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

	mail-cache-sync-update.c revision 74eff344f67ca582eec8c38dfdc6f5f6faa21fd8
/* Copyright (C) 2004 Timo Sirainen */

#include "lib.h"
#include "file-cache.h"
#include "mail-cache-private.h"
#include "mail-index-view-private.h"
#include "mail-index-sync-private.h"

struct mail_cache_sync_context {
    unsigned int locked:1;
    unsigned int lock_failed:1;
};

static void mail_cache_handler_deinit(struct mail_index_sync_map_ctx *sync_ctx,
                      struct mail_cache_sync_context *ctx)
{
    if (ctx == NULL)
        return;

    if (ctx->locked)
        mail_cache_unlock(sync_ctx->view->index->cache);
    i_free(ctx);
}

static int mail_cache_handler_init(struct mail_cache_sync_context **ctx_r,
                   struct mail_cache *cache)
{
    struct mail_cache_sync_context *ctx = *ctx_r;
    int ret;

    if (ctx == NULL)
        ctx = *ctx_r = i_new(struct mail_cache_sync_context, 1);

    if (ctx->locked)
        return 1;
    if (ctx->lock_failed)
        return 0;

    if (!ctx->locked) {
        if ((ret = mail_cache_lock(cache)) <= 0) {
                        ctx->lock_failed = TRUE;
            return ret;
        }
        ctx->locked = TRUE;
    }
    return 1;
}

static int get_cache_file_seq(struct mail_index_view *view,
                  uint32_t *cache_file_seq_r)
{
    const struct mail_index_ext *ext;

    ext = mail_index_view_get_ext(view, view->index->cache->ext_id);
    if (ext == NULL)
        return 0;

    *cache_file_seq_r = ext->reset_id;
    return 1;
}

int mail_cache_expunge_handler(struct mail_index_sync_map_ctx *sync_ctx,
                   uint32_t seq __attr_unused__,
                   const void *data, void **context)
{
    struct mail_index_view *view = sync_ctx->view;
    struct mail_cache_sync_context *ctx = *context;
    struct mail_cache *cache = view->index->cache;
    const uint32_t *cache_offset = data;
    uint32_t cache_file_seq;
    int ret;

    if (data == NULL) {
        mail_cache_handler_deinit(sync_ctx, ctx);
        *context = NULL;
        return 1;
    }

    if (*cache_offset == 0)
        return 1;

    if (MAIL_CACHE_IS_UNUSABLE(cache))
        return 1;

    ret = mail_cache_handler_init(&ctx, cache);
    *context = ctx;
    if (ret <= 0)
        return ret < 0 ? -1 : 1;

    if (!get_cache_file_seq(view, &cache_file_seq))
        return 1;

    if (!MAIL_CACHE_IS_UNUSABLE(cache) &&
        cache_file_seq != cache->hdr->file_seq)
        (void)mail_cache_delete(cache, *cache_offset);
    return 1;
}

int mail_cache_sync_handler(struct mail_index_sync_map_ctx *sync_ctx,
                uint32_t seq __attr_unused__,
                void *old_data, const void *new_data,
                void **context)
{
    struct mail_index_view *view = sync_ctx->view;
    struct mail_cache *cache = view->index->cache;
    struct mail_cache_sync_context *ctx = *context;
    const uint32_t *old_cache_offset = old_data;
    const uint32_t *new_cache_offset = new_data;
    uint32_t cache_file_seq;
    int ret;

    if (new_cache_offset == NULL) {
        mail_cache_handler_deinit(sync_ctx, ctx);
        *context = NULL;
        return 1;
    }

    if (MAIL_CACHE_IS_UNUSABLE(cache))
        return 1;

    if (cache->file_cache != NULL) {
        file_cache_invalidate(cache->file_cache, *new_cache_offset,
                      (uoff_t)-1);
    }

    if (*old_cache_offset == 0 ||
        sync_ctx->type != MAIL_INDEX_SYNC_HANDLER_INDEX)
        return 1;

    /* we'll need to link the old and new cache records */
    ret = mail_cache_handler_init(&ctx, cache);
    *context = ctx;
    if (ret <= 0)
        return ret < 0 ? -1 : 1;

    if (!get_cache_file_seq(view, &cache_file_seq))
        return 1;

    if (cache_file_seq != cache->hdr->file_seq) {
        /* cache has been compressed, don't modify it */
        return 1;
    }

    if (mail_cache_link(cache, *old_cache_offset, *new_cache_offset) < 0)
        return -1;

    return 1;
}