From 023521fcb6713e1151a04e4358bb58695dd6e479 Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Mon, 7 Feb 2022 16:24:43 -0800 Subject: http_static: cleanup file handler and cache Type: refactor Signed-off-by: Florin Coras Change-Id: I7aff3a02315f9f92039dd2e3af1cbd8312aec662 --- src/plugins/http_static/http_cache.c | 450 +++++++++++++++++++++++++++++++++++ 1 file changed, 450 insertions(+) create mode 100644 src/plugins/http_static/http_cache.c (limited to 'src/plugins/http_static/http_cache.c') diff --git a/src/plugins/http_static/http_cache.c b/src/plugins/http_static/http_cache.c new file mode 100644 index 00000000000..8b9751b7f78 --- /dev/null +++ b/src/plugins/http_static/http_cache.c @@ -0,0 +1,450 @@ +/* + * Copyright (c) 2022 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include +#include +#include +#include + +static void +hss_cache_lock (hss_cache_t *hc) +{ + clib_spinlock_lock (&hc->cache_lock); +} + +static void +hss_cache_unlock (hss_cache_t *hc) +{ + clib_spinlock_unlock (&hc->cache_lock); +} + +/** \brief Sanity-check the forward and reverse LRU lists + */ +static inline void +lru_validate (hss_cache_t *hc) +{ +#if CLIB_DEBUG > 0 + f64 last_timestamp; + u32 index; + int i; + hss_cache_entry_t *ce; + + last_timestamp = 1e70; + for (i = 1, index = hc->first_index; index != ~0;) + { + ce = pool_elt_at_index (hc->cache_pool, index); + /* Timestamps should be smaller (older) as we walk the fwd list */ + if (ce->last_used > last_timestamp) + { + clib_warning ("%d[%d]: last used %.6f, last_timestamp %.6f", index, + i, ce->last_used, last_timestamp); + } + index = ce->next_index; + last_timestamp = ce->last_used; + i++; + } + + last_timestamp = 0.0; + for (i = 1, index = hc->last_index; index != ~0;) + { + ce = pool_elt_at_index (hc->cache_pool, index); + /* Timestamps should be larger (newer) as we walk the rev list */ + if (ce->last_used < last_timestamp) + { + clib_warning ("%d[%d]: last used %.6f, last_timestamp %.6f", index, + i, ce->last_used, last_timestamp); + } + index = ce->prev_index; + last_timestamp = ce->last_used; + i++; + } +#endif +} + +/** \brief Remove a data cache entry from the LRU lists + */ +static inline void +lru_remove (hss_cache_t *hc, hss_cache_entry_t *ce) +{ + hss_cache_entry_t *next_ep, *prev_ep; + u32 ce_index; + + lru_validate (hc); + + ce_index = ce - hc->cache_pool; + + /* Deal with list heads */ + if (ce_index == hc->first_index) + hc->first_index = ce->next_index; + if (ce_index == hc->last_index) + hc->last_index = ce->prev_index; + + /* Fix next->prev */ + if (ce->next_index != ~0) + { + next_ep = pool_elt_at_index (hc->cache_pool, ce->next_index); + next_ep->prev_index = ce->prev_index; + } + /* Fix prev->next */ + if (ce->prev_index != ~0) + { + prev_ep = pool_elt_at_index (hc->cache_pool, ce->prev_index); + prev_ep->next_index = ce->next_index; + } + lru_validate (hc); +} + +/** \brief Add an entry to the LRU lists, tag w/ supplied timestamp + */ +static inline void +lru_add (hss_cache_t *hc, hss_cache_entry_t *ce, f64 now) +{ + hss_cache_entry_t *next_ce; + u32 ce_index; + + lru_validate (hc); + + ce_index = ce - hc->cache_pool; + + /* + * Re-add at the head of the forward LRU list, + * tail of the reverse LRU list + */ + if (hc->first_index != ~0) + { + next_ce = pool_elt_at_index (hc->cache_pool, hc->first_index); + next_ce->prev_index = ce_index; + } + + ce->prev_index = ~0; + + /* ep now the new head of the LRU forward list */ + ce->next_index = hc->first_index; + hc->first_index = ce_index; + + /* single session case: also the tail of the reverse LRU list */ + if (hc->last_index == ~0) + hc->last_index = ce_index; + ce->last_used = now; + + lru_validate (hc); +} + +/** \brief Remove and re-add a cache entry from/to the LRU lists + */ +static inline void +lru_update (hss_cache_t *hc, hss_cache_entry_t *ep, f64 now) +{ + lru_remove (hc, ep); + lru_add (hc, ep, now); +} + +static void +hss_cache_attach_entry (hss_cache_t *hc, u32 ce_index, u8 **data, + u64 *data_len) +{ + hss_cache_entry_t *ce; + + /* Expect ce_index to be validated outside */ + ce = pool_elt_at_index (hc->cache_pool, ce_index); + ce->inuse++; + *data = ce->data; + *data_len = vec_len (ce->data); + + /* Update the cache entry, mark it in-use */ + lru_update (hc, ce, vlib_time_now (vlib_get_main ())); + + if (hc->debug_level > 1) + clib_warning ("index %d refcnt now %d", ce_index, ce->inuse); +} + +/** \brief Detach cache entry from session + */ +void +hss_cache_detach_entry (hss_cache_t *hc, u32 ce_index) +{ + hss_cache_entry_t *ce; + + hss_cache_lock (hc); + + ce = pool_elt_at_index (hc->cache_pool, ce_index); + ce->inuse--; + + if (hc->debug_level > 1) + clib_warning ("index %d refcnt now %d", ce_index, ce->inuse); + + hss_cache_unlock (hc); +} + +static u32 +hss_cache_lookup (hss_cache_t *hc, u8 *path) +{ + BVT (clib_bihash_kv) kv; + int rv; + + kv.key = (u64) path; + kv.value = ~0; + + /* Value updated only if lookup succeeds */ + rv = BV (clib_bihash_search) (&hc->name_to_data, &kv, &kv); + ASSERT (!rv || kv.value == ~0); + + if (hc->debug_level > 1) + clib_warning ("lookup '%s' %s", kv.key, kv.value == ~0 ? "fail" : "found"); + + return kv.value; +} + +u32 +hss_cache_lookup_and_attach (hss_cache_t *hc, u8 *path, u8 **data, + u64 *data_len) +{ + u32 ce_index; + + /* Make sure nobody removes the entry while we look it up */ + hss_cache_lock (hc); + + ce_index = hss_cache_lookup (hc, path); + if (ce_index != ~0) + hss_cache_attach_entry (hc, ce_index, data, data_len); + + hss_cache_unlock (hc); + + return ce_index; +} + +static void +hss_cache_do_evictions (hss_cache_t *hc) +{ + BVT (clib_bihash_kv) kv; + hss_cache_entry_t *ce; + u32 free_index; + + free_index = hc->last_index; + + while (free_index != ~0) + { + /* pick the LRU */ + ce = pool_elt_at_index (hc->cache_pool, free_index); + /* Which could be in use... */ + if (ce->inuse) + { + if (hc->debug_level > 1) + clib_warning ("index %d in use refcnt %d", free_index, ce->inuse); + } + free_index = ce->prev_index; + kv.key = (u64) (ce->filename); + kv.value = ~0ULL; + if (BV (clib_bihash_add_del) (&hc->name_to_data, &kv, 0 /* is_add */) < + 0) + { + clib_warning ("LRU delete '%s' FAILED!", ce->filename); + } + else if (hc->debug_level > 1) + clib_warning ("LRU delete '%s' ok", ce->filename); + + lru_remove (hc, ce); + hc->cache_size -= vec_len (ce->data); + hc->cache_evictions++; + vec_free (ce->filename); + vec_free (ce->data); + + if (hc->debug_level > 1) + clib_warning ("pool put index %d", ce - hc->cache_pool); + + pool_put (hc->cache_pool, ce); + if (hc->cache_size < hc->cache_limit) + break; + } +} + +u32 +hss_cache_add_and_attach (hss_cache_t *hc, u8 *path, u8 **data, u64 *data_len) +{ + BVT (clib_bihash_kv) kv; + hss_cache_entry_t *ce; + clib_error_t *error; + u8 *file_data; + u32 ce_index; + + hss_cache_lock (hc); + + /* Need to recycle one (or more cache) entries? */ + if (hc->cache_size > hc->cache_limit) + hss_cache_do_evictions (hc); + + /* Read the file */ + error = clib_file_contents ((char *) path, &file_data); + if (error) + { + clib_warning ("Error reading '%s'", path); + clib_error_report (error); + return ~0; + } + + /* Create a cache entry for it */ + pool_get_zero (hc->cache_pool, ce); + ce->filename = vec_dup (path); + ce->data = file_data; + + /* Attach cache entry without additional lock */ + ce->inuse++; + *data = file_data; + *data_len = vec_len (file_data); + lru_add (hc, ce, vlib_time_now (vlib_get_main ())); + + hc->cache_size += vec_len (ce->data); + ce_index = ce - hc->cache_pool; + + if (hc->debug_level > 1) + clib_warning ("index %d refcnt now %d", ce_index, ce->inuse); + + /* Add to the lookup table */ + + kv.key = (u64) vec_dup (path); + kv.value = ce_index; + + if (hc->debug_level > 1) + clib_warning ("add '%s' value %lld", kv.key, kv.value); + + if (BV (clib_bihash_add_del) (&hc->name_to_data, &kv, 1 /* is_add */) < 0) + { + clib_warning ("BUG: add failed!"); + } + + hss_cache_unlock (hc); + + return ce_index; +} + +u32 +hss_cache_clear (hss_cache_t *hc) +{ + u32 free_index, busy_items = 0; + hss_cache_entry_t *ce; + BVT (clib_bihash_kv) kv; + + hss_cache_lock (hc); + + /* Walk the LRU list to find active entries */ + free_index = hc->last_index; + while (free_index != ~0) + { + ce = pool_elt_at_index (hc->cache_pool, free_index); + free_index = ce->prev_index; + /* Which could be in use... */ + if (ce->inuse) + { + busy_items++; + free_index = ce->next_index; + continue; + } + kv.key = (u64) (ce->filename); + kv.value = ~0ULL; + if (BV (clib_bihash_add_del) (&hc->name_to_data, &kv, 0 /* is_add */) < + 0) + { + clib_warning ("BUG: cache clear delete '%s' FAILED!", ce->filename); + } + + lru_remove (hc, ce); + hc->cache_size -= vec_len (ce->data); + hc->cache_evictions++; + vec_free (ce->filename); + vec_free (ce->data); + if (hc->debug_level > 1) + clib_warning ("pool put index %d", ce - hc->cache_pool); + pool_put (hc->cache_pool, ce); + free_index = hc->last_index; + } + + hss_cache_unlock (hc); + + return busy_items; +} + +void +hss_cache_init (hss_cache_t *hc, uword cache_size, u8 debug_level) +{ + clib_spinlock_init (&hc->cache_lock); + + /* Init path-to-cache hash table */ + BV (clib_bihash_init) (&hc->name_to_data, "http cache", 128, 32 << 20); + + hc->cache_limit = cache_size; + hc->debug_level = debug_level; + hc->first_index = hc->last_index = ~0; +} + +/** \brief format a file cache entry + */ +static u8 * +format_hss_cache_entry (u8 *s, va_list *args) +{ + hss_cache_entry_t *ep = va_arg (*args, hss_cache_entry_t *); + f64 now = va_arg (*args, f64); + + /* Header */ + if (ep == 0) + { + s = format (s, "%40s%12s%20s", "File", "Size", "Age"); + return s; + } + s = format (s, "%40s%12lld%20.2f", ep->filename, vec_len (ep->data), + now - ep->last_used); + return s; +} + +u8 * +format_hss_cache (u8 *s, va_list *args) +{ + hss_cache_t *hc = va_arg (*args, hss_cache_t *); + u32 verbose = va_arg (*args, u32); + hss_cache_entry_t *ce; + vlib_main_t *vm; + u32 index; + f64 now; + + if (verbose == 0) + { + s = format (s, "cache size %lld bytes, limit %lld bytes, evictions %lld", + hc->cache_size, hc->cache_limit, hc->cache_evictions); + return 0; + } + + vm = vlib_get_main (); + now = vlib_time_now (vm); + + s = format (s, "%U", format_hss_cache_entry, 0 /* header */, now); + + for (index = hc->first_index; index != ~0;) + { + ce = pool_elt_at_index (hc->cache_pool, index); + index = ce->next_index; + s = format (s, "%U", format_hss_cache_entry, ce, now); + } + + s = format (s, "%40s%12lld", "Total Size", hc->cache_size); + + return s; +} + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ -- cgit 1.2.3-korg