ngx_int_t hustdb_ha_read_handler(
ngx_bool_t read_body,
ngx_bool_t key_in_body,
hustdb_ha_check_parameter_t check_parameter,
ngx_str_t * backend_uri,
ngx_http_request_t *r)
{
hustdb_ha_ctx_t * ctx = ngx_http_get_addon_module_ctx(r);
if (!ctx)
{
if (read_body && !(r->method & NGX_HTTP_POST))
{
return NGX_HTTP_NOT_ALLOWED;
}
if (check_parameter && !check_parameter(backend_uri, r))
{
return NGX_ERROR;
}
return read_body ? __post_read(key_in_body, backend_uri, r) : __start_read(backend_uri, r);
}
if (NGX_HTTP_OK != r->headers_out.status)
{
ctx->peer = ngx_http_get_next_peer(ctx->peer);
return ctx->peer ? ngx_http_run_subrequest(
r, &ctx->base, ctx->peer->peer) : hustdb_ha_send_response(
NGX_HTTP_NOT_FOUND, NULL, NULL, r);
}
return hustdb_ha_send_response(NGX_HTTP_OK, ctx->version, &ctx->base.response, r);
}
static ngx_int_t __write_sync_data(
uint8_t method,
ngx_bool_t has_tb,
ngx_http_request_t *r,
ngx_http_hustdb_ha_write_ctx_t * ctx)
{
do
{
time_t now = time(NULL);
uint32_t ttl = (0 == ctx->ttl) ? 0 : (uint32_t) (now + ctx->ttl);
ngx_buf_t * value = NULL;
ngx_buf_t * head = __encode_head(method, ctx->proto, has_tb, ctx->base.version, ctx->base.key, ctx->base.tb, ttl, r->pool);
if (r->request_body)
{
if (!ngx_http_insert_head_to_body(head, r))
{
break;
}
value = ngx_http_get_request_body(r);
}
else
{
value = head;
}
if (!value)
{
break;
}
ngx_http_hustdb_ha_main_conf_t * mcf = hustdb_ha_get_module_main_conf(r);
ngx_str_t * server = &ctx->error_peer->peer->server;
if (!hustdb_ha_write_log(&mcf->zlog_mdc, server, value, r->pool))
{
break;
}
static ngx_str_t SYNC_KEY = ngx_string("Sync");
if (!ngx_http_add_field_to_headers_out(&SYNC_KEY, server, r))
{
break;
}
return hustdb_ha_send_response(NGX_HTTP_OK, ctx->base.version, NULL, r);
} while (0);
return hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
}
static ngx_int_t __on_write_master1_complete(
uint8_t method,
ngx_bool_t has_tb,
ngx_http_request_t *r,
ngx_http_hustdb_ha_write_ctx_t * ctx)
{
__update_error(method, r->headers_out.status, ctx);
ctx->base.peer = ctx->base.peer->next;
ngx_bool_t alive = ngx_http_peer_is_alive(ctx->base.peer->peer);
ngx_http_hustdb_ha_main_conf_t * mcf = hustdb_ha_get_module_main_conf(r);
if (mcf->debug_sync)
{
alive = false;
}
if (alive) // master2
{
ctx->state = STATE_WRITE_MASTER2;
return ngx_http_run_subrequest(r, &ctx->base.base, ctx->base.peer->peer);
}
// master2 dead
++ctx->error_count;
ctx->error_peer = ctx->base.peer;
if (ctx->error_count > 1) // both master1 & master2 fail
{
return hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
}
return __write_sync_data(method, has_tb, r, ctx);
}
static void __post_handler(ngx_http_request_t *r)
{
--r->main->count;
ngx_http_hustdb_ha_write_ctx_t * ctx = ngx_http_get_addon_module_ctx(r);
ngx_bool_t rc = true;
if (ctx->key_in_body)
{
if (!__init_write_ctx_by_body(r, ctx))
{
rc = false;
}
}
else
{
if (ctx->check_body_len)
{
rc = hustdb_ha_check_body(r);
}
}
if (!rc)
{
hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
return;
}
ngx_http_gen_subrequest(
ctx->base.base.backend_uri,
r,
ctx->base.peer->peer,
&ctx->base.base,
hustdb_ha_on_subrequest_complete);
}
// -------------------------------------------------------------
// |skip | 0 | 1 | 2 | 0 | 1 | 2 | 0 |
// -------------------------------------------------------------
// |err | 0 | 0 | 0 | 1 | 1 | 0 | 2 |
// -------------------------------------------------------------
// |action | 200 | 200 | 404 | 200&log | 404 | 404 | 404 |
// -------------------------------------------------------------
static ngx_int_t __send_write_response(
uint8_t method,
ngx_bool_t has_tb,
ngx_http_request_t *r,
ngx_http_hustdb_ha_write_ctx_t * ctx)
{
if (0 == ctx->skip_error_count && 1 == ctx->error_count)
{
return __write_sync_data(method, has_tb, r, ctx);
}
if (0 == ctx->skip_error_count && 0 == ctx->error_count)
{
return hustdb_ha_send_response(NGX_HTTP_OK, &ctx->base.version, NULL, r);
}
return hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
}
ngx_int_t hustdb_ha_start_post(
ngx_bool_t support_post_only,
ngx_bool_t key_in_body,
ngx_bool_t has_tb,
ngx_bool_t check_body_len,
ngx_str_t * backend_uri,
ngx_http_request_t *r)
{
ngx_http_hustdb_ha_write_ctx_t * ctx = __create_write_ctx(r);
if (!ctx)
{
return hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
}
ctx->check_body_len = check_body_len;
ctx->base.base.backend_uri = backend_uri;
if (support_post_only && !(r->method & NGX_HTTP_POST))
{
return NGX_HTTP_NOT_ALLOWED;
}
if (key_in_body)
{
ctx->key_in_body = true;
ctx->has_tb = has_tb;
}
else
{
write_ctx_t tmp;
if (!__set_write_context(NULL, has_tb, r, &tmp))
{
return hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
}
__copy_data(&tmp, ctx);
}
ngx_int_t rc = ngx_http_read_client_request_body(r, __post_handler);
if ( rc >= NGX_HTTP_SPECIAL_RESPONSE )
{
return rc;
}
return NGX_DONE;
}
static ngx_int_t __on_write_master2_complete(
uint8_t method,
ngx_bool_t has_tb,
ngx_http_request_t *r,
ngx_http_hustdb_ha_write_ctx_t * ctx)
{
__update_error(method, r->headers_out.status, ctx);
if (ctx->error_count > 1) // both master1 & master2 fail
{
return hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
}
else if (1 == ctx->error_count) // master1 or master2 fail
{
return __write_sync_data(method, has_tb, r, ctx);
}
if (ctx->skip_error_count > 1) // both master1 and master2 return 404 for del
{
return hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
}
return hustdb_ha_send_response(NGX_HTTP_OK, ctx->base.version, NULL, r);
}
static ngx_int_t __start_zwrite(ngx_str_t * backend_uri, ngx_http_request_t *r)
{
ngx_http_hustdb_ha_write_ctx_t * ctx = __create_zwrite_ctx(r);
if (!ctx)
{
return hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
}
ctx->base.base.backend_uri = backend_uri;
write_ctx_t tmp;
if (!__parse_args(true, true, r, &tmp))
{
return hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
}
__copy_data(&tmp, ctx);
ngx_int_t rc = ngx_http_read_client_request_body(r, __post_body_handler);
if ( rc >= NGX_HTTP_SPECIAL_RESPONSE )
{
return rc;
}
return NGX_DONE;
}
static void __post_body_handler(ngx_http_request_t *r)
{
--r->main->count;
ngx_http_hustdb_ha_write_ctx_t * ctx = ngx_http_get_addon_module_ctx(r);
ctx->base.key = hustdb_ha_get_key(r);
if (!ctx->base.key)
{
hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
return;
}
ngx_http_gen_subrequest(
ctx->base.base.backend_uri,
r,
ctx->base.peer->peer,
&ctx->base.base,
hustdb_ha_on_subrequest_complete);
}
static void __post_handler(ngx_http_request_t *r)
{
--r->main->count;
hustdb_ha_ctx_t * ctx = ngx_http_get_addon_module_ctx(r);
ngx_http_subrequest_peer_t * peer = __get_readable_peer(ctx->key_in_body, r);
if (!peer)
{
hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
}
else
{
ctx->peer = peer;
ngx_http_gen_subrequest(
ctx->base.backend_uri,
r,
peer->peer,
&ctx->base,
hustdb_ha_on_subrequest_complete);
}
}
static ngx_bool_t __init_write_ctx_by_body(ngx_http_request_t *r, ngx_http_hustdb_ha_write_ctx_t * ctx)
{
do
{
char * key = hustdb_ha_get_key_from_body(r);
if (!key)
{
break;
}
write_ctx_t tmp;
if (!__set_write_context(key, ctx->has_tb, r, &tmp))
{
break;
}
__copy_data(&tmp, ctx);
return true;
} while (0);
hustdb_ha_send_response(NGX_HTTP_NOT_FOUND, NULL, NULL, r);
return false;
}