path: root/camel/providers/imap/camel-imap-search.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-imap-search.c: IMAP folder search */

/*
 *  Authors:
 *    Dan Winship <danw@ximian.com>
 *    Michael Zucchi <notzed@ximian.com>
 *
 *  Copyright 2000, 2001, 2002 Ximian, Inc.
 *
 * 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 <string.h>

#include "camel-imap-command.h"
#include "camel-imap-folder.h"
#include "camel-imap-store.h"
#include "camel-imap-search.h"
#include "camel-imap-private.h"
#include "camel-imap-utils.h"
#include "camel-imap-summary.h"

#include "e-util/md5-utils.h"   /* md5 hash building */
#include "camel-mime-utils.h"   /* base64 encoding */

#include "camel-seekable-stream.h"

#define d(x) x

/*
  File is:
   BODY  (as in body search)
   Last uid when search performed
   termcount: number of search terms
   matchcount: number of matches
   term0, term1 ...
   match0, match1, match2, ...
*/

/* size of in-memory cache */
#define MATCH_CACHE_SIZE (32)

/* Also takes care of 'endianness' file magic */
#define MATCH_MARK (('B' << 24) | ('O' << 16) | ('D' << 8) | 'Y')

/* on-disk header, in native endianness format, matches follow */
struct _match_header {
    guint32 mark;
    guint32 validity;   /* uidvalidity for this folder */
    guint32 lastuid;
    guint32 termcount;
    guint32 matchcount;
};

/* in-memory record */
struct _match_record {
    struct _match_record *next;
    struct _match_record *prev;

    char hash[17];

    guint32 lastuid;
    guint32 validity;

    unsigned int termcount;
    char **terms;
    GArray *matches;
};


static void free_match(CamelImapSearch *is, struct _match_record *mr);
static ESExpResult *imap_body_contains (struct _ESExp *f, int argc, struct _ESExpResult **argv, CamelFolderSearch *s);

static CamelFolderSearchClass *imap_search_parent_class;

static void
camel_imap_search_class_init (CamelImapSearchClass *camel_imap_search_class)
{
    /* virtual method overload */
    CamelFolderSearchClass *camel_folder_search_class =
        CAMEL_FOLDER_SEARCH_CLASS (camel_imap_search_class);

    imap_search_parent_class = (CamelFolderSearchClass *)camel_type_get_global_classfuncs (camel_folder_search_get_type ());
    
    /* virtual method overload */
    camel_folder_search_class->body_contains = imap_body_contains;
}

static void
camel_imap_search_init(CamelImapSearch *is)
{
    e_dlist_init(&is->matches);
    is->matches_hash = g_hash_table_new(g_str_hash, g_str_equal);
    is->matches_count = 0;
    is->lastuid = 0;
}

static void
camel_imap_search_finalise(CamelImapSearch *is)
{
    struct _match_record *mr;

    while ( (mr = (struct _match_record *)e_dlist_remtail(&is->matches)) )
        free_match(is, mr);
    g_hash_table_destroy(is->matches_hash);
    if (is->cache)
        camel_object_unref((CamelObject *)is->cache);
}

CamelType
camel_imap_search_get_type (void)
{
    static CamelType camel_imap_search_type = CAMEL_INVALID_TYPE;
    
    if (camel_imap_search_type == CAMEL_INVALID_TYPE) {
        camel_imap_search_type = camel_type_register (
            CAMEL_FOLDER_SEARCH_TYPE, "CamelImapSearch",
            sizeof (CamelImapSearch),
            sizeof (CamelImapSearchClass),
            (CamelObjectClassInitFunc) camel_imap_search_class_init, NULL,
            (CamelObjectInitFunc) camel_imap_search_init,
            (CamelObjectFinalizeFunc) camel_imap_search_finalise);
    }

    return camel_imap_search_type;
}

/**
 * camel_imap_search_new:
 *
 * Return value: A new CamelImapSearch widget.
 **/
CamelFolderSearch *
camel_imap_search_new (const char *cachedir)
{
    CamelFolderSearch *new = CAMEL_FOLDER_SEARCH (camel_object_new (camel_imap_search_get_type ()));
    CamelImapSearch *is = (CamelImapSearch *)new;

    camel_folder_search_construct (new);

    is->cache = camel_data_cache_new(cachedir, 0, NULL);
    if (is->cache) {
        /* Expire entries after 14 days of inactivity */
        camel_data_cache_set_expire_access(is->cache, 60*60*24*14);
    }

    return new;
}


static void
hash_match(char hash[17], int argc, struct _ESExpResult **argv)
{
    MD5Context ctx;
    unsigned char digest[16];
    unsigned int state = 0, save = 0;
    int i;

    md5_init(&ctx);
    for (i=0;i<argc;i++) {
        if (argv[i]->type == ESEXP_RES_STRING)
            md5_update(&ctx, argv[i]->value.string, strlen(argv[i]->value.string));
    }
    md5_final(&ctx, digest);

    base64_encode_close(digest, 12, FALSE, hash, &state, &save);

    for (i=0;i<16;i++) {
        if (hash[i] == '+')
            hash[i] = ',';
        if (hash[i] == '/')
            hash[i] = '_';
    }

    hash[16] = 0;
}

static int
save_match(CamelImapSearch *is, struct _match_record *mr)
{
    guint32 mark = MATCH_MARK;
    int ret = 0;
    struct _match_header header;
    CamelStream *stream;

    /* since its a cache, doesn't matter if it doesn't save, at least we have the in-memory cache
       for this session */
    if (is->cache == NULL)
        return -1;

    stream = camel_data_cache_add(is->cache, "search/body-contains", mr->hash, NULL);
    if (stream == NULL)
        return -1;

    d(printf("Saving search cache entry to '%s': %s\n", mr->hash, mr->terms[0]));
    
    /* we write the whole thing, then re-write the header magic, saves fancy sync code */
    memcpy(&header.mark, "    ", 4);
    header.termcount = 0;
    header.matchcount = mr->matches->len;
    header.lastuid = mr->lastuid;
    header.validity = mr->validity;

    if (camel_stream_write(stream, (char *)&header, sizeof(header)) != sizeof(header)
        || camel_stream_write(stream, mr->matches->data, mr->matches->len*sizeof(guint32)) != mr->matches->len*sizeof(guint32)
        || camel_seekable_stream_seek((CamelSeekableStream *)stream, 0, CAMEL_STREAM_SET) == -1
        || camel_stream_write(stream, (char *)&mark, sizeof(mark)) != sizeof(mark)) {
        d(printf(" saving failed, removing cache entry\n"));
        camel_data_cache_remove(is->cache, "search/body-contains", mr->hash, NULL);
        ret = -1;
    }

    camel_object_unref((CamelObject *)stream);
    return ret;
}

static void
free_match(CamelImapSearch *is, struct _match_record *mr)
{
    int i;

    for (i=0;i<mr->termcount;i++)
        g_free(mr->terms[i]);
    g_free(mr->terms);
    g_array_free(mr->matches, TRUE);
    g_free(mr);
}

static struct _match_record *
load_match(CamelImapSearch *is, char hash[17], int argc, struct _ESExpResult **argv)
{
    struct _match_record *mr;
    CamelStream *stream = NULL;
    struct _match_header header;
    int i;

    mr = g_malloc0(sizeof(*mr));
    mr->matches = g_array_new(0, 0, sizeof(guint32));
    g_assert(strlen(hash) == 16);
    strcpy(mr->hash, hash);
    mr->terms = g_malloc0(sizeof(mr->terms[0]) * argc);
    for (i=0;i<argc;i++) {
        if (argv[i]->type == ESEXP_RES_STRING) {
            mr->termcount++;
            mr->terms[i] = g_strdup(argv[i]->value.string);
        }
    }

    d(printf("Loading search cache entry to '%s': %s\n", mr->hash, mr->terms[0]));

    memset(&header, 0, sizeof(header));
    if (is->cache)
        stream = camel_data_cache_get(is->cache, "search/body-contains", mr->hash, NULL);
    if (stream != NULL) {
        /* 'cause i'm gonna be lazy, i'm going to have the termcount == 0 for now,
           and not load or save them since i can't think of a nice way to do it, the hash
           should be sufficient to key it */
        /* This check should also handle endianness changes, we just throw away
           the data (its only a cache) */
        if (camel_stream_read(stream, (char *)&header, sizeof(header)) == sizeof(header)
            && header.validity == is->validity
            && header.mark == MATCH_MARK
            && header.termcount == 0) {
            d(printf(" found %d matches\n", header.matchcount));
            g_array_set_size(mr->matches, header.matchcount);
            camel_stream_read(stream, mr->matches->data, sizeof(guint32)*header.matchcount);
        } else {
            d(printf(" file format invalid/validity changed\n"));
            memset(&header, 0, sizeof(header));
        }
        camel_object_unref((CamelObject *)stream);
    } else {
        d(printf(" no cache entry found\n"));
    }

    mr->validity = header.validity;
    if (mr->validity != is->validity)
        mr->lastuid = 0;
    else
        mr->lastuid = header.lastuid;

    return mr;
}

static int
sync_match(CamelImapSearch *is, struct _match_record *mr)
{
    char *p, *result, *lasts = NULL;
    CamelImapResponse *response;
    guint32 uid;
    CamelFolder *folder = ((CamelFolderSearch *)is)->folder;
    CamelImapStore *store = (CamelImapStore *)folder->parent_store;

    if (mr->lastuid >= is->lastuid && mr->validity == is->validity)
        return 0;

    d(printf("updating match record for uid's %d:%d\n", mr->lastuid+1, is->lastuid));

    /* TODO: Handle multiple search terms */

    response = camel_imap_command (store, folder, NULL,
                       "UID SEARCH UID %d:%d BODY \"%s\"",
                       mr->lastuid+1, is->lastuid, mr->terms[0]);
    if (!response)
        return -1;
    result = camel_imap_response_extract (store, response, "SEARCH", NULL);
    if (!result)
        return -1;
    
    p = result + sizeof ("* SEARCH");
    for (p = strtok_r (p, " ", &lasts); p; p = strtok_r (NULL, " ", &lasts)) {
        uid = strtoul(p, NULL, 10);
        g_array_append_vals(mr->matches, &uid, 1);
    }
    g_free(result);

    mr->validity = is->validity;
    mr->lastuid = is->lastuid;
    save_match(is, mr);

    return 0;
}

static struct _match_record *
get_match(CamelImapSearch *is, int argc, struct _ESExpResult **argv)
{
    char hash[17];
    struct _match_record *mr;

    hash_match(hash, argc, argv);

    mr = g_hash_table_lookup(is->matches_hash, hash);
    if (mr == NULL) {
        while (is->matches_count >= MATCH_CACHE_SIZE) {
            mr = (struct _match_record *)e_dlist_remtail(&is->matches);
            if (mr) {
                printf("expiring match '%s' (%s)\n", mr->hash, mr->terms[0]);
                g_hash_table_remove(is->matches_hash, mr->hash);
                free_match(is, mr);
                is->matches_count--;
            } else {
                is->matches_count = 0;
            }
        }
        mr = load_match(is, hash, argc, argv);
        g_hash_table_insert(is->matches_hash, mr->hash, mr);
        is->matches_count++;
    } else {
        e_dlist_remove((EDListNode *)mr);
    }

    e_dlist_addhead(&is->matches, (EDListNode *)mr);

    /* what about offline mode? */
    /* We could cache those results too, or should we cache them elsewhere? */
    sync_match(is, mr);

    return mr;
}

static ESExpResult *
imap_body_contains (struct _ESExp *f, int argc, struct _ESExpResult **argv, CamelFolderSearch *s)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (s->folder->parent_store);
    CamelImapSearch *is = (CamelImapSearch *)s;
    char *uid;
    ESExpResult *r;
    CamelMessageInfo *info; 
    GHashTable *uid_hash = NULL;
    GPtrArray *array;
    int i, j;
    struct _match_record *mr;
    guint32 uidn, *uidp;

    d(printf("Performing body search '%s'\n", argv[0]->value.string));

    /* TODO: Cache offline searches too? */

    /* If offline, search using the parent class, which can handle this manually */
    if (!camel_disco_store_check_online (CAMEL_DISCO_STORE (store), NULL))
        return imap_search_parent_class->body_contains(f, argc, argv, s);

    /* optimise the match "" case - match everything */
    if (argc == 1 && argv[0]->value.string[0] == '\0') {
        if (s->current) {
            r = e_sexp_result_new(f, ESEXP_RES_BOOL);
            r->value.bool = TRUE;
        } else {
            r = e_sexp_result_new(f, ESEXP_RES_ARRAY_PTR);
            r->value.ptrarray = g_ptr_array_new ();
            for (i = 0; i < s->summary->len; i++) {
                info = g_ptr_array_index(s->summary, i);
                g_ptr_array_add(r->value.ptrarray, (char *)camel_message_info_uid(info));
            }
        }
    } else if (argc == 0 || s->summary->len == 0) {
        /* nothing to match case, do nothing (should be handled higher up?) */
        if (s->current) {
            r = e_sexp_result_new(f, ESEXP_RES_BOOL);
            r->value.bool = FALSE;
        } else {
            r = e_sexp_result_new(f, ESEXP_RES_ARRAY_PTR);
            r->value.ptrarray = g_ptr_array_new ();
        }
    } else {
        int truth = FALSE;

        /* setup lastuid/validity for synchronising */
        info = g_ptr_array_index(s->summary, s->summary->len-1);
        is->lastuid = strtoul(camel_message_info_uid(info), NULL, 10);
        is->validity = ((CamelImapSummary *)(s->folder->summary))->validity;

        mr = get_match(is, argc, argv);

        if (s->current) {
            uidn = strtoul(camel_message_info_uid(s->current), NULL, 10);
            uidp = (guint32 *)mr->matches->data;
            j = mr->matches->len;
            for (i=0;i<j && !truth;i++)
                truth = *uidp++ == uidn;
            r = e_sexp_result_new(f, ESEXP_RES_BOOL);
            r->value.bool = truth;
        } else {
            r = e_sexp_result_new(f, ESEXP_RES_ARRAY_PTR);
            array = r->value.ptrarray = g_ptr_array_new();

            /* We use a hash to map the uid numbers to uid strings as required by the search api */
            /* We use the summary's strings so we dont need to alloc more */
            uid_hash = g_hash_table_new(NULL, NULL);
            for (i = 0; i < s->summary->len; i++) {
                info = s->summary->pdata[i];
                uid = (char *)camel_message_info_uid(info);
                uidn = strtoul(uid, NULL, 10);
                g_hash_table_insert(uid_hash, (void *)uidn, uid);
            }

            uidp = (guint32 *)mr->matches->data;
            j = mr->matches->len;
            for (i=0;i<j && !truth;i++) {
                uid = g_hash_table_lookup(uid_hash, (void *)*uidp++);
                if (uid)
                    g_ptr_array_add(array, uid);
            }

            g_hash_table_destroy(uid_hash);
        }
    }

    return r;
}