path: root/camel/providers/local/camel-mh-store.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2000 Ximian, Inc.
 *
 * Authors: Michael Zucchi <notzed@ximian.com>
 *
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of version 2 of the GNU General Public 
 * License as published by the Free Software Foundation.
 *
 * 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 <sys/stat.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <dirent.h>

#include "camel-mh-store.h"
#include "camel-mh-folder.h"
#include "camel-exception.h"
#include "camel-url.h"
#include "camel-private.h"

#include <camel/camel-stream-fs.h>
#include <camel/camel-stream-buffer.h>

static CamelLocalStoreClass *parent_class = NULL;

#define d(x)

/* Returns the class for a CamelMhStore */
#define CMHS_CLASS(so) CAMEL_MH_STORE_CLASS (CAMEL_OBJECT_GET_CLASS(so))
#define CF_CLASS(so) CAMEL_FOLDER_CLASS (CAMEL_OBJECT_GET_CLASS(so))
#define CMHF_CLASS(so) CAMEL_MH_FOLDER_CLASS (CAMEL_OBJECT_GET_CLASS(so))

static void construct (CamelService *service, CamelSession *session, CamelProvider *provider, CamelURL *url, CamelException *ex);
static CamelFolder *get_folder(CamelStore * store, const char *folder_name, guint32 flags, CamelException * ex);
static CamelFolder *get_inbox (CamelStore *store, CamelException *ex);
static void delete_folder(CamelStore * store, const char *folder_name, CamelException * ex);
static void rename_folder(CamelStore *store, const char *old, const char *new, CamelException *ex);
static CamelFolderInfo * get_folder_info (CamelStore *store, const char *top, guint32 flags, CamelException *ex);

static void camel_mh_store_class_init(CamelObjectClass * camel_mh_store_class)
{
    CamelStoreClass *camel_store_class = CAMEL_STORE_CLASS(camel_mh_store_class);
    CamelServiceClass *camel_service_class = CAMEL_SERVICE_CLASS(camel_mh_store_class);

    parent_class = (CamelLocalStoreClass *)camel_type_get_global_classfuncs(camel_local_store_get_type());

    /* virtual method overload, use defaults for most */
    camel_service_class->construct = construct;

    camel_store_class->get_folder = get_folder;
    camel_store_class->get_inbox = get_inbox;
    camel_store_class->delete_folder = delete_folder;
    camel_store_class->rename_folder = rename_folder;
    camel_store_class->get_folder_info = get_folder_info;
}

CamelType camel_mh_store_get_type(void)
{
    static CamelType camel_mh_store_type = CAMEL_INVALID_TYPE;

    if (camel_mh_store_type == CAMEL_INVALID_TYPE) {
        camel_mh_store_type = camel_type_register(CAMEL_LOCAL_STORE_TYPE, "CamelMhStore",
                              sizeof(CamelMhStore),
                              sizeof(CamelMhStoreClass),
                              (CamelObjectClassInitFunc) camel_mh_store_class_init,
                              NULL,
                              NULL,
                              NULL);
    }

    return camel_mh_store_type;
}

static void
construct (CamelService *service, CamelSession *session, CamelProvider *provider, CamelURL *url, CamelException *ex)
{
    CamelMhStore *mh_store = (CamelMhStore *)service;

    CAMEL_SERVICE_CLASS (parent_class)->construct (service, session, provider, url, ex);
    if (camel_exception_is_set (ex))
        return;

    if (camel_url_get_param(url, "dotfolders"))
        mh_store->flags |= CAMEL_MH_DOTFOLDERS;
}

enum {
    UPDATE_NONE,
    UPDATE_ADD,
    UPDATE_REMOVE,
};

/* update the .folders file if it exists, or create it if it doesn't */
static void
folders_update(const char *root, const char *folder, int mode)
{
    char *tmp, *tmpnew, *line = NULL;
    CamelStream *stream, *in = NULL, *out = NULL;

    tmpnew = alloca(strlen(root)+16);
    sprintf(tmpnew, "%s.folders~", root);
    
    out = camel_stream_fs_new_with_name(tmpnew, O_WRONLY|O_CREAT|O_TRUNC, 0666);
    if (out == NULL)
        goto fail;

    tmp = alloca(strlen(root)+16);
    sprintf(tmp, "%s.folders", root);
    stream = camel_stream_fs_new_with_name(tmp, O_RDONLY, 0);
    if (stream) {
        in = camel_stream_buffer_new(stream, CAMEL_STREAM_BUFFER_READ);
        camel_object_unref(stream);
    }
    if (in == NULL || stream == NULL) {
        if (mode == UPDATE_ADD && camel_stream_printf(out, "%s\n", folder) == -1)
            goto fail;
        goto done;
    }

    while ((line = camel_stream_buffer_read_line((CamelStreamBuffer *)in))) {
        int copy = TRUE;

        switch (mode) {
        case UPDATE_REMOVE:
            if (strcmp(line, folder) == 0)
                copy = FALSE;
            break;
        case UPDATE_ADD: {
            int cmp = strcmp(line, folder);

            if (cmp > 0) {
                /* found insertion point */
                if (camel_stream_printf(out, "%s\n", folder) == -1)
                    goto fail;
                mode = UPDATE_NONE;
            } else if (tmp == 0) {
                /* already there */
                mode = UPDATE_NONE;
            }
            break; }
        case UPDATE_NONE:
            break;
        }

        if (copy && camel_stream_printf(out, "%s\n", line) == -1)
            goto fail;

        g_free(line);
        line = NULL;
    }

    /* add to end? */
    if (mode == UPDATE_ADD && camel_stream_printf(out, "%s\n", folder) == -1)
        goto fail;

    if (camel_stream_close(out) == -1)
        goto fail;

done:
    /* should we care if this fails?  I suppose so ... */
    rename(tmpnew, tmp);
fail:
    unlink(tmpnew);     /* remove it if its there */
    g_free(line);
    if (in)
        camel_object_unref(in);
    if (out)
        camel_object_unref(out);
}

static CamelFolder *get_folder(CamelStore * store, const char *folder_name, guint32 flags, CamelException * ex)
{
    char *name;
    struct stat st;

    (void) ((CamelStoreClass *)parent_class)->get_folder(store, folder_name, flags, ex);
    if (camel_exception_is_set(ex))
        return NULL;

    name = g_strdup_printf("%s%s", CAMEL_LOCAL_STORE(store)->toplevel_dir, folder_name);

    if (stat(name, &st) == -1) {
        if (errno != ENOENT) {
            camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                         _("Could not open folder `%s':\n%s"),
                         folder_name, g_strerror(errno));
            g_free (name);
            return NULL;
        }
        if ((flags & CAMEL_STORE_FOLDER_CREATE) == 0) {
            camel_exception_setv(ex, CAMEL_EXCEPTION_STORE_NO_FOLDER,
                         _("Folder `%s' does not exist."), folder_name);
            g_free (name);
            return NULL;
        }

        if (mkdir(name, 0700) != 0) {
            camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                         _("Could not create folder `%s':\n%s"),
                         folder_name, g_strerror(errno));
            g_free (name);
            return NULL;
        }

        /* add to .folders if we are supposed to */
        /* FIXME: throw exception on error */
        if (((CamelMhStore *)store)->flags & CAMEL_MH_DOTFOLDERS)
            folders_update(((CamelLocalStore *)store)->toplevel_dir, folder_name, UPDATE_ADD);

    } else if (!S_ISDIR(st.st_mode)) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_STORE_NO_FOLDER,
                     _("`%s' is not a directory."), name);
        g_free (name);
        return NULL;
    }
    g_free(name);

    return camel_mh_folder_new(store, folder_name, flags, ex);
}

static CamelFolder *
get_inbox (CamelStore *store, CamelException *ex)
{
    return get_folder (store, "inbox", 0, ex);
}

static void delete_folder(CamelStore * store, const char *folder_name, CamelException * ex)
{
    char *name;

    /* remove folder directory - will fail if not empty */
    name = g_strdup_printf("%s%s", CAMEL_LOCAL_STORE(store)->toplevel_dir, folder_name);
    if (rmdir(name) == -1) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Could not delete folder `%s': %s"),
                     folder_name, strerror(errno));
        g_free(name);
        return;
    }
    g_free(name);

    /* remove from .folders if we are supposed to */
    if (((CamelMhStore *)store)->flags & CAMEL_MH_DOTFOLDERS)
        folders_update(((CamelLocalStore *)store)->toplevel_dir, folder_name, UPDATE_REMOVE);

    /* and remove metadata */
    ((CamelStoreClass *)parent_class)->delete_folder(store, folder_name, ex);
}

static void
rename_folder(CamelStore *store, const char *old, const char *new, CamelException *ex)
{
    CamelException e;

    camel_exception_init(&e);
    ((CamelStoreClass *)parent_class)->rename_folder(store, old, new, &e);
    if (camel_exception_is_set(&e)) {
        camel_exception_xfer(ex, &e);
        return;
    }
    camel_exception_clear(&e);

    if (((CamelMhStore *)store)->flags & CAMEL_MH_DOTFOLDERS) {
        /* yeah this is messy, but so is mh! */
        folders_update(((CamelLocalStore *)store)->toplevel_dir, new, UPDATE_ADD);
        folders_update(((CamelLocalStore *)store)->toplevel_dir, old, UPDATE_REMOVE);
    }
}

static CamelFolderInfo *folder_info_new(CamelStore *store, const char *root, const char *path)
{
    CamelFolderInfo *fi;
    char *base;
    CamelFolder *folder;

    base = strrchr(path, '/');

    /* Build the folder info structure. */
    fi = g_malloc0(sizeof(*fi));
    fi->url = g_strdup_printf("mh:%s#%s", root, path);
    fi->full_name = g_strdup(path);
    fi->name = g_strdup(base?base+1:path);
    fi->unread_message_count = 0;

    /* check unread count if open */
    CAMEL_STORE_LOCK(store, cache_lock);
    folder = g_hash_table_lookup(store->folders, path);
    if (folder) {
        if ((((CamelMhStore *)store)->flags & CAMEL_STORE_FOLDER_INFO_FAST) == 0)
            camel_folder_refresh_info(folder, NULL);
        fi->unread_message_count = camel_folder_get_unread_message_count(folder);
    }
    CAMEL_STORE_UNLOCK(store, cache_lock);

    /* We could: if we have no folder, and FAST isn't specified, perform a full
       scan of all messages for their status flags.  But its probably not worth
       it as we need to read the top of every file, i.e. very very slow */

    camel_folder_info_build_path(fi, '/');

    d(printf("New folderinfo:\n '%s'\n '%s'\n '%s'\n", fi->full_name, fi->url, fi->path));

    return fi;
}

/* used to find out where we've visited already */
struct _inode {
    dev_t dnode;
    ino_t inode;
};

/* Scan path, under root, for directories to add folders for.  Both
 * root and path should have a trailing "/" if they aren't empty. */
static void recursive_scan(CamelStore *store, CamelFolderInfo **fip, CamelFolderInfo *parent, GHashTable *visited, const char *root, const char *path)
{
    char *fullpath, *tmp;
    DIR *dp;
    struct dirent *d;
    struct stat st;
    CamelFolderInfo *fi;
    struct _inode in, *inew;

    /* Open the specified directory. */
    if (path[0]) {
        fullpath = alloca(strlen(root)+strlen(path)+2);
        sprintf(fullpath, "%s/%s", root, path);
    } else 
        fullpath = (char *)root;

    if (stat(fullpath, &st) == -1 || !S_ISDIR(st.st_mode))
        return;

    in.dnode = st.st_dev;
    in.inode = st.st_ino;

    /* see if we've visited already */
    if (g_hash_table_lookup(visited, &in) != NULL)
        return;

    inew = g_malloc(sizeof(*inew));
    *inew = in;
    g_hash_table_insert(visited, inew, inew);

    /* link in ... */
    fi = folder_info_new(store, root, path);
    fi->parent = parent;
    fi->sibling = *fip;
    *fip = fi;

    if ((( ((CamelMhStore *)store)->flags & CAMEL_STORE_FOLDER_INFO_RECURSIVE) || parent == NULL)) {
        /* now check content for possible other directories */
        dp = opendir(fullpath);
        if (dp == NULL)
            return;

        /* Look for subdirectories to add and scan. */
        while ((d = readdir(dp)) != NULL) {
            /* Skip current and parent directory. */
            if (strcmp(d->d_name, ".") == 0
                || strcmp(d->d_name, "..") == 0)
                continue;

            /* skip fully-numerical entries (i.e. mh messages) */
            strtoul(d->d_name, &tmp, 10);
            if (*tmp == 0)
                continue;

            /* otherwise, treat at potential node, and recurse, a bit more expensive than needed, but tough! */
            if (path[0]) {
                tmp = g_strdup_printf("%s/%s", path, d->d_name);
                recursive_scan(store, &fi->child, fi, visited, root, tmp);
                g_free(tmp);
            } else {
                recursive_scan(store, &fi->child, fi, visited, root, d->d_name);
            }
        }

        closedir(dp);
    }
}

/* scan a .folders file */
static void
folders_scan(CamelStore *store, const char *root, const char *top, CamelFolderInfo **fip)
{
    CamelFolderInfo *fi;
    char  line[512], *path, *tmp;
    CamelStream *stream, *in;
    struct stat st;
    GPtrArray *folders;
    GHashTable *visited;
    int len;

    tmp = alloca(strlen(root)+16);
    sprintf(tmp, "%s/.folders", root);
    stream = camel_stream_fs_new_with_name(tmp, 0, O_RDONLY);
    if (stream == NULL)
        return;

    in = camel_stream_buffer_new(stream, CAMEL_STREAM_BUFFER_READ);
    camel_object_unref(stream);
    if (in == NULL)
        return;

    visited = g_hash_table_new(g_str_hash, g_str_equal);
    folders = g_ptr_array_new();

    while ( (len = camel_stream_buffer_gets((CamelStreamBuffer *)in, line, sizeof(line))) > 0) {
        /* ignore blank lines */
        if (len <= 1)
            continue;
        /* check for invalidly long lines, we abort evreything and fallback */
        if (line[len-1] != '\n') {
            int i;

            for (i=0;i<folders->len;i++)
                camel_folder_info_free(folders->pdata[i]);
            g_ptr_array_set_size(folders, 0);
            break;
        }
        line[len-1] = 0;

        /* check for \r ? */

        if (top && top[0]) {
            int toplen = strlen(top);

            /* check is subdir */
            if (strncmp(top, line, len) != 0)
                continue;
        
            /* check is not sub-subdir if not recursive */
            if (( ((CamelMhStore *)store)->flags & CAMEL_STORE_FOLDER_INFO_RECURSIVE) == 0
                && (tmp = strrchr(line, '/'))
                && tmp > line+toplen)
                continue;
        }

        if (g_hash_table_lookup(visited, line) != NULL)
            continue;

        tmp = g_strdup(line);
        g_hash_table_insert(visited, tmp, tmp);

        path = g_strdup_printf("%s/%s", root, line);
        if (stat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
            fi = folder_info_new(store, root, line);
            g_ptr_array_add(folders, fi);
        }
        g_free(path);
    }

    if (folders->len)
        *fip = camel_folder_info_build(folders, NULL, '/', TRUE);
    g_ptr_array_free(folders, TRUE);

    g_hash_table_foreach(visited, (GHFunc)g_free, NULL);
    g_hash_table_destroy(visited);

    camel_object_unref(in);
}

/* FIXME: move to camel-local, this is shared with maildir code */
static guint inode_hash(const void *d)
{
    const struct _inode *v = d;

    return v->inode ^ v->dnode;
}

static gboolean inode_equal(const void *a, const void *b)
{
    const struct _inode *v1 = a, *v2 = b;
    
    return v1->inode == v2->inode && v1->dnode == v2->dnode;
}

static void inode_free(void *k, void *v, void *d)
{
    g_free(k);
}

static CamelFolderInfo *
get_folder_info (CamelStore *store, const char *top, guint32 flags, CamelException *ex)
{
    CamelFolderInfo *fi = NULL;
    char *root;

    root = ((CamelService *)store)->url->path;
    
    /* use .folders if we are supposed to */
    if (((CamelMhStore *)store)->flags & CAMEL_MH_DOTFOLDERS) {
        folders_scan(store, root, top, &fi);
    } else {
        GHashTable *visited = g_hash_table_new(inode_hash, inode_equal);

        if (top == NULL)
            top = "";

        recursive_scan(store, &fi, NULL, visited, root, top);

        /* if we actually scanned from root, we have a "" root node we dont want */
        if (fi != NULL && top[0] == 0) {
            CamelFolderInfo *rfi;

            rfi = fi;
            fi = rfi->child;
            rfi->child = NULL;
            camel_folder_info_free(rfi);
        }

        g_hash_table_foreach(visited, inode_free, NULL);
        g_hash_table_destroy(visited);
    }

    return fi;
}