src/lib-storage/mail-search.c

	mail-search.c revision c9c35f9fa45b22f4b74eab759462d375e285b4c8
/* Copyright (c) 2002-2007 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "buffer.h"
#include "mail-search.h"

void mail_search_args_reset(struct mail_search_arg *args, bool full_reset)
{
    while (args != NULL) {
        if (args->type == SEARCH_OR || args->type == SEARCH_SUB)
            mail_search_args_reset(args->value.subargs, full_reset);

        if (!args->match_always)
            args->result = -1;
        else {
            if (!full_reset)
                args->result = 1;
            else {
                args->match_always = FALSE;
                args->result = -1;
            }
        }

        args = args->next;
    }
}

static void search_arg_foreach(struct mail_search_arg *arg,
                   mail_search_foreach_callback_t *callback,
                   void *context)
{
    struct mail_search_arg *subarg;

    if (arg->result != -1)
        return;

    if (arg->type == SEARCH_SUB) {
        /* sublist of conditions */
        i_assert(arg->value.subargs != NULL);

        arg->result = 1;
        subarg = arg->value.subargs;
        while (subarg != NULL) {
            if (subarg->result == -1)
                search_arg_foreach(subarg, callback, context);

            if (subarg->result == -1)
                arg->result = -1;
            else if (subarg->result == 0) {
                /* didn't match */
                arg->result = 0;
                break;
            }

            subarg = subarg->next;
        }
        if (arg->not && arg->result != -1)
            arg->result = !arg->result;
    } else if (arg->type == SEARCH_OR) {
        /* OR-list of conditions */
        i_assert(arg->value.subargs != NULL);

        subarg = arg->value.subargs;
        arg->result = 0;
        while (subarg != NULL) {
            if (subarg->result == -1)
                search_arg_foreach(subarg, callback, context);

            if (subarg->result == -1)
                arg->result = -1;
            else if (subarg->result > 0) {
                /* matched */
                arg->result = 1;
                break;
            }

            subarg = subarg->next;
        }
        if (arg->not && arg->result != -1)
            arg->result = !arg->result;
    } else {
        /* just a single condition */
        callback(arg, context);
    }
}

#undef mail_search_args_foreach
int mail_search_args_foreach(struct mail_search_arg *args,
                 mail_search_foreach_callback_t *callback,
                 void *context)
{
    int result;

    result = 1;
    for (; args != NULL; args = args->next) {
        search_arg_foreach(args, callback, context);

        if (args->result == 0) {
            /* didn't match */
            return 0;
        }

        if (args->result == -1)
            result = -1;
    }

    return result;
}

static void
search_arg_analyze(struct mail_search_arg *arg, buffer_t *headers,
           bool *have_body, bool *have_text)
{
    static const char *date_hdr = "Date";
    struct mail_search_arg *subarg;

    if (arg->result != -1)
        return;

    switch (arg->type) {
    case SEARCH_OR:
    case SEARCH_SUB:
        subarg = arg->value.subargs;
        while (subarg != NULL) {
            if (subarg->result == -1) {
                search_arg_analyze(subarg, headers,
                           have_body, have_text);
            }

            subarg = subarg->next;
        }
        break;
    case SEARCH_SENTBEFORE:
    case SEARCH_SENTON:
    case SEARCH_SENTSINCE:
        buffer_append(headers, &date_hdr, sizeof(const char *));
        break;
    case SEARCH_HEADER:
    case SEARCH_HEADER_ADDRESS:
        buffer_append(headers, &arg->hdr_field_name,
                  sizeof(const char *));
        break;
    case SEARCH_BODY:
    case SEARCH_BODY_FAST:
        *have_body = TRUE;
        break;
    case SEARCH_TEXT:
    case SEARCH_TEXT_FAST:
        *have_text = TRUE;
        *have_body = TRUE;
        break;
    default:
        break;
    }
}

const char *const *
mail_search_args_analyze(struct mail_search_arg *args,
             bool *have_headers, bool *have_body)
{
    const char *null = NULL;
    buffer_t *headers;
    bool have_text;

    *have_headers = *have_body = have_text = FALSE;

    headers = buffer_create_dynamic(pool_datastack_create(), 128);
    for (; args != NULL; args = args->next)
        search_arg_analyze(args, headers, have_body, &have_text);

    *have_headers = have_text || headers->used != 0;

    if (headers->used == 0 || have_text)
        return NULL;

    buffer_append(headers, &null, sizeof(const char *));
    return buffer_get_data(headers, NULL);
}

static void
mail_search_args_simplify_sub(struct mail_search_arg *args, bool parent_and)
{
    struct mail_search_arg *sub, *prev = NULL;
    struct mail_search_arg *prev_flags_arg, *prev_not_flags_arg;

    prev_flags_arg = prev_not_flags_arg = NULL;
    for (; args != NULL;) {
        if (args->not && (args->type == SEARCH_SUB ||
                  args->type == SEARCH_OR)) {
            /* neg(p and q and ..) == neg(p) or neg(q) or ..
               neg(p or q or ..) == neg(p) and neg(q) and .. */
            args->type = args->type == SEARCH_SUB ?
                SEARCH_OR : SEARCH_SUB;
            args->not = FALSE;
            sub = args->value.subargs;
            for (; sub != NULL; sub = sub->next)
                sub->not = !sub->not;
        }

        if ((args->type == SEARCH_SUB && parent_and) ||
            (args->type == SEARCH_OR && !parent_and)) {
            /* p and (q and ..) == p and q and ..
               p or (q or ..) == p or q or .. */
            sub = args->value.subargs;
            for (; sub->next != NULL; sub = sub->next) ;
            sub->next = args->next;
            *args = *args->value.subargs;
            continue;
        }

        if (args->type == SEARCH_SUB || args->type == SEARCH_OR) {
            mail_search_args_simplify_sub(args->value.subargs,
                              args->type == SEARCH_SUB);
        }

        /* merge all flags arguments */
        if (args->type == SEARCH_FLAGS && !args->not) {
            if (prev_flags_arg == NULL)
                prev_flags_arg = args;
            else {
                prev_flags_arg->value.flags |=
                    args->value.flags;
                prev->next = args->next;
                args = args->next;
                continue;
            }
        } else if (args->type == SEARCH_FLAGS && args->not) {
            if (prev_not_flags_arg == NULL)
                prev_not_flags_arg = args;
            else {
                prev_not_flags_arg->value.flags |=
                    args->value.flags;
                prev->next = args->next;
                args = args->next;
                continue;
            }
        }

        prev = args;
        args = args->next;
    }
}

void mail_search_args_simplify(struct mail_search_arg *args)
{
    mail_search_args_simplify_sub(args, TRUE);
}