Add import for 'important' headers.

Process and normalize some headers that will be used in quickly recalling
messages.

db/util.go

@@ -5,6 +5,7 @@ import (
 	"flag"
 	"fmt"
 	"net/mail"
+	"time"
 	"unicode/utf8"
 
 	"github.com/golang/glog"
@@ -140,7 +141,7 @@ VALUES
 	for k, vs := range hdrs {
 		for _, v := range vs {
 			if !utf8.ValidString(v) {
-				glog.Infof("%s: value for %q invalid UTF-8 %q", hash, k, v)
+				glog.Warningf("%s: value for %q invalid UTF-8 %q", hash, k, v)
 				continue
 			}
 			if _, err := stmt.Exec(hash, k, v); err != nil {
@@ -150,3 +151,75 @@ VALUES
 	}
 	return nil
 }
+
+func (c *Conn) InsertSearchHeaders(hash string, hdrs mail.Header) (err error) {
+	var tx *sql.Tx
+	tx, err = c.Begin()
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			if err := tx.Rollback(); err != nil {
+				glog.Error(err)
+			}
+			return
+		}
+		err = tx.Commit()
+	}()
+
+	stmt, err := tx.Prepare(`
+INSERT INTO
+    search_header (hash, name, value)
+VALUES
+    ($1, $2, $3)
+`)
+	if err != nil {
+		return err
+	}
+
+	// Save the following headers to the database untouched.
+	otherHdrs := []string{"Subject", "Message-Id", "In-Reply-To", "References"}
+	for _, k := range otherHdrs {
+		for _, v := range hdrs[k] {
+			if !utf8.ValidString(v) {
+				glog.Warningf("%s: value for %q invalid UTF-8 %q", hash, k, v)
+				continue
+			}
+			if _, err := stmt.Exec(hash, k, v); err != nil {
+				return err
+			}
+		}
+	}
+
+	// Parse the following headers as addresses, and save each email address
+	// found to the database independently.
+	addrHdrs := []string{"To", "From", "Cc"}
+	for _, k := range addrHdrs {
+		for _, value := range hdrs[k] {
+			addrs, err := mail.ParseAddressList(value)
+			if err != nil {
+				glog.Warningf("%s: error parsing address list for %q: %v", hash, k, err)
+				continue
+			}
+
+			for _, v := range addrs {
+				if _, err := stmt.Exec(hash, k, v.Address); err != nil {
+					return err
+				}
+			}
+		}
+	}
+
+	// Normalize date field.
+	t, err := hdrs.Date()
+	if err != nil {
+		glog.Warningf("%s: failed to parse date header: %v", hash, err)
+		return nil
+	}
+	v := t.UTC().Format(time.RFC3339Nano)
+	if _, err := stmt.Exec(hash, "Date", v); err != nil {
+		return err
+	}
+	return nil
+}