/* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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. */ /* * Rules for managing obj->refcount: * refcount should be incremented when an object is placed in the cache. Insertion * of an object into the cache and the refcount increment should happen under * protection of the sconf->lock. * * refcount should be decremented when the object is removed from the cache. * Object should be removed from the cache and the refcount decremented while * under protection of the sconf->lock. * * refcount should be incremented when an object is retrieved from the cache * by a worker thread. The retrieval/find operation and refcount increment * should occur under protection of the sconf->lock * * refcount can be atomically decremented w/o protection of the sconf->lock * by worker threads. * * Any object whose refcount drops to 0 should be freed/cleaned up. A refcount * of 0 means the object is not in the cache and no worker threads are accessing * it. */ #define CORE_PRIVATE #include "mod_cache.h" #include "cache_pqueue.h" #include "cache_cache.h" #include "ap_provider.h" #include "ap_mpm.h" #include "apr_thread_mutex.h" #if APR_HAVE_UNISTD_H #include <unistd.h> #endif #if !APR_HAS_THREADS #error This module does not currently compile unless you have a thread-capable APR. Sorry! #endif module AP_MODULE_DECLARE_DATA mem_cache_module; typedef enum { CACHE_TYPE_FILE = 1, CACHE_TYPE_HEAP, CACHE_TYPE_MMAP } cache_type_e; typedef struct mem_cache_object { apr_pool_t *pool; cache_type_e type; apr_table_t *header_out; apr_table_t *req_hdrs; /* for Vary negotiation */ apr_size_t m_len; void *m; apr_os_file_t fd; apr_int32_t flags; /* File open flags */ long priority; /**< the priority of this entry */ long total_refs; /**< total number of references this entry has had */ apr_uint32_t pos; /**< the position of this entry in the cache */ } mem_cache_object_t; typedef struct { apr_thread_mutex_t *lock; cache_cache_t *cache_cache; /* Fields set by config directives */ apr_size_t min_cache_object_size; /* in bytes */ apr_size_t max_cache_object_size; /* in bytes */ apr_size_t max_cache_size; /* in bytes */ apr_size_t max_object_cnt; cache_pqueue_set_priority cache_remove_algorithm; /* maximum amount of data to buffer on a streamed response where * we haven't yet seen EOS */ apr_off_t max_streaming_buffer_size; } mem_cache_conf; static mem_cache_conf *sconf; #define DEFAULT_MAX_CACHE_SIZE 100*1024 #define DEFAULT_MIN_CACHE_OBJECT_SIZE 1 #define DEFAULT_MAX_CACHE_OBJECT_SIZE 10000 #define DEFAULT_MAX_OBJECT_CNT 1009 #define DEFAULT_MAX_STREAMING_BUFFER_SIZE 100000 #define CACHEFILE_LEN 20 /* Forward declarations */ static int remove_entity(cache_handle_t *h); static apr_status_t store_headers(cache_handle_t *h, request_rec *r, cache_info *i); static apr_status_t store_body(cache_handle_t *h, request_rec *r, apr_bucket_brigade *b); static apr_status_t recall_headers(cache_handle_t *h, request_rec *r); static apr_status_t recall_body(cache_handle_t *h, apr_pool_t *p, apr_bucket_brigade *bb); static void cleanup_cache_object(cache_object_t *obj); static long memcache_get_priority(void*a) { cache_object_t *obj = (cache_object_t *)a; mem_cache_object_t *mobj = obj->vobj; return mobj->priority; } static void memcache_inc_frequency(void*a) { cache_object_t *obj = (cache_object_t *)a; mem_cache_object_t *mobj = obj->vobj; mobj->total_refs++; mobj->priority = 0; } static void memcache_set_pos(void *a, apr_ssize_t pos) { cache_object_t *obj = (cache_object_t *)a; mem_cache_object_t *mobj = obj->vobj; apr_atomic_set32(&mobj->pos, pos); } static apr_ssize_t memcache_get_pos(void *a) { cache_object_t *obj = (cache_object_t *)a; mem_cache_object_t *mobj = obj->vobj; return apr_atomic_read32(&mobj->pos); } static apr_size_t memcache_cache_get_size(void*a) { cache_object_t *obj = (cache_object_t *)a; mem_cache_object_t *mobj = obj->vobj; return mobj->m_len; } /** callback to get the key of a item */ static const char* memcache_cache_get_key(void*a) { cache_object_t *obj = (cache_object_t *)a; return obj->key; } /** * memcache_cache_free() * memcache_cache_free is a callback that is only invoked by a thread * running in cache_insert(). cache_insert() runs under protection * of sconf->lock. By the time this function has been entered, the cache_object * has been ejected from the cache. decrement the refcount and if the refcount drops * to 0, cleanup the cache object. */ static void memcache_cache_free(void*a) { cache_object_t *obj = (cache_object_t *)a; /* Decrement the refcount to account for the object being ejected * from the cache. If the refcount is 0, free the object. */ if (!apr_atomic_dec32(&obj->refcount)) { cleanup_cache_object(obj); } } /* * functions return a 'negative' score since priority queues * dequeue the object with the highest value first */ static long memcache_lru_algorithm(long queue_clock, void *a) { cache_object_t *obj = (cache_object_t *)a; mem_cache_object_t *mobj = obj->vobj; if (mobj->priority == 0) mobj->priority = queue_clock - mobj->total_refs; /* * a 'proper' LRU function would just be * mobj->priority = mobj->total_refs; */ return mobj->priority; } static long memcache_gdsf_algorithm(long queue_clock, void *a) { cache_object_t *obj = (cache_object_t *)a; mem_cache_object_t *mobj = obj->vobj; if (mobj->priority == 0) mobj->priority = queue_clock - (long)(mobj->total_refs*1000 / mobj->m_len); return mobj->priority; } static void cleanup_cache_object(cache_object_t *obj) { mem_cache_object_t *mobj = obj->vobj; /* Cleanup the mem_cache_object_t */ if (mobj) { if (mobj->m) { free(mobj->m); } if (mobj->type == CACHE_TYPE_FILE && mobj->fd) { #ifdef WIN32 CloseHandle(mobj->fd); #else close(mobj->fd); #endif } } apr_pool_destroy(mobj->pool); } static apr_status_t decrement_refcount(void *arg) { cache_object_t *obj = (cache_object_t *) arg; /* If obj->complete is not set, the cache update failed and the * object needs to be removed from the cache then cleaned up. * The garbage collector may have ejected the object from the * cache already, so make sure it is really still in the cache * before attempting to remove it. */ if (!obj->complete) { cache_object_t *tobj = NULL; if (sconf->lock) { apr_thread_mutex_lock(sconf->lock); } tobj = cache_find(sconf->cache_cache, obj->key); if (tobj == obj) { cache_remove(sconf->cache_cache, obj); apr_atomic_dec32(&obj->refcount); } if (sconf->lock) { apr_thread_mutex_unlock(sconf->lock); } } /* If the refcount drops to 0, cleanup the cache object */ if (!apr_atomic_dec32(&obj->refcount)) { cleanup_cache_object(obj); } return APR_SUCCESS; } static apr_status_t cleanup_cache_mem(void *sconfv) { cache_object_t *obj; mem_cache_conf *co = (mem_cache_conf*) sconfv; if (!co) { return APR_SUCCESS; } if (!co->cache_cache) { return APR_SUCCESS; } if (sconf->lock) { apr_thread_mutex_lock(sconf->lock); } obj = cache_pop(co->cache_cache); while (obj) { /* Iterate over the cache and clean up each unreferenced entry */ if (!apr_atomic_dec32(&obj->refcount)) { cleanup_cache_object(obj); } obj = cache_pop(co->cache_cache); } /* Cache is empty, free the cache table */ cache_free(co->cache_cache); if (sconf->lock) { apr_thread_mutex_unlock(sconf->lock); } return APR_SUCCESS; } /* * TODO: enable directives to be overridden in various containers */ static void *create_cache_config(apr_pool_t *p, server_rec *s) { sconf = apr_pcalloc(p, sizeof(mem_cache_conf)); sconf->min_cache_object_size = DEFAULT_MIN_CACHE_OBJECT_SIZE; sconf->max_cache_object_size = DEFAULT_MAX_CACHE_OBJECT_SIZE; /* Number of objects in the cache */ sconf->max_object_cnt = DEFAULT_MAX_OBJECT_CNT; /* Size of the cache in bytes */ sconf->max_cache_size = DEFAULT_MAX_CACHE_SIZE; sconf->cache_cache = NULL; sconf->cache_remove_algorithm = memcache_gdsf_algorithm; sconf->max_streaming_buffer_size = DEFAULT_MAX_STREAMING_BUFFER_SIZE; return sconf; } static int create_entity(cache_handle_t *h, cache_type_e type_e, request_rec *r, const char *key, apr_off_t len) { apr_status_t rv; apr_pool_t *pool; cache_object_t *obj, *tmp_obj; mem_cache_object_t *mobj; if (len == -1) { /* Caching a streaming response. Assume the response is * less than or equal to max_streaming_buffer_size. We will * correct all the cache size counters in store_body once * we know exactly know how much we are caching. */ len = sconf->max_streaming_buffer_size; } /* Note: cache_insert() will automatically garbage collect * objects from the cache if the max_cache_size threshold is * exceeded. This means mod_mem_cache does not need to implement * max_cache_size checks. */ if (len < sconf->min_cache_object_size || len > sconf->max_cache_object_size) { ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, "mem_cache: URL %s failed the size check and will not be cached.", key); return DECLINED; } if (type_e == CACHE_TYPE_FILE) { /* CACHE_TYPE_FILE is only valid for local content handled by the * default handler. Need a better way to check if the file is * local or not. */ if (!r->filename) { return DECLINED; } } rv = apr_pool_create(&pool, NULL); if (rv != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_WARNING, rv, r->server, "mem_cache: Failed to create memory pool."); return DECLINED; } /* Allocate and initialize cache_object_t */ obj = apr_pcalloc(pool, sizeof(*obj)); obj->key = apr_pstrdup(pool, key); /* Allocate and init mem_cache_object_t */ mobj = apr_pcalloc(pool, sizeof(*mobj)); mobj->pool = pool; /* Finish initing the cache object */ apr_atomic_set32(&obj->refcount, 1); mobj->total_refs = 1; obj->complete = 0; obj->vobj = mobj; /* Safe cast: We tested < sconf->max_cache_object_size above */ mobj->m_len = (apr_size_t)len; mobj->type = type_e; /* Place the cache_object_t into the hash table. * Note: Perhaps we should wait to put the object in the * hash table when the object is complete? I add the object here to * avoid multiple threads attempting to cache the same content only * to discover at the very end that only one of them will succeed. * Furthermore, adding the cache object to the table at the end could * open up a subtle but easy to exploit DoS hole: someone could request * a very large file with multiple requests. Better to detect this here * rather than after the cache object has been completely built and * initialized... * XXX Need a way to insert into the cache w/o such coarse grained locking */ if (sconf->lock) { apr_thread_mutex_lock(sconf->lock); } tmp_obj = (cache_object_t *) cache_find(sconf->cache_cache, key); if (!tmp_obj) { cache_insert(sconf->cache_cache, obj); /* Add a refcount to account for the reference by the * hashtable in the cache. Refcount should be 2 now, one * for this thread, and one for the cache. */ apr_atomic_inc32(&obj->refcount); } if (sconf->lock) { apr_thread_mutex_unlock(sconf->lock); } if (tmp_obj) { /* This thread collided with another thread loading the same object * into the cache at the same time. Defer to the other thread which * is further along. */ cleanup_cache_object(obj); return DECLINED; } apr_pool_cleanup_register(r->pool, obj, decrement_refcount, apr_pool_cleanup_null); /* Populate the cache handle */ h->cache_obj = obj; return OK; } static int create_mem_entity(cache_handle_t *h, request_rec *r, const char *key, apr_off_t len) { return create_entity(h, CACHE_TYPE_HEAP, r, key, len); } static int create_fd_entity(cache_handle_t *h, request_rec *r, const char *key, apr_off_t len) { return create_entity(h, CACHE_TYPE_FILE, r, key, len); } static int open_entity(cache_handle_t *h, request_rec *r, const char *key) { cache_object_t *obj; /* Look up entity keyed to 'url' */ if (sconf->lock) { apr_thread_mutex_lock(sconf->lock); } obj = (cache_object_t *) cache_find(sconf->cache_cache, key); if (obj) { if (obj->complete) { request_rec *rmain=r, *rtmp; apr_atomic_inc32(&obj->refcount); /* cache is worried about overall counts, not 'open' ones */ cache_update(sconf->cache_cache, obj); /* If this is a subrequest, register the cleanup against * the main request. This will prevent the cache object * from being cleaned up from under the request after the * subrequest is destroyed. */ rtmp = r; while (rtmp) { rmain = rtmp; rtmp = rmain->main; } apr_pool_cleanup_register(rmain->pool, obj, decrement_refcount, apr_pool_cleanup_null); } else { obj = NULL; } } if (sconf->lock) { apr_thread_mutex_unlock(sconf->lock); } if (!obj) { return DECLINED; } /* Initialize the cache_handle */ h->cache_obj = obj; h->req_hdrs = NULL; /* Pick these up in recall_headers() */ return OK; } /* remove_entity() * Notes: * refcount should be at least 1 upon entry to this function to account * for this thread's reference to the object. If the refcount is 1, then * object has been removed from the cache by another thread and this thread * is the last thread accessing the object. */ static int remove_entity(cache_handle_t *h) { cache_object_t *obj = h->cache_obj; cache_object_t *tobj = NULL; if (sconf->lock) { apr_thread_mutex_lock(sconf->lock); } /* If the entity is still in the cache, remove it and decrement the * refcount. If the entity is not in the cache, do nothing. In both cases * decrement_refcount called by the last thread referencing the object will * trigger the cleanup. */ tobj = cache_find(sconf->cache_cache, obj->key); if (tobj == obj) { cache_remove(sconf->cache_cache, obj); apr_atomic_dec32(&obj->refcount); } if (sconf->lock) { apr_thread_mutex_unlock(sconf->lock); } return OK; } /* Define request processing hook handlers */ /* remove_url() * Notes: */ static int remove_url(cache_handle_t *h, apr_pool_t *p) { cache_object_t *obj; int cleanup = 0; if (sconf->lock) { apr_thread_mutex_lock(sconf->lock); } obj = h->cache_obj; if (obj) { cache_remove(sconf->cache_cache, obj); /* For performance, cleanup cache object after releasing the lock */ cleanup = !apr_atomic_dec32(&obj->refcount); } if (sconf->lock) { apr_thread_mutex_unlock(sconf->lock); } if (cleanup) { cleanup_cache_object(obj); } return OK; } static apr_table_t *deep_table_copy(apr_pool_t *p, const apr_table_t *table) { const apr_array_header_t *array = apr_table_elts(table); apr_table_entry_t *elts = (apr_table_entry_t *) array->elts; apr_table_t *copy = apr_table_make(p, array->nelts); int i; for (i = 0; i < array->nelts; i++) { if (elts[i].key) { apr_table_add(copy, elts[i].key, elts[i].val); } } return copy; } static apr_status_t recall_headers(cache_handle_t *h, request_rec *r) { mem_cache_object_t *mobj = (mem_cache_object_t*) h->cache_obj->vobj; h->req_hdrs = deep_table_copy(r->pool, mobj->req_hdrs); h->resp_hdrs = deep_table_copy(r->pool, mobj->header_out); return OK; } static apr_status_t recall_body(cache_handle_t *h, apr_pool_t *p, apr_bucket_brigade *bb) { apr_bucket *b; mem_cache_object_t *mobj = (mem_cache_object_t*) h->cache_obj->vobj; if (mobj->type == CACHE_TYPE_FILE) { /* CACHE_TYPE_FILE */ apr_file_t *file; apr_os_file_put(&file, &mobj->fd, mobj->flags, p); b = apr_bucket_file_create(file, 0, mobj->m_len, p, bb->bucket_alloc); } else { /* CACHE_TYPE_HEAP */ b = apr_bucket_immortal_create(mobj->m, mobj->m_len, bb->bucket_alloc); } APR_BRIGADE_INSERT_TAIL(bb, b); b = apr_bucket_eos_create(bb->bucket_alloc); APR_BRIGADE_INSERT_TAIL(bb, b); return APR_SUCCESS; } static apr_status_t store_headers(cache_handle_t *h, request_rec *r, cache_info *info) { cache_object_t *obj = h->cache_obj; mem_cache_object_t *mobj = (mem_cache_object_t*) obj->vobj; apr_table_t *headers_out; /* * The cache needs to keep track of the following information: * - Date, LastMod, Version, ReqTime, RespTime, ContentLength * - The original request headers (for Vary) * - The original response headers (for returning with a cached response) * - The body of the message */ mobj->req_hdrs = deep_table_copy(mobj->pool, r->headers_in); /* Precompute how much storage we need to hold the headers */ headers_out = ap_cache_cacheable_hdrs_out(r->pool, r->headers_out, r->server); /* If not set in headers_out, set Content-Type */ if (!apr_table_get(headers_out, "Content-Type") && r->content_type) { apr_table_setn(headers_out, "Content-Type", ap_make_content_type(r, r->content_type)); } headers_out = apr_table_overlay(r->pool, headers_out, r->err_headers_out); mobj->header_out = deep_table_copy(mobj->pool, headers_out); /* Init the info struct */ obj->info.status = info->status; if (info->date) { obj->info.date = info->date; } if (info->response_time) { obj->info.response_time = info->response_time; } if (info->request_time) { obj->info.request_time = info->request_time; } if (info->expire) { obj->info.expire = info->expire; } return APR_SUCCESS; } static apr_status_t store_body(cache_handle_t *h, request_rec *r, apr_bucket_brigade *b) { apr_status_t rv; cache_object_t *obj = h->cache_obj; cache_object_t *tobj = NULL; mem_cache_object_t *mobj = (mem_cache_object_t*) obj->vobj; apr_read_type_e eblock = APR_BLOCK_READ; apr_bucket *e; char *cur; int eos = 0; if (mobj->type == CACHE_TYPE_FILE) { apr_file_t *file = NULL; int fd = 0; int other = 0; /* We can cache an open file descriptor if: * - the brigade contains one and only one file_bucket && * - the brigade is complete && * - the file_bucket is the last data bucket in the brigade */ for (e = APR_BRIGADE_FIRST(b); e != APR_BRIGADE_SENTINEL(b); e = APR_BUCKET_NEXT(e)) { if (APR_BUCKET_IS_EOS(e)) { eos = 1; } else if (APR_BUCKET_IS_FILE(e)) { apr_bucket_file *a = e->data; fd++; file = a->fd; } else { other++; } } if (fd == 1 && !other && eos) { apr_file_t *tmpfile; const char *name; /* Open a new XTHREAD handle to the file */ apr_file_name_get(&name, file); mobj->flags = ((APR_SENDFILE_ENABLED & apr_file_flags_get(file)) | APR_READ | APR_BINARY | APR_XTHREAD | APR_FILE_NOCLEANUP); rv = apr_file_open(&tmpfile, name, mobj->flags, APR_OS_DEFAULT, r->pool); if (rv != APR_SUCCESS) { return rv; } apr_file_inherit_unset(tmpfile); apr_os_file_get(&(mobj->fd), tmpfile); /* Open for business */ ap_log_error(APLOG_MARK, APLOG_INFO, 0, r->server, "mem_cache: Cached file: %s with key: %s", name, obj->key); obj->complete = 1; return APR_SUCCESS; } /* Content not suitable for fd caching. Cache in-memory instead. */ mobj->type = CACHE_TYPE_HEAP; } /* * FD cacheing is not enabled or the content was not * suitable for fd caching. */ if (mobj->m == NULL) { mobj->m = malloc(mobj->m_len); if (mobj->m == NULL) { return APR_ENOMEM; } obj->count = 0; } cur = (char*) mobj->m + obj->count; /* Iterate accross the brigade and populate the cache storage */ for (e = APR_BRIGADE_FIRST(b); e != APR_BRIGADE_SENTINEL(b); e = APR_BUCKET_NEXT(e)) { const char *s; apr_size_t len; if (APR_BUCKET_IS_EOS(e)) { if (mobj->m_len > obj->count) { /* Caching a streamed response. Reallocate a buffer of the * correct size and copy the streamed response into that * buffer */ mobj->m = realloc(mobj->m, obj->count); if (!mobj->m) { return APR_ENOMEM; } /* Now comes the crufty part... there is no way to tell the * cache that the size of the object has changed. We need * to remove the object, update the size and re-add the * object, all under protection of the lock. */ if (sconf->lock) { apr_thread_mutex_lock(sconf->lock); } /* Has the object been ejected from the cache? */ tobj = (cache_object_t *) cache_find(sconf->cache_cache, obj->key); if (tobj == obj) { /* Object is still in the cache, remove it, update the len field then * replace it under protection of sconf->lock. */ cache_remove(sconf->cache_cache, obj); /* For illustration, cache no longer has reference to the object * so decrement the refcount * apr_atomic_dec32(&obj->refcount); */ mobj->m_len = obj->count; cache_insert(sconf->cache_cache, obj); /* For illustration, cache now has reference to the object, so * increment the refcount * apr_atomic_inc32(&obj->refcount); */ } else if (tobj) { /* Different object with the same key found in the cache. Doing nothing * here will cause the object refcount to drop to 0 in decrement_refcount * and the object will be cleaned up. */ } else { /* Object has been ejected from the cache, add it back to the cache */ mobj->m_len = obj->count; cache_insert(sconf->cache_cache, obj); apr_atomic_inc32(&obj->refcount); } if (sconf->lock) { apr_thread_mutex_unlock(sconf->lock); } } /* Open for business */ ap_log_error(APLOG_MARK, APLOG_INFO, 0, r->server, "mem_cache: Cached url: %s", obj->key); obj->complete = 1; break; } rv = apr_bucket_read(e, &s, &len, eblock); if (rv != APR_SUCCESS) { return rv; } if (len) { /* Check for buffer overflow */ if ((obj->count + len) > mobj->m_len) { return APR_ENOMEM; } else { memcpy(cur, s, len); cur+=len; obj->count+=len; } } /* This should not fail, but if it does, we are in BIG trouble * cause we just stomped all over the heap. */ AP_DEBUG_ASSERT(obj->count <= mobj->m_len); } return APR_SUCCESS; } /** * Configuration and start-up */ static int mem_cache_post_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s) { int threaded_mpm; /* Sanity check the cache configuration */ if (sconf->min_cache_object_size >= sconf->max_cache_object_size) { ap_log_error(APLOG_MARK, APLOG_CRIT, 0, s, "MCacheMaxObjectSize must be greater than MCacheMinObjectSize"); return DONE; } if (sconf->max_cache_object_size >= sconf->max_cache_size) { ap_log_error(APLOG_MARK, APLOG_CRIT, 0, s, "MCacheSize must be greater than MCacheMaxObjectSize"); return DONE; } if (sconf->max_streaming_buffer_size > sconf->max_cache_object_size) { /* Issue a notice only if something other than the default config * is being used */ if (sconf->max_streaming_buffer_size != DEFAULT_MAX_STREAMING_BUFFER_SIZE && sconf->max_cache_object_size != DEFAULT_MAX_CACHE_OBJECT_SIZE) { ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, s, "MCacheMaxStreamingBuffer must be less than or equal to MCacheMaxObjectSize. " "Resetting MCacheMaxStreamingBuffer to MCacheMaxObjectSize."); } sconf->max_streaming_buffer_size = sconf->max_cache_object_size; } if (sconf->max_streaming_buffer_size < sconf->min_cache_object_size) { ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, "MCacheMaxStreamingBuffer must be greater than or equal to MCacheMinObjectSize. " "Resetting MCacheMaxStreamingBuffer to MCacheMinObjectSize."); sconf->max_streaming_buffer_size = sconf->min_cache_object_size; } ap_mpm_query(AP_MPMQ_IS_THREADED, &threaded_mpm); if (threaded_mpm) { apr_thread_mutex_create(&sconf->lock, APR_THREAD_MUTEX_DEFAULT, p); } sconf->cache_cache = cache_init(sconf->max_object_cnt, sconf->max_cache_size, memcache_get_priority, sconf->cache_remove_algorithm, memcache_get_pos, memcache_set_pos, memcache_inc_frequency, memcache_cache_get_size, memcache_cache_get_key, memcache_cache_free); apr_pool_cleanup_register(p, sconf, cleanup_cache_mem, apr_pool_cleanup_null); if (sconf->cache_cache) return OK; return -1; } static const char *set_max_cache_size(cmd_parms *parms, void *in_struct_ptr, const char *arg) { apr_size_t val; if (sscanf(arg, "%" APR_SIZE_T_FMT, &val) != 1) { return "MCacheSize argument must be an integer representing the max cache size in KBytes."; } sconf->max_cache_size = val*1024; return NULL; } static const char *set_min_cache_object_size(cmd_parms *parms, void *in_struct_ptr, const char *arg) { apr_size_t val; if (sscanf(arg, "%" APR_SIZE_T_FMT, &val) != 1) { return "MCacheMinObjectSize value must be an positive integer (bytes)"; } if (val > 0) sconf->min_cache_object_size = val; else return "MCacheMinObjectSize value must be an positive integer (bytes)"; return NULL; } static const char *set_max_cache_object_size(cmd_parms *parms, void *in_struct_ptr, const char *arg) { apr_size_t val; if (sscanf(arg, "%" APR_SIZE_T_FMT, &val) != 1) { return "MCacheMaxObjectSize value must be an integer (bytes)"; } sconf->max_cache_object_size = val; return NULL; } static const char *set_max_object_count(cmd_parms *parms, void *in_struct_ptr, const char *arg) { apr_size_t val; if (sscanf(arg, "%" APR_SIZE_T_FMT, &val) != 1) { return "MCacheMaxObjectCount value must be an integer"; } sconf->max_object_cnt = val; return NULL; } static const char *set_cache_removal_algorithm(cmd_parms *parms, void *name, const char *arg) { if (strcasecmp("LRU", arg)) { sconf->cache_remove_algorithm = memcache_lru_algorithm; } else { if (strcasecmp("GDSF", arg)) { sconf->cache_remove_algorithm = memcache_gdsf_algorithm; } else { return "currently implemented algorithms are LRU and GDSF"; } } return NULL; } static const char *set_max_streaming_buffer(cmd_parms *parms, void *dummy, const char *arg) { char *err; if (apr_strtoff(&sconf->max_streaming_buffer_size, arg, &err, 10) || *err) { return "MCacheMaxStreamingBuffer value must be a number"; } return NULL; } static const command_rec cache_cmds[] = { AP_INIT_TAKE1("MCacheSize", set_max_cache_size, NULL, RSRC_CONF, "The maximum amount of memory used by the cache in KBytes"), AP_INIT_TAKE1("MCacheMaxObjectCount", set_max_object_count, NULL, RSRC_CONF, "The maximum number of objects allowed to be placed in the cache"), AP_INIT_TAKE1("MCacheMinObjectSize", set_min_cache_object_size, NULL, RSRC_CONF, "The minimum size (in bytes) of an object to be placed in the cache"), AP_INIT_TAKE1("MCacheMaxObjectSize", set_max_cache_object_size, NULL, RSRC_CONF, "The maximum size (in bytes) of an object to be placed in the cache"), AP_INIT_TAKE1("MCacheRemovalAlgorithm", set_cache_removal_algorithm, NULL, RSRC_CONF, "The algorithm used to remove entries from the cache (default: GDSF)"), AP_INIT_TAKE1("MCacheMaxStreamingBuffer", set_max_streaming_buffer, NULL, RSRC_CONF, "Maximum number of bytes of content to buffer for a streamed response"), {NULL} }; static const cache_provider cache_mem_provider = { &remove_entity, &store_headers, &store_body, &recall_headers, &recall_body, &create_mem_entity, &open_entity, &remove_url, }; static const cache_provider cache_fd_provider = { &remove_entity, &store_headers, &store_body, &recall_headers, &recall_body, &create_fd_entity, &open_entity, &remove_url, }; static void register_hooks(apr_pool_t *p) { ap_hook_post_config(mem_cache_post_config, NULL, NULL, APR_HOOK_MIDDLE); /* cache initializer */ /* cache_hook_init(cache_mem_init, NULL, NULL, APR_HOOK_MIDDLE); */ /* cache_hook_create_entity(create_entity, NULL, NULL, APR_HOOK_MIDDLE); cache_hook_open_entity(open_entity, NULL, NULL, APR_HOOK_MIDDLE); cache_hook_remove_url(remove_url, NULL, NULL, APR_HOOK_MIDDLE); */ ap_register_provider(p, CACHE_PROVIDER_GROUP, "mem", "0", &cache_mem_provider); ap_register_provider(p, CACHE_PROVIDER_GROUP, "fd", "0", &cache_fd_provider); } module AP_MODULE_DECLARE_DATA mem_cache_module = { STANDARD20_MODULE_STUFF, NULL, /* create per-directory config structure */ NULL, /* merge per-directory config structures */ create_cache_config, /* create per-server config structure */ NULL, /* merge per-server config structures */ cache_cmds, /* command apr_table_t */ register_hooks };
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