Author SHA1 Message Date
sneak d90bef8580 Add the required README sections (closes #75)
check / check (push) Failing after 1s
Policy names five README sections that were missing or misnamed.

The Description first line now names the project, purpose, category,
WTFPL license, and author. A new Getting Started section gives a
copy-pasteable build-from-source block and gen/check/fetch usage; every
command was run against a built binary. Problem Statement and Proposed
Solution are consolidated under a new Rationale heading, keeping the
prose rather than duplicating it. A new Design section documents the
package layout: mfer/ library, internal/cli commands, internal/log and
internal/bork support, cmd/mfer entrypoint, and the committed protobuf
code. Authors is renamed Author with the canonical link.

Getting Started uses go build because the make build target invokes
protoc, which script/bootstrap does not install.

Model: opus-4-8
2026-09-21 08:03:30 +00:00
6 changed files with 121 additions and 65 deletions
+64 -11
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@@ -1,12 +1,12 @@
# mfer # mfer
[mfer](https://git.eeqj.de/sneak/mfer) is a reference implementation library and [mfer](https://git.eeqj.de/sneak/mfer) is a [WTFPL](https://wtfpl.net)-licensed
thin wrapper command-line utility written in [Go](https://golang.org) and first (public domain) [Go](https://golang.org) library and command-line tool by
published in 2022 under the [WTFPL](https://wtfpl.net) (public domain) license. [@sneak](https://sneak.berlin) that specifies and generates `.mf` manifest files
It specifies and generates `.mf` manifest files over a directory tree of files over a directory tree to encapsulate metadata about the files — such as
to encapsulate metadata about them (such as cryptographic checksums or cryptographic checksums and signatures over same — to aid in archiving,
signatures over same) to aid in archiving, downloading, and streaming, or downloading, streaming, and mirroring. It was first published in 2022. The
mirroring. The manifest files' data is serialized with Google's manifest files' data is serialized with Google's
[protobuf serialization format](https://developers.google.com/protocol-buffers). [protobuf serialization format](https://developers.google.com/protocol-buffers).
The structure of these files can be found The structure of these files can be found
[in the format specification](https://git.eeqj.de/sneak/mfer/src/branch/main/mfer/mf.proto) [in the format specification](https://git.eeqj.de/sneak/mfer/src/branch/main/mfer/mf.proto)
@@ -21,6 +21,36 @@ This project was started by [@sneak](https://sneak.berlin) to scratch an itch in
as a de-facto standard and be incorporated into other software. A compatible as a de-facto standard and be incorporated into other software. A compatible
javascript library is planned. javascript library is planned.
# Getting Started
`mfer` builds from source with a Go 1.23+ toolchain. The generated protobuf code
is committed, so no `protoc` toolchain is required:
```sh
git clone https://git.eeqj.de/sneak/mfer.git
cd mfer
go build -o bin/mfer ./cmd/mfer
```
Generate a manifest for a directory tree, verify it later, and fetch a published
tree by URL:
```sh
# Write .index.mf describing every file under the current directory.
bin/mfer gen .
# Verify the files on disk against the manifest. Exits nonzero if any file
# is missing or corrupted.
bin/mfer check .index.mf
# Download and cryptographically verify a tree published over HTTP: mfer
# fetches <url>/index.mf, then downloads every file it lists.
bin/mfer fetch https://example.com/tree/
```
Run `bin/mfer help` for the full command list, or `bin/mfer <command> --help`
for a single command's options.
# Build Status # Build Status
CI runs via `script/cibuild` (`docker build .`), which executes `make check` CI runs via `script/cibuild` (`docker build .`), which executes `make check`
@@ -81,7 +111,9 @@ Any changes submitted to this project must also be
See [`REPO_POLICIES.md`](REPO_POLICIES.md) for detailed coding standards, See [`REPO_POLICIES.md`](REPO_POLICIES.md) for detailed coding standards,
tooling requirements, and workflow conventions. tooling requirements, and workflow conventions.
# Problem Statement # Rationale
## The problem
Given a plain URL, there is no standard way to safely and programmatically Given a plain URL, there is no standard way to safely and programmatically
download everything "under" that URL path. `wget -r` can traverse directory download everything "under" that URL path. `wget -r` can traverse directory
@@ -105,7 +137,7 @@ Real issues I face:
- when I download a large file via HTTP, I have no way of knowing if the file - when I download a large file via HTTP, I have no way of knowing if the file
content is what it's supposed to be content is what it's supposed to be
# Proposed Solution ## The solution
A standard, a manifest file format, and a tool for generating same. A standard, a manifest file format, and a tool for generating same.
@@ -137,6 +169,27 @@ The manifest file would do several important things:
- maybe a bittorrent chunklist for torrent client compatibility? perhaps a - maybe a bittorrent chunklist for torrent client compatibility? perhaps a
top-level infohash for the whole manifest? top-level infohash for the whole manifest?
# Design
The repository is split into a reusable library and a thin command-line wrapper
around it.
- `mfer/` is the reusable library and the heart of the project: it defines the
manifest format and implements building, scanning, checking, serialization,
and signing. The protobuf schema is `mfer/mf.proto`, and the generated code it
produces (`mfer/mf.pb.go`) is committed alongside it so the library builds
with `go get` and needs no `protoc` toolchain.
- `internal/cli/` holds the command implementations — `gen`, `check`, `freshen`,
`export`, `list`, and `fetch` — that wire the library to the command-line
interface.
- `internal/log/` provides the logging used across the commands.
- `internal/bork/` provides error-handling support.
- `cmd/mfer/` is the entrypoint: its `main` package assembles the pieces above
into the `mfer` binary.
Everything under `internal/` is private to this repository; only the `mfer/`
package is intended for import by other software.
# Design Goals # Design Goals
- Replace SHASUMS/SHASUMS.asc files - Replace SHASUMS/SHASUMS.asc files
@@ -462,9 +515,9 @@ proto `go_package` option. Which is canonical?
- Issues: - Issues:
[https://git.eeqj.de/sneak/mfer/issues](https://git.eeqj.de/sneak/mfer/issues) [https://git.eeqj.de/sneak/mfer/issues](https://git.eeqj.de/sneak/mfer/issues)
# Authors # Author
- [@sneak &lt;sneak@sneak.berlin&gt;](mailto:sneak@sneak.berlin) - [@sneak](https://sneak.berlin)
# License # License
+6 -3
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@@ -24,9 +24,11 @@ only thing left of the `chore/align-repo-policies` branch is the list below.
# Completed Steps # Completed Steps
- 2026-09-21: rewrote `script/test` to the canonical pattern (30s timeout, - 2026-09-21: added the required README sections — named author, license, and
`-race -cover`, quiet-first with verbose-on-failure rerun) and fixed the category in the Description first line; added Getting Started (verified
process-global logger data race it surfaced (#67) install/usage block), Rationale (folding in Problem Statement and Proposed
Solution), and a Design section for the package layout; renamed Authors to
Author (#75)
- 2026-09-21: added the canonical `.editorconfig`, made `.gitignore` cover - 2026-09-21: added the canonical `.editorconfig`, made `.gitignore` cover
secrets, OS, editor, and Go artifacts, and removed the dead Drone CI secrets, OS, editor, and Go artifacts, and removed the dead Drone CI
references from `.gitignore` and `bin/gitrev.sh` (#72) references from `.gitignore` and `bin/gitrev.sh` (#72)
@@ -68,6 +70,7 @@ only thing left of the `chore/align-repo-policies` branch is the list below.
- Move FORMAT.md from repo root to docs/ and update the AGENTS.md reference - Move FORMAT.md from repo root to docs/ and update the AGENTS.md reference
- Pin Makefile-installed Go tools (`protoc-gen-go@v1.28.1`, - Pin Makefile-installed Go tools (`protoc-gen-go@v1.28.1`,
`golangci-lint@v2.12.2`) by module hash, not mutable tag `golangci-lint@v2.12.2`) by module hash, not mutable tag
- Set `make test` timeout to 30s (currently 10s)
- Add explicit README "Rationale" heading (content exists under other - Add explicit README "Rationale" heading (content exists under other
names); name the author in the README Description first line names); name the author in the README Description first line
- Reconcile root-level AGENTS.md with directory-hygiene policy (keep or - Reconcile root-level AGENTS.md with directory-hygiene policy (keep or
+8 -10
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@@ -679,13 +679,11 @@ func TestCheckDetectsManifestCorruption(t *testing.T) {
fs := afero.NewMemMapFs() fs := afero.NewMemMapFs()
rng := rand.New(rand.NewSource(42)) //nolint:gosec // deterministic test data rng := rand.New(rand.NewSource(42)) //nolint:gosec // deterministic test data
// Create many small files with random names so the manifest has many // Create many small files with random names to generate a ~1MB manifest
// entries and random single-byte flips land at varied offsets. Each // Each manifest entry is roughly 50-60 bytes, so we need ~20000 files
// manifest entry is roughly 50-60 bytes. Kept modest so the suite stays
// within its wall-clock budget under -race.
require.NoError(t, fs.MkdirAll(testDir, 0o755)) require.NoError(t, fs.MkdirAll(testDir, 0o755))
numFiles := 1500 numFiles := 20000
for range numFiles { for range numFiles {
// Generate random filename // Generate random filename
filename := fmt.Sprintf("/testdir/%08x%08x%08x.dat", filename := fmt.Sprintf("/testdir/%08x%08x%08x.dat",
@@ -701,11 +699,11 @@ func TestCheckDetectsManifestCorruption(t *testing.T) {
exitCode := runCLI(opts) exitCode := runCLI(opts)
require.Equal(t, 0, exitCode, "generate should succeed") require.Equal(t, 0, exitCode, "generate should succeed")
// Read the valid manifest and verify it has real size. // Read the valid manifest and verify it's approximately 1MB
validManifest, err := afero.ReadFile(fs, testManifest) validManifest, err := afero.ReadFile(fs, testManifest)
require.NoError(t, err) require.NoError(t, err)
require.GreaterOrEqual(t, len(validManifest), 64*1024, require.GreaterOrEqual(t, len(validManifest), 1024*1024,
"manifest should be at least 64KB, got %d bytes", len(validManifest)) "manifest should be at least 1MB, got %d bytes", len(validManifest))
t.Logf("manifest size: %d bytes (%d files)", len(validManifest), numFiles) t.Logf("manifest size: %d bytes (%d files)", len(validManifest), numFiles)
// First corruption: truncate the manifest // First corruption: truncate the manifest
@@ -728,8 +726,8 @@ func TestCheckDetectsManifestCorruption(t *testing.T) {
exitCode = runCLI(opts) exitCode = runCLI(opts)
require.Equal(t, 0, exitCode, "check should pass with valid manifest") require.Equal(t, 0, exitCode, "check should pass with valid manifest")
// Now do 100 random corruption iterations // Now do 500 random corruption iterations
for i := range 100 { for i := range 500 {
// Corrupt: write a random byte at a random offset // Corrupt: write a random byte at a random offset
corrupted := make([]byte, len(validManifest)) corrupted := make([]byte, len(validManifest))
copy(corrupted, validManifest) copy(corrupted, validManifest)
+1 -1
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@@ -357,6 +357,6 @@ func (mfa *CLIApp) run(args []string) {
if err != nil { if err != nil {
mfa.exitCode = 1 mfa.exitCode = 1
log.Errorf("%s", err) log.WithError(err).Debugf("exiting")
} }
} }
+41 -34
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@@ -112,16 +112,13 @@ func DisableStyling() {
} }
// Init initializes the logger with the CLI handler and default log level. // Init initializes the logger with the CLI handler and default log level.
//
// It reconfigures the process-global apex/log logger under the write lock so
// the global is never mutated while another goroutine holds the read lock to
// read it in emit. Without this, parallel callers (e.g. the test suite) race
// Init's SetLevel/SetHandler against concurrent log calls.
func Init() { func Init() {
mu.Lock() mu.RLock()
defer mu.Unlock()
log.SetHandler(acli.New(stderr)) w := stderr
mu.RUnlock()
log.SetHandler(acli.New(w))
log.SetLevel(log.DebugLevel) // Let apex/log pass everything; we filter ourselves log.SetLevel(log.DebugLevel) // Let apex/log pass everything; we filter ourselves
} }
@@ -133,66 +130,74 @@ func isEnabled(l Level) bool {
return l >= currentLevel return l >= currentLevel
} }
// emit calls fn while holding the read lock if messages at level l are
// enabled. Holding the read lock across the apex/log call keeps the global
// logger from being read while Init reconfigures it under the write lock.
func emit(l Level, fn func()) {
mu.RLock()
defer mu.RUnlock()
if l >= currentLevel {
fn()
}
}
// Fatalf logs a formatted message at fatal level. // Fatalf logs a formatted message at fatal level.
func Fatalf(format string, args ...any) { func Fatalf(format string, args ...any) {
emit(FatalLevel, func() { log.Fatalf(format, args...) }) if isEnabled(FatalLevel) {
log.Fatalf(format, args...)
}
} }
// Fatal logs a message at fatal level. // Fatal logs a message at fatal level.
func Fatal(arg string) { func Fatal(arg string) {
emit(FatalLevel, func() { log.Fatal(arg) }) if isEnabled(FatalLevel) {
log.Fatal(arg)
}
} }
// Errorf logs a formatted message at error level. // Errorf logs a formatted message at error level.
func Errorf(format string, args ...any) { func Errorf(format string, args ...any) {
emit(ErrorLevel, func() { log.Errorf(format, args...) }) if isEnabled(ErrorLevel) {
log.Errorf(format, args...)
}
} }
// Error logs a message at error level. // Error logs a message at error level.
func Error(arg string) { func Error(arg string) {
emit(ErrorLevel, func() { log.Error(arg) }) if isEnabled(ErrorLevel) {
log.Error(arg)
}
} }
// Warnf logs a formatted message at warn level. // Warnf logs a formatted message at warn level.
func Warnf(format string, args ...any) { func Warnf(format string, args ...any) {
emit(WarnLevel, func() { log.Warnf(format, args...) }) if isEnabled(WarnLevel) {
log.Warnf(format, args...)
}
} }
// Warn logs a message at warn level. // Warn logs a message at warn level.
func Warn(arg string) { func Warn(arg string) {
emit(WarnLevel, func() { log.Warn(arg) }) if isEnabled(WarnLevel) {
log.Warn(arg)
}
} }
// Infof logs a formatted message at info level. // Infof logs a formatted message at info level.
func Infof(format string, args ...any) { func Infof(format string, args ...any) {
emit(InfoLevel, func() { log.Infof(format, args...) }) if isEnabled(InfoLevel) {
log.Infof(format, args...)
}
} }
// Info logs a message at info level. // Info logs a message at info level.
func Info(arg string) { func Info(arg string) {
emit(InfoLevel, func() { log.Info(arg) }) if isEnabled(InfoLevel) {
log.Info(arg)
}
} }
// Verbosef logs a formatted message at verbose level. // Verbosef logs a formatted message at verbose level.
func Verbosef(format string, args ...any) { func Verbosef(format string, args ...any) {
emit(VerboseLevel, func() { log.Infof(format, args...) }) if isEnabled(VerboseLevel) {
log.Infof(format, args...)
}
} }
// Verbose logs a message at verbose level. // Verbose logs a message at verbose level.
func Verbose(arg string) { func Verbose(arg string) {
emit(VerboseLevel, func() { log.Info(arg) }) if isEnabled(VerboseLevel) {
log.Info(arg)
}
} }
// Debugf logs a formatted message at debug level with caller location. // Debugf logs a formatted message at debug level with caller location.
@@ -211,10 +216,7 @@ func Debug(arg string) {
// DebugReal logs at debug level with caller info from the specified stack depth. // DebugReal logs at debug level with caller info from the specified stack depth.
func DebugReal(arg string, cs int) { func DebugReal(arg string, cs int) {
mu.RLock() if !isEnabled(DebugLevel) {
defer mu.RUnlock()
if DebugLevel < currentLevel {
return return
} }
@@ -273,6 +275,11 @@ func GetLevel() Level {
return currentLevel return currentLevel
} }
// WithError returns a log entry with the error attached.
func WithError(e error) *log.Entry {
return log.Log.WithError(e)
}
// Progressf prints a progress message that overwrites the current line. // Progressf prints a progress message that overwrites the current line.
// Use ProgressDone() when progress is complete to move to the next line. // Use ProgressDone() when progress is complete to move to the next line.
func Progressf(format string, args ...any) { func Progressf(format string, args ...any) {
+1 -6
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@@ -17,12 +17,7 @@ ensure_pb() {
main() { main() {
cd "$ROOT" cd "$ROOT"
ensure_pb ensure_pb
go test -timeout 30s -race -cover ./... || go test -v --timeout 10s ./...
{
echo "--- Rerunning with -v for details ---"
go test -timeout 30s -race -v ./...
exit 1
}
} }
main "$@" main "$@"