Rename private notmuch_message_t to notmuch_message_file_t

This is in preparation for a new, public notmuch_message_t.

Eventually, the public notmuch_message_t is going to grow enough
features to need to be file-backed and will likely need everything
that's now in message-file.c. So we may fold these back into one
object/implementation in the future.

1 files changed, 302 insertions, 0 deletions

diff --git a/message-file.c b/message-file.c
new file mode 100644
index 00000000..4f4f551b
--- /dev/null
+++ b/message-file.c
@@ -0,0 +1,302 @@
+/* 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> /* GHashTable */
+
+typedef struct {
+    char *str;
+    size_t size;
+    size_t len;
+} header_value_closure_t;
+
+struct _notmuch_message_file {
+    /* File object */
+    FILE *file;
+
+    /* Header storage */
+    int restrict_headers;
+    GHashTable *headers;
+    int broken_headers;
+    int good_headers;
+
+    /* Parsing state */
+    char *line;
+    size_t line_size;
+    header_value_closure_t value;
+
+    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_file_t *
+notmuch_message_file_open (const char *filename)
+{
+    notmuch_message_file_t *message;
+
+    message = xcalloc (1, sizeof (notmuch_message_file_t));
+
+    message->file = fopen (filename, "r");
+    if (message->file == NULL)
+	goto FAIL;
+
+    message->headers = g_hash_table_new_full (strcase_hash,
+					      strcase_equal,
+					      free,
+					      free);
+
+    message->parsing_started = 0;
+    message->parsing_finished = 0;
+
+    return message;
+
+  FAIL:
+    fprintf (stderr, "Error opening %s: %s\n", filename, strerror (errno));
+    notmuch_message_file_close (message);
+
+    return NULL;
+}
+
+void
+notmuch_message_file_close (notmuch_message_file_t *message)
+{
+    if (message == NULL)
+	return;
+
+    if (message->line)
+	free (message->line);
+
+    if (message->value.size)
+	free (message->value.str);
+
+    if (message->headers)
+	g_hash_table_destroy (message->headers);
+
+    if (message->file)
+	fclose (message->file);
+
+    free (message);
+}
+
+void
+notmuch_message_file_restrict_headersv (notmuch_message_file_t *message,
+					va_list va_headers)
+{
+    char *header;
+
+    if (message->parsing_started ) {
+	fprintf (stderr, "Error: notmuch_message_file_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_file_restrict_headers (notmuch_message_file_t *message, ...)
+{
+    va_list va_headers;
+
+    va_start (va_headers, message);
+
+    notmuch_message_file_restrict_headersv (message, va_headers);
+}
+
+void
+copy_header_unfolding (header_value_closure_t *value,
+		       const char *chunk)
+{
+    char *last;
+
+    if (chunk == NULL)
+	return;
+
+    while (*chunk == ' ' || *chunk == '\t')
+	chunk++;
+
+    if (value->len + 1 + strlen (chunk) + 1 > value->size) {
+	int new_size = value->size;
+	if (value->size == 0)
+	    new_size = strlen (chunk) + 1;
+	else
+	    while (value->len + 1 + strlen (chunk) + 1 > new_size)
+		new_size *= 2;
+	value->str = xrealloc (value->str, new_size);
+	value->size = new_size;
+    }
+
+    last = value->str + value->len;
+    if (value->len) {
+	*last = ' ';
+	last++;
+	value->len++;
+    }
+
+    strcpy (last, chunk);
+    value->len += strlen (chunk);
+
+    last = value->str + value->len - 1;
+    if (*last == '\n') {
+	*last = '\0';
+	value->len--;
+    }
+}
+
+const char *
+notmuch_message_file_get_header (notmuch_message_file_t *message,
+				 const char *header_desired)
+{
+    int contains;
+    char *header, *value;
+    const char *s, *colon;
+    int match;
+
+    message->parsing_started = 1;
+
+    contains = g_hash_table_lookup_extended (message->headers,
+					     header_desired, NULL,
+					     (gpointer *) &value);
+    if (contains && value)
+	return value;
+
+    if (message->parsing_finished)
+	return NULL;
+
+#define NEXT_HEADER_LINE(closure)				\
+    do {							\
+	ssize_t bytes_read = getline (&message->line,		\
+				      &message->line_size,	\
+				      message->file);		\
+	if (bytes_read == -1) {					\
+	    message->parsing_finished = 1;			\
+	    break;						\
+	}							\
+	if (*message->line == '\n') {				\
+	    message->parsing_finished = 1;			\
+	    break;						\
+	}							\
+	if (closure &&						\
+	    (*message->line == ' ' || *message->line == '\t'))	\
+	{							\
+	    copy_header_unfolding ((closure), message->line);	\
+	}							\
+    } while (*message->line == ' ' || *message->line == '\t');
+
+    if (message->line == NULL)
+	NEXT_HEADER_LINE (NULL);
+
+    while (1) {
+
+	if (message->parsing_finished)
+	    break;
+
+	colon = strchr (message->line, ':');
+
+	if (colon == NULL) {
+	    message->broken_headers++;
+	    /* A simple heuristic for giving up on things that just
+	     * don't look like mail messages. */
+	    if (message->broken_headers >= 10 &&
+		message->good_headers < 5)
+	    {
+		message->parsing_finished = 1;
+		continue;
+	    }
+	    NEXT_HEADER_LINE (NULL);
+	    continue;
+	}
+
+	message->good_headers++;
+
+	header = xstrndup (message->line, colon - message->line);
+
+	if (message->restrict_headers &&
+	    ! g_hash_table_lookup_extended (message->headers,
+					    header, NULL, NULL))
+	{
+	    free (header);
+	    NEXT_HEADER_LINE (NULL);
+	    continue;
+	}
+
+	s = colon + 1;
+	while (*s == ' ' || *s == '\t')
+	    s++;
+
+	message->value.len = 0;
+	copy_header_unfolding (&message->value, s);
+
+	NEXT_HEADER_LINE (&message->value);
+
+	match = (strcasecmp (header, header_desired) == 0);
+
+	value = xstrdup (message->value.str);
+
+	g_hash_table_insert (message->headers, header, value);
+
+	if (match)
+	    return value;
+    }
+
+    if (message->line)
+	free (message->line);
+    message->line = NULL;
+
+    if (message->value.size) {
+	free (message->value.str);
+	message->value.str = NULL;
+	message->value.size = 0;
+	message->value.len = 0;
+    }
+
+    return NULL;
+}