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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 06:33:50 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 06:33:50 +0000
commitfe39ffb8b90ae4e002ed73fe98617cd590abb467 (patch)
treeb80e5956907d8aeaaffe4e4f0c068c0e6157ce8b /modules/cache/mod_file_cache.c
parentInitial commit. (diff)
downloadapache2-upstream/2.4.56.tar.xz
apache2-upstream/2.4.56.zip
Adding upstream version 2.4.56.upstream/2.4.56
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--modules/cache/mod_file_cache.c414
1 files changed, 414 insertions, 0 deletions
diff --git a/modules/cache/mod_file_cache.c b/modules/cache/mod_file_cache.c
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+/* 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.
+ */
+
+/*
+ * Author: mod_file_cache by Bill Stoddard <stoddard apache.org>
+ * Based on mod_mmap_static by Dean Gaudet <dgaudet arctic.org>
+ *
+ * v0.01: initial implementation
+ */
+
+/*
+ Documentation:
+
+ Some sites have a set of static files that are really busy, and
+ change infrequently (or even on a regular schedule). Save time
+ by caching open handles to these files. This module, unlike
+ mod_mmap_static, caches open file handles, not file content.
+ On systems (like Windows) with heavy system call overhead and
+ that have an efficient sendfile implementation, caching file handles
+ offers several advantages over caching content. First, the file system
+ can manage the memory, allowing infrequently hit cached files to
+ be paged out. Second, since caching open handles does not consume
+ significant resources, it will be possible to enable an AutoLoadCache
+ feature where static files are dynamically loaded in the cache
+ as the server runs. On systems that have file change notification,
+ this module can be enhanced to automatically garbage collect
+ cached files that change on disk.
+
+ This module should work on Unix systems that have sendfile. Place
+ cachefile directives into your configuration to direct files to
+ be cached.
+
+ cachefile /path/to/file1
+ cachefile /path/to/file2
+ ...
+
+ These files are only cached when the server is restarted, so if you
+ change the list, or if the files are changed, then you'll need to
+ restart the server.
+
+ To reiterate that point: if the files are modified *in place*
+ without restarting the server you may end up serving requests that
+ are completely bogus. You should update files by unlinking the old
+ copy and putting a new copy in place.
+
+ There's no such thing as inheriting these files across vhosts or
+ whatever... place the directives in the main server only.
+
+ Known problems:
+
+ Don't use Alias or RewriteRule to move these files around... unless
+ you feel like paying for an extra stat() on each request. This is
+ a deficiency in the Apache API that will hopefully be solved some day.
+ The file will be served out of the file handle cache, but there will be
+ an extra stat() that's a waste.
+*/
+
+#include "apr.h"
+
+#if !(APR_HAS_SENDFILE || APR_HAS_MMAP)
+#error mod_file_cache only works on systems with APR_HAS_SENDFILE or APR_HAS_MMAP
+#endif
+
+#include "apr_mmap.h"
+#include "apr_strings.h"
+#include "apr_hash.h"
+#include "apr_buckets.h"
+
+#define APR_WANT_STRFUNC
+#include "apr_want.h"
+
+#if APR_HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#include "httpd.h"
+#include "http_config.h"
+#include "http_log.h"
+#include "http_protocol.h"
+#include "http_request.h"
+#include "http_core.h"
+
+module AP_MODULE_DECLARE_DATA file_cache_module;
+
+typedef struct {
+#if APR_HAS_SENDFILE
+ apr_file_t *file;
+#endif
+ const char *filename;
+ apr_finfo_t finfo;
+ int is_mmapped;
+#if APR_HAS_MMAP
+ apr_mmap_t *mm;
+#endif
+ char mtimestr[APR_RFC822_DATE_LEN];
+ char sizestr[21]; /* big enough to hold any 64-bit file size + null */
+} a_file;
+
+typedef struct {
+ apr_hash_t *fileht;
+} a_server_config;
+
+
+static void *create_server_config(apr_pool_t *p, server_rec *s)
+{
+ a_server_config *sconf = apr_palloc(p, sizeof(*sconf));
+
+ sconf->fileht = apr_hash_make(p);
+ return sconf;
+}
+
+static void cache_the_file(cmd_parms *cmd, const char *filename, int mmap)
+{
+ a_server_config *sconf;
+ a_file *new_file;
+ a_file tmp;
+ apr_file_t *fd = NULL;
+ apr_status_t rc;
+ const char *fspec;
+
+ fspec = ap_server_root_relative(cmd->pool, filename);
+ if (!fspec) {
+ ap_log_error(APLOG_MARK, APLOG_WARNING, APR_EBADPATH, cmd->server, APLOGNO(00794)
+ "invalid file path "
+ "%s, skipping", filename);
+ return;
+ }
+ if ((rc = apr_stat(&tmp.finfo, fspec, APR_FINFO_MIN,
+ cmd->temp_pool)) != APR_SUCCESS) {
+ ap_log_error(APLOG_MARK, APLOG_WARNING, rc, cmd->server, APLOGNO(00795)
+ "unable to stat(%s), skipping", fspec);
+ return;
+ }
+ if (tmp.finfo.filetype != APR_REG) {
+ ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server, APLOGNO(00796)
+ "%s isn't a regular file, skipping", fspec);
+ return;
+ }
+ if (tmp.finfo.size > AP_MAX_SENDFILE) {
+ ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server, APLOGNO(00797)
+ "%s is too large to cache, skipping", fspec);
+ return;
+ }
+
+ rc = apr_file_open(&fd, fspec, APR_READ | APR_BINARY | APR_XTHREAD,
+ APR_OS_DEFAULT, cmd->pool);
+ if (rc != APR_SUCCESS) {
+ ap_log_error(APLOG_MARK, APLOG_WARNING, rc, cmd->server, APLOGNO(00798)
+ "unable to open(%s, O_RDONLY), skipping", fspec);
+ return;
+ }
+ apr_file_inherit_set(fd);
+
+ /* WooHoo, we have a file to put in the cache */
+ new_file = apr_pcalloc(cmd->pool, sizeof(a_file));
+ new_file->finfo = tmp.finfo;
+
+#if APR_HAS_MMAP
+ if (mmap) {
+ /* MMAPFile directive. MMAP'ing the file
+ * XXX: APR_HAS_LARGE_FILES issue; need to reject this request if
+ * size is greater than MAX(apr_size_t) (perhaps greater than 1M?).
+ */
+ if ((rc = apr_mmap_create(&new_file->mm, fd, 0,
+ (apr_size_t)new_file->finfo.size,
+ APR_MMAP_READ, cmd->pool)) != APR_SUCCESS) {
+ apr_file_close(fd);
+ ap_log_error(APLOG_MARK, APLOG_WARNING, rc, cmd->server, APLOGNO(00799)
+ "unable to mmap %s, skipping", filename);
+ return;
+ }
+ apr_file_close(fd);
+ new_file->is_mmapped = TRUE;
+ }
+#endif
+#if APR_HAS_SENDFILE
+ if (!mmap) {
+ /* CacheFile directive. Caching the file handle */
+ new_file->is_mmapped = FALSE;
+ new_file->file = fd;
+ }
+#endif
+
+ new_file->filename = fspec;
+ apr_rfc822_date(new_file->mtimestr, new_file->finfo.mtime);
+ apr_snprintf(new_file->sizestr, sizeof new_file->sizestr, "%" APR_OFF_T_FMT, new_file->finfo.size);
+
+ sconf = ap_get_module_config(cmd->server->module_config, &file_cache_module);
+ apr_hash_set(sconf->fileht, new_file->filename, strlen(new_file->filename), new_file);
+
+}
+
+static const char *cachefilehandle(cmd_parms *cmd, void *dummy, const char *filename)
+{
+#if APR_HAS_SENDFILE
+ cache_the_file(cmd, filename, 0);
+#else
+ /* Sendfile not supported by this OS */
+ ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server, APLOGNO(00800)
+ "unable to cache file: %s. Sendfile is not supported on this OS", filename);
+#endif
+ return NULL;
+}
+static const char *cachefilemmap(cmd_parms *cmd, void *dummy, const char *filename)
+{
+#if APR_HAS_MMAP
+ cache_the_file(cmd, filename, 1);
+#else
+ /* MMAP not supported by this OS */
+ ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server, APLOGNO(00801)
+ "unable to cache file: %s. MMAP is not supported by this OS", filename);
+#endif
+ return NULL;
+}
+
+static int file_cache_post_config(apr_pool_t *p, apr_pool_t *plog,
+ apr_pool_t *ptemp, server_rec *s)
+{
+ /* Hummm, anything to do here? */
+ return OK;
+}
+
+/* If it's one of ours, fill in r->finfo now to avoid extra stat()... this is a
+ * bit of a kludge, because we really want to run after core_translate runs.
+ */
+static int file_cache_xlat(request_rec *r)
+{
+ a_server_config *sconf;
+ a_file *match;
+ int res;
+
+ sconf = ap_get_module_config(r->server->module_config, &file_cache_module);
+
+ /* we only operate when at least one cachefile directive was used */
+ if (!apr_hash_count(sconf->fileht)) {
+ return DECLINED;
+ }
+
+ res = ap_core_translate(r);
+ if (res != OK || !r->filename) {
+ return res;
+ }
+
+ /* search the cache */
+ match = (a_file *) apr_hash_get(sconf->fileht, r->filename, APR_HASH_KEY_STRING);
+ if (match == NULL)
+ return DECLINED;
+
+ /* pass search results to handler */
+ ap_set_module_config(r->request_config, &file_cache_module, match);
+
+ /* shortcircuit the get_path_info() stat() calls and stuff */
+ r->finfo = match->finfo;
+ return OK;
+}
+
+static int mmap_handler(request_rec *r, a_file *file)
+{
+#if APR_HAS_MMAP
+ conn_rec *c = r->connection;
+ apr_bucket *b;
+ apr_mmap_t *mm;
+ apr_bucket_brigade *bb = apr_brigade_create(r->pool, c->bucket_alloc);
+
+ apr_mmap_dup(&mm, file->mm, r->pool);
+ b = apr_bucket_mmap_create(mm, 0, (apr_size_t)file->finfo.size,
+ c->bucket_alloc);
+ APR_BRIGADE_INSERT_TAIL(bb, b);
+ b = apr_bucket_eos_create(c->bucket_alloc);
+ APR_BRIGADE_INSERT_TAIL(bb, b);
+
+ if (ap_pass_brigade(r->output_filters, bb) != APR_SUCCESS)
+ return AP_FILTER_ERROR;
+#endif
+ return OK;
+}
+
+static int sendfile_handler(request_rec *r, a_file *file)
+{
+#if APR_HAS_SENDFILE
+ conn_rec *c = r->connection;
+ apr_bucket *b;
+ apr_bucket_brigade *bb = apr_brigade_create(r->pool, c->bucket_alloc);
+
+ apr_brigade_insert_file(bb, file->file, 0, file->finfo.size, r->pool);
+
+ b = apr_bucket_eos_create(c->bucket_alloc);
+ APR_BRIGADE_INSERT_TAIL(bb, b);
+
+ if (ap_pass_brigade(r->output_filters, bb) != APR_SUCCESS)
+ return AP_FILTER_ERROR;
+#endif
+ return OK;
+}
+
+static int file_cache_handler(request_rec *r)
+{
+ a_file *match;
+ int errstatus;
+ int rc = OK;
+
+ /* Bail out if r->handler isn't the default value, and doesn't look like a Content-Type
+ * XXX: Even though we made the user explicitly list each path to cache?
+ */
+ if (ap_strcmp_match(r->handler, "*/*") && !AP_IS_DEFAULT_HANDLER_NAME(r->handler)) {
+ return DECLINED;
+ }
+
+ /* we don't handle anything but GET */
+ if (r->method_number != M_GET) return DECLINED;
+
+ /* did xlat phase find the file? */
+ match = ap_get_module_config(r->request_config, &file_cache_module);
+
+ if (match == NULL) {
+ return DECLINED;
+ }
+
+ /* note that we would handle GET on this resource */
+ r->allowed |= (AP_METHOD_BIT << M_GET);
+
+ /* This handler has no use for a request body (yet), but we still
+ * need to read and discard it if the client sent one.
+ */
+ if ((errstatus = ap_discard_request_body(r)) != OK)
+ return errstatus;
+
+ ap_update_mtime(r, match->finfo.mtime);
+
+ /* ap_set_last_modified() always converts the file mtime to a string
+ * which is slow. Accelerate the common case.
+ * ap_set_last_modified(r);
+ */
+ {
+ apr_time_t mod_time;
+ char *datestr;
+
+ mod_time = ap_rationalize_mtime(r, r->mtime);
+ if (mod_time == match->finfo.mtime)
+ datestr = match->mtimestr;
+ else {
+ datestr = apr_palloc(r->pool, APR_RFC822_DATE_LEN);
+ apr_rfc822_date(datestr, mod_time);
+ }
+ apr_table_setn(r->headers_out, "Last-Modified", datestr);
+ }
+
+ /* ap_set_content_length() always converts the same number and never
+ * returns an error. Accelerate it.
+ */
+ r->clength = match->finfo.size;
+ apr_table_setn(r->headers_out, "Content-Length", match->sizestr);
+
+ ap_set_etag(r);
+ if ((errstatus = ap_meets_conditions(r)) != OK) {
+ return errstatus;
+ }
+
+ /* Call appropriate handler */
+ if (!r->header_only) {
+ if (match->is_mmapped == TRUE)
+ rc = mmap_handler(r, match);
+ else
+ rc = sendfile_handler(r, match);
+ }
+
+ return rc;
+}
+
+static const command_rec file_cache_cmds[] =
+{
+AP_INIT_ITERATE("cachefile", cachefilehandle, NULL, RSRC_CONF,
+ "A space separated list of files to add to the file handle cache at config time"),
+AP_INIT_ITERATE("mmapfile", cachefilemmap, NULL, RSRC_CONF,
+ "A space separated list of files to mmap at config time"),
+ {NULL}
+};
+
+static void register_hooks(apr_pool_t *p)
+{
+ ap_hook_handler(file_cache_handler, NULL, NULL, APR_HOOK_LAST);
+ ap_hook_post_config(file_cache_post_config, NULL, NULL, APR_HOOK_MIDDLE);
+ ap_hook_translate_name(file_cache_xlat, NULL, NULL, APR_HOOK_MIDDLE);
+ /* This trick doesn't work apparently because the translate hooks
+ are single shot. If the core_hook returns OK, then our hook is
+ not called.
+ ap_hook_translate_name(file_cache_xlat, aszPre, NULL, APR_HOOK_MIDDLE);
+ */
+
+}
+
+AP_DECLARE_MODULE(file_cache) =
+{
+ STANDARD20_MODULE_STUFF,
+ NULL, /* create per-directory config structure */
+ NULL, /* merge per-directory config structures */
+ create_server_config, /* create per-server config structure */
+ NULL, /* merge per-server config structures */
+ file_cache_cmds, /* command handlers */
+ register_hooks /* register hooks */
+};