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

	mail-index-sync.c revision 757726d9acbd04cf0d0d4be8ce14e11525476a0b
/* Copyright (C) 2003-2004 Timo Sirainen */

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

#include <stdlib.h>

static void
mail_index_sync_sort_flags(buffer_t *dest_buf,
               const struct mail_transaction_flag_update *src,
               size_t src_size)
{
    const struct mail_transaction_flag_update *src_end;
    struct mail_transaction_flag_update *dest;
    struct mail_transaction_flag_update new_update, tmp_update;
    size_t i, dest_count;
    int j;

    dest = buffer_get_modifyable_data(dest_buf, &dest_count);
    dest_count /= sizeof(*dest);

    if (dest_count == 0) {
        buffer_append(dest_buf, src, src_size);
        return;
    }

    src_end = PTR_OFFSET(src, src_size);
    for (i = 0; src != src_end; src++) {
        new_update = *src;

        /* insert it into buffer, split and merge it with existing
           updates if needed. */
        for (; i < dest_count; i++) {
            if (new_update.uid1 > dest[i].uid2)
                continue;

            if (new_update.uid2 < dest[i].uid1)
                break;

            /* at least partially overlapping */

            if (new_update.uid1 < dest[i].uid1) {
                /* { 5..6 } + { 1..5 } -> { 1..4 } + { 5..6 } */
                tmp_update = new_update;
                tmp_update.uid2 = dest[i].uid1-1;
                new_update.uid1 = dest[i].uid1;
                buffer_insert(dest_buf, i * sizeof(tmp_update),
                          &tmp_update, sizeof(tmp_update));
                dest = buffer_get_modifyable_data(dest_buf,
                                  NULL);
                dest_count++; i++;
            } else if (new_update.uid1 > dest[i].uid1) {
                /* { 5..7 } + { 6..6 } ->
                   split old to { 5..5 } + { 6..7 } */
                tmp_update = dest[i];
                tmp_update.uid2 = new_update.uid1-1;
                dest[i].uid1 = new_update.uid1;
                buffer_insert(dest_buf, i * sizeof(tmp_update),
                          &tmp_update, sizeof(tmp_update));
                dest = buffer_get_modifyable_data(dest_buf,
                                  NULL);
                dest_count++; i++;
            }
            i_assert(new_update.uid1 == dest[i].uid1);

            if (new_update.uid2 < dest[i].uid2) {
                /* { 5..7 } + { 5..6 } -> { 5..6 } + { 7..7 } */
                tmp_update = dest[i];
                tmp_update.uid1 = new_update.uid2+1;
                dest[i].uid2 = new_update.uid2;
                buffer_insert(dest_buf,
                          (i+1) * sizeof(tmp_update),
                          &tmp_update, sizeof(tmp_update));
                dest = buffer_get_modifyable_data(dest_buf,
                                  NULL);
                dest_count++;
                new_update.uid2 = 0;
            } else {
                /* full match, or continues. */
                new_update.uid1 = dest[i].uid2+1;
            }

            /* dest[i] now contains the overlapping area.
               merge them - new_update overrides old changes. */
            dest[i].add_flags |= new_update.add_flags;
            dest[i].add_flags &= ~new_update.remove_flags;
            dest[i].remove_flags |= new_update.remove_flags;
            dest[i].remove_flags &= ~new_update.add_flags;

            for (j = 0; j < INDEX_KEYWORDS_BYTE_COUNT; j++) {
                dest[i].add_keywords[j] |=
                    new_update.add_keywords[j];
                dest[i].add_keywords[j] &=
                    ~new_update.remove_keywords[j];
                dest[i].remove_keywords[j] |=
                    new_update.remove_keywords[j];
                dest[i].remove_keywords[j] &=
                    ~new_update.add_keywords[j];
            }
        }

        if (new_update.uid1 <= new_update.uid2) {
            buffer_insert(dest_buf, i * sizeof(new_update),
                      &new_update, sizeof(new_update));
            dest = buffer_get_modifyable_data(dest_buf, NULL);
            dest_count++;
        }
    }
}

static void mail_index_sync_sort_transaction(struct mail_index_sync_ctx *ctx)
{
    switch (ctx->hdr->type & MAIL_TRANSACTION_TYPE_MASK) {
    case MAIL_TRANSACTION_EXPUNGE:
        mail_transaction_log_sort_expunges(ctx->expunges_buf,
                           ctx->data, ctx->hdr->size);
        break;
    case MAIL_TRANSACTION_FLAG_UPDATE:
        mail_index_sync_sort_flags(ctx->updates_buf, ctx->data,
                       ctx->hdr->size);
        break;
    case MAIL_TRANSACTION_APPEND: {
        const struct mail_index_record *rec = ctx->data;

        if (ctx->append_uid_first == 0 ||
            rec->uid < ctx->append_uid_first)
            ctx->append_uid_first = rec->uid;

        rec = CONST_PTR_OFFSET(ctx->data,
                       ctx->hdr->size - sizeof(*rec));
        if (rec->uid > ctx->append_uid_last)
            ctx->append_uid_last = rec->uid;

                ctx->sync_appends = TRUE;
        break;
    }
    }
}

static int mail_index_sync_add_dirty_updates(struct mail_index_sync_ctx *ctx)
{
    struct mail_transaction_flag_update update;
    const struct mail_index_record *rec;
    uint32_t seq, messages_count;
    int i;

    memset(&update, 0, sizeof(update));

    messages_count = mail_index_view_get_message_count(ctx->view);
    for (seq = 1; seq <= messages_count; seq++) {
        if (mail_index_lookup(ctx->view, seq, &rec) < 0)
            return -1;

        if ((rec->flags & MAIL_INDEX_MAIL_FLAG_DIRTY) == 0)
            continue;

        update.uid1 = update.uid2 = rec->uid;
        update.add_flags = rec->flags;
        update.remove_flags = ~update.add_flags;
        memcpy(update.add_keywords, rec->keywords,
               INDEX_KEYWORDS_BYTE_COUNT);
        for (i = 0; i < INDEX_KEYWORDS_BYTE_COUNT; i++)
            update.remove_keywords[i] = ~update.add_keywords[i];

        mail_index_sync_sort_flags(ctx->updates_buf,
                       &update, sizeof(update));
    }
    return 0;
}

static int mail_index_sync_add_recent_updates(struct mail_index_sync_ctx *ctx)
{
    struct mail_transaction_flag_update update;
    const struct mail_index_record *rec;
    uint32_t seq, messages_count;

    memset(&update, 0, sizeof(update));

    messages_count = mail_index_view_get_message_count(ctx->view);
    for (seq = 1; seq <= messages_count; seq++) {
        if (mail_index_lookup(ctx->view, seq, &rec) < 0)
            return -1;

        if ((rec->flags & MAIL_RECENT) == 0)
            continue;

        update.uid1 = update.uid2 = rec->uid;
        mail_index_sync_sort_flags(ctx->updates_buf,
                       &update, sizeof(update));
    }
    return 0;
}

static int
mail_index_sync_read_and_sort(struct mail_index_sync_ctx *ctx, int sync_recent)
{
    size_t size;
    int ret;

    if ((ctx->view->map->hdr->flags & MAIL_INDEX_HDR_FLAG_HAVE_DIRTY) &&
        ctx->sync_dirty) {
        /* show dirty flags as flag updates */
        if (mail_index_sync_add_dirty_updates(ctx) < 0)
            return -1;
    }

    if (sync_recent) {
        if (mail_index_sync_add_recent_updates(ctx) < 0)
            return -1;
    }

    while ((ret = mail_transaction_log_view_next(ctx->view->log_view,
                             &ctx->hdr,
                             &ctx->data, NULL)) > 0) {
        if ((ctx->hdr->type & MAIL_TRANSACTION_EXTERNAL) == 0)
            mail_index_sync_sort_transaction(ctx);
    }

    ctx->expunges = buffer_get_data(ctx->expunges_buf, &size);
    ctx->expunges_count = size / sizeof(*ctx->expunges);
    ctx->updates = buffer_get_data(ctx->updates_buf, &size);
    ctx->updates_count = size / sizeof(*ctx->updates);

    return ret;
}

static int mail_index_need_lock(struct mail_index *index, int sync_recent,
                uint32_t log_file_seq, uoff_t log_file_offset)
{
    if (sync_recent && index->hdr->recent_messages_count > 0)
        return 1;

    if (index->hdr->log_file_seq > log_file_seq ||
         (index->hdr->log_file_seq == log_file_seq &&
          index->hdr->log_file_offset >= log_file_offset)) {
        /* already synced */
        return mail_cache_need_compress(index->cache);
    }

    return 1;
}

int mail_index_sync_begin(struct mail_index *index,
                          struct mail_index_sync_ctx **ctx_r,
              struct mail_index_view **view_r,
              uint32_t log_file_seq, uoff_t log_file_offset,
              int sync_recent, int sync_dirty)
{
    struct mail_index_sync_ctx *ctx;
    uint32_t seq;
    uoff_t offset;
    unsigned int lock_id;

    if (mail_transaction_log_sync_lock(index->log, &seq, &offset) < 0)
        return -1;

    if (mail_index_lock_shared(index, TRUE, &lock_id) < 0) {
        mail_transaction_log_sync_unlock(index->log);
        return -1;
    }

    if (mail_index_map(index, FALSE) <= 0) {
        mail_transaction_log_sync_unlock(index->log);
        mail_index_unlock(index, lock_id);
        return -1;
    }

    if (!mail_index_need_lock(index, sync_recent,
                  log_file_seq, log_file_offset)) {
        mail_index_unlock(index, lock_id);
        mail_transaction_log_sync_unlock(index->log);
        return 0;
    }

    ctx = i_new(struct mail_index_sync_ctx, 1);
    ctx->index = index;
    ctx->lock_id = lock_id;
    ctx->sync_dirty = sync_dirty;

    ctx->view = mail_index_view_open(index);
    ctx->view->external = TRUE;

    if (mail_transaction_log_view_set(ctx->view->log_view,
                      index->hdr->log_file_seq,
                      index->hdr->log_file_offset,
                      seq, offset,
                      MAIL_TRANSACTION_TYPE_MASK) < 0) {
                mail_index_sync_rollback(ctx);
        return -1;
    }

    /* we need to have all the transactions sorted to optimize
       caller's mailbox access patterns */
    ctx->expunges_buf = buffer_create_dynamic(default_pool,
                          1024, (size_t)-1);
    ctx->updates_buf = buffer_create_dynamic(default_pool,
                         1024, (size_t)-1);
    if (mail_index_sync_read_and_sort(ctx, sync_recent) < 0) {
                mail_index_sync_rollback(ctx);
        return -1;
    }

    *ctx_r = ctx;
    *view_r = ctx->view;
    return 1;
}

void
mail_index_sync_get_expunge(struct mail_index_sync_rec *rec,
                const struct mail_transaction_expunge *exp)
{
    rec->type = MAIL_INDEX_SYNC_TYPE_EXPUNGE;
    rec->uid1 = exp->uid1;
    rec->uid2 = exp->uid2;
}

void
mail_index_sync_get_update(struct mail_index_sync_rec *rec,
               const struct mail_transaction_flag_update *update)
{
    rec->type = MAIL_INDEX_SYNC_TYPE_FLAGS;
    rec->uid1 = update->uid1;
    rec->uid2 = update->uid2;

    rec->add_flags = update->add_flags;
    memcpy(rec->add_keywords, update->add_keywords,
           sizeof(rec->add_keywords));
    rec->remove_flags = update->remove_flags;
    memcpy(rec->remove_keywords, update->remove_keywords,
           sizeof(rec->remove_keywords));
}

static int mail_index_sync_rec_check(struct mail_index_view *view,
                     struct mail_index_sync_rec *rec)
{
    switch (rec->type) {
    case MAIL_INDEX_SYNC_TYPE_EXPUNGE:
    case MAIL_INDEX_SYNC_TYPE_FLAGS:
        if (rec->uid1 > rec->uid2 || rec->uid1 == 0) {
            mail_transaction_log_view_set_corrupted(view->log_view,
                "Broken UID range: %u..%u (type 0x%x)",
                rec->uid1, rec->uid2, rec->type);
            return FALSE;
        }
        break;
    case MAIL_INDEX_SYNC_TYPE_APPEND:
        break;
    }
    return TRUE;
}

int mail_index_sync_next(struct mail_index_sync_ctx *ctx,
             struct mail_index_sync_rec *sync_rec)
{
    const struct mail_transaction_expunge *next_exp;
    const struct mail_transaction_flag_update *next_update;

    next_exp = ctx->expunge_idx == ctx->expunges_count ? NULL :
        &ctx->expunges[ctx->expunge_idx];
    next_update = ctx->update_idx == ctx->updates_count ? NULL :
        &ctx->updates[ctx->update_idx];

    if (next_update != NULL &&
        (next_exp == NULL || next_update->uid1 < next_exp->uid1)) {
        mail_index_sync_get_update(sync_rec, next_update);
        if (next_exp != NULL && next_exp->uid1 <= next_update->uid2) {
            /* it's overlapping with next expunge */
            sync_rec->uid2 = next_exp->uid1-1;
        }

        if (sync_rec->uid1 < ctx->next_uid) {
            /* overlapping with previous expunge */
            if (ctx->next_uid > sync_rec->uid2) {
                /* hide this update completely */
                ctx->update_idx++;
                                return mail_index_sync_next(ctx, sync_rec);
            }
            sync_rec->uid1 = ctx->next_uid;
        }

        i_assert(sync_rec->uid1 <= sync_rec->uid2);
        ctx->update_idx++;
        return mail_index_sync_rec_check(ctx->view, sync_rec);
    }

    if (next_exp != NULL) {
        mail_index_sync_get_expunge(sync_rec, next_exp);
        if (mail_index_sync_rec_check(ctx->view, sync_rec) < 0)
            return -1;

        ctx->expunge_idx++;
        ctx->next_uid = next_exp->uid2+1;
        return 1;
    }

    if (ctx->sync_appends) {
        ctx->sync_appends = FALSE;
        sync_rec->type = MAIL_INDEX_SYNC_TYPE_APPEND;
        sync_rec->uid1 = ctx->append_uid_first;
        sync_rec->uid2 = ctx->append_uid_last;
        return 1;
    }

    return 0;
}

int mail_index_sync_have_more(struct mail_index_sync_ctx *ctx)
{
    return (ctx->update_idx != ctx->updates_count) ||
        (ctx->expunge_idx != ctx->expunges_count) ||
        ctx->sync_appends;
}

static void mail_index_sync_end(struct mail_index_sync_ctx *ctx)
{
    mail_index_unlock(ctx->index, ctx->lock_id);
        i_assert(!ctx->index->map->write_to_disk);
    mail_transaction_log_sync_unlock(ctx->index->log);
    mail_index_view_close(ctx->view);

    if (ctx->expunges_buf != NULL)
        buffer_free(ctx->expunges_buf);
    if (ctx->updates_buf != NULL)
        buffer_free(ctx->updates_buf);
    i_free(ctx);
}

int mail_index_sync_commit(struct mail_index_sync_ctx *ctx)
{
    const struct mail_index_header *hdr;
    uint32_t seq, seq2;
    uoff_t offset, offset2;
    int ret = 0;

    if (mail_transaction_log_view_is_corrupted(ctx->view->log_view))
        ret = -1;

    mail_transaction_log_get_head(ctx->index->log, &seq, &offset);

    if (ret == 0) {
        hdr = ctx->index->hdr;

        if (mail_transaction_log_view_set(ctx->view->log_view,
                hdr->log_file_seq, hdr->log_file_offset,
                seq, offset, MAIL_TRANSACTION_TYPE_MASK) < 0)
            ret = -1;
        else if (mail_index_sync_update_index(ctx) < 0)
            ret = -1;
    }

    if (ret == 0 && mail_cache_need_compress(ctx->index->cache)) {
        if (mail_cache_compress(ctx->index->cache, ctx->view) < 0)
            ret = -1;
        else {
            /* cache_offsets have changed, sync them */
            mail_transaction_log_get_head(ctx->index->log,
                              &seq2, &offset2);
            if (mail_transaction_log_view_set(ctx->view->log_view,
                    seq, offset, seq2, offset2,
                    MAIL_TRANSACTION_TYPE_MASK) < 0)
                ret = -1;
            else if (mail_index_sync_update_index(ctx) < 0)
                ret = -1;
        }
    }

    mail_index_sync_end(ctx);
    return ret;
}

void mail_index_sync_rollback(struct mail_index_sync_ctx *ctx)
{
    mail_index_sync_end(ctx);
}

void mail_index_sync_flags_apply(const struct mail_index_sync_rec *sync_rec,
                 uint8_t *flags, keywords_mask_t keywords)
{
    int i;

    i_assert(sync_rec->type == MAIL_INDEX_SYNC_TYPE_FLAGS);

    *flags = (*flags & ~sync_rec->remove_flags) | sync_rec->add_flags;
    for (i = 0; i < INDEX_KEYWORDS_BYTE_COUNT; i++) {
        keywords[i] = (keywords[i] & ~sync_rec->remove_keywords[i]) |
            sync_rec->add_keywords[i];
    }
}