feat: initial goget release — modern IPv6-first download utility

internal/warc/writer.go

@@ -0,0 +1,50 @@
+//go:build linux || freebsd
+// +build linux freebsd
+
+// Package warc provides Web ARChive (WARC) format reading and writing.
+// It implements WARC/1.0 as defined by ISO 28500.
+package warc
+
+import (
+	"fmt"
+	"os"
+	"time"
+)
+
+// Writer writes WARC records to a file.
+type Writer struct {
+	path string
+}
+
+// NewWriter creates a new WARC writer that writes records to the given file.
+// Each call to WriteRecord or WriteRecordFile overwrites the file.
+func NewWriter(path string) *Writer {
+	return &Writer{path: path}
+}
+
+// WriteRecord writes a WARC response record from raw byte data.
+// targetURI is the original URL of the downloaded resource.
+func (w *Writer) WriteRecord(targetURI string, data []byte) error {
+	now := time.Now().UTC().Format(time.RFC3339)
+	warcData := fmt.Sprintf(
+		"WARC/1.0\r\n"+
+			"WARC-Type: response\r\n"+
+			"WARC-Date: %s\r\n"+
+			"WARC-Target-URI: %s\r\n"+
+			"Content-Length: %d\r\n"+
+			"\r\n"+
+			"%s\r\n\r\n",
+		now, targetURI, len(data), string(data))
+
+	return os.WriteFile(w.path, []byte(warcData), 0644)
+}
+
+// WriteRecordFile reads the file at filePath and writes it as a WARC record.
+// targetURI is the original URL of the downloaded resource.
+func (w *Writer) WriteRecordFile(targetURI, filePath string) error {
+	data, err := os.ReadFile(filePath)
+	if err != nil {
+		return fmt.Errorf("failed to read file for WARC: %w", err)
+	}
+	return w.WriteRecord(targetURI, data)
+}