DOC: conn-stream: Add comments on functions of the new CS api

With the conn-stream refactoring, new functions were added. This patch adds
missing comments to help devs to use them.
This commit is contained in:
Christopher Faulet 2022-04-12 08:51:15 +02:00
parent 265e165d82
commit 9ed7742673
2 changed files with 67 additions and 12 deletions

View File

@ -146,6 +146,18 @@ struct data_cb {
};
/* cs_endpoint is the link between the conn-stream and the endpoint (mux or
* appctx). It is created by the mux/applet on the client side and share with
* the conn-stream. On the server side, it is the opposite. A cs-endpoint
* without conn-stream is called an orphan endpoint. A cs-endpoint with no
* mux/applet is called a detached endpoint. On detach, the conn-stream
* transfers the whole responsibility to the mux/applet and eventually create a
* new cs-endpoint (for instance on connection retries).
*
* <target> is the mux or the appctx
* <ctx> is the context set and used by <target>
* <flags> CS_EP_*
*/
struct cs_endpoint {
void *target;
void *ctx;

View File

@ -81,7 +81,7 @@ struct data_cb cs_data_applet_cb = {
};
/* Initializes an endpoint */
void cs_endpoint_init(struct cs_endpoint *endp)
{
endp->target = NULL;
@ -89,6 +89,7 @@ void cs_endpoint_init(struct cs_endpoint *endp)
endp->flags = CS_EP_NONE;
}
/* Tries to alloc an endpoint and initialize it. Returns NULL on failure. */
struct cs_endpoint *cs_endpoint_new()
{
struct cs_endpoint *endp;
@ -101,13 +102,18 @@ struct cs_endpoint *cs_endpoint_new()
return endp;
}
/* Releases an endpoint. It is the caller responsibility to be sure it is safe
* and it is not shared with another entity
*/
void cs_endpoint_free(struct cs_endpoint *endp)
{
pool_free(pool_head_cs_endpoint, endp);
}
/* Tries to allocate a new conn_stream and initialize its main fields. On
* failure, nothing is allocated and NULL is returned.
* failure, nothing is allocated and NULL is returned. It is an internal
* function. The caller must, at least, set the CS_EP_ORPHAN or CS_EP_DETAC§HED
* flag.
*/
static struct conn_stream *cs_new(struct cs_endpoint *endp)
{
@ -129,6 +135,7 @@ static struct conn_stream *cs_new(struct cs_endpoint *endp)
cs->wait_event.tasklet = NULL;
cs->wait_event.events = 0;
/* If there is no endpoint, allocate a new one now */
if (!endp) {
endp = cs_endpoint_new();
if (unlikely(!endp))
@ -143,6 +150,10 @@ static struct conn_stream *cs_new(struct cs_endpoint *endp)
return NULL;
}
/* Creates a new conn-stream and its associated stream from a mux. <endp> must be
* defined. It returns NULL on error. On success, the new conn-stream is
* returned. In this case, CS_EP_ORPHAN flag is removed.
*/
struct conn_stream *cs_new_from_mux(struct cs_endpoint *endp, struct session *sess, struct buffer *input)
{
struct conn_stream *cs;
@ -158,6 +169,11 @@ struct conn_stream *cs_new_from_mux(struct cs_endpoint *endp, struct session *se
return cs;
}
/* Creates a new conn-stream and its associated stream from an applet. <endp>
* must be defined. It returns NULL on error. On success, the new conn-stream is
* returned. In this case, CS_EP_ORPHAN flag is removed. The created CS is used
* to set the appctx owner.
*/
struct conn_stream *cs_new_from_applet(struct cs_endpoint *endp, struct session *sess, struct buffer *input)
{
struct conn_stream *cs;
@ -175,6 +191,10 @@ struct conn_stream *cs_new_from_applet(struct cs_endpoint *endp, struct session
return cs;
}
/* Creates a new conn-stream from an stream. There is no endpoint here, thus it
* will be created by cs_new(). So the CS_EP_DETACHED flag is set. It returns
* NULL on error. On success, the new conn-stream is returned.
*/
struct conn_stream *cs_new_from_strm(struct stream *strm, unsigned int flags)
{
struct conn_stream *cs;
@ -190,6 +210,10 @@ struct conn_stream *cs_new_from_strm(struct stream *strm, unsigned int flags)
return cs;
}
/* Creates a new conn-stream from an health-check. There is no endpoint here,
* thus it will be created by cs_new(). So the CS_EP_DETACHED flag is set. It
* returns NULL on error. On success, the new conn-stream is returned.
*/
struct conn_stream *cs_new_from_check(struct check *check, unsigned int flags)
{
struct conn_stream *cs;
@ -204,8 +228,8 @@ struct conn_stream *cs_new_from_check(struct check *check, unsigned int flags)
return cs;
}
/* Releases a conn_stream previously allocated by cs_new(), as well as any
* buffer it would still hold.
/* Releases a conn_stream previously allocated by cs_new(), as well as its
* endpoint, if it exists. This function is called internally or on error path.
*/
void cs_free(struct conn_stream *cs)
{
@ -221,7 +245,10 @@ void cs_free(struct conn_stream *cs)
}
/* Attaches a conn_stream to an mux endpoint and sets the endpoint ctx */
/* Attaches a conn_stream to a mux endpoint and sets the endpoint ctx. Returns
* -1 on error and 0 on sucess. CS_EP_DETACHED flag is removed. This function is
* called from a mux when it is attached to a stream or a health-check.
*/
int cs_attach_mux(struct conn_stream *cs, void *target, void *ctx)
{
struct connection *conn = ctx;
@ -250,7 +277,11 @@ int cs_attach_mux(struct conn_stream *cs, void *target, void *ctx)
return 0;
}
/* Attaches a conn_stream to an applet endpoint and sets the endpoint ctx */
/* Attaches a conn_stream to an applet endpoint and sets the endpoint
* ctx. Returns -1 on error and 0 on sucess. CS_EP_DETACHED flag is
* removed. This function is called by a stream when a backend applet is
* registered.
*/
static void cs_attach_applet(struct conn_stream *cs, void *target, void *ctx)
{
struct appctx *appctx = target;
@ -266,7 +297,11 @@ static void cs_attach_applet(struct conn_stream *cs, void *target, void *ctx)
}
}
/* Attaches a conn_stream to a app layer and sets the relevant callbacks */
/* Attaches a conn_stream to a app layer and sets the relevant
* callbacks. Returns -1 on error and 0 on success. CS_EP_ORPHAN flag is
* removed. This function is called by a stream when it is created to attach it
* on the conn-stream on the client side.
*/
int cs_attach_strm(struct conn_stream *cs, struct stream *strm)
{
cs->app = &strm->obj_type;
@ -293,11 +328,12 @@ int cs_attach_strm(struct conn_stream *cs, struct stream *strm)
return 0;
}
/* Detach the conn_stream from the endpoint, if any. For a connecrion, if a mux
* owns the connection ->detach() callback is called. Otherwise, it means the
* conn-stream owns the connection. In this case the connection is closed and
* released. For an applet, the appctx is released. At the end, the conn-stream
* is not released but some fields a reset.
/* Detaches the conn_stream from the endpoint, if any. For a connecrion, if a
* mux owns the connection ->detach() callback is called. Otherwise, it means
* the conn-stream owns the connection. In this case the connection is closed
* and released. For an applet, the appctx is released. If still allocated, the
* endpoint is reset and flag as detached. If the app layer is also detached,
* the conn-stream is released.
*/
void cs_detach_endp(struct conn_stream *cs)
{
@ -354,6 +390,9 @@ void cs_detach_endp(struct conn_stream *cs)
cs_free(cs);
}
/* Detaches the conn_stream from the app layer. If there is no endpoint attached
* to the conn_stream
*/
void cs_detach_app(struct conn_stream *cs)
{
cs->app = NULL;
@ -370,6 +409,10 @@ void cs_detach_app(struct conn_stream *cs)
cs_free(cs);
}
/* Resets the conn-stream endpoint. It happens when the app layer want to renew
* its endpoint. For a connection retry for instance. If a mux or an applet is
* attached, a new endpoint is created. Returns -1 on error and 0 on sucess.
*/
int cs_reset_endp(struct conn_stream *cs)
{
struct cs_endpoint *new_endp;