ngx_hash.c

来自「Nginx是一个高性能的HTTP和反向代理服务器」· C语言 代码 · 共 956 行 · 第 1/2 页

#endif

        dot = 0;

        for (len = 0; len < names[n].key.len; len++) {
            if (names[n].key.data[len] == '.') {
                dot = 1;
                break;
            }
        }

        name = ngx_array_push(&curr_names);
        if (name == NULL) {
            return NGX_ERROR;
        }

        name->key.len = len;
        name->key.data = names[n].key.data;
        name->key_hash = hinit->key(name->key.data, name->key.len);
        name->value = names[n].value;

#if 0
        ngx_log_error(NGX_LOG_ALERT, hinit->pool->log, 0,
                      "wc1: \"%V\" %ui", &name->key, dot);
#endif

        dot_len = len + 1;

        if (dot) {
            len++;
        }

        next_names.nelts = 0;

        if (names[n].key.len != len) {
            next_name = ngx_array_push(&next_names);
            if (next_name == NULL) {
                return NGX_ERROR;
            }

            next_name->key.len = names[n].key.len - len;
            next_name->key.data = names[n].key.data + len;
            next_name->key_hash= 0;
            next_name->value = names[n].value;

#if 0
            ngx_log_error(NGX_LOG_ALERT, hinit->pool->log, 0,
                          "wc2: \"%V\"", &next_name->key);
#endif
        }

        for (i = n + 1; i < nelts; i++) {
            if (ngx_strncmp(names[n].key.data, names[i].key.data, len) != 0) {
                break;
            }

            if (!dot
                && names[i].key.len > len
                && names[i].key.data[len] != '.')
            {
                break;
            }

            next_name = ngx_array_push(&next_names);
            if (next_name == NULL) {
                return NGX_ERROR;
            }

            next_name->key.len = names[i].key.len - dot_len;
            next_name->key.data = names[i].key.data + dot_len;
            next_name->key_hash= 0;
            next_name->value = names[i].value;

#if 0
            ngx_log_error(NGX_LOG_ALERT, hinit->pool->log, 0,
                          "wc3: \"%V\"", &next_name->key);
#endif
        }

        if (next_names.nelts) {

            h = *hinit;
            h.hash = NULL;

            if (ngx_hash_wildcard_init(&h, (ngx_hash_key_t *) next_names.elts,
                                       next_names.nelts)
                != NGX_OK)
            {
                return NGX_ERROR;
            }

            wdc = (ngx_hash_wildcard_t *) h.hash;

            if (names[n].key.len == len) {
                wdc->value = names[n].value;
#if 0
                ngx_log_error(NGX_LOG_ALERT, hinit->pool->log, 0,
                              "wdc: \"%V\"", wdc->value);
#endif
            }

            name->value = (void *) ((uintptr_t) wdc | (dot ? 1 : 3));
        }
    }

    if (ngx_hash_init(hinit, (ngx_hash_key_t *) curr_names.elts,
                      curr_names.nelts)
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    return NGX_OK;
}


ngx_uint_t
ngx_hash_key(u_char *data, size_t len)
{
    ngx_uint_t  i, key;

    key = 0;

    for (i = 0; i < len; i++) {
        key = ngx_hash(key, data[i]);
    }

    return key;
}


ngx_uint_t
ngx_hash_key_lc(u_char *data, size_t len)
{
    ngx_uint_t  i, key;

    key = 0;

    for (i = 0; i < len; i++) {
        key = ngx_hash(key, ngx_tolower(data[i]));
    }

    return key;
}


ngx_int_t
ngx_hash_keys_array_init(ngx_hash_keys_arrays_t *ha, ngx_uint_t type)
{
    ngx_uint_t  asize;

    if (type == NGX_HASH_SMALL) {
        asize = 4;
        ha->hsize = 107;

    } else {
        asize = NGX_HASH_LARGE_ASIZE;
        ha->hsize = NGX_HASH_LARGE_HSIZE;
    }

    if (ngx_array_init(&ha->keys, ha->temp_pool, asize, sizeof(ngx_hash_key_t))
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    if (ngx_array_init(&ha->dns_wc_head, ha->temp_pool, asize,
                       sizeof(ngx_hash_key_t))
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    if (ngx_array_init(&ha->dns_wc_tail, ha->temp_pool, asize,
                       sizeof(ngx_hash_key_t))
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    ha->keys_hash = ngx_pcalloc(ha->temp_pool, sizeof(ngx_array_t) * ha->hsize);
    if (ha->keys_hash == NULL) {
        return NGX_ERROR;
    }

    ha->dns_wc_head_hash = ngx_pcalloc(ha->temp_pool,
                                       sizeof(ngx_array_t) * ha->hsize);
    if (ha->dns_wc_head_hash == NULL) {
        return NGX_ERROR;
    }

    ha->dns_wc_tail_hash = ngx_pcalloc(ha->temp_pool,
                                       sizeof(ngx_array_t) * ha->hsize);
    if (ha->dns_wc_tail_hash == NULL) {
        return NGX_ERROR;
    }

    return NGX_OK;
}


ngx_int_t
ngx_hash_add_key(ngx_hash_keys_arrays_t *ha, ngx_str_t *key, void *value,
    ngx_uint_t flags)
{
    size_t           len;
    u_char          *p;
    ngx_str_t       *name;
    ngx_uint_t       i, k, n, skip, last;
    ngx_array_t     *keys, *hwc;
    ngx_hash_key_t  *hk;

    last = key->len;

    if (flags & NGX_HASH_WILDCARD_KEY) {

        /*
         * supported wildcards:
         *     "*.example.com", ".example.com", and "www.example.*"
         */

        n = 0;

        for (i = 0; i < key->len; i++) {

            if (key->data[i] == '*') {
                if (++n > 1) {
                    return NGX_DECLINED;
                }
            }

            if (key->data[i] == '.' && key->data[i + 1] == '.') {
                return NGX_DECLINED;
            }
        }

        if (key->len > 1 && key->data[0] == '.') {
            skip = 1;
            goto wildcard;
        }

        if (key->len > 2) {

            if (key->data[0] == '*' && key->data[1] == '.') {
                skip = 2;
                goto wildcard;
            }

            if (key->data[i - 2] == '.' && key->data[i - 1] == '*') {
                skip = 0;
                last -= 2;
                goto wildcard;
            }
        }

        if (n) {
            return NGX_DECLINED;
        }
    }

    /* exact hash */

    k = 0;

    for (i = 0; i < last; i++) {
        if (!(flags & NGX_HASH_READONLY_KEY)) {
            key->data[i] = ngx_tolower(key->data[i]);
        }
        k = ngx_hash(k, key->data[i]);
    }

    k %= ha->hsize;

    /* check conflicts in exact hash */

    name = ha->keys_hash[k].elts;

    if (name) {
        for (i = 0; i < ha->keys_hash[k].nelts; i++) {
            if (last != name[i].len) {
                continue;
            }

            if (ngx_strncmp(key->data, name[i].data, last) == 0) {
                return NGX_BUSY;
            }
        }

    } else {
        if (ngx_array_init(&ha->keys_hash[k], ha->temp_pool, 4,
                           sizeof(ngx_str_t))
            != NGX_OK)
        {
            return NGX_ERROR;
        }
    }

    name = ngx_array_push(&ha->keys_hash[k]);
    if (name == NULL) {
        return NGX_ERROR;
    }

    *name = *key;

    hk = ngx_array_push(&ha->keys);
    if (hk == NULL) {
        return NGX_ERROR;
    }

    hk->key = *key;
    hk->key_hash = ngx_hash_key(key->data, last);
    hk->value = value;

    return NGX_OK;


wildcard:

    /* wildcard hash */

    k = 0;

    for (i = skip; i < last; i++) {
        key->data[i] = ngx_tolower(key->data[i]);
        k = ngx_hash(k, key->data[i]);
    }

    k %= ha->hsize;

    if (skip == 1) {

        /* check conflicts in exact hash for ".example.com" */

        name = ha->keys_hash[k].elts;

        if (name) {
            len = last - skip;

            for (i = 0; i < ha->keys_hash[k].nelts; i++) {
                if (len != name[i].len) {
                    continue;
                }

                if (ngx_strncmp(&key->data[1], name[i].data, len) == 0) {
                    return NGX_BUSY;
                }
            }

        } else {
            if (ngx_array_init(&ha->keys_hash[k], ha->temp_pool, 4,
                               sizeof(ngx_str_t))
                != NGX_OK)
            {
                return NGX_ERROR;
            }
        }

        name = ngx_array_push(&ha->keys_hash[k]);
        if (name == NULL) {
            return NGX_ERROR;
        }

        name->len = last - 1;
        name->data = ngx_palloc(ha->temp_pool, name->len);
        if (name->data == NULL) {
            return NGX_ERROR;
        }

        ngx_memcpy(name->data, &key->data[1], name->len);
    }


    if (skip) {

        /*
         * convert "*.example.com" to "com.example.\0"
         *      and ".example.com" to "com.example\0"
         */

        p = ngx_palloc(ha->temp_pool, last);
        if (p == NULL) {
            return NGX_ERROR;
        }

        len = 0;
        n = 0;

        for (i = last - 1; i; i--) {
            if (key->data[i] == '.') {
                ngx_memcpy(&p[n], &key->data[i + 1], len);
                n += len;
                p[n++] = '.';
                len = 0;
                continue;
            }

            len++;
        }

        if (len) {
            ngx_memcpy(&p[n], &key->data[1], len);
            n += len;
        }

        p[n] = '\0';

        hwc = &ha->dns_wc_head;
        keys = &ha->dns_wc_head_hash[k];

    } else {

        /* convert "www.example.*" to "www.example\0" */

        last++;

        p = ngx_palloc(ha->temp_pool, last);
        if (p == NULL) {
            return NGX_ERROR;
        }

        ngx_cpystrn(p, key->data, last);

        hwc = &ha->dns_wc_tail;
        keys = &ha->dns_wc_tail_hash[k];
    }


    hk = ngx_array_push(hwc);
    if (hk == NULL) {
        return NGX_ERROR;
    }

    hk->key.len = last - 1;
    hk->key.data = p;
    hk->key_hash = 0;
    hk->value = value;


    /* check conflicts in wildcard hash */

    name = keys->elts;

    if (name) {
        len = last - skip;

        for (i = 0; i < keys->nelts; i++) {
            if (len != name[i].len) {
                continue;
            }

            if (ngx_strncmp(key->data + skip, name[i].data, len) == 0) {
                return NGX_BUSY;
            }
        }

    } else {
        if (ngx_array_init(keys, ha->temp_pool, 4, sizeof(ngx_str_t)) != NGX_OK)
        {
            return NGX_ERROR;
        }
    }

    name = ngx_array_push(keys);
    if (name == NULL) {
        return NGX_ERROR;
    }

    name->len = last - skip;
    name->data = ngx_palloc(ha->temp_pool, name->len);
    if (name->data == NULL) {
        return NGX_ERROR;
    }

    ngx_memcpy(name->data, key->data + skip, name->len);

    return NGX_OK;
}