[PATCH v3 6/6] lib: parse messages only once

[Jani Nikula]

Use the previously parsed gmime message for indexing instead of
running an extra parsing pass.

After this change, we'll only do unnecessary parsing of the message
body for duplicates and non-messages. For regular non-duplicate
messages, we have now shaved off an extra header parsing round during
indexing.
---
 lib/database.cc       |  2 +-
 lib/index.cc          | 59 ++++++---------------------------------------------
 lib/message-file.c    |  9 ++++++++
 lib/notmuch-private.h | 16 ++++++++++++--
 4 files changed, 30 insertions(+), 56 deletions(-)

diff --git a/lib/database.cc b/lib/database.cc
index d1bea88..3a29fe7 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -2029,7 +2029,7 @@ notmuch_database_add_message (notmuch_database_t *notmuch,
 	    date = notmuch_message_file_get_header (message_file, "date");
 	    _notmuch_message_set_header_values (message, date, from, subject);
 
-	    ret = _notmuch_message_index_file (message, filename);
+	    ret = _notmuch_message_index_file (message, message_file);
 	    if (ret)
 		goto DONE;
 	} else {
diff --git a/lib/index.cc b/lib/index.cc
index 976e49f..71397da 100644
--- a/lib/index.cc
+++ b/lib/index.cc
@@ -425,52 +425,15 @@ _index_mime_part (notmuch_message_t *message,
 
 notmuch_status_t
 _notmuch_message_index_file (notmuch_message_t *message,
-			     const char *filename)
+			     notmuch_message_file_t *message_file)
 {
-    GMimeStream *stream = NULL;
-    GMimeParser *parser = NULL;
-    GMimeMessage *mime_message = NULL;
+    GMimeMessage *mime_message;
     InternetAddressList *addresses;
-    FILE *file = NULL;
     const char *from, *subject;
-    notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;
-    static int initialized = 0;
-    char from_buf[5];
-    bool is_mbox = false;
-
-    if (! initialized) {
-	g_mime_init (GMIME_ENABLE_RFC2047_WORKAROUNDS);
-	initialized = 1;
-    }
-
-    file = fopen (filename, "r");
-    if (! file) {
-	fprintf (stderr, "Error opening %s: %s\n", filename, strerror (errno));
-	ret = NOTMUCH_STATUS_FILE_ERROR;
-	goto DONE;
-    }
-
-    /* Is this mbox? */
-    if (fread (from_buf, sizeof (from_buf), 1, file) == 1 &&
-	strncmp (from_buf, "From ", 5) == 0)
-	is_mbox = true;
-    rewind (file);
-
-    /* Evil GMime steals my FILE* here so I won't fclose it. */
-    stream = g_mime_stream_file_new (file);
-
-    parser = g_mime_parser_new_with_stream (stream);
-    g_mime_parser_set_scan_from (parser, is_mbox);
 
-    mime_message = g_mime_parser_construct_message (parser);
-
-    if (is_mbox) {
-	if (!g_mime_parser_eos (parser)) {
-	    /* This is a multi-message mbox. */
-	    ret = NOTMUCH_STATUS_FILE_NOT_EMAIL;
-	    goto DONE;
-	}
-    }
+    mime_message = notmuch_message_file_get_mime_message (message_file);
+    if (! mime_message)
+	return NOTMUCH_STATUS_FILE_NOT_EMAIL; /* more like internal error */
 
     from = g_mime_message_get_sender (mime_message);
 
@@ -491,15 +454,5 @@ _notmuch_message_index_file (notmuch_message_t *message,
 
     _index_mime_part (message, g_mime_message_get_mime_part (mime_message));
 
-  DONE:
-    if (mime_message)
-	g_object_unref (mime_message);
-
-    if (parser)
-	g_object_unref (parser);
-
-    if (stream)
-	g_object_unref (stream);
-
-    return ret;
+    return NOTMUCH_STATUS_SUCCESS;
 }
diff --git a/lib/message-file.c b/lib/message-file.c
index 33f6468..99e1dc8 100644
--- a/lib/message-file.c
+++ b/lib/message-file.c
@@ -250,6 +250,15 @@ mboxes is deprecated and may be removed in the future.\n", message->filename);
     return NOTMUCH_STATUS_SUCCESS;
 }
 
+GMimeMessage *
+notmuch_message_file_get_mime_message (notmuch_message_file_t *message)
+{
+    if (! message->parsed)
+	return NULL;
+
+    return message->message;
+}
+
 /* return NULL on errors, empty string for non-existing headers */
 const char *
 notmuch_message_file_get_header (notmuch_message_file_t *message,
diff --git a/lib/notmuch-private.h b/lib/notmuch-private.h
index 7277df1..7559521 100644
--- a/lib/notmuch-private.h
+++ b/lib/notmuch-private.h
@@ -46,6 +46,8 @@ NOTMUCH_BEGIN_DECLS
 
 #include <talloc.h>
 
+#include <gmime/gmime.h>
+
 #include "xutil.h"
 #include "error_util.h"
 
@@ -320,9 +322,11 @@ notmuch_message_get_author (notmuch_message_t *message);
 
 /* index.cc */
 
+typedef struct _notmuch_message_file notmuch_message_file_t;
+
 notmuch_status_t
 _notmuch_message_index_file (notmuch_message_t *message,
-			     const char *filename);
+			     notmuch_message_file_t *message_file);
 
 /* message-file.c */
 
@@ -330,7 +334,6 @@ _notmuch_message_index_file (notmuch_message_t *message,
  * into the public interface in notmuch.h
  */
 
-typedef struct _notmuch_message_file notmuch_message_file_t;
 
 /* Open a file containing a single email message.
  *
@@ -377,6 +380,15 @@ void
 notmuch_message_file_restrict_headersv (notmuch_message_file_t *message,
 					va_list va_headers);
 
+/* Get the gmime message of a parsed message file.
+ *
+ * Returns NULL if the message file has not been parsed.
+ *
+ * XXX: Would be nice to not have to expose GMimeMessage here.
+ */
+GMimeMessage *
+notmuch_message_file_get_mime_message (notmuch_message_file_t *message);
+
 /* Get the value of the specified header from the message as a UTF-8 string.
  *
  * The header name is case insensitive.
-- 
1.8.5.2