From d735ff81293a2de1860a99afef891ac3fc6c1c09 Mon Sep 17 00:00:00 2001 From: Jose Bollo Date: Fri, 15 Nov 2019 14:39:04 +0100 Subject: [PATCH] afb-session: Expose a local id for sessions Also, improve readability and memory footprint Bug-AGL: SPEC-2968 Change-Id: I90104fb19a44e2810b92bef51d774acf734fd90f Signed-off-by: Jose Bollo --- src/afb-apiset.c | 2 +- src/afb-session.c | 122 ++++++++++++++++++++++++++++++++++++------------------ src/afb-session.h | 1 + 3 files changed, 83 insertions(+), 42 deletions(-) diff --git a/src/afb-apiset.c b/src/afb-apiset.c index 16ded968..0a8b3390 100644 --- a/src/afb-apiset.c +++ b/src/afb-apiset.c @@ -21,8 +21,8 @@ #include #include #include +#include -#include "afb-session.h" #include "verbose.h" #include "afb-api.h" #include "afb-apiset.h" diff --git a/src/afb-session.c b/src/afb-session.c index 3e267fd2..8addd7eb 100644 --- a/src/afb-session.c +++ b/src/afb-session.c @@ -33,7 +33,15 @@ #include "pearson.h" #include "uuid.h" -#define HEADCOUNT 16 +#define SESSION_COUNT_MIN 5 +#define SESSION_COUNT_MAX 1000 + +/* + * Handling of cookies. + * Cookies are stored by session. + * The cookie count COOKIECOUNT must be a power of 2, possible values: 1, 2, 4, 8, 16, 32, 64, ... + * For low memory profile, small values are better, 1 is possible. + */ #define COOKIECOUNT 8 #define COOKIEMASK (COOKIECOUNT - 1) @@ -59,7 +67,8 @@ struct cookie struct afb_session { struct afb_session *next; /**< link to the next */ - unsigned refcount; /**< count of reference to the session */ + uint16_t refcount; /**< count of reference to the session */ + uint16_t id; /**< local id of the session */ int timeout; /**< timeout of the session */ time_t expiration; /**< expiration time of the session */ pthread_mutex_t mutex; /**< mutex of the session */ @@ -68,24 +77,27 @@ struct afb_session uint8_t closed: 1; /**< is the session closed ? */ uint8_t autoclose: 1; /**< close the session when unreferenced */ uint8_t notinset: 1; /**< session removed from the set of sessions */ - uuid_stringz_t uuid; /**< indentification of client seesion */ + uint8_t hash; /**< hash value of the uuid */ + uuid_stringz_t uuid; /**< identification of client session */ }; /** * structure for managing sessions */ static struct { - int count; /**< current number of sessions */ - int max; /**< maximum count of sessions */ - int timeout; /**< common initial timeout */ - struct afb_session *heads[HEADCOUNT]; /**< sessions */ + uint16_t count; /**< current number of sessions */ + uint16_t max; /**< maximum count of sessions */ + uint16_t genid; /**< for generating ids */ + int timeout; /**< common initial timeout */ + struct afb_session *first; /**< sessions */ struct afb_token *initok;/**< common initial token */ - pthread_mutex_t mutex; /**< declare a mutex to protect hash table */ + pthread_mutex_t mutex; /**< declare a mutex to protect hash table */ } sessions = { .count = 0, .max = 10, + .genid = 1, .timeout = 3600, - .heads = { 0 }, + .first = 0, .initok = 0, .mutex = PTHREAD_MUTEX_INITIALIZER }; @@ -121,8 +133,23 @@ static struct afb_session *sessionset_search(const char *uuid, uint8_t hashidx) { struct afb_session *session; - session = sessions.heads[hashidx]; - while (session && strcmp(uuid, session->uuid)) + session = sessions.first; + while (session && hashidx != session->hash && strcmp(uuid, session->uuid)) + session = session->next; + + return session; +} + +/* + * search within the set of sessions the session of 'id'. + * return the session or NULL + */ +static struct afb_session *sessionset_search_id(uint16_t id) +{ + struct afb_session *session; + + session = sessions.first; + while (session && id != session->id) session = session->next; return session; @@ -138,8 +165,8 @@ static int sessionset_add(struct afb_session *session, uint8_t hashidx) } /* add the session */ - session->next = sessions.heads[hashidx]; - sessions.heads[hashidx] = session; + session->next = sessions.first; + sessions.first = session; sessions.count++; return 0; } @@ -251,6 +278,9 @@ static struct afb_session *session_add(const char *uuid, int timeout, time_t now strcpy(session->uuid, uuid); session->timeout = timeout; session_update_expiration(session, now); + session->id = ++sessions.genid; + while (session->id == 0 || sessionset_search_id(session->id) != NULL) + session->id = ++sessions.genid; /* add */ if (sessionset_add(session, hashidx)) { @@ -269,29 +299,26 @@ static struct afb_session *session_add(const char *uuid, int timeout, time_t now static time_t sessionset_cleanup (int force) { struct afb_session *session, **prv; - int idx; time_t now; /* Loop on Sessions Table and remove anything that is older than timeout */ now = NOW; - for (idx = 0 ; idx < HEADCOUNT; idx++) { - prv = &sessions.heads[idx]; - while ((session = *prv)) { - session_lock(session); - if (force || session->expiration < now) - session_close(session); - if (!session->closed) - prv = &session->next; - else { - *prv = session->next; - sessions.count--; - session->notinset = 1; - if ( !session->refcount) { - session_destroy(session); - continue; - } - } + prv = &sessions.first; + while ((session = *prv)) { + session_lock(session); + if (force || session->expiration < now) + session_close(session); + if (!session->closed) { + prv = &session->next; session_unlock(session); + } else { + *prv = session->next; + sessions.count--; + session->notinset = 1; + if (session->refcount) + session_unlock(session); + else + session_destroy(session); } } return now; @@ -321,7 +348,12 @@ int afb_session_init (int max_session_count, int timeout, const char *initok) /* init the sessionset (after cleanup) */ sessionset_lock(); sessionset_cleanup(1); - sessions.max = max_session_count; + if (max_session_count > SESSION_COUNT_MAX) + sessions.max = SESSION_COUNT_MAX; + else if (max_session_count < SESSION_COUNT_MIN) + sessions.max = SESSION_COUNT_MIN; + else + sessions.max = (uint16_t)max_session_count; sessions.timeout = timeout; if (initok == NULL) { uuid_new_stringz(uuid); @@ -344,17 +376,14 @@ int afb_session_init (int max_session_count, int timeout, const char *initok) void afb_session_foreach(void (*callback)(void *closure, struct afb_session *session), void *closure) { struct afb_session *session; - int idx; /* Loop on Sessions Table and remove anything that is older than timeout */ sessionset_lock(); - for (idx = 0 ; idx < HEADCOUNT; idx++) { - session = sessions.heads[idx]; - while (session) { - if (!session->closed) - callback(closure, session); - session = session->next; - } + session = sessions.first; + while (session) { + if (!session->closed) + callback(closure, session); + session = session->next; } sessionset_unlock(); } @@ -420,7 +449,8 @@ int afb_session_timeout(struct afb_session *session) */ int afb_session_what_remains(struct afb_session *session) { - return (int)(session->expiration - NOW); + int diff = (int)(session->expiration - NOW); + return diff < 0 ? 0 : diff; } /* This function will return exiting session or newly created session */ @@ -530,17 +560,27 @@ const char *afb_session_uuid (struct afb_session *session) return session->uuid; } +/* Returns the local id of 'session' */ +uint16_t afb_session_id (struct afb_session *session) +{ + return session->id; +} + /** * Get the index of the 'key' in the cookies array. * @param key the key to scan * @return the index of the list for key within cookies */ +#if COOKIEMASK static int cookeyidx(const void *key) { intptr_t x = (intptr_t)key; unsigned r = (unsigned)((x >> 5) ^ (x >> 15)); return r & COOKIEMASK; } +#else +# define cookeyidx(key) 0 +#endif /** * Set, get, replace, remove a cookie of 'key' for the 'session' diff --git a/src/afb-session.h b/src/afb-session.h index f5a28b75..bd1c47c7 100644 --- a/src/afb-session.h +++ b/src/afb-session.h @@ -32,6 +32,7 @@ extern struct afb_session *afb_session_create (int timeout); extern struct afb_session *afb_session_search (const char *uuid); extern struct afb_session *afb_session_get (const char *uuid, int timeout, int *created); extern const char *afb_session_uuid (struct afb_session *session); +extern uint16_t afb_session_id (struct afb_session *session); extern struct afb_session *afb_session_addref(struct afb_session *session); extern void afb_session_unref(struct afb_session *session); -- 2.16.6