cvs: pecl /apc INSTALL apc_cache.c apc_globals.h php_apc.c

rasmus          Fri Jul 29 16:54:12 2005 EDT

  Modified files:              
    /pecl/apc   INSTALL apc_cache.c apc_globals.h php_apc.c 
  Log:
  Add file_update_protection configuration directive.  See the INSTALL file
  for a full description.
  
  
http://cvs.php.net/diff.php/pecl/apc/INSTALL?r1=3.43&r2=3.44&ty=u
Index: pecl/apc/INSTALL
diff -u pecl/apc/INSTALL:3.43 pecl/apc/INSTALL:3.44
--- pecl/apc/INSTALL:3.43       Thu Jul 21 04:11:13 2005
+++ pecl/apc/INSTALL    Fri Jul 29 16:54:10 2005
@@ -285,3 +285,25 @@
                             against cache slams.  Setting this to 0 disables 
this
                             feature.
                             (Default: 0)
+
+    apc.file_update_protection
+                            When you modify a file on a live web server you 
really
+                            should do so in an atomic manner.  That is, write 
to a
+                            temporary file and rename (mv) the file into its 
permanent
+                            position when it is ready.  Many text editors, cp, 
tar and
+                            other such programs don't do this.  This means 
that there
+                            is a chance that a file is accessed (and cached) 
while it
+                            is still being written to.  This 
file_update_protection
+                            setting puts a delay on caching brand new files.  
The
+                            default is 2 seconds which means that if the 
modification
+                            timestamp (mtime) on a file shows that it is less 
than 2
+                            seconds old when it is accessed, it will not be 
cached.  
+                            The unfortunate person who accessed this 
half-written file
+                            will still see weirdness, but at least it won't 
persist.
+                            If you are certain you always atomically update 
your files
+                            by using something like rsync which does this 
correctly, you
+                            can turn this protection off by setting it to 0.  
If you
+                            have a system that is flooded with io causing some 
update
+                            procedure to take longer than 2 seconds, you may 
want to
+                            increase this a bit.
+                            (Default: 2)
http://cvs.php.net/diff.php/pecl/apc/apc_cache.c?r1=3.89&r2=3.90&ty=u
Index: pecl/apc/apc_cache.c
diff -u pecl/apc/apc_cache.c:3.89 pecl/apc/apc_cache.c:3.90
--- pecl/apc/apc_cache.c:3.89   Fri Jul 29 04:19:30 2005
+++ pecl/apc/apc_cache.c        Fri Jul 29 16:54:11 2005
@@ -28,7 +28,7 @@
 
  */
 
-/* $Id: apc_cache.c,v 3.89 2005/07/29 08:19:30 rasmus Exp $ */
+/* $Id: apc_cache.c,v 3.90 2005/07/29 20:54:11 rasmus Exp $ */
 
 #include "apc_cache.h"
 #include "apc_lock.h"
@@ -571,7 +571,8 @@
                                           TSRMLS_DC)
 {
     struct stat buf, *tmp_buf=NULL;
-               
+       
+    TSRMLS_FETCH();            
     assert(key != NULL);
 
     if (!filename || !SG(request_info).path_translated) {
@@ -605,27 +606,16 @@
      * request time and we want to avoid caching files that have not been
      * completely written.  Of course, people should be using atomic 
      * mechanisms to push files onto live web servers, but adding this
-     * tiny safety is easier than educating the world.
+     * tiny safety is easier than educating the world.  This is now
+     * configurable, but the default is still 2 seconds.
      */
-    if(t - buf.st_mtime < 2) { 
+    if(APCG(file_update_protection) && (t - buf.st_mtime < 
APCG(file_update_protection))) { 
 #ifdef __DEBUG_APC__
                fprintf(stderr,"File is too new %s (%d - %d) - 
bailing\n",filename,t,buf.st_mtime);
 #endif
                return 0;
        }
 
-    /*
-     * This is an even bigger hack than the above.
-     *
-     * Basically this will cause a file only to be cached on a percentage
-     * of the attempts.  This is to avoid cache slams when starting up a
-     * very busy server or when modifying files on a very busy live server.
-     * There is no point having many processes all trying to cache the same
-     * file at the same time.  By introducing a chance of being cached
-     * we theoretically cut the cache slam problem by the given percentage.
-     * For example if apc.slam_defense is set to 66 then 2/3 of the attempts
-     * to cache an uncached file will be ignored.
-     */
     key->data.file.device = buf.st_dev;
     key->data.file.inode  = buf.st_ino;
     /* 
@@ -636,7 +626,9 @@
      * "older" template.  At some point the Smarty templating system did this.
      * I generally disagree with using the ctime here because you lose the 
      * ability to warm up new content by saving it to a temporary file, hitting
-     * it once to cache it and then renaming it into its permanent location.
+     * it once to cache it and then renaming it into its permanent location so
+     * I am leaving this commented out by default.  If you need this, uncomment
+     * it.
      */
     /* key->mtime  = (buf.st_ctime > buf.st_mtime) ? buf.st_ctime : 
buf.st_mtime; */
     key->mtime = buf.st_mtime;
http://cvs.php.net/diff.php/pecl/apc/apc_globals.h?r1=3.16&r2=3.17&ty=u
Index: pecl/apc/apc_globals.h
diff -u pecl/apc/apc_globals.h:3.16 pecl/apc/apc_globals.h:3.17
--- pecl/apc/apc_globals.h:3.16 Fri Jul 29 04:19:31 2005
+++ pecl/apc/apc_globals.h      Fri Jul 29 16:54:11 2005
@@ -29,7 +29,7 @@
 
  */
 
-/* $Id: apc_globals.h,v 3.16 2005/07/29 08:19:31 rasmus Exp $ */
+/* $Id: apc_globals.h,v 3.17 2005/07/29 20:54:11 rasmus Exp $ */
 
 #ifndef APC_GLOBALS_H
 #define APC_GLOBALS_H
@@ -67,6 +67,7 @@
                             /* false if files should only be cached if 
filtered in */
     int slam_defense;       /* Probability of a process not caching an 
uncached file */
     size_t* mem_size_ptr;   /* size of blocks allocated to file being cached 
(NULL outside my_compile_file) */
+    int file_update_protection; /* Age in seconds before a file is eligible to 
be cached - 0 to disable */
 ZEND_END_MODULE_GLOBALS(apc)
 
 /* (the following declaration is defined in php_apc.c) */
http://cvs.php.net/diff.php/pecl/apc/php_apc.c?r1=3.57&r2=3.58&ty=u
Index: pecl/apc/php_apc.c
diff -u pecl/apc/php_apc.c:3.57 pecl/apc/php_apc.c:3.58
--- pecl/apc/php_apc.c:3.57     Fri Jul 29 04:19:32 2005
+++ pecl/apc/php_apc.c  Fri Jul 29 16:54:11 2005
@@ -26,7 +26,7 @@
 
  */
 
-/* $Id: php_apc.c,v 3.57 2005/07/29 08:19:32 rasmus Exp $ */
+/* $Id: php_apc.c,v 3.58 2005/07/29 20:54:11 rasmus Exp $ */
 
 #include "php_apc.h"
 #include "apc_cache.h"
@@ -116,7 +116,8 @@
 #endif
     PHP_INI_ENTRY("apc.filters",        "",     PHP_INI_SYSTEM, 
OnUpdate_filters)
 STD_PHP_INI_BOOLEAN("apc.cache_by_default", "1",  PHP_INI_SYSTEM, OnUpdateInt, 
         cache_by_default, zend_apc_globals, apc_globals)
-STD_PHP_INI_BOOLEAN("apc.slam_defense", "0",      PHP_INI_SYSTEM, OnUpdateInt, 
         slam_defense,   zend_apc_globals, apc_globals)
+STD_PHP_INI_BOOLEAN("apc.slam_defense", "0",      PHP_INI_SYSTEM, OnUpdateInt, 
         slam_defense,     zend_apc_globals, apc_globals)
+STD_PHP_INI_BOOLEAN("apc.file_update_protection", "2", PHP_INI_SYSTEM, 
OnUpdateInt,file_update_protection, zend_apc_globals, apc_globals)
 PHP_INI_END()
 
 /* }}} */
@@ -133,7 +134,7 @@
 #else
        php_info_print_table_row(2, "MMAP Support", "Disabled");
 #endif
-       php_info_print_table_row(2, "Revision", "$Revision: 3.57 $");
+       php_info_print_table_row(2, "Revision", "$Revision: 3.58 $");
        php_info_print_table_row(2, "Build Date", __DATE__ " " __TIME__);
        php_info_print_table_end();
     DISPLAY_INI_ENTRIES();