src/lib-index/mail-index-transaction.c

	mail-index-transaction.c revision b44a50ea4123f21dfc8e1b6c602f690fd9721b67
/* Copyright (C) 2003-2004 Timo Sirainen */

/* Inside transaction we keep messages stored in sequences in uid fields.
   Before they're written to transaction log the sequences are changed to
   UIDs. This is because we're able to compress sequence ranges better. */

#include "lib.h"
#include "buffer.h"
#include "mail-index-view-private.h"
#include "mail-transaction-log.h"
#include "mail-index-transaction-private.h"

#include <stddef.h>

static void mail_index_transaction_add_last(struct mail_index_transaction *t);

struct mail_index_transaction *
mail_index_transaction_begin(struct mail_index_view *view, int hide)
{
    struct mail_index_transaction *t;

    /* don't allow syncing view while there's ongoing transactions */
    mail_index_view_transaction_ref(view);

    t = i_new(struct mail_index_transaction, 1);
    t->view = view;
    t->hide_transaction = hide;
    return t;
}

static void mail_index_transaction_free(struct mail_index_transaction *t)
{
    unsigned int i;

    mail_index_view_transaction_unref(t->view);

    for (i = 0; i < t->view->index->extra_records_count; i++) {
        if (t->extra_rec_updates[i] != NULL)
            buffer_free(t->extra_rec_updates[i]);
    }

    if (t->appends != NULL)
        buffer_free(t->appends);
    if (t->expunges != NULL)
        buffer_free(t->expunges);
    if (t->updates != NULL)
        buffer_free(t->updates);
    if (t->cache_updates != NULL)
        buffer_free(t->cache_updates);
    i_free(t);
}

static void
mail_index_buffer_convert_to_uids(struct mail_index_view *view,
                  buffer_t *buf, size_t record_size, int range)
{
    unsigned char *data;
    size_t size, i;
    uint32_t *seq;

    if (buf == NULL)
        return;

    /* @UNSAFE */
    data = buffer_get_modifyable_data(buf, &size);
    for (i = 0; i < size; i += record_size) {
        seq = (uint32_t *)&data[i];
        i_assert(seq[0] <= view->map->records_count);

        seq[0] = MAIL_INDEX_MAP_IDX(view->index, view->map,
                        seq[0]-1)->uid;
        if (range) {
            i_assert(seq[1] <= view->map->records_count);
            seq[1] = MAIL_INDEX_MAP_IDX(view->index, view->map,
                            seq[1]-1)->uid;
        }
    }
}

static int
mail_index_transaction_convert_to_uids(struct mail_index_transaction *t)
{
    struct mail_index *index = t->view->index;
    unsigned int i;

    if (mail_index_view_lock(t->view) < 0)
        return -1;

    for (i = 0; i < index->extra_records_count; i++) {
        if (t->extra_rec_updates[i] == NULL)
            continue;

        mail_index_buffer_convert_to_uids(t->view,
                          t->extra_rec_updates[i],
                                                  sizeof(uint32_t) +
                          index->extra_records[i].size,
                          FALSE);
    }

    mail_index_buffer_convert_to_uids(t->view, t->expunges,
        sizeof(struct mail_transaction_expunge), TRUE);
    mail_index_buffer_convert_to_uids(t->view, t->updates,
        sizeof(struct mail_transaction_flag_update), TRUE);
    mail_index_buffer_convert_to_uids(t->view, t->cache_updates,
        sizeof(struct mail_transaction_cache_update), FALSE);
    return 0;
}

int mail_index_transaction_commit(struct mail_index_transaction *t,
                  uint32_t *log_file_seq_r,
                  uoff_t *log_file_offset_r)
{
    int ret;

    if (mail_index_view_is_inconsistent(t->view)) {
        mail_index_transaction_free(t);
        return -1;
    }

    if (t->last_update.uid1 != 0)
        mail_index_transaction_add_last(t);

    if (mail_index_transaction_convert_to_uids(t) < 0)
        ret = -1;
    else {
        ret = mail_transaction_log_append(t, log_file_seq_r,
                          log_file_offset_r);
    }

    mail_index_transaction_free(t);
    return ret;
}

void mail_index_transaction_rollback(struct mail_index_transaction *t)
{
        mail_index_transaction_free(t);
}

static struct mail_index_record *
mail_index_lookup_append(struct mail_index_transaction *t, uint32_t seq)
{
    size_t pos;

    i_assert(seq >= t->first_new_seq && seq <= t->last_new_seq);

    pos = (seq - t->first_new_seq) * t->view->index->record_size;
    return buffer_get_space_unsafe(t->appends, pos,
                       t->view->index->record_size);
}

int mail_index_transaction_lookup(struct mail_index_transaction *t,
                  uint32_t seq,
                  const struct mail_index_record **rec_r)
{
    if (t->first_new_seq != 0 && seq >= t->first_new_seq) {
        *rec_r = mail_index_lookup_append(t, seq);
        return 1;
    } else {
        return mail_index_lookup(t->view, seq, rec_r);
    }
}

void mail_index_append(struct mail_index_transaction *t, uint32_t uid,
               uint32_t *seq_r)
{
        struct mail_index_record *rec;

    if (t->appends == NULL) {
        t->appends = buffer_create_dynamic(default_pool,
                           4096, (size_t)-1);
    }

    /* sequence number is visible only inside given view,
       so let it generate it */
    if (t->last_new_seq != 0)
        *seq_r = ++t->last_new_seq;
    else {
        *seq_r = t->first_new_seq = t->last_new_seq =
            mail_index_view_get_message_count(t->view)+1;
    }

    rec = buffer_append_space_unsafe(t->appends,
                     t->view->index->record_size);
    memset(rec, 0, t->view->index->record_size);
    rec->uid = uid;
}

void mail_index_expunge(struct mail_index_transaction *t, uint32_t seq)
{
        struct mail_transaction_expunge exp, *data;
    unsigned int idx, left_idx, right_idx;
    size_t size;

    i_assert(seq > 0 && seq <= mail_index_view_get_message_count(t->view));

    exp.uid1 = exp.uid2 = seq;

    /* expunges is a sorted array of {seq1, seq2, ..}, .. */

    if (t->expunges == NULL) {
        t->expunges = buffer_create_dynamic(default_pool,
                            1024, (size_t)-1);
        buffer_append(t->expunges, &exp, sizeof(exp));
        return;
    }

    data = buffer_get_modifyable_data(t->expunges, &size);
    size /= sizeof(*data);
    i_assert(size > 0);

    /* quick checks */
    if (data[size-1].uid2 == seq-1) {
        /* grow last range */
        data[size-1].uid2 = seq;
        return;
    }
    if (data[size-1].uid2 < seq) {
        buffer_append(t->expunges, &exp, sizeof(exp));
        return;
    }
    if (data[0].uid1 == seq+1) {
        /* grow down first range */
        data[0].uid1 = seq;
        return;
    }
    if (data[0].uid1 > seq) {
        buffer_insert(t->expunges, 0, &exp, sizeof(exp));
        return;
    }

    /* somewhere in the middle, array is sorted so find it with
       binary search */
    idx = 0; left_idx = 0; right_idx = size;
    while (left_idx < right_idx) {
        idx = (left_idx + right_idx) / 2;

        if (data[idx].uid1 < seq)
            left_idx = idx+1;
        else if (data[idx].uid1 > seq)
            right_idx = idx;
        else
            break;
    }

    if (data[idx].uid2 < seq)
        idx++;

        /* idx == size couldn't happen because we already handle it above */
    i_assert(idx < size && data[idx].uid1 >= seq);

    if (data[idx].uid1 <= seq && data[idx].uid2 >= seq) {
        /* already expunged */
        return;
    }

    if (data[idx].uid1 == seq+1) {
        data[idx].uid1 = seq;
        if (idx > 0 && data[idx-1].uid2 == seq-1) {
            /* merge */
            data[idx-1].uid2 = data[idx].uid2;
            buffer_delete(t->expunges, idx * sizeof(*data),
                      sizeof(*data));
        }
    } else if (data[idx].uid2 == seq-1) {
        i_assert(idx+1 < size); /* already handled above */
        data[idx].uid2 = seq;
        if (data[idx+1].uid1 == seq+1) {
            /* merge */
            data[idx+1].uid1 = data[idx].uid1;
            buffer_delete(t->expunges, idx * sizeof(*data),
                      sizeof(*data));
        }
    } else {
        buffer_insert(t->expunges, idx * sizeof(*data),
                              &exp, sizeof(exp));
    }
}

static void mail_index_record_modify_flags(struct mail_index_record *rec,
                       enum modify_type modify_type,
                       enum mail_flags flags,
                       keywords_mask_t keywords)
{
    int i;

    switch (modify_type) {
    case MODIFY_REPLACE:
        rec->flags = flags;
        memcpy(rec->keywords, keywords, INDEX_KEYWORDS_BYTE_COUNT);
        break;
    case MODIFY_ADD:
        rec->flags |= flags;
        for (i = 0; i < INDEX_KEYWORDS_BYTE_COUNT; i++)
            rec->keywords[i] |= keywords[i];
        break;
    case MODIFY_REMOVE:
        rec->flags &= ~flags;
        for (i = 0; i < INDEX_KEYWORDS_BYTE_COUNT; i++)
            rec->keywords[i] &= ~keywords[i];
        break;
    }
}

#define IS_COMPATIBLE_UPDATE(t, modify_type, flags, keywords) \
    ((t)->last_update_modify_type == (modify_type) && \
     (t)->last_update.add_flags == (flags) && \
     memcmp((t)->last_update.add_keywords, keywords, \
            INDEX_KEYWORDS_BYTE_COUNT) == 0)

void mail_index_update_flags(struct mail_index_transaction *t, uint32_t seq,
                 enum modify_type modify_type,
                 enum mail_flags flags, keywords_mask_t keywords)
{
    struct mail_index_record *rec;

    if (t->first_new_seq != 0 && seq >= t->first_new_seq) {
        /* just appended message, modify it directly */
                rec = mail_index_lookup_append(t, seq);
        mail_index_record_modify_flags(rec, modify_type,
                           flags, keywords);
        return;
    }

    i_assert(seq > 0 && seq <= mail_index_view_get_message_count(t->view));

    /* first get group updates into same structure. this allows faster
       updates if same mails have multiple flag updates during same
       transaction (eg. 1:10 +seen, 1:10 +deleted) */
    if (t->last_update.uid2 == seq-1) {
        if (t->last_update.uid1 != 0 &&
            IS_COMPATIBLE_UPDATE(t, modify_type, flags, keywords)) {
            t->last_update.uid2 = seq;
            return;
        }
    } else if (t->last_update.uid1 == seq+1) {
        if (t->last_update.uid1 != 0 &&
            IS_COMPATIBLE_UPDATE(t, modify_type, flags, keywords)) {
            t->last_update.uid1 = seq;
            return;
        }
    }

    if (t->last_update.uid1 != 0)
        mail_index_transaction_add_last(t);

    t->last_update_modify_type = modify_type;
    t->last_update.uid1 = t->last_update.uid2 = seq;
    t->last_update.add_flags = flags;
    memcpy(t->last_update.add_keywords, keywords,
           INDEX_KEYWORDS_BYTE_COUNT);
}

static void
mail_index_transaction_get_last(struct mail_index_transaction *t,
                struct mail_transaction_flag_update *update)
{
    int i;

    *update = t->last_update;
    switch (t->last_update_modify_type) {
    case MODIFY_REPLACE:
        /* remove_flags = ~add_flags */
        update->remove_flags =
            ~update->add_flags & MAIL_INDEX_FLAGS_MASK;
        for (i = 0; i < INDEX_KEYWORDS_BYTE_COUNT; i++)
            update->remove_keywords[i] = ~update->add_keywords[i];
        break;
    case MODIFY_ADD:
        /* already in add_flags */
        break;
    case MODIFY_REMOVE:
        /* add_flags -> remove_flags */
        update->remove_flags = update->add_flags;
        memcpy(&update->remove_keywords, &update->add_keywords,
               INDEX_KEYWORDS_BYTE_COUNT);
        update->add_flags = 0;
        memset(&update->add_keywords, 0, INDEX_KEYWORDS_BYTE_COUNT);
        break;
    }
}

static void mail_index_transaction_add_last(struct mail_index_transaction *t)
{
    struct mail_transaction_flag_update update, *data;
    unsigned int idx, left_idx, right_idx;
    uint32_t last;
    size_t size;

        mail_index_transaction_get_last(t, &update);

    if (t->updates == NULL) {
        t->updates = buffer_create_dynamic(default_pool,
                           4096, (size_t)-1);
    }

    data = buffer_get_modifyable_data(t->updates, &size);
    size /= sizeof(*data);

    /* find the nearest sequence from existing updates */
    idx = 0; left_idx = 0; right_idx = size;
    while (left_idx < right_idx) {
        idx = (left_idx + right_idx) / 2;

        if (data[idx].uid1 < update.uid1)
            left_idx = idx+1;
        else if (data[idx].uid1 > update.uid1)
            right_idx = idx;
        else
            break;
    }
    if (idx < size && data[idx].uid2 < update.uid1)
        idx++;

    i_assert(idx == size || data[idx].uid1 <= update.uid1);

    /* insert it into buffer, split it in multiple parts if needed
       to make sure the ordering stays the same */
    for (; idx < size; idx++) {
        if (data[idx].uid1 > update.uid2)
            break;

        /* partial */
        last = update.uid2;
        update.uid2 = data[idx].uid1-1;

        if (update.uid1 <= update.uid2) {
            buffer_insert(t->updates, idx * sizeof(update),
                      &update, sizeof(update));
            data = buffer_get_modifyable_data(t->updates, NULL);
            size++;
        }

        update.uid1 = update.uid2+1;
        update.uid2 = last;
    }

    buffer_insert(t->updates, idx * sizeof(update),
              &update, sizeof(update));
}

static void mail_index_update_seq_buffer(buffer_t **buffer, uint32_t seq,
                     const void *record, size_t record_size)
{
    unsigned int idx, left_idx, right_idx;
    void *data;
    uint32_t full_record_size, *seq_p;
    size_t size;

    full_record_size = record_size + sizeof(uint32_t);

    if (*buffer == NULL)
        *buffer = buffer_create_dynamic(default_pool, 1024, (size_t)-1);
    data = buffer_get_modifyable_data(*buffer, &size);

    /* we're probably appending it, check */
    if (size == 0)
        idx = 0;
    else if (*((uint32_t *)PTR_OFFSET(data, size-full_record_size)) < seq)
        idx = size / full_record_size;
    else {
        idx = 0; left_idx = 0; right_idx = size / full_record_size;
        while (left_idx < right_idx) {
            idx = (left_idx + right_idx) / 2;

            seq_p = PTR_OFFSET(data, idx * full_record_size);
            if (*seq_p < seq)
                left_idx = idx+1;
            else if (*seq_p > seq)
                right_idx = idx;
            else {
                /* already there, update */
                memcpy(seq_p+1, record, record_size);
                return;
            }
        }
    }

    idx *= full_record_size;
    if (idx != size) {
        buffer_copy(*buffer, idx + full_record_size,
                *buffer, idx, (size_t)-1);
    }
    seq_p = buffer_get_space_unsafe(*buffer, idx, full_record_size);

    *seq_p = seq;
    memcpy(seq_p+1, record, record_size);
}

void mail_index_reset_cache(struct mail_index_transaction *t,
                uint32_t new_file_seq)
{
    t->new_cache_file_seq = new_file_seq;
}

void mail_index_update_cache(struct mail_index_transaction *t,
                 uint32_t seq, uint32_t offset)
{
    struct mail_index_record *rec;

    if (t->first_new_seq != 0 && seq >= t->first_new_seq) {
        /* just appended message, modify it directly */
        rec = mail_index_lookup_append(t, seq);
        rec->cache_offset = offset;
    } else {
        mail_index_update_seq_buffer(&t->cache_updates, seq,
                         &offset, sizeof(offset));
    }
}

void mail_index_update_extra_rec(struct mail_index_transaction *t,
                 uint32_t seq, uint32_t data_id,
                 const void *data)
{
    struct mail_index *index = t->view->index;
    struct mail_index_record *rec;

    i_assert(data_id < index->extra_records_count);

    if (t->first_new_seq != 0 && seq >= t->first_new_seq) {
        /* just appended message, modify it directly */
        /* FIXME: do data_id mapping conversion */
        rec = mail_index_lookup_append(t, seq);
        memcpy(PTR_OFFSET(rec, index->extra_records[data_id].offset),
               data, index->extra_records[data_id].size);
    } else {
        mail_index_update_seq_buffer(&t->extra_rec_updates[data_id],
            seq, data, index->extra_records[data_id].size);
    }
}

void mail_index_update_header(struct mail_index_transaction *t,
                  size_t offset, const void *data, size_t size)
{
    i_assert(offset < sizeof(t->hdr_change));
    i_assert(size <= sizeof(t->hdr_change) - offset);

    t->hdr_changed = TRUE;

    memcpy(t->hdr_change + offset, data, size);
    for (; size > 0; size--)
        t->hdr_mask[offset++] = 1;
}