[CLEANUP] stick_table: add/clarify some comments
diff --git a/include/types/pattern.h b/include/types/pattern.h
index 01fb69c..d9346d9 100644
--- a/include/types/pattern.h
+++ b/include/types/pattern.h
@@ -28,10 +28,10 @@
/* pattern in and out types */
enum {
- PATTERN_TYPE_IP = 0, /* ipv4 type */
- PATTERN_TYPE_INTEGER = 1, /* unsigned 32bits integer type */
- PATTERN_TYPE_STRING = 2, /* char string type */
- PATTERN_TYPES
+ PATTERN_TYPE_IP = 0, /* ipv4 type */
+ PATTERN_TYPE_INTEGER, /* unsigned 32bits integer type */
+ PATTERN_TYPE_STRING, /* char string type */
+ PATTERN_TYPES /* number of types, must always be last */
};
/* pattern fetch direction */
@@ -40,9 +40,9 @@
/* pattern result data */
union pattern_data {
- struct in_addr ip; /* used for ipv4 type */
- uint32_t integer; /* used for unsigned 32bits integer type */
- struct chunk str; /* used for char string type */
+ struct in_addr ip; /* used for ipv4 type */
+ uint32_t integer; /* used for unsigned 32bits integer type */
+ struct chunk str; /* used for char string type */
};
/* pattern result */
diff --git a/include/types/stick_table.h b/include/types/stick_table.h
index fd0c806..b63b790 100644
--- a/include/types/stick_table.h
+++ b/include/types/stick_table.h
@@ -31,46 +31,49 @@
#include <common/memory.h>
/* stick table key types */
-#define STKTABLE_TYPE_IP 0 /* table key is ipv4 */
-#define STKTABLE_TYPE_INTEGER 1 /* table key is unsigned 32bit integer */
-#define STKTABLE_TYPE_STRING 2 /* table key is a null terminated string */
-
-#define STKTABLE_TYPES 3 /* Increase this value if you add a type */
+enum {
+ STKTABLE_TYPE_IP = 0, /* table key is ipv4 */
+ STKTABLE_TYPE_INTEGER, /* table key is unsigned 32bit integer */
+ STKTABLE_TYPE_STRING, /* table key is a null terminated string */
+ STKTABLE_TYPES /* Number of types, must always be last */
+};
-/* stick table type flags */
-#define STKTABLE_TYPEFLAG_CUSTOMKEYSIZE 0x00000001 /* this table type maxsize is configurable */
+/* stick table key type flags */
+#define STK_F_CUSTOM_KEYSIZE 0x00000001 /* this table's key size is configurable */
/* stick table keyword type */
struct stktable_type {
- const char *kw; /* keyword string */
- int flags; /* type flags */
- size_t default_size; /* default key size */
+ const char *kw; /* keyword string */
+ int flags; /* type flags */
+ size_t default_size; /* default key size */
};
-/* stuck session */
+/* sticky session */
struct stksess {
- int sid; /* id of server to use for session */
+ int sid; /* id of server to use for this session */
unsigned int expire; /* session expiration date */
struct eb32_node exps; /* ebtree node used to hold the session in expiration tree */
struct ebmb_node keys; /* ebtree node used to hold the session in table */
+ /* WARNING! do not put anything after <keys>, it's used by the key */
};
-
/* stick table */
struct stktable {
- struct eb_root keys; /* head of stuck session tree */
- struct eb_root exps; /* head of stuck session expiration tree */
- struct pool_head *pool; /* pool used to allocate stuck sessions */
+ struct eb_root keys; /* head of sticky session tree */
+ struct eb_root exps; /* head of sticky session expiration tree */
+ struct pool_head *pool; /* pool used to allocate sticky sessions */
struct task *exp_task; /* expiration task */
- unsigned long type; /* type of table (determine key format) */
+ unsigned long type; /* type of table (determines key format) */
size_t key_size; /* size of a key, maximum size in case of string */
- unsigned int size; /* maximum stuck session in table */
- unsigned int current; /* number of stuck session in table */
- int nopurge; /* 1 never purge stuck sessions */
- int exp_next; /* next epiration date */
- int expire; /* duration before expiration of stuck session */
+ unsigned int size; /* maximum number of sticky sessions in table */
+ unsigned int current; /* number of sticky sessions currently in table */
+ int nopurge; /* if non-zero, don't purge sticky sessions when full */
+ int exp_next; /* next expiration date (ticks) */
+ int expire; /* time to live for sticky sessions (milliseconds) */
};
+/*** The definitions below should probably be better placed in pattern.h ***/
+
/* stick table key data */
union stktable_key_data {
struct in_addr ip; /* used to store an ip key */
diff --git a/src/stick_table.c b/src/stick_table.c
index 0d70e32..bc75f67 100644
--- a/src/stick_table.c
+++ b/src/stick_table.c
@@ -29,22 +29,23 @@
/*
- * Free an allocate sticked session <ts>.
- * Decrease table <t> sticked session counter .
+ * Free an allocated sticky session <ts>, and decrease sticky sessions counter
+ * in table <t>.
*/
void stksess_free(struct stktable *t, struct stksess *ts)
{
t->current--;
- pool_free2(t->pool,ts);
+ pool_free2(t->pool, ts);
}
/*
- * Init or modify <key> of th sticked session <ts> present in table <t>.
+ * Initialize or update the key in the sticky session <ts> present in table <t>
+ * from the value present in <key>.
*/
void stksess_key(struct stktable *t, struct stksess *ts, struct stktable_key *key)
{
if (t->type != STKTABLE_TYPE_STRING)
- memcpy(ts->keys.key, key->key , t->key_size);
+ memcpy(ts->keys.key, key->key, t->key_size);
else {
memcpy(ts->keys.key, key->key, MIN(t->key_size - 1, key->key_len));
ts->keys.key[MIN(t->key_size - 1, key->key_len)] = 0;
@@ -53,7 +54,7 @@
/*
- * Init sticked session <ts> using <key>.
+ * Init sticky session <ts> of table <t> using <key>.
*/
struct stksess *stksess_init(struct stktable *t, struct stksess * ts, struct stktable_key *key)
{
@@ -66,8 +67,8 @@
}
/*
- * Trash oldest <to_batch> sticked sessions from table <t>
- * Returns number of trashed sticked session.
+ * Trash oldest <to_batch> sticky sessions from table <t>
+ * Returns number of trashed sticky sessions.
*/
static int stktable_trash_oldest(struct stktable *t, int to_batch)
{
@@ -109,8 +110,8 @@
continue;
}
- /* session expired, trash it */
+ /* session expired, trash it */
ebmb_delete(&ts->keys);
stksess_free(t, ts);
batched++;
@@ -120,11 +121,10 @@
}
/*
- * Allocate and initialise a new sticked session.
- * The new sticked session is returned or NULL in case of lack of memory.
- * Sticked sessions should only be allocated this way, and must be
- * freed using stksess_free().
- * Increase table <t> sticked session counter.
+ * Allocate and initialise a new sticky session.
+ * The new sticky session is returned or NULL in case of lack of memory.
+ * Sticky sessions should only be allocated this way, and must be freed using
+ * stksess_free(). Increase table <t> sticky session counter.
*/
struct stksess *stksess_new(struct stktable *t, struct stktable_key *key)
{
@@ -148,14 +148,13 @@
}
/*
- * Lookup in table <t> for a sticked session identified by <key>.
- * Returns pointer on requested sticked session or NULL if no one found.
+ * Looks in table <t> for a sticky session matching <key>.
+ * Returns pointer on requested sticky session or NULL if none was found.
*/
struct stksess *stktable_lookup(struct stktable *t, struct stktable_key *key)
{
struct ebmb_node *eb;
- /* lookup on track session */
if (t->type == STKTABLE_TYPE_STRING)
eb = ebst_lookup_len(&t->keys, key->key, key->key_len);
else
@@ -166,39 +165,40 @@
return NULL;
}
- /* Existing session, returns server id */
return ebmb_entry(eb, struct stksess, keys);
}
-/*
- * Store sticked session if not present in table.
- * Il already present, update the existing session.
+/* Try to store sticky session <ts> in the table. If another entry already
+ * exists with the same key, its server ID is updated with <sid> and a non
+ * zero value is returned so that the caller knows it can release its stksess.
+ * If no similar entry was present, <ts> is inserted into the tree and assigned
+ * server ID <sid>. Zero is returned in this case, and the caller must not
+ * release the stksess.
*/
-int stktable_store(struct stktable *t, struct stksess *tsess, int sid)
+int stktable_store(struct stktable *t, struct stksess *ts, int sid)
{
- struct stksess *ts;
struct ebmb_node *eb;
if (t->type == STKTABLE_TYPE_STRING)
- eb = ebst_lookup(&(t->keys), (char *)tsess->keys.key);
+ eb = ebst_lookup(&(t->keys), (char *)ts->keys.key);
else
- eb = ebmb_lookup(&(t->keys), tsess->keys.key, t->key_size);
+ eb = ebmb_lookup(&(t->keys), ts->keys.key, t->key_size);
if (unlikely(!eb)) {
- tsess->sid = sid;
- ebmb_insert(&t->keys, &tsess->keys, t->key_size);
+ /* no existing session, insert ours */
+ ts->sid = sid;
+ ebmb_insert(&t->keys, &ts->keys, t->key_size);
- tsess->exps.key = tsess->expire = tick_add(now_ms, MS_TO_TICKS(t->expire));
- eb32_insert(&t->exps, &tsess->exps);
+ ts->exps.key = ts->expire = tick_add(now_ms, MS_TO_TICKS(t->expire));
+ eb32_insert(&t->exps, &ts->exps);
if (t->expire) {
- t->exp_task->expire = t->exp_next = tick_first(tsess->expire, t->exp_next);
+ t->exp_task->expire = t->exp_next = tick_first(ts->expire, t->exp_next);
task_queue(t->exp_task);
}
return 0;
}
- /* Existing track session */
ts = ebmb_entry(eb, struct stksess, keys);
if ( ts->sid != sid )
@@ -207,7 +207,8 @@
}
/*
- * Trash expired sticked sessions from table <t>.
+ * Trash expired sticky sessions from table <t>. The next expiration date is
+ * returned.
*/
static int stktable_trash_expired(struct stktable *t)
{
@@ -262,9 +263,10 @@
}
/*
- * Task processing function to trash expired sticked sessions.
+ * Task processing function to trash expired sticky sessions. A pointer to the
+ * task itself is returned since it never dies.
*/
-static struct task *process_table_expire(struct task * task)
+static struct task *process_table_expire(struct task *task)
{
struct stktable *t = (struct stktable *)task->context;
@@ -272,7 +274,7 @@
return task;
}
-/* Perform minimal intializations, report 0 in case of error, 1 if OK. */
+/* Perform minimal stick table intializations, report 0 in case of error, 1 if OK. */
int stktable_init(struct stktable *t)
{
if (t->size) {
@@ -298,7 +300,7 @@
*/
struct stktable_type stktable_types[STKTABLE_TYPES] = { { "ip", 0, 4 } ,
{ "integer", 0, 4 },
- { "string", STKTABLE_TYPEFLAG_CUSTOMKEYSIZE, 32 } };
+ { "string", STK_F_CUSTOM_KEYSIZE, 32 } };
/*
@@ -315,7 +317,7 @@
*key_size = stktable_types[*type].default_size;
(*myidx)++;
- if (stktable_types[*type].flags & STKTABLE_TYPEFLAG_CUSTOMKEYSIZE) {
+ if (stktable_types[*type].flags & STK_F_CUSTOM_KEYSIZE) {
if (strcmp("len", args[*myidx]) == 0) {
(*myidx)++;
*key_size = atol(args[*myidx]);