Add support for DNS cache timeouts via the CURLOPT_DNS_CACHE_TIMEOUT option.

The default cache timeout for this is 60 seconds, which is arbitrary and
completely subject to change :)
This commit is contained in:
Sterling Hughes 2002-01-08 04:26:47 +00:00
parent 87037136ef
commit 22ac08e06d
4 changed files with 63 additions and 14 deletions

View File

@ -491,6 +491,9 @@ typedef enum {
/* Non-zero value means to use the global dns cache */ /* Non-zero value means to use the global dns cache */
CINIT(DNS_USE_GLOBAL_CACHE, LONG, 91), CINIT(DNS_USE_GLOBAL_CACHE, LONG, 91),
/* DNS cache timeout */
CINIT(DNS_CACHE_TIMEOUT, LONG, 92),
CURLOPT_LASTENTRY /* the last unusued */ CURLOPT_LASTENTRY /* the last unusued */
} CURLoption; } CURLoption;

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@ -93,24 +93,59 @@ void Curl_global_host_cache_dtor(void)
} }
} }
struct curl_dns_cache_entry {
Curl_addrinfo *addr;
int timestamp;
};
Curl_addrinfo *Curl_resolv(struct SessionHandle *data, Curl_addrinfo *Curl_resolv(struct SessionHandle *data,
char *hostname, char *hostname,
int port, int port,
char **bufp) char **bufp)
{ {
Curl_addrinfo *addr = NULL; struct curl_dns_cache_entry *p = NULL;
size_t hostname_len = strlen(hostname)+1; size_t hostname_len;
time_t now;
if (curl_hash_find(data->hostcache, hostname, hostname_len, (void **) &addr)) { /* If the host cache timeout is 0, we don't do DNS cach'ing
return addr; so fall through */
if (data->set.dns_cache_timeout == 0) {
return Curl_getaddrinfo(data, hostname, port, bufp);
} }
addr = Curl_getaddrinfo(data, hostname, port, bufp);
if (!addr)
return NULL;
curl_hash_add(data->hostcache, hostname, hostname_len, (const void *) addr); hostname_len = strlen(hostname)+1;
return addr;
time(&now);
/* See if its already in our dns cache */
if (curl_hash_find(data->hostcache, hostname, hostname_len, (void **) &p)) {
/* Do we need to check for a cache timeout? */
if (data->set.dns_cache_timeout != -1) {
/* Return if the entry has not timed out */
if ((now - p->timestamp) < data->set.dns_cache_timeout) {
return p->addr;
}
}
else {
return p->addr;
}
}
/* Create a new cache entry */
p = (struct curl_dns_cache_entry *) malloc(sizeof(struct curl_dns_cache_entry));
if (!p) {
return NULL;
}
p->addr = Curl_getaddrinfo(data, hostname, port, bufp);
if (!p->addr) {
return NULL;
}
p->timestamp = now;
/* Save it in our host cache */
curl_hash_update(data->hostcache, hostname, hostname_len, (const void *) p);
return p->addr;
} }
/* /*
@ -120,11 +155,15 @@ Curl_addrinfo *Curl_resolv(struct SessionHandle *data,
*/ */
void Curl_freeaddrinfo(void *freethis) void Curl_freeaddrinfo(void *freethis)
{ {
struct curl_dns_cache_entry *p = (struct curl_dns_cache_entry *) freethis;
#ifdef ENABLE_IPV6 #ifdef ENABLE_IPV6
freeaddrinfo(freethis); freeaddrinfo(p->addr);
#else #else
free(freethis); free(p->addr);
#endif #endif
free(p);
} }
/* --- resolve name or IP-number --- */ /* --- resolve name or IP-number --- */

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@ -251,13 +251,15 @@ CURLcode Curl_open(struct SessionHandle **curl)
data->set.httpreq = HTTPREQ_GET; /* Default HTTP request */ data->set.httpreq = HTTPREQ_GET; /* Default HTTP request */
data->set.ftp_use_epsv = TRUE; /* FTP defaults to EPSV operations */ data->set.ftp_use_epsv = TRUE; /* FTP defaults to EPSV operations */
data->set.dns_cache_timeout = 60; /* Timeout every 60 seconds by default */
/* make libcurl quiet by default: */ /* make libcurl quiet by default: */
data->set.hide_progress = TRUE; /* CURLOPT_NOPROGRESS changes these */ data->set.hide_progress = TRUE; /* CURLOPT_NOPROGRESS changes these */
data->progress.flags |= PGRS_HIDE; data->progress.flags |= PGRS_HIDE;
/* Set the default size of the SSL session ID cache */ /* Set the default size of the SSL session ID cache */
data->set.ssl.numsessions = 5; data->set.ssl.numsessions = 5;
/* create an array with connection data struct pointers */ /* create an array with connection data struct pointers */
data->state.numconnects = 5; /* hard-coded right now */ data->state.numconnects = 5; /* hard-coded right now */
data->state.connects = (struct connectdata **) data->state.connects = (struct connectdata **)
@ -284,7 +286,11 @@ CURLcode Curl_setopt(struct SessionHandle *data, CURLoption option, ...)
va_start(param, option); va_start(param, option);
switch(option) { switch(option) {
case CURLOPT_DNS_USE_GLOBAL_CACHE: { case CURLOPT_DNS_CACHE_TIMEOUT:
data->set.dns_cache_timeout = va_arg(param, int);
break;
case CURLOPT_DNS_USE_GLOBAL_CACHE:
{
int use_cache = va_arg(param, int); int use_cache = va_arg(param, int);
if (use_cache) { if (use_cache) {
Curl_global_host_cache_init(); Curl_global_host_cache_init();

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@ -647,6 +647,7 @@ struct UserDefined {
bool ftp_use_epsv; /* if EPSV is to be attempted or not */ bool ftp_use_epsv; /* if EPSV is to be attempted or not */
bool global_dns_cache; bool global_dns_cache;
bool dns_cache_timeout;
}; };
/* /*