Header import, and dumporiginal extensions.

Add ability to dump headers or mimetypes for original messages.
Add ability to dump all messages, instead of just hashes listed.
Add new command  cmd/headers to import all headers from messages in table
    original.  Utility can work incrementally or do fully table imports.
Moved 'fetch all original messages' code to db/util.go.  Added conditional
version given table name that will only return original messages that do not
    have matching hashes in the specified table.

cmd/dumporiginal/dumporiginal.go

@@ -1,14 +1,107 @@
 package main
 
 import (
+	"bytes"
 	"flag"
 	"fmt"
-	"os"
+	"io"
+	"mime"
+	"net/mail"
+	"sort"
 	"xinu.tv/email/db"
 
 	"github.com/golang/glog"
 )
 
+var (
+	dumpMime = flag.Bool("mime", false, "show multipart mime types for message")
+	headers  = flag.Bool("headers", false, "show only headers")
+)
+
+func printMultipartMime(hash string, r io.Reader) error {
+	msg, err := mail.ReadMessage(r)
+	if err != nil {
+		return err
+	}
+
+	mediatype, params, err := mime.ParseMediaType(msg.Header.Get("Content-Type"))
+	if err != nil {
+		return err
+	}
+	glog.Infof("%s mt: %s p: %v", hash, mediatype, params)
+
+	return nil
+}
+
+func printHeaders(hash string, r io.Reader) error {
+	msg, err := mail.ReadMessage(r)
+	if err != nil {
+		return err
+	}
+	hdrs := make([]string, 0, len(msg.Header))
+	for k := range msg.Header {
+		hdrs = append(hdrs, k)
+	}
+	fmt.Println(hash)
+	sort.Strings(hdrs)
+	for _, k := range hdrs {
+		vs := msg.Header[k]
+		fmt.Printf("%s:", k)
+		for _, v := range vs {
+			fmt.Printf(" %s", v)
+		}
+		fmt.Println()
+	}
+	return nil
+}
+
+func printOneBlob(hash string, blob []byte) error {
+	r := bytes.NewReader(blob)
+	switch {
+	case *dumpMime:
+		if err := printMultipartMime(hash, r); err != nil {
+			// err != nil expected when mime type not found, so we log and
+			// squelch the error.
+			glog.Warningf("%s: %v", hash, err)
+			return nil
+		}
+	case *headers:
+		if err := printHeaders(hash, r); err != nil {
+			return err
+		}
+	default:
+		fmt.Println(string(blob))
+	}
+	return nil
+}
+
+type hashError struct {
+	hash string
+	error
+}
+
+func (he hashError) Error() string {
+	return fmt.Sprintf("%s: %v", he.hash, he.error)
+}
+
+func printAllBlobs(c *db.Conn) error {
+	oCh := make(chan db.Original)
+	errc := make(chan error)
+	donec := make(chan struct{})
+	defer close(donec)
+	go c.Originals(oCh, errc, donec)
+	for {
+		select {
+		case o := <-oCh:
+			if err := printOneBlob(o.Hash, o.Blob); err != nil {
+				return hashError{hash: o.Hash, error: err}
+			}
+		case err := <-errc:
+			return err
+		}
+	}
+}
+
 func main() {
 	defer glog.Flush()
 	flag.Parse()
@@ -19,8 +112,10 @@ func main() {
 	}
 
 	if flag.NArg() == 0 {
-		fmt.Println("Must specify message hashes to print")
-		os.Exit(1)
+		if err := printAllBlobs(c); err != nil {
+			glog.Fatal(err)
+		}
+		return
 	}
 
 	var blob []byte
@@ -28,6 +123,8 @@ func main() {
 		if err := c.OriginalBlobByHash(hash, &blob); err != nil {
 			glog.Fatal(err)
 		}
-		fmt.Println(string(blob))
+		if err := printOneBlob(hash, blob); err != nil {
+			glog.Fatal(err)
+		}
 	}
 }