|
|
else
|
|
# Single files are turned into a directory containing that file or nothing.
|
|
_create (dirOf root) {
|
|
${baseNameOf root} = fromFile (baseNameOf root) rootType;
|
|
};
|
|
|
|
# Support for `builtins.fetchGit` with `submodules = true` was introduced in 2.4
|
|
# https://github.com/NixOS/nix/commit/55cefd41d63368d4286568e2956afd535cb44018
|
|
_fetchGitSubmodulesMinver = "2.4";
|
|
|
|
# Support for `builtins.fetchGit` with `shallow = true` was introduced in 2.4
|
|
# https://github.com/NixOS/nix/commit/d1165d8791f559352ff6aa7348e1293b2873db1c
|
|
_fetchGitShallowMinver = "2.4";
|
|
|
|
# Mirrors the contents of a Nix store path relative to a local path as a file set.
|
|
# Some notes:
|
|
# - The store path is read at evaluation time.
|
|
# - The store path must not include files that don't exist in the respective local path.
|
|
#
|
|
# Type: Path -> String -> FileSet
|
|
_mirrorStorePath =
|
|
localPath: storePath:
|
|
let
|
|
recurse =
|
|
focusedStorePath:
|
|
mapAttrs (
|
|
name: type: if type == "directory" then recurse (focusedStorePath + "/${name}") else type
|
|
) (builtins.readDir focusedStorePath);
|
|
in
|
|
_create localPath (recurse storePath);
|
|
|
|
# Create a file set from the files included in the result of a fetchGit call
|
|
# Type: String -> String -> Path -> Attrs -> FileSet
|
|
_fromFetchGit =
|
|
function: argument: path: extraFetchGitAttrs:
|
|
let
|
|
# The code path for when isStorePath is true
|
|
tryStorePath =
|
|
if pathExists (path + "/.git") then
|
|
# If there is a `.git` directory in the path,
|
|
# it means that the path was imported unfiltered into the Nix store.
|
|
# This function should throw in such a case, because
|
|
# - `fetchGit` doesn't generally work with `.git` directories in store paths
|
|
# - Importing the entire path could include Git-tracked files
|
|
throw ''
|
|
lib.fileset.${function}: The ${argument} (${toString path}) is a store path within a working tree of a Git repository.
|
|
This indicates that a source directory was imported into the store using a method such as `import "''${./.}"` or `path:.`.
|
|
This function currently does not support such a use case, since it currently relies on `builtins.fetchGit`.
|
|
You could make this work by using a fetcher such as `fetchGit` instead of copying the whole repository.
|
|
If you can't avoid copying the repo to the store, see https://github.com/NixOS/nix/issues/9292.''
|
|
else
|
|
# Otherwise we're going to assume that the path was a Git directory originally,
|
|
# but it was fetched using a method that already removed files not tracked by Git,
|
|
# such as `builtins.fetchGit`, `pkgs.fetchgit` or others.
|
|
# So we can just import the path in its entirety.
|
|
_singleton path;
|
|
|
|
# The code path for when isStorePath is false
|
|
tryFetchGit =
|
|
let
|
|
# This imports the files unnecessarily, which currently can't be avoided
|
|
# because `builtins.fetchGit` is the only function exposing which files are tracked by Git.
|
|
# With the [lazy trees PR](https://github.com/NixOS/nix/pull/6530),
|
|
# the unnecessarily import could be avoided.
|
|
# However a simpler alternative still would be [a builtins.gitLsFiles](https://github.com/NixOS/nix/issues/2944).
|
|
fetchResult = fetchGit (
|
|
{
|
|
url = path;
|
|
}
|
|
# In older Nix versions, repositories were always assumed to be deep clones, which made `fetchGit` fail for shallow clones
|
|
# For newer versions this was fixed, but the `shallow` flag is required.
|
|
# The only behavioral difference is that for shallow clones, `fetchGit` doesn't return a `revCount`,
|
|
# which we don't need here, so it's fine to always pass it.
|
|
|
|
# Unfortunately this means older Nix versions get a poor error message for shallow repositories, and there's no good way to improve that.
|
|
# Checking for `.git/shallow` doesn't seem worth it, especially since that's more of an implementation detail,
|
|
# and would also require more code to handle worktrees where `.git` is a file.
|
|
// optionalAttrs (versionAtLeast nixVersion _fetchGitShallowMinver) { shallow = true; }
|
|
// extraFetchGitAttrs
|
|
);
|
|
in
|
|
# We can identify local working directories by checking for .git,
|
|
# see https://git-scm.com/docs/gitrepository-layout#_description.
|
|
# Note that `builtins.fetchGit` _does_ work for bare repositories (where there's no `.git`),
|
|
# even though `git ls-files` wouldn't return any files in that case.
|
|
if !pathExists (path + "/.git") then
|
|
throw "lib.fileset.${function}: Expected the ${argument} (${toString path}) to point to a local working tree of a Git repository, but it's not."
|
|
else
|
|
_mirrorStorePath path fetchResult.outPath;
|
|
|
|
in
|
|
if !isPath path then
|
|
throw "lib.fileset.${function}: Expected the ${argument} to be a path, but it's a ${typeOf path} instead."
|
|
else if pathType path != "directory" then
|
|
throw "lib.fileset.${function}: Expected the ${argument} (${toString path}) to be a directory, but it's a file instead."
|
|
else if hasStorePathPrefix path then
|
|
tryStorePath
|
|
else
|
|
tryFetchGit;
|
|
|
|
}
|