Verify an installation

Check that the llama.cpp libraries are the files that the release published.

yzma install downloads shared libraries and your program then runs them. Thus yzma checks each file.

See Verification for how the checks work. This page shows the commands and the Go code.

Check an installation

yzma verify --lib /path/to/lib

Flag	What it does
`--lib`, `-l`	The directory with the libraries. Also reads `YZMA_LIB`.
`--version`, `-v`	The `llama.cpp` version that must be there.
`--strict`	Also fails when the directory holds a file that this install did not put there.
`--json`	Writes the report as JSON.

The check reads the manifest that the install kept, so it needs no network.

Set the policy at install time

yzma install --lib /path/to/lib --verify require

Value	What it does
`available`	Checks a digest when there is one. Accepts an asset with none. This is the default.
`require`	Fails when an asset has no digest.
`off`	Does no check.

The YZMA_VERIFY environment variable sets the same thing.

Use require in a build that must be repeatable. The builds from llama-cpp-builder have digests. The llama.cpp release page publishes none, so an install from there gives ErrNoFileDigests.

Pin the digest

Put the digest of the manifest after the version:

yzma install --lib /path/to/lib --version b10783@sha256:abc123...

This gives you a value from outside the release host to check the manifest against. Use it when you must know that the files never change.

Nothing in a pinned setup makes an unpinned version stop working. Thus an application can install a llama.cpp release that is newer than the one this yzma release pins.

Check from Go code

report, err := download.VerifyInstall(context.Background(), libPath, "")
if err != nil {
	return err
}

if !report.OK() {
	return fmt.Errorf("%d changed, %d missing", report.Changed, report.Missing)
}

An empty tag takes the release from the record. Give a tag to name the release that must be there. The record sits beside the libraries, so anything that can change the libraries can change the record. A tag makes the check resolve the assets of that release itself.

Set the policy from Go code

err := download.Install(ctx, target, libPath, download.ProgressTracker, nil,
	download.WithVerify(download.VerifyRequired))

ParseVerifyPolicy turns a string such as "require" into a policy.

What the report says

State	What it means
`FileOK`	The file matches the digest.
`FileChanged`	The file is there but the digest does not match.
`FileMissing`	The file is not there.
`FileUnexpected`	The directory holds a file that no asset of this install holds.

FileUnexpected does not make OK false, because one directory can hold more than one install. Use --strict to make it fail. The record and the manifest belong to the install, so neither is counted.

An older installation

An installation that an earlier release of yzma made has no manifest. The first check then fetches one and keeps it. That first check needs a network. No check after that does.

Check the bindings

yzma-checker is a separate tool. It compares the FFI types and the constants in yzma against the llama.cpp headers for the build that yzma installs. It checks 265 bindings, 170 constants, 4 callbacks, and 5 function pointer members.

make check-ffi

This is a tool for the people who build yzma. It is not part of a normal installation.