MINOR: cache: Add "Age" header.
This patch makes the cache capable of adding an "Age" header as defined by
rfc7234.
During the storage of new HTTP objects we memorize ->eoh value and
the value of the "Age" header coming from the origin server.
These information may then be reused to return the cached HTTP objects
with a new "Age" header.
May be backported to 1.8.
diff --git a/src/cache.c b/src/cache.c
index b9ac2d5..96a251a 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -65,12 +65,15 @@
struct cache_entry {
unsigned int latest_validation; /* latest validation date */
unsigned int expire; /* expiration date */
+ unsigned int age; /* Origin server "Age" header value */
+ unsigned int eoh; /* Origin server end of headers offset. */
struct eb32_node eb; /* ebtree node used to hold the cache object */
char hash[20];
unsigned char data[0];
};
#define CACHE_BLOCKSIZE 1024
+#define CACHE_ENTRY_MAX_AGE 2147483648
static struct list caches = LIST_HEAD_INIT(caches);
static struct cache *tmp_cache_config = NULL;
@@ -411,6 +414,8 @@
enum act_return http_action_store_cache(struct act_rule *rule, struct proxy *px,
struct session *sess, struct stream *s, int flags)
{
+ unsigned int age;
+ long long hdr_age;
struct http_txn *txn = s->txn;
struct http_msg *msg = &txn->rsp;
struct filter *filter;
@@ -454,6 +459,17 @@
if (!(txn->flags & TX_CACHEABLE) || !(txn->flags & TX_CACHE_COOK))
goto out;
+ age = 0;
+ ctx.idx = 0;
+ if (http_find_header2("Age", 3, ci_head(txn->rsp.chn), &txn->hdr_idx, &ctx)) {
+ if (!strl2llrc(ctx.line + ctx.val, ctx.vlen, &hdr_age) && hdr_age > 0) {
+ if (unlikely(hdr_age > CACHE_ENTRY_MAX_AGE))
+ hdr_age = CACHE_ENTRY_MAX_AGE;
+ age = hdr_age;
+ }
+ http_remove_header2(msg, &txn->hdr_idx, &ctx);
+ }
+
shctx_lock(shctx);
first = shctx_row_reserve_hot(shctx, NULL, sizeof(struct cache_entry) + msg->sov);
if (!first) {
@@ -468,6 +484,8 @@
object = (struct cache_entry *)first->data;
object->eb.node.leaf_p = NULL;
object->eb.key = 0;
+ object->age = age;
+ object->eoh = msg->eoh;
/* reserve space for the cache_entry structure */
first->len = sizeof(struct cache_entry);
@@ -529,9 +547,10 @@
return ACT_RET_CONT;
}
-#define HTTP_CACHE_INIT 0
-#define HTTP_CACHE_FWD 1
-#define HTTP_CACHE_END 2
+#define HTTP_CACHE_INIT 0 /* Initial state. */
+#define HTTP_CACHE_HEADER 1 /* Cache entry headers forwarded. */
+#define HTTP_CACHE_FWD 2 /* Cache entry completely forwarded. */
+#define HTTP_CACHE_END 3 /* Cache entry treatment terminated. */
static void http_cache_applet_release(struct appctx *appctx)
{
@@ -544,6 +563,27 @@
shctx_unlock(shctx_ptr(cache));
}
+/*
+ * Append an "Age" header into <chn> channel for this <ce> cache entry.
+ * This is the responsability of the caller to insure there is enough
+ * data in the channel.
+ *
+ * Returns the number of bytes inserted if succeeded, 0 if failed.
+ */
+static int cache_channel_append_age_header(struct cache_entry *ce, struct channel *chn)
+{
+ unsigned int age;
+
+ age = MAX(0, (int)(now.tv_sec - ce->latest_validation)) + ce->age;
+ if (unlikely(age > CACHE_ENTRY_MAX_AGE))
+ age = CACHE_ENTRY_MAX_AGE;
+
+ chunk_reset(&trash);
+ chunk_printf(&trash, "Age: %u", age);
+
+ return ci_insert_line2(chn, ce->eoh, trash.area, trash.data);
+}
+
static int cache_channel_row_data_get(struct appctx *appctx, int len)
{
int ret, total;
@@ -612,7 +652,7 @@
appctx->st0 = HTTP_CACHE_END;
/* buffer are aligned there, should be fine */
- if (appctx->st0 == HTTP_CACHE_INIT) {
+ if (appctx->st0 == HTTP_CACHE_HEADER || appctx->st0 == HTTP_CACHE_INIT) {
int len = first->len - *sent - sizeof(struct cache_entry);
if (len > 0) {
@@ -623,6 +663,9 @@
appctx->st0 = HTTP_CACHE_END;
else
*sent += ret;
+ if (appctx->st0 == HTTP_CACHE_INIT && *sent > cache_ptr->eoh &&
+ cache_channel_append_age_header(cache_ptr, res))
+ appctx->st0 = HTTP_CACHE_HEADER;
}
else {
*sent = 0;