Artifact [20f5a211e9]

Artifact 20f5a211e98895b472cea2b1b3585889b5f7283fd0466422ccebdc82fe2a05f2:

• File cli/repo_delta.go — part of check-in [f5744359d3] at 2026-04-19 16:30:54 on branch trunk — Initial open source release

  libfossil is a pure-Go implementation of the Fossil SCM, reading and writing the same .fossil SQLite repository format as upstream Fossil.

  This is the first public release of code that previously lived in a private repository. The module path is github.com/danmestas/libfossil and the binary is named libfossil to avoid $PATH collisions with upstream fossil.

  Included: - Repo lifecycle (create, clone), checkout/checkin, timeline, merge, diff, annotate, shun, tag, branch, bisect, stash, undo/redo - Sync-over-HTTP protocol (client and handler) - Two SQLite drivers: modernc (pure Go, default) and ncruces (wasm-capable) - Observer interfaces (SyncObserver, CheckoutObserver) with an optional OpenTelemetry implementation in observer/otel (separate submodule) - Deterministic simulation testing harness with BUGGIFY fault injection - Kong-based embeddable CLI under cli/ and a standalone binary under cmd/libfossil/ (user: [email protected], size: 1688) [annotate] [blame] [check-ins using]

package cli

import (
	"fmt"
	"os"

	"github.com/danmestas/libfossil/internal/delta"
)

// RepoDeltaCmd groups delta create/apply operations.
type RepoDeltaCmd struct {
	Create RepoDeltaCreateCmd `cmd:"" help:"Create a delta between two files"`
	Apply  RepoDeltaApplyCmd  `cmd:"" help:"Apply a delta to a source file"`
}

// RepoDeltaCreateCmd creates a delta between two files.
type RepoDeltaCreateCmd struct {
	Source string `arg:"" help:"Source (original) file"`
	Target string `arg:"" help:"Target (new) file"`
	Output string `short:"o" help:"Output file (default: stdout)"`
}

func (c *RepoDeltaCreateCmd) Run(g *Globals) error {
	src, err := os.ReadFile(c.Source)
	if err != nil {
		return fmt.Errorf("reading source: %w", err)
	}
	tgt, err := os.ReadFile(c.Target)
	if err != nil {
		return fmt.Errorf("reading target: %w", err)
	}

	d := delta.Create(src, tgt)

	if c.Output != "" {
		return os.WriteFile(c.Output, d, 0o644)
	}
	os.Stdout.Write(d)
	return nil
}

// RepoDeltaApplyCmd applies a delta to a source file.
type RepoDeltaApplyCmd struct {
	Source string `arg:"" help:"Source (original) file"`
	Delta  string `arg:"" help:"Delta file"`
	Output string `short:"o" help:"Output file (default: stdout)"`
}

func (c *RepoDeltaApplyCmd) Run(g *Globals) error {
	src, err := os.ReadFile(c.Source)
	if err != nil {
		return fmt.Errorf("reading source: %w", err)
	}
	d, err := os.ReadFile(c.Delta)
	if err != nil {
		return fmt.Errorf("reading delta: %w", err)
	}

	result, err := delta.Apply(src, d)
	if err != nil {
		return fmt.Errorf("applying delta: %w", err)
	}

	if c.Output != "" {
		return os.WriteFile(c.Output, result, 0o644)
	}
	os.Stdout.Write(result)
	return nil
}