path: root/camel/providers/imap/camel-imap-message-cache.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-imap-message-cache.c: Class for an IMAP message cache */

/* 
 * Author: 
 *   Dan Winship <danw@ximian.com>
 *
 * Copyright (C) 2001 Ximian, Inc. (www.ximian.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
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <string.h>

#include "camel-imap-message-cache.h"
#include "camel-data-wrapper.h"
#include "camel-exception.h"
#include "camel-stream-fs.h"

static void finalize (CamelImapMessageCache *cache);
static void stream_finalize (CamelObject *stream, gpointer event_data, gpointer user_data);


CamelType
camel_imap_message_cache_get_type (void)
{
    static CamelType camel_imap_message_cache_type = CAMEL_INVALID_TYPE;
    
    if (camel_imap_message_cache_type == CAMEL_INVALID_TYPE) {
        camel_imap_message_cache_type = camel_type_register (
            CAMEL_OBJECT_TYPE, "CamelImapMessageCache",
            sizeof (CamelImapMessageCache),
            sizeof (CamelImapMessageCacheClass),
            NULL,
            NULL,
            NULL,
            (CamelObjectFinalizeFunc) finalize);
    }

    return camel_imap_message_cache_type;
}

static void
free_part (gpointer key, gpointer value, gpointer data)
{
    if (value) {
        if (strchr (key, '.')) {
            camel_object_unhook_event (value, "finalize",
                           stream_finalize, data);
            camel_object_unref (value);
        } else
            g_ptr_array_free (value, TRUE);
    }
    g_free (key);
}

static void
finalize (CamelImapMessageCache *cache)
{
    if (cache->path)
        g_free (cache->path);
    if (cache->parts) {
        g_hash_table_foreach (cache->parts, free_part, cache);
        g_hash_table_destroy (cache->parts);
    }
    if (cache->cached)
        g_hash_table_destroy (cache->cached);
}

static void
cache_put (CamelImapMessageCache *cache, const char *uid, const char *key,
       CamelStream *stream)
{
    char *hash_key;
    GPtrArray *subparts;
    gpointer okey, ostream;
    guint32 uidval;

    uidval = strtoul (uid, NULL, 10);
    if (uidval > cache->max_uid)
        cache->max_uid = uidval;

    subparts = g_hash_table_lookup (cache->parts, uid);
    if (!subparts) {
        subparts = g_ptr_array_new ();
        g_hash_table_insert (cache->parts, g_strdup (uid), subparts);
    }

    if (g_hash_table_lookup_extended (cache->parts, key, &okey, &ostream)) {
        if (ostream) {
            camel_object_unhook_event (ostream, "finalize",
                           stream_finalize, cache);
            g_hash_table_remove (cache->cached, ostream);
            camel_object_unref (ostream);
        }
        hash_key = okey;
    } else {
        hash_key = g_strdup (key);
        g_ptr_array_add (subparts, hash_key);
    }

    g_hash_table_insert (cache->parts, hash_key, stream);
    g_hash_table_insert (cache->cached, stream, hash_key);

    if (stream) {
        camel_object_hook_event (CAMEL_OBJECT (stream), "finalize",
                     stream_finalize, cache);
    }
}

/**
 * camel_imap_message_cache_new:
 * @path: directory to use for storage
 * @summary: CamelFolderSummary for the folder we are caching
 * @ex: a CamelException
 *
 * Return value: a new CamelImapMessageCache object using @path for
 * storage. If cache files already exist in @path, then any that do not
 * correspond to messages in @summary will be deleted.
 **/
CamelImapMessageCache *
camel_imap_message_cache_new (const char *path, CamelFolderSummary *summary,
                  CamelException *ex)
{
    CamelImapMessageCache *cache;
    DIR *dir;
    struct dirent *d;
    char *uid, *p;
    GPtrArray *deletes;
    CamelMessageInfo *info;

    dir = opendir (path);
    if (!dir) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Could not open cache directory: %s"),
                      g_strerror (errno));
        return NULL;
    }

    cache = (CamelImapMessageCache *)camel_object_new (CAMEL_IMAP_MESSAGE_CACHE_TYPE);
    cache->path = g_strdup (path);

    cache->parts = g_hash_table_new (g_str_hash, g_str_equal);
    cache->cached = g_hash_table_new (NULL, NULL);
    deletes = g_ptr_array_new ();
    while ((d = readdir (dir))) {
        if (!isdigit (d->d_name[0]))
            continue;

        p = strchr (d->d_name, '.');
        if (p)
            uid = g_strndup (d->d_name, p - d->d_name);
        else
            uid = g_strdup (d->d_name);

        info = camel_folder_summary_uid (summary, uid);
        if (info) {
            camel_folder_summary_info_free (summary, info);
            cache_put (cache, uid, d->d_name, NULL);
        } else
            g_ptr_array_add (deletes, g_strdup_printf ("%s/%s", cache->path, d->d_name));
        g_free (uid);
    }
    closedir (dir);

    while (deletes->len) {
        unlink (deletes->pdata[0]);
        g_free (deletes->pdata[0]);
        g_ptr_array_remove_index_fast (deletes, 0);
    }
    g_ptr_array_free (deletes, TRUE);

    if (camel_exception_is_set (ex)) {
        camel_object_unref (CAMEL_OBJECT (cache));
        return NULL;
    }

    return cache;
}

/**
 * camel_imap_message_cache_max_uid:
 * @cache: the cache
 *
 * Return value: the largest (real) UID in the cache.
 **/
guint32
camel_imap_message_cache_max_uid (CamelImapMessageCache *cache)
{
    return cache->max_uid;
}

static void
stream_finalize (CamelObject *stream, gpointer event_data, gpointer user_data)
{
    CamelImapMessageCache *cache = user_data;
    char *key;

    key = g_hash_table_lookup (cache->cached, stream);
    if (!key)
        return;
    g_hash_table_remove (cache->cached, stream);
    g_hash_table_insert (cache->parts, key, NULL);
}


static CamelStream *
insert_setup (CamelImapMessageCache *cache, const char *uid, const char *part_spec,
          char **path, char **key, CamelException *ex)
{
    CamelStream *stream;
    int fd;
    
    *path = g_strdup_printf ("%s/%s.%s", cache->path, uid, part_spec);
    *key = strrchr (*path, '/') + 1;
    stream = g_hash_table_lookup (cache->parts, *key);
    if (stream)
        camel_object_unref (CAMEL_OBJECT (stream));
    
    fd = open (*path, O_RDWR | O_CREAT | O_TRUNC, 0600);
    if (fd == -1) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Failed to cache message %s: %s"),
                      uid, g_strerror (errno));
        g_free (*path);
        return NULL;
    }
    
    return camel_stream_fs_new_with_fd (fd);
}

static CamelStream *
insert_abort (char *path, CamelStream *stream)
{
    unlink (path);
    g_free (path);
    camel_object_unref (CAMEL_OBJECT (stream));
    return NULL;
}

static CamelStream *
insert_finish (CamelImapMessageCache *cache, const char *uid, char *path,
           char *key, CamelStream *stream)
{
    camel_stream_flush (stream);
    camel_stream_reset (stream);
    cache_put (cache, uid, key, stream);
    g_free (path);

    return stream;
}

/**
 * camel_imap_message_cache_insert:
 * @cache: the cache
 * @uid: UID of the message data to cache
 * @part_spec: the IMAP part_spec of the data
 * @data: the data
 * @len: length of @data
 *
 * Caches the provided data into @cache.
 *
 * Return value: a CamelStream containing the cached data, which the
 * caller must unref.
 **/
CamelStream *
camel_imap_message_cache_insert (CamelImapMessageCache *cache, const char *uid,
                 const char *part_spec, const char *data,
                 int len, CamelException *ex)
{
    char *path, *key;
    CamelStream *stream;
    
    stream = insert_setup (cache, uid, part_spec, &path, &key, ex);
    if (!stream)
        return NULL;
    
    if (camel_stream_write (stream, data, len) == -1) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Failed to cache message %s: %s"),
                      uid, g_strerror (errno));
        return insert_abort (path, stream);
    }
    
    return insert_finish (cache, uid, path, key, stream);
}

/**
 * camel_imap_message_cache_insert_stream:
 * @cache: the cache
 * @uid: UID of the message data to cache
 * @part_spec: the IMAP part_spec of the data
 * @data_stream: the stream to cache
 *
 * Caches the provided data into @cache.
 **/
void
camel_imap_message_cache_insert_stream (CamelImapMessageCache *cache,
                    const char *uid, const char *part_spec,
                    CamelStream *data_stream, CamelException *ex)
{
    char *path, *key;
    CamelStream *stream;
    
    stream = insert_setup (cache, uid, part_spec, &path, &key, ex);
    if (!stream)
        return;
    
    if (camel_stream_write_to_stream (data_stream, stream) == -1) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Failed to cache message %s: %s"),
                      uid, g_strerror (errno));
        insert_abort (path, stream);
    } else {
        insert_finish (cache, uid, path, key, stream);
        camel_object_unref (CAMEL_OBJECT (stream));
    }
}

/**
 * camel_imap_message_cache_insert_wrapper:
 * @cache: the cache
 * @uid: UID of the message data to cache
 * @part_spec: the IMAP part_spec of the data
 * @wrapper: the wrapper to cache
 *
 * Caches the provided data into @cache.
 **/
void
camel_imap_message_cache_insert_wrapper (CamelImapMessageCache *cache,
                     const char *uid, const char *part_spec,
                     CamelDataWrapper *wrapper, CamelException *ex)
{
    char *path, *key;
    CamelStream *stream;

    stream = insert_setup (cache, uid, part_spec, &path, &key, ex);
    if (!stream)
        return;
    
    if (camel_data_wrapper_write_to_stream (wrapper, stream) == -1) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Failed to cache message %s: %s"),
                      uid, g_strerror (errno));
        insert_abort (path, stream);
    } else {
        insert_finish (cache, uid, path, key, stream);
        camel_object_unref (CAMEL_OBJECT (stream));
    }
}


/**
 * camel_imap_message_cache_get:
 * @cache: the cache
 * @uid: the UID of the data to get
 * @part_spec: the part_spec of the data to get
 *
 * Return value: a CamelStream containing the cached data (which the
 * caller must unref), or %NULL if that data is not cached.
 **/
CamelStream *
camel_imap_message_cache_get (CamelImapMessageCache *cache, const char *uid,
                  const char *part_spec)
{
    CamelStream *stream;
    char *path, *key;

    path = g_strdup_printf ("%s/%s.%s", cache->path, uid, part_spec);
    key = strrchr (path, '/') + 1;
    stream = g_hash_table_lookup (cache->parts, key);
    if (stream) {
        camel_stream_reset (CAMEL_STREAM (stream));
        camel_object_ref (CAMEL_OBJECT (stream));
        return stream;
    }

    stream = camel_stream_fs_new_with_name (path, O_RDONLY, 0);
    if (stream)
        cache_put (cache, uid, key, stream);
    g_free (path);

    return stream;
}

/**
 * camel_imap_message_cache_remove:
 * @cache: the cache
 * @uid: UID of the data to remove
 *
 * Removes all data associated with @uid from @cache.
 **/
void
camel_imap_message_cache_remove (CamelImapMessageCache *cache, const char *uid)
{
    GPtrArray *subparts;
    char *key, *path;
    CamelObject *stream;
    int i;

    subparts = g_hash_table_lookup (cache->parts, uid);
    if (!subparts)
        return;
    for (i = 0; i < subparts->len; i++) {
        key = subparts->pdata[i];
        path = g_strdup_printf ("%s/%s", cache->path, key);
        unlink (path);
        g_free (path);
        stream = g_hash_table_lookup (cache->parts, key);
        if (stream) {
            camel_object_unhook_event (stream, "finalize",
                           stream_finalize, cache);
            camel_object_unref (stream);
            g_hash_table_remove (cache->cached, stream);
        }
        g_hash_table_remove (cache->parts, key);
        g_free (key);
    }
    g_hash_table_remove (cache->parts, uid);
    g_ptr_array_free (subparts, TRUE);
}

static void
add_uids (gpointer key, gpointer value, gpointer data)
{
    if (!strchr (key, '.'))
        g_ptr_array_add (data, key);
}

/**
 * camel_imap_message_cache_clear:
 * @cache: the cache
 *
 * Removes all cached data from @cache.
 **/
void
camel_imap_message_cache_clear (CamelImapMessageCache *cache)
{
    GPtrArray *uids;
    int i;

    uids = g_ptr_array_new ();
    g_hash_table_foreach (cache->parts, add_uids, uids);

    for (i = 0; i < uids->len; i++)
        camel_imap_message_cache_remove (cache, uids->pdata[i]);
    g_ptr_array_free (uids, TRUE);
}


/**
 * camel_imap_message_cache_copy:
 * @source: the source message cache
 * @source_uid: UID of a message in @source
 * @dest: the destination message cache
 * @dest_uid: UID of the message in @dest
 *
 * Copies all cached parts from @source_uid in @source to @dest_uid in
 * @destination.
 **/
void
camel_imap_message_cache_copy (CamelImapMessageCache *source,
                   const char *source_uid,
                   CamelImapMessageCache *dest,
                   const char *dest_uid,
                   CamelException *ex)
{
    GPtrArray *subparts;
    CamelStream *stream;
    char *part;
    int i;

    subparts = g_hash_table_lookup (source->parts, source_uid);
    if (!subparts || !subparts->len)
        return;

    for (i = 0; i < subparts->len; i++) {
        part = strchr (subparts->pdata[i], '.');
        if (!part++)
            continue;
        stream = camel_imap_message_cache_get (source, source_uid, part);
        camel_imap_message_cache_insert_stream (dest, dest_uid, part, stream, ex);
        camel_object_unref (CAMEL_OBJECT (stream));
    }
}