notmuch: Switch from gmime to custom, ad-hoc parsing of headers.

Since we're currently just trying to stitch together In-Reply-To
and References headers we don't need that much sophistication.
It's when we later add full-text searching that GMime will be
useful.

So for now, even though my own code here is surely very buggy
compared to GMime it's also a lot faster. And speed is what
we're after for the initial index creation.

5 files changed, 534 insertions, 55 deletions

diff --git a/Makefile b/Makefile
index 4af5a2e..b7ebfb8 100644
--- a/Makefile
+++ b/Makefile
@@ -1,9 +1,9 @@
 PROGS=notmuch notmuch-index-message xapian-dump
 
-MYCFLAGS=-Wall -O0 -g `pkg-config --cflags gmime-2.4`
+MYCFLAGS=-Wall -O0 -g `pkg-config --cflags glib-2.0`
 MYCXXFLAGS=$(MYCFLAGS) `xapian-config --cxxflags`
 
-MYLDFLAGS=`pkg-config --libs gmime-2.4` `xapian-config --libs`
+MYLDFLAGS=`pkg-config --libs glib-2.0` `xapian-config --libs`
 
 all: $(PROGS)
 
@@ -13,7 +13,7 @@ all: $(PROGS)
 %.o: %.c
 	$(CC) -c $(CFLAGS) $(MYCFLAGS) $^ -o $@
 
-notmuch: notmuch.o database.o xutil.o
+notmuch: notmuch.o database.o message.o xutil.o
 	$(CC) $(MYLDFLAGS) $^ -o $@
 
 notmuch-index-message: notmuch-index-message.cc
diff --git a/database.cc b/database.cc
index 36b1b58..7ea1f41 100644
--- a/database.cc
+++ b/database.cc
@@ -20,20 +20,12 @@
 
 #include "notmuch-private.h"
 
-#include <stdio.h>
-#include <errno.h>
-#include <time.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/time.h>
-
 #include <iostream>
 
-#include <gmime/gmime.h>
-
 #include <xapian.h>
 
+#include <glib.h>
+
 using namespace std;
 
 struct _notmuch_database {
@@ -278,26 +270,113 @@ find_thread_ids (Xapian::Database *db,
     return result;
 }
 
-/* Add a term for each message-id in the References header of the
- * message. */
+/* Advance 'str' past any whitespace or RFC 822 comments. A comment is
+ * a (potentially nested) parenthesized sequence with '\' used to
+ * escape any character (including parentheses).
+ *
+ * If the sequence to be skipped continues to the end of the string,
+ * then 'str' will be left pointing at the final terminating '\0'
+ * character.
+ */
+static void
+skip_space_and_comments (const char **str)
+{
+    const char *s;
+
+    s = *str;
+    while (*s && (isspace (*s) || *s == '(')) {
+	while (*s && isspace (*s))
+	    s++;
+	if (*s == '(') {
+	    int nesting = 1;
+	    s++;
+	    while (*s && nesting) {
+		if (*s == '(')
+		    nesting++;
+		else if (*s == ')')
+		    nesting--;
+		else if (*s == '\\')
+		    if (*(s+1))
+			s++;
+		s++;
+	    }
+	}
+    }
+
+    *str = s;
+}
+
+/* Parse an RFC 822 message-id, discarding whitespace, any RFC 822
+ * comments, and the '<' and '>' delimeters.
+ *
+ * If not NULL, then *next will be made to point to the first character
+ * not parsed, (possibly pointing to the final '\0' terminator.
+ *
+ * Returns a newly allocated string which the caller should free()
+ * when done with it.
+ *
+ * Returns NULL if there is any error parsing the message-id. */
+static char *
+parse_message_id (const char *message_id, const char **next)
+{
+    const char *s, *end;
+
+    if (message_id == NULL)
+	return NULL;
+
+    s = message_id;
+
+    skip_space_and_comments (&s);
+
+    /* Skip any unstructured text as well. */
+    while (*s && *s != '<')
+	s++;
+
+    if (*s == '<') {
+	s++;
+    } else {
+	if (next)
+	    *next = s;
+	return NULL;
+    }
+
+    skip_space_and_comments (&s);
+
+    end = s;
+    while (*end && *end != '>')
+	end++;
+    if (next) {
+	if (*end)
+	    *next = end + 1;
+	else
+	    *next = end;
+    }
+
+    if (end > s && *end == '>')
+	end--;
+    if (end > s)
+	return strndup (s, end - s + 1);
+    else
+	return NULL;
+}
+
+/* Parse a References header value, putting a copy of each referenced
+ * message-id into 'array'. */
 static void
 parse_references (GPtrArray *array,
-		  const char *refs_str)
+		  const char *refs)
 {
-    GMimeReferences *refs, *r;
-    const char *message_id;
+    char *ref;
 
-    if (refs_str == NULL)
+    if (refs == NULL)
 	return;
 
-    refs = g_mime_references_decode (refs_str);
+    while (*refs) {
+	ref = parse_message_id (refs, &refs);
 
-    for (r = refs; r; r = r->next) {
-	message_id = g_mime_references_get_message_id (r);
-	g_ptr_array_add (array, g_strdup (message_id));
+	if (ref)
+	    g_ptr_array_add (array, ref);
     }
-
-    g_mime_references_free (refs);
 }
 
 notmuch_database_t *
@@ -344,8 +423,6 @@ notmuch_database_open (const char *path)
     struct stat st;
     int err;
 
-    g_mime_init (0);
-
     notmuch_path = g_strdup_printf ("%s/%s", path, ".notmuch");
 
     err = stat (notmuch_path, &st);
@@ -397,31 +474,17 @@ notmuch_database_add_message (notmuch_database_t *notmuch,
 {
     Xapian::WritableDatabase *db = notmuch->xapian_db;
     Xapian::Document doc;
+    notmuch_message_t *message;
 
-    GMimeStream *stream;
-    GMimeParser *parser;
-    GMimeMessage *message;
     GPtrArray *parents, *thread_ids;
 
-    FILE *file;
-
-    const char *refs, *in_reply_to;
-    const char *message_id;
+    const char *refs, *in_reply_to, *date, *header;
+    char *message_id;
 
-    time_t time;
+    time_t time_value;
     unsigned int i;
 
-    file = fopen (filename, "r");
-    if (! file) {
-	fprintf (stderr, "Error opening %s: %s\n", filename, strerror (errno));
-	exit (1);
-    }
-
-    stream = g_mime_stream_file_new (file);
-
-    parser = g_mime_parser_new_with_stream (stream);
-
-    message = g_mime_parser_construct_message (parser);
+    message = notmuch_message_open (filename);
 
     try {
 	doc = Xapian::Document ();
@@ -430,16 +493,27 @@ notmuch_database_add_message (notmuch_database_t *notmuch,
 
 	parents = g_ptr_array_new ();
 
-	refs = g_mime_object_get_header (GMIME_OBJECT (message), "references");
+	refs = notmuch_message_get_header (message, "references");
 	parse_references (parents, refs);
 
-	in_reply_to = g_mime_object_get_header (GMIME_OBJECT (message),
-						"in-reply-to");
+	in_reply_to = notmuch_message_get_header (message, "in-reply-to");
 	parse_references (parents, in_reply_to);
+
 	for (i = 0; i < parents->len; i++)
 	    add_term (doc, "ref", (char *) g_ptr_array_index (parents, i));
 
-	message_id = g_mime_message_get_message_id (message);
+	header = notmuch_message_get_header (message, "message-id");
+	if (header) {
+	    message_id = parse_message_id (header, NULL);
+	    /* So the header value isn't RFC-compliant, but it's
+	     * better than no message-id at all. */
+	    if (message_id == NULL)
+		message_id = xstrdup (header);
+	} else {
+	    /* XXX: Should generate a message_id here, (such as a SHA1
+	     * sum of the message itself) */
+	    message_id = NULL;
+	}
 
 	thread_ids = find_thread_ids (db, parents, message_id);
 
@@ -478,8 +552,15 @@ notmuch_database_add_message (notmuch_database_t *notmuch,
 	    doc.add_value (NOTMUCH_VALUE_THREAD, thread_id.str);
 	}
 
-	g_mime_message_get_date (message, &time, NULL);
-	doc.add_value (NOTMUCH_VALUE_DATE, Xapian::sortable_serialise (time));
+	free (message_id);
+
+/*
+	date = notmuch_message_get_header (message, "date");
+	time_value = notmuch_parse_date (date, NULL);
+
+	doc.add_value (NOTMUCH_VALUE_DATE,
+		       Xapian::sortable_serialise (time_value));
+*/
 
 	db->add_document (doc);
     } catch (const Xapian::Error &error) {
@@ -488,9 +569,7 @@ notmuch_database_add_message (notmuch_database_t *notmuch,
 	return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
     }
 
-    g_object_unref (message);
-    g_object_unref (parser);
-    g_object_unref (stream);
+    notmuch_message_close (message);
 
     return NOTMUCH_STATUS_SUCCESS;
 }
diff --git a/message.c b/message.c
new file mode 100644
index 0000000..ea5d239
--- /dev/null
+++ b/message.c
@@ -0,0 +1,300 @@
+/* message.c - Utility functions for parsing an email message for notmuch.
+ *
+ * Copyright © 2009 Carl Worth
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/ .
+ *
+ * Author: Carl Worth <cworth@cworth.org>
+ */
+
+#include <stdarg.h>
+
+#include "notmuch-private.h"
+
+#include <glib.h>
+
+struct _notmuch_message {
+    /* File objects */
+    int fd;
+    void *map;
+
+    /* Header storage */
+    int restrict_headers;
+    GHashTable *headers;
+
+    /* Parsing state */
+    char *start;
+    size_t size;
+    const char *next_line;
+    int parsing_started;
+    int parsing_finished;
+};
+
+static int
+strcase_equal (const void *a, const void *b)
+{
+    return strcasecmp (a, b) == 0;
+}
+
+static unsigned int
+strcase_hash (const void *ptr)
+{
+    const char *s = ptr;
+
+    /* This is the djb2 hash. */
+    unsigned int hash = 5381;
+    while (s && *s) {
+	hash = ((hash << 5) + hash) + tolower (*s);
+	s++;
+    }
+
+    return hash;
+}
+
+notmuch_message_t *
+notmuch_message_open (const char *filename)
+{
+    notmuch_message_t *message;
+    struct stat st;
+
+    message = xcalloc (1, sizeof (notmuch_message_t));
+
+    message->fd = open (filename, O_RDONLY);
+    if (message->fd < 0)
+	goto FAIL;
+
+    if (fstat (message->fd, &st) < 0)
+	goto FAIL;
+
+    message->map = mmap (NULL, st.st_size, PROT_READ, MAP_PRIVATE,
+			message->fd, 0);
+    if (message->map == MAP_FAILED)
+	goto FAIL;
+
+    message->headers = g_hash_table_new_full (strcase_hash,
+					      strcase_equal,
+					      free,
+					      free);
+
+    message->start = (char *) message->map;
+    message->size = st.st_size;
+    message->next_line = message->start;
+    message->parsing_started = 0;
+    message->parsing_finished = 0;
+
+    return message;
+
+  FAIL:
+    fprintf (stderr, "Error opening %s: %s\n", filename, strerror (errno));
+    notmuch_message_close (message);
+
+    return NULL;
+}
+
+void
+notmuch_message_close (notmuch_message_t *message)
+{
+    if (message == NULL)
+	return;
+
+    if (message->headers)
+	g_hash_table_unref (message->headers);
+
+    if (message->map)
+	munmap (message->map, message->size);
+    if (message->fd)
+	close (message->fd);
+
+    free (message);
+}
+
+void
+notmuch_message_restrict_headersv (notmuch_message_t *message,
+				   va_list va_headers)
+{
+    char *header;
+
+    if (message->parsing_started ) {
+	fprintf (stderr, "Error: notmuch_message_restrict_headers called after parsing has started\n");
+	exit (1);
+    }
+
+    while (1) {
+	header = va_arg (va_headers, char*);
+	if (header == NULL)
+	    break;
+	g_hash_table_insert (message->headers,
+			     xstrdup (header), NULL);
+    }
+
+    message->restrict_headers = 1;
+}
+
+void
+notmuch_message_restrict_headers (notmuch_message_t *message, ...)
+{
+    va_list va_headers;
+
+    va_start (va_headers, message);
+
+    notmuch_message_restrict_headersv (message, va_headers);
+}
+
+/* With our mmapped file, we don't get the benefit of terminated
+ * strings, so we can't use things like strchr(). We don't even know
+ * if there's a newline at the end of the file so we also have to be
+ * careful of that. Basically, every time we advance a pointer while
+ * parsing we must ensure we don't go beyond our buffer.
+ */
+#define WITHIN(s) (((s) - message->start) < (message->size -1))
+
+/* In each of the macros below, "without overrunning the buffer" means
+ * that the macro will never dereference a character beyond the end of
+ * the buffer. However, all of the macros may return a pointer
+ * pointing to the first character beyond the buffer. So callers
+ * should test with WITHIN before dereferencing the result. */
+
+/* Advance 'ptr' until pointing at a non-space character in the same
+ * line, (without overrunning the buffer) */
+#define SKIP_SPACE_IN_LINE(ptr)				      \
+    while (WITHIN (ptr) && (*(ptr) == ' ' || *(ptr) == '\t')) \
+	(ptr)++;
+
+/* Advance 'ptr' until pointing at a non-space character, (without
+ * overrunning the buffer) */
+#define SKIP_SPACE(ptr)				\
+    while (WITHIN (ptr) && isspace(*(ptr)))	\
+	(ptr)++;
+
+/* Advance 'ptr' to the first occurrence of 'c' within the same
+ * line, (without overrunning the buffer). */
+#define ADVANCE_TO(ptr, c)			\
+    while (WITHIN (ptr) && *(ptr) != '\n' &&    \
+	   *(ptr) != (c))			\
+    {						\
+	(ptr)++;				\
+    }
+
+/* Advance 'ptr' to the beginning of the next line not starting with
+ * an initial tab character, (without overruning the buffer). */
+#define ADVANCE_TO_NEXT_HEADER_LINE(ptr)	\
+    do {					\
+	ADVANCE_TO ((ptr), '\n');		\
+	if (WITHIN (ptr))			\
+	    (ptr)++;				\
+    } while (WITHIN (ptr) &&			\
+	     (*(ptr) == '\t' || *(ptr) == ' '));
+        
+char *
+copy_header_value (const char *start, const char *end)
+{
+    const char *s;
+    char *result, *r;
+    int was_newline = 0;
+
+    result = xmalloc (end - start + 1);
+
+    s = start;
+    r = result;
+
+    while (s < end) {
+	if (*s == '\n') {
+	    was_newline = 1;
+	} else {
+	    if (*s == '\t' && was_newline)
+		*r = ' ';
+	    else
+		*r = *s;
+	    r++;
+	    was_newline = 0;
+	}
+	s++;
+    }
+
+    *r = '\0';
+
+    return result;
+}
+
+const char *
+notmuch_message_get_header (notmuch_message_t *message,
+			    const char *header_desired)
+{
+    int contains;
+    const char *s, *colon;
+    char *header, *value;
+    int match;
+
+    message->parsing_started = 1;
+
+    contains = g_hash_table_lookup_extended (message->headers,
+					     header_desired, NULL,
+					     (gpointer *) &value);
+    if (contains)
+	return value;
+
+    if (message->parsing_finished)
+	return NULL;
+
+    while (1) {
+	s = message->next_line;
+
+	if (*s == '\n') {
+	    message->parsing_finished = 1;
+	    return NULL;
+	}
+
+	if (*s == '\t') {
+	    fprintf (stderr, "Warning: Unexpected continued value\n");
+	    ADVANCE_TO_NEXT_HEADER_LINE (message->next_line);
+	    continue;
+	}
+
+	colon = s;
+	ADVANCE_TO (colon, ':');
+
+	if (! WITHIN (colon) || *colon == '\n') {
+	    fprintf (stderr, "Warning: Unexpected non-header line: %s\n", s);
+	    ADVANCE_TO_NEXT_HEADER_LINE (message->next_line);
+	    continue;
+	}
+
+	header = xstrndup (s, colon - s);
+
+	if (message->restrict_headers &&
+	    ! g_hash_table_lookup_extended (message->headers,
+					    header, NULL, NULL))
+	{
+	    free (header);
+	    message->next_line = colon;
+	    ADVANCE_TO_NEXT_HEADER_LINE (message->next_line);
+	    continue;
+	}
+
+	s = colon + 1;
+	SKIP_SPACE_IN_LINE (s);
+
+	message->next_line = s;
+	ADVANCE_TO_NEXT_HEADER_LINE (message->next_line);
+
+	value = copy_header_value (s, message->next_line);
+
+	match = (strcasecmp (header, header_desired) == 0);
+
+	g_hash_table_insert (message->headers, header, value);
+
+	if (match)
+	    return value;
+    }
+}
diff --git a/message.h b/message.h
new file mode 100644
index 0000000..d0a34a1
--- /dev/null
+++ b/message.h
@@ -0,0 +1,19 @@
+/* message.h - Utility functions for parsing an email message for notmuch.
+ *
+ * Copyright © 2009 Carl Worth
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/ .
+ *
+ * Author: Carl Worth <cworth@cworth.org>
+ */
diff --git a/notmuch-private.h b/notmuch-private.h
index 15d6db4..b7d27e9 100644
--- a/notmuch-private.h
+++ b/notmuch-private.h
@@ -23,8 +23,17 @@
 
 #include "notmuch.h"
 
+#include <stdio.h>
 #include <stdlib.h>
+#include <stdarg.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
 #include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <ctype.h>
 
 NOTMUCH_BEGIN_DECLS
 
@@ -44,6 +53,78 @@ xstrdup (const char *s);
 char *
 xstrndup (const char *s, size_t n);
 
+/* message.c */
+
+/* XXX: I haven't decided yet whether these will actually get exported
+ * into the public interface in notmuch.h
+ */
+
+typedef struct _notmuch_message notmuch_message_t;
+
+/* Open a file containing a single email message.
+ *
+ * The caller should call notmuch_message_close when done with this.
+ *
+ * Returns NULL if any error occurs.
+ */
+notmuch_message_t *
+notmuch_message_open (const char *filename);
+
+/* Close a notmuch message preivously opened with notmuch_message_open. */
+void
+notmuch_message_close (notmuch_message_t *message);
+
+/* Restrict 'message' to only save the named headers.
+ *
+ * When the caller is only interested in a short list of headers,
+ * known in advance, calling this function can avoid wasted time and
+ * memory parsing/saving header values that will never be needed.
+ *
+ * The variable arguments should be a list of const char * with a
+ * final '(const char *) NULL' to terminate the list.
+ *
+ * If this function is called, it must be called before any calls to
+ * notmuch_message_get_header for this message.
+ *
+ * After calling this function, if notmuch_message_get_header is
+ * called with a header name not in this list, then NULL will be
+ * returned even if that header exists in the actual message.
+ */
+void
+notmuch_message_restrict_headers (notmuch_message_t *message, ...);
+
+/* Identical to notmuch_message_restrict_headers but accepting a va_list. */
+void
+notmuch_message_restrict_headersv (notmuch_message_t *message,
+				   va_list va_headers);
+
+/* Get the value of the specified header from the message.
+ *
+ * The header name is case insensitive.
+ *
+ * The returned value is owned by the notmuch message and is valid
+ * only until the message is closed. The caller should copy it if
+ * needing to modify the value or to hold onto it for longer.
+ *
+ * Returns NULL if the message does not contain a header line matching
+ * 'header'.
+ */
+const char *
+notmuch_message_get_header (notmuch_message_t *message,
+			    const char *header);
+
+/* date.c */
+
+/* Parse an RFC 8222 date string to a time_t value.
+ *
+ * The tz_offset argument can be used to also obtain the time-zone
+ * offset, (but can be NULL if the call is not interested in that).
+ *
+ * Returns 0 on error.
+ */
+time_t
+notmuch_parse_date (const char *str, int *tz_offset);
+
 NOTMUCH_END_DECLS
 
 #endif