New code to keep an on-disk cache of what UIDs have been seen in a folder.

	* camel-uid-cache.c: New code to keep an on-disk cache of what
	UIDs have been seen in a folder.

	* camel-provider.h: Add new flags CAMEL_PROVIDER_IS_SOURCE (mail
	can arrive in it by non-Camel means) and CAMEL_PROVIDER_IS_STORAGE
	(you can work with mail directly without needing to copy it local).

	* providers/*/camel-*-provider.c: Add flags as needed: imap and
	mbox are SOURCE and STORAGE. mh and nntp are just STORAGE, pop3 is
	just SOURCE.

	* camel-mime-message.c (process_header): Add another subject
	g_strstrip that fejj's earlier commit missed.

svn path=/trunk/; revision=4616

1 files changed, 186 insertions, 0 deletions

diff --git a/camel/camel-uid-cache.c b/camel/camel-uid-cache.c
new file mode 100644
index 0000000000..2b5faddb91
--- /dev/null
+++ b/camel/camel-uid-cache.c
@@ -0,0 +1,186 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+/* camel-uid-cache.c: UID caching code. */
+
+/* 
+ * Authors:
+ *  Dan Winship <danw@helixcode.com>
+ *
+ * Copyright 2000 Helix Code, Inc. (http://www.helixcode.com)
+ *
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA
+ */
+
+#include "config.h"
+#include "camel-uid-cache.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+static void free_uid (gpointer key, gpointer value, gpointer data);
+static void maybe_write_uid (gpointer key, gpointer value, gpointer data);
+
+/**
+ * camel_uid_cache_new:
+ * @filename: path to load the cache from
+ *
+ * Creates a new UID cache, initialized from @filename. If @filename
+ * doesn't already exist, the UID cache will be empty. Otherwise, if
+ * it does exist but can't be read, the function will return %NULL.
+ *
+ * Return value: a new UID cache, or %NULL
+ **/
+CamelUIDCache *
+camel_uid_cache_new (const char *filename)
+{
+	CamelUIDCache *cache;
+	struct stat st;
+	char *buf, **uids;
+	int fd, i;
+
+	fd = open (filename, O_RDWR | O_CREAT, 0700);
+	if (fd == -1)
+		return NULL;
+
+	if (fstat (fd, &st) != 0) {
+		close (fd);
+		return NULL;
+	}
+	buf = g_malloc (st.st_size + 1);
+
+	if (read (fd, buf, st.st_size) == -1) {
+		close (fd);
+		g_free (buf);
+		return NULL;
+	}
+	buf[st.st_size] = '\0';
+
+	cache = g_new (CamelUIDCache, 1);
+	cache->fd = fd;
+	cache->level = 1;
+	cache->uids = g_hash_table_new (g_str_hash, g_str_equal);
+
+	uids = g_strsplit (buf, "\n", 0);
+	g_free (buf);
+	for (i = 0; uids[i]; i++) {
+		g_hash_table_insert (cache->uids, uids[i],
+				     GINT_TO_POINTER (cache->level));
+	}
+	g_free (uids);
+
+	return cache;
+}
+
+/**
+ * camel_uid_cache_save:
+ * @cache: a CamelUIDCache
+ *
+ * Attempts to save @cache back to disk.
+ *
+ * Return value: success or failure
+ **/
+gboolean
+camel_uid_cache_save (CamelUIDCache *cache)
+{
+	if (lseek (cache->fd, 0, SEEK_SET) != 0)
+		return FALSE;
+	g_hash_table_foreach (cache->uids, maybe_write_uid, cache);
+	return ftruncate (cache->fd, lseek (cache->fd, 0, SEEK_CUR)) == 0;
+}
+
+static void
+maybe_write_uid (gpointer key, gpointer value, gpointer data)
+{
+	CamelUIDCache *cache = data;
+
+	if (GPOINTER_TO_INT (value) == cache->level) {
+		write (cache->fd, key, strlen (key));
+		write (cache->fd, "\n", 1);
+	}
+}
+
+/**
+ * camel_uid_cache_destroy:
+ * @cache: a CamelUIDCache
+ *
+ * Destroys @cache and frees its data.
+ **/
+void
+camel_uid_cache_destroy (CamelUIDCache *cache)
+{
+	g_hash_table_foreach (cache->uids, free_uid, NULL);
+	g_hash_table_destroy (cache->uids);
+	close (cache->fd);
+	g_free (cache);
+}
+
+static void
+free_uid (gpointer key, gpointer value, gpointer data)
+{
+	g_free (key);
+}
+
+/**
+ * camel_uid_cache_get_new_uids:
+ * @cache: a CamelUIDCache
+ * @uids: an array of UIDs
+ *
+ * Returns an array of UIDs from @uids that are not in @cache, and
+ * removes UIDs from @cache that aren't in @uids.
+ *
+ * Return value: an array of new UIDs, which must be freed with
+ * camel_uid_cache_free_uids().
+ **/
+GPtrArray *
+camel_uid_cache_get_new_uids (CamelUIDCache *cache, GPtrArray *uids)
+{
+	GPtrArray *new_uids;
+	char *uid;
+	int i;
+
+	new_uids = g_ptr_array_new ();
+	cache->level++;
+
+	for (i = 0; i < uids->len; i++) {
+		uid = uids->pdata[i];
+		if (g_hash_table_lookup (cache->uids, uid))
+			g_hash_table_remove (cache->uids, uid);
+		else
+			g_ptr_array_add (new_uids, g_strdup (uid));
+		g_hash_table_insert (cache->uids, g_strdup (uid),
+				     GINT_TO_POINTER (cache->level));
+	}
+
+	return new_uids;
+}
+
+/**
+ * camel_uid_cache_free_uids:
+ * @uids: an array returned from camel_uid_cache_get_new_uids()
+ *
+ * Frees the array of UIDs.
+ **/
+void
+camel_uid_cache_free_uids (GPtrArray *uids)
+{
+	int i;
+
+	for (i = 0; i < uids->len; i++)
+		g_free (uids->pdata[i]);
+	g_ptr_array_free (uids, TRUE);
+}