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Diffstat (limited to 'rubbos/app/httpd-2.0.64/modules/cache/mod_file_cache.c')
| -rw-r--r-- | rubbos/app/httpd-2.0.64/modules/cache/mod_file_cache.c | 416 |
1 files changed, 416 insertions, 0 deletions
diff --git a/rubbos/app/httpd-2.0.64/modules/cache/mod_file_cache.c b/rubbos/app/httpd-2.0.64/modules/cache/mod_file_cache.c new file mode 100644 index 00000000..947b8f2c --- /dev/null +++ b/rubbos/app/httpd-2.0.64/modules/cache/mod_file_cache.c @@ -0,0 +1,416 @@ +/* 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 + +#define CORE_PRIVATE + +#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, + "mod_file_cache: 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, + "mod_file_cache: unable to stat(%s), skipping", fspec); + return; + } + if (tmp.finfo.filetype != APR_REG) { + ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server, + "mod_file_cache: %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, + "mod_file_cache: %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, + "mod_file_cache: 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, + "mod_file_cache: 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, + "mod_file_cache: 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, + "mod_file_cache: 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, 0); + 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 HTTP_INTERNAL_SERVER_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); + + b = apr_bucket_file_create(file->file, 0, (apr_size_t)file->finfo.size, + r->pool, 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 HTTP_INTERNAL_SERVER_ERROR; +#endif + return OK; +} + +static int file_cache_handler(request_rec *r) +{ + a_file *match; + int errstatus; + int rc = OK; + + /* XXX: not sure if this is right yet + * see comment in http_core.c:default_handler + */ + if (ap_strcmp_match(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_etag(r); + if ((errstatus = ap_meets_conditions(r)) != OK) { + return errstatus; + } + + /* 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); + + /* 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 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); + */ + +} + +module AP_MODULE_DECLARE_DATA file_cache_module = +{ + 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 */ +}; |