index/pop3c/pop3c-mail.c

	pop3c-mail.c revision 5f8d497e88fae77fbeb625246bc18260f6775b83
/* Copyright (c) 2011-2016 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "ioloop.h"
#include "istream.h"
#include "index-mail.h"
#include "pop3c-settings.h"
#include "pop3c-client.h"
#include "pop3c-sync.h"
#include "pop3c-storage.h"

struct mail *
pop3c_mail_alloc(struct mailbox_transaction_context *t,
         enum mail_fetch_field wanted_fields,
         struct mailbox_header_lookup_ctx *wanted_headers)
{
    struct pop3c_mail *mail;
    pool_t pool;

    pool = pool_alloconly_create("mail", 2048);
    mail = p_new(pool, struct pop3c_mail, 1);
    mail->imail.mail.pool = pool;

    index_mail_init(&mail->imail, t, wanted_fields, wanted_headers);
    return &mail->imail.mail.mail;
}

static void pop3c_mail_close(struct mail *_mail)
{
    struct pop3c_mail *pmail = (struct pop3c_mail *)_mail;
    struct pop3c_mailbox *mbox = (struct pop3c_mailbox *)_mail->box;

    /* wait for any prefetch to finish before closing the mail */
    while (pmail->prefetching)
        pop3c_client_wait_one(mbox->client);
    if (pmail->prefetch_stream != NULL)
        i_stream_unref(&pmail->prefetch_stream);
    index_mail_close(_mail);
}

static int pop3c_mail_get_received_date(struct mail *_mail, time_t *date_r)
{
    struct pop3c_mailbox *mbox = (struct pop3c_mailbox *)_mail->box;
    int tz;

    if (mbox->storage->set->pop3c_quick_received_date) {
        /* we don't care about the date, just return the current date */
        *date_r = ioloop_time;
        return 0;
    }

    /* FIXME: we could also parse the first Received: header and get
       the date from there, but since this code is unlikely to be called
       except during migration, I don't think it really matters. */
    return index_mail_get_date(_mail, date_r, &tz);
}

static int pop3c_mail_get_save_date(struct mail *_mail, time_t *date_r)
{
    struct index_mail *mail = (struct index_mail *)_mail;
    struct index_mail_data *data = &mail->data;

    if (data->save_date == (time_t)-1) {
        /* FIXME: we could use a value stored in cache */
        return pop3c_mail_get_received_date(_mail, date_r);
    }
    *date_r = data->save_date;
    return 0;
}

static int pop3c_mail_get_physical_size(struct mail *_mail, uoff_t *size_r)
{
    struct index_mail *mail = (struct index_mail *)_mail;
    struct pop3c_mailbox *mbox = (struct pop3c_mailbox *)_mail->box;
    struct message_size hdr_size, body_size;
    struct istream *input;

    if (mail->data.virtual_size != (uoff_t)-1) {
        /* virtual size is already known. it's the same as our
           (correct) physical size */
        *size_r = mail->data.virtual_size;
        return 0;
    }
    if (index_mail_get_physical_size(_mail, size_r) == 0) {
        *size_r = mail->data.physical_size;
        return 0;
    }

    if (_mail->lookup_abort == MAIL_LOOKUP_ABORT_READ_MAIL &&
        (_mail->box->flags & MAILBOX_FLAG_POP3_SESSION) != 0) {
        /* kludge: we want output for POP3 LIST with
           pop3_fast_size_lookups=yes. use the remote's LIST values
           regardless of their correctness */
        if (mbox->msg_sizes == NULL) {
            if (pop3c_sync_get_sizes(mbox) < 0)
                return -1;
        }
        i_assert(_mail->seq <= mbox->msg_count);
        *size_r = mbox->msg_sizes[_mail->seq-1];
        return 0;
    }

    /* slow way: get the whole message body */
    if (mail_get_stream(_mail, &hdr_size, &body_size, &input) < 0)
        return -1;

    i_assert(mail->data.physical_size != (uoff_t)-1);
    *size_r = mail->data.physical_size;
    return 0;
}

static void pop3c_mail_cache_size(struct index_mail *mail)
{
    struct mail *_mail = &mail->mail.mail;
    uoff_t size;
    unsigned int cache_idx;

    if (i_stream_get_size(mail->data.stream, TRUE, &size) <= 0)
        return;
    mail->data.virtual_size = size;

    cache_idx = mail->ibox->cache_fields[MAIL_CACHE_VIRTUAL_FULL_SIZE].idx;
    if (mail_cache_field_exists(_mail->transaction->cache_view,
                    _mail->seq, cache_idx) == 0) {
        index_mail_cache_add_idx(mail, cache_idx, &size, sizeof(size));
        /* make sure it's not cached twice */
        mail->data.dont_cache_fetch_fields |=
            MAIL_CACHE_VIRTUAL_FULL_SIZE;
    }
}

static void
pop3c_mail_prefetch_done(enum pop3c_command_state state,
             const char *reply ATTR_UNUSED, void *context)
{
    struct pop3c_mail *pmail = context;

    switch (state) {
    case POP3C_COMMAND_STATE_OK:
        break;
    case POP3C_COMMAND_STATE_ERR:
    case POP3C_COMMAND_STATE_DISCONNECTED:
        i_stream_unref(&pmail->prefetch_stream);
        /* let pop3c_mail_get_stream() figure out the error handling.
           in case of a -ERR a retry might even work. */
        break;
    }
    pmail->prefetching = FALSE;
}

static bool pop3c_mail_prefetch(struct mail *_mail)
{
    struct pop3c_mail *pmail = (struct pop3c_mail *)_mail;
    struct pop3c_mailbox *mbox = (struct pop3c_mailbox *)_mail->box;
    enum pop3c_capability capa;
    const char *cmd;

    if (pmail->imail.data.access_part != 0 &&
        pmail->imail.data.stream == NULL) {
        capa = pop3c_client_get_capabilities(mbox->client);
        pmail->prefetching_body = (capa & POP3C_CAPABILITY_TOP) == 0 ||
            (pmail->imail.data.access_part & (READ_BODY | PARSE_BODY)) != 0;
        if (pmail->prefetching_body)
            cmd = t_strdup_printf("RETR %u\r\n", _mail->seq);
        else
            cmd = t_strdup_printf("TOP %u 0\r\n", _mail->seq);

        pmail->prefetching = TRUE;
        pmail->prefetch_stream =
            pop3c_client_cmd_stream_async(mbox->client, cmd,
                pop3c_mail_prefetch_done, pmail);
        i_stream_set_name(pmail->prefetch_stream, t_strcut(cmd, '\r'));
        return !pmail->prefetching;
    }
    return index_mail_prefetch(_mail);
}

static int
pop3c_mail_get_stream(struct mail *_mail, bool get_body,
              struct message_size *hdr_size,
              struct message_size *body_size, struct istream **stream_r)
{
    struct pop3c_mail *pmail = (struct pop3c_mail *)_mail;
    struct index_mail *mail = &pmail->imail;
    struct pop3c_mailbox *mbox = (struct pop3c_mailbox *)_mail->box;
    enum pop3c_capability capa;
    const char *name, *cmd, *error;
    struct istream *input;

    if ((mail->data.access_part & (READ_BODY | PARSE_BODY)) != 0)
        get_body = TRUE;

    while (pmail->prefetching) {
        /* wait for prefetch to finish */
        pop3c_client_wait_one(mbox->client);
    }

    if (pmail->prefetch_stream != NULL && mail->data.stream == NULL) {
        mail->data.stream = pmail->prefetch_stream;
        pmail->prefetch_stream = NULL;
    }

    if (get_body && mail->data.stream != NULL) {
        name = i_stream_get_name(mail->data.stream);
        if (strncmp(name, "RETR", 4) == 0) {
            /* we've fetched the body */
        } else if (strncmp(name, "TOP", 3) == 0) {
            /* we've fetched the header, but we need the body
               now too */
            index_mail_close_streams(mail);
        } else {
            i_panic("Unexpected POP3 stream name: %s", name);
        }
    }

    if (mail->data.stream == NULL) {
        capa = pop3c_client_get_capabilities(mbox->client);
        if (get_body || (capa & POP3C_CAPABILITY_TOP) == 0) {
            cmd = t_strdup_printf("RETR %u\r\n", _mail->seq);
            get_body = TRUE;
        } else {
            cmd = t_strdup_printf("TOP %u 0\r\n", _mail->seq);
        }
        if (pop3c_client_cmd_stream(mbox->client, cmd,
                        &input, &error) < 0) {
            mail_storage_set_error(mbox->box.storage,
                !pop3c_client_is_connected(mbox->client) ?
                MAIL_ERROR_TEMP : MAIL_ERROR_EXPUNGED, error);
            return -1;
        }
        mail->data.stream = input;
        if (mail->mail.v.istream_opened != NULL) {
            if (mail->mail.v.istream_opened(_mail,
                            &mail->data.stream) < 0) {
                index_mail_close_streams(mail);
                return -1;
            }
        }
        i_stream_set_name(mail->data.stream, t_strcut(cmd, '\r'));
        if (get_body)
            pop3c_mail_cache_size(mail);
    }
    /* if this stream is used by some filter stream, make the
       filter stream blocking */
    mail->data.stream->blocking = TRUE;
    return index_mail_init_stream(mail, hdr_size, body_size, stream_r);
}

static int
pop3c_mail_get_special(struct mail *_mail, enum mail_fetch_field field,
               const char **value_r)
{
    struct pop3c_mailbox *mbox = (struct pop3c_mailbox *)_mail->box;

    switch (field) {
    case MAIL_FETCH_UIDL_BACKEND:
    case MAIL_FETCH_GUID:
        if (mbox->msg_uidls == NULL) {
            if (pop3c_sync_get_uidls(mbox) < 0)
                return -1;
        }
        i_assert(_mail->seq <= mbox->msg_count);
        *value_r = mbox->msg_uidls[_mail->seq-1];
        return 0;
    default:
        return index_mail_get_special(_mail, field, value_r);
    }
}

struct mail_vfuncs pop3c_mail_vfuncs = {
    pop3c_mail_close,
    index_mail_free,
    index_mail_set_seq,
    index_mail_set_uid,
    index_mail_set_uid_cache_updates,
    pop3c_mail_prefetch,
    index_mail_precache,
    index_mail_add_temp_wanted_fields,

    index_mail_get_flags,
    index_mail_get_keywords,
    index_mail_get_keyword_indexes,
    index_mail_get_modseq,
    index_mail_get_pvt_modseq,
    index_mail_get_parts,
    index_mail_get_date,
    pop3c_mail_get_received_date,
    pop3c_mail_get_save_date,
    index_mail_get_virtual_size,
    pop3c_mail_get_physical_size,
    index_mail_get_first_header,
    index_mail_get_headers,
    index_mail_get_header_stream,
    pop3c_mail_get_stream,
    index_mail_get_binary_stream,
    pop3c_mail_get_special,
    index_mail_get_real_mail,
    index_mail_update_flags,
    index_mail_update_keywords,
    index_mail_update_modseq,
    index_mail_update_pvt_modseq,
    NULL,
    index_mail_expunge,
    index_mail_set_cache_corrupted,
    index_mail_opened
};