Return an output port for use as 'current-build-output-port' that calls PROC with its current state value, initialized with SEED, on every build event. Build events passed to PROC are tuples corresponding to the "build traces" produced by the daemon:

(build-started "/gnu/store/...-foo.drv" ...) (substituter-started "/gnu/store/...-foo" ...)

and so on.

The second return value is a thunk to retrieve the current state.

Return a new download.

Register all of ITEMS, a list of <store-info> records as returned by 'read-reference-graph', in DB. ITEMS must be in topological order (with leaves first.) REGISTRATION-TIME must be the registration time to be recorded in the database; #f means "now". Write a progress report to LOG-PORT. All of ITEMS must be protected from GC and locked during execution of this, typically by adding them as temp-roots.

Reset the modification time on FILE and on all the files it contains, if it's a directory. Canonicalize file permissions unless PRESERVE-PERMISSIONS? is true.

If PATH exists in the 'ValidPaths' table, return its numerical identifier. Otherwise, return #f.

Registers this stuff in DB. PATH is the store item to register and REFERENCES is the list of store items PATH refers to; DERIVER is the '.drv' that produced PATH, HASH is the base16-encoded Nix sha256 hash of PATH (prefixed with "sha256:"), and NAR-SIZE is the size in bytes PATH after being converted to nar form. TIME is the registration time to be recorded in the database or #f, meaning "right now".

Every store item in REFERENCES must already be registered.

Return the store database file name, taking PREFIX and STATE-DIRECTORY into account when provided.

Pass PROC a database record corresponding to FILE. If FILE doesn't exist, create it and initialize it as a new database. Unless WAL-MODE? is set to #f, set journal_mode=WAL.

Gives the sha256 hash of a file and the size of the file in nar form.

Write SIZE bytes read from INPUT to FILE. TYPE is a symbol, either 'regular or 'executable.

This procedure is suitable as a #:dump-file argument to 'restore-file'. When used that way, it deduplicates files on the fly as they are restored, thereby removing the need for a deduplication pass that would re-read all the files down the road.

Check if a store item with sha256 hash HASH already exists. If so, replace PATH with a hardlink to the already-existing one. If not, register PATH so that future duplicates can hardlink to it. PATH is assumed to be under STORE.

Like 'copy-file', but additionally deduplicate TARGET in STORE.

Return the list of garbage collector roots ("GC roots"). This includes "regular" roots found in %GC-ROOTS-DIRECTORY as well as indirect roots that are user-controlled symlinks stored anywhere on the file system.

Return the list of store items used by the currently running processes.

This code should typically run as root; it allows the garbage collector to determine which store items must not be deleted.

Return true if ROOT exists and is owned by UID, false otherwise.