src/lib-storage/mailbox-header.c

/* Copyright (c) 2003-2018 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "sort.h"
#include "mail-cache.h"
#include "mail-storage-private.h"


static struct mailbox_header_lookup_ctx *
mailbox_header_lookup_init_real(struct mailbox *box,
                const char *const headers[])
{
    struct mail_cache_field *fields, header_field = {
        .type = MAIL_CACHE_FIELD_HEADER,
        .decision = MAIL_CACHE_DECISION_TEMP
    };
    struct mailbox_header_lookup_ctx *ctx;
    const char *const *name;
    const char **sorted_headers, **dest_name;
    pool_t pool;
    unsigned int i, j, count;

    i_assert(*headers != NULL);

    for (count = 0, name = headers; *name != NULL; name++)
        count++;

    /* @UNSAFE: headers need to be sorted for filter stream. */
    sorted_headers = t_new(const char *, count);
    memcpy(sorted_headers, headers, count * sizeof(*sorted_headers));
    i_qsort(sorted_headers, count, sizeof(*sorted_headers), i_strcasecmp_p);
    headers = sorted_headers;

    /* @UNSAFE */
    fields = t_new(struct mail_cache_field, count);
    for (i = j = 0; i < count; i++) {
        if (i > 0 && strcasecmp(headers[i-1], headers[i]) == 0)
            continue;
        header_field.name = t_strconcat("hdr.", headers[i], NULL);
        fields[j++] = header_field;
    }
    count = j;
    mail_cache_register_fields(box->cache, fields, count);

    pool = pool_alloconly_create("mailbox_header_lookup_ctx", 1024);
    ctx = p_new(pool, struct mailbox_header_lookup_ctx, 1);
    ctx->box = box;
    ctx->refcount = 1;
    ctx->pool = pool;
    ctx->count = count;

    ctx->idx = p_new(pool, unsigned int, count);

    /* @UNSAFE */
    dest_name = p_new(pool, const char *, count + 1);
    for (i = 0; i < count; i++) {
        ctx->idx[i] = fields[i].idx;
        dest_name[i] = p_strdup(pool, fields[i].name + strlen("hdr."));
    }
    ctx->name = dest_name;
    return ctx;
}

struct mailbox_header_lookup_ctx *
mailbox_header_lookup_init(struct mailbox *box, const char *const headers[])
{
    struct mailbox_header_lookup_ctx *ctx;

    T_BEGIN {
        ctx = mailbox_header_lookup_init_real(box, headers);
    } T_END;
    return ctx;
}

void mailbox_header_lookup_ref(struct mailbox_header_lookup_ctx *ctx)
{
    i_assert(ctx->refcount > 0);
    ctx->refcount++;
}

void mailbox_header_lookup_unref(struct mailbox_header_lookup_ctx **_ctx)
{
    struct mailbox_header_lookup_ctx *ctx = *_ctx;

    if (ctx == NULL)
        return;

    *_ctx = NULL;

    i_assert(ctx->refcount > 0);
    if (--ctx->refcount > 0)
        return;

    pool_unref(&ctx->pool);
}