rewriting stat-prefetch translator

- stat-prefetch aims to optimize operations like 'ls -l' where a readdir
   is immediately followed by stat calls on each of the directory entry read.
   More details on design can be found in doc/stat-prefetch-design.txt

Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 221 (stat prefetch implementation)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=221

3 files changed, 46 insertions, 498 deletions

diff --git a/xlators/performance/stat-prefetch/src/Makefile.am b/xlators/performance/stat-prefetch/src/Makefile.am
index e52f2df48..b16c133a1 100644
--- a/xlators/performance/stat-prefetch/src/Makefile.am
+++ b/xlators/performance/stat-prefetch/src/Makefile.am
@@ -1,11 +1,14 @@
-xlator_PROGRAMS = stat-prefetch.so
+xlator_LTLIBRARIES = stat-prefetch.la
 xlatordir = $(libdir)/glusterfs/$(PACKAGE_VERSION)/xlator/performance
 
-stat_prefetch_so_SOURCES = stat-prefetch.c
+stat_prefetch_la_LDFLAGS = -module -avoidversion
+stat_prefetch_la_SOURCES = stat-prefetch.c
 noinst_HEADERS = stat-prefetch.h
 
-AM_CFLAGS = -fPIC -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -Wall \
-	-I$(top_srcdir)/libglusterfs/src -shared -nostartfiles
+stat_prefetch_la_LIBADD = $(top_builddir)/libglusterfs/src/libglusterfs.la
+
+AM_CFLAGS = -fPIC -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -Wall -D$(GF_HOST_OS)\
+	-I$(top_srcdir)/libglusterfs/src -shared -nostartfiles $(GF_CFLAGS)
 
 CLEANFILES = 
 
diff --git a/xlators/performance/stat-prefetch/src/stat-prefetch.c b/xlators/performance/stat-prefetch/src/stat-prefetch.c
index c6bf1e684..6a10ac4c4 100644
--- a/xlators/performance/stat-prefetch/src/stat-prefetch.c
+++ b/xlators/performance/stat-prefetch/src/stat-prefetch.c
@@ -1,508 +1,53 @@
 /*
-   Copyright (c) 2006-2009 Z RESEARCH, Inc. <http://www.zresearch.com>
-   This file is part of GlusterFS.
-
-   GlusterFS is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published
-   by the Free Software Foundation; either version 3 of the License,
-   or (at your option) any later version.
-
-   GlusterFS is distributed in the hope that it will be useful, but
-   WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see
-   <http://www.gnu.org/licenses/>.
+  Copyright (c) 2009-2010 Z RESEARCH, Inc. <http://www.zresearch.com>
+  This file is part of GlusterFS.
+
+  GlusterFS is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published
+  by the Free Software Foundation; either version 3 of the License,
+  or (at your option) any later version.
+
+  GlusterFS is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see
+  <http://www.gnu.org/licenses/>.
 */
 
-#ifndef _CONFIG_H
-#define _CONFIG_H
-#include "config.h"
-#endif
-
-#include "glusterfs.h"
 #include "stat-prefetch.h"
-#include "dict.h"
-#include "xlator.h"
-#include <sys/time.h>
-
-struct sp_cache {
-  struct sp_cache *next;
-  struct sp_cache *prev;
-  pid_t pid;
-  long long tv_time;
-  char *dirname;
-  dir_entry_t entries;
-  int32_t count;
-  pthread_mutex_t lock;
-};
-
-static void
-stat_prefetch_cache_flush (struct sp_cache *cache, int32_t force)
-{
-  struct sp_cache *trav;
-  struct timeval tv;
-  long long tv_time;
-
-  gettimeofday (&tv, NULL);
-  tv_time = (tv.tv_usec + (tv.tv_sec * 1000000));
-
-  pthread_mutex_lock (&cache->lock);
-
-  trav = cache->next;
-  while (trav != cache) {
-    struct sp_cache *next = trav->next;
-    {
-      if (tv_time > trav->tv_time || force) {
-	gf_log ("stat-prefetch",
-		GF_LOG_DEBUG,
-		"flush on: %s",
-		trav->dirname);
-	dir_entry_t *entries;
-
-	trav->prev->next = trav->next;
-	trav->next->prev = trav->prev;
-
-	entries = trav->entries.next;
-
-	while (entries) {
-	  dir_entry_t *nextentry = entries->next;
-	  {
-	    free (entries->name);
-	    free (entries);
-	  }
-	  entries = nextentry;
-	}
-	free (trav->dirname);
-	free (trav);
-      }
-    }
-    trav = next;
-  }
-
-  pthread_mutex_unlock (&cache->lock);
-}
-
-static int32_t
-stat_prefetch_cache_fill (struct sp_cache *cache,
-			  pid_t pid,
-			  char *dirname,
-			  dir_entry_t *entries)
-{
-  struct sp_cache *trav;
-  struct timeval tv;
-
-  pthread_mutex_unlock (&cache->lock);
-  trav = cache->next;
-  while (trav != cache) {
-    //    if (trav->pid == pid && !strcmp (trav->dirname, dirname)) {
-    if (!strcmp (trav->dirname, dirname)) {
-      break;
-    }
-    trav = trav->next;
-  }
-
-  if (trav == cache) {
-    trav = CALLOC (1, sizeof (*trav));
-    ERR_ABORT (trav);
-    trav->pid = pid;
-    trav->dirname = dirname;
-
-    trav->prev = cache->prev;
-    trav->next = cache;
-    trav->next->prev = trav;
-    trav->prev->next = trav;
-  } else {
-    free (dirname);
-  }
-
-  while (trav->entries.next) {
-    dir_entry_t *tmp = trav->entries.next;
-
-    trav->entries.next = trav->entries.next->next;
-    free (tmp->name);
-    free (tmp);
-  }
-  trav->entries.next = entries->next;
-  entries->next = NULL;
-
-  gettimeofday (&tv, NULL);
-  trav->tv_time = (tv.tv_usec + (tv.tv_sec * 1000000)) + cache->tv_time;
-
-  pthread_mutex_unlock (&cache->lock);
-  return 0;
-}
-
-static int32_t
-stat_prefetch_cache_lookup (struct sp_cache *cache,
-			    pid_t pid,
-			    const char *path,
-			    struct stat *buf)
-{
-  struct sp_cache *trav;
-  char *dirname = strdup (path);
-  char *filename = strrchr (dirname, '/');
-  dir_entry_t *entries;
-  dir_entry_t *prev = NULL;
-
-  *filename = '\0';
-  filename ++;
-
-  pthread_mutex_lock (&cache->lock);
-  trav = cache->next;
-  while (trav != cache) {
-    //    if ((trav->pid == pid) && !strcmp (dirname, trav->dirname))
-    if (!strcmp (dirname, trav->dirname))
-      break;
-    trav = trav->next;
-  }
-  if (trav == cache) {
-    free (dirname);
-    pthread_mutex_unlock (&cache->lock);
-    return -1;
-  }
-
-  entries = trav->entries.next;
-  prev = &trav->entries;
-  while (entries) {
-    if (!strcmp (entries->name, filename))
-      break;
-    prev = entries;
-    entries = entries->next;
-  }
-  if (!entries) {
-    free (dirname);
-    pthread_mutex_unlock (&cache->lock);
-    return -1;
-  }
-
-  *buf = entries->buf;
-  prev->next = entries->next;
-  free (entries->name);
-  free (entries);
-  free (dirname);
-
-  pthread_mutex_unlock (&cache->lock);
-
-  return 0;
-}
-
-			    
-int32_t
-stat_prefetch_readdir_cbk (call_frame_t *frame,
-			   void *cookie,
-			   xlator_t *this,
-			   int32_t op_ret,
-			   int32_t op_errno,
-			   dir_entry_t *entries,
-			   int32_t count)
-{
-  char *path = frame->local;
-  pid_t pid = frame->root->pid;
-  frame->local = NULL;
-
-  STACK_UNWIND (frame, op_ret, op_errno, entries, count);
-
-  if (op_ret == 0)
-    stat_prefetch_cache_fill (this->private,
-			      pid,
-			      path,
-			      entries);
-  else
-    free (path);
-
-  return 0;
-}
-
-int32_t
-stat_prefetch_readdir (call_frame_t *frame,
-		       xlator_t *this,
-		       const char *path)
-{
-  stat_prefetch_cache_flush (this->private, 0);
-
-  frame->local = strdup (path);
-  STACK_WIND (frame,
-	      stat_prefetch_readdir_cbk,
-	      FIRST_CHILD(this),
-	      FIRST_CHILD(this)->fops->readdir,
-	      path);
-  return 0;
-}
-
-
-int32_t
-stat_prefetch_getattr_cbk (call_frame_t *frame,
-			   void *cookie,
-			   xlator_t *this,
-			   int32_t op_ret,
-			   int32_t op_errno,
-			   struct stat *buf)
-{
-  STACK_UNWIND (frame, op_ret, op_errno, buf);
-  return 0;
-}
-
-int32_t
-stat_prefetch_getattr (call_frame_t *frame,
-		       struct xlator *this,
-		       const char *path)
-{
-  struct stat buf;
-  pid_t pid = frame->root->pid;
-  stat_prefetch_cache_flush (this->private, 0);
-
-  if (stat_prefetch_cache_lookup (this->private,
-				  pid,
-				  path,
-				  &buf) == 0) {
-    STACK_UNWIND (frame, 0, 0, &buf);
-    return 0;
-  }
-
-  STACK_WIND (frame,
-	      stat_prefetch_getattr_cbk,
-	      FIRST_CHILD(this),
-	      FIRST_CHILD(this)->fops->getattr,
-	      path);
-
-  return 0;
-}
-
-
-int32_t
-stat_prefetch_unlink_cbk (call_frame_t *frame,
-                          void *cookie,
-                          xlator_t *this,
-                          int32_t op_ret,
-                          int32_t op_errno)
-{
-  STACK_UNWIND (frame, op_ret, op_errno);
-  return 0;
-}
-
-int32_t
-stat_prefetch_unlink (call_frame_t *frame,
-                      struct xlator *this,
-                      const char *path)
-{
-  stat_prefetch_cache_flush (this->private, 1);
-
-  STACK_WIND (frame,
-              stat_prefetch_unlink_cbk,
-              FIRST_CHILD(this),
-              FIRST_CHILD(this)->fops->unlink,
-              path);
-
-  return 0;
-}
-
-
-int32_t
-stat_prefetch_chmod_cbk (call_frame_t *frame,
-			 void *cookie,
-			 xlator_t *this,
-			 int32_t op_ret,
-			 int32_t op_errno,
-			 struct stat *buf)
-{
-  STACK_UNWIND (frame, op_ret, op_errno, buf);
-  return 0;
-}
-
-int32_t
-stat_prefetch_chmod (call_frame_t *frame,
-		     struct xlator *this,
-		     const char *path,
-		     mode_t mode)
-{
-  stat_prefetch_cache_flush (this->private, 1);
-
-  STACK_WIND (frame,
-              stat_prefetch_chmod_cbk,
-              FIRST_CHILD(this),
-              FIRST_CHILD(this)->fops->chmod,
-              path,
-	      mode);
-
-  return 0;
-}
-
-
-int32_t
-stat_prefetch_chown_cbk (call_frame_t *frame,
-			 void *cookie,
-			 xlator_t *this,
-			 int32_t op_ret,
-			 int32_t op_errno,
-			 struct stat *buf)
-{
-  STACK_UNWIND (frame, op_ret, op_errno, buf);
-  return 0;
-}
-
-int32_t
-stat_prefetch_chown (call_frame_t *frame,
-		     struct xlator *this,
-		     const char *path,
-		     uid_t uid,
-		     gid_t gid)
-{
-  stat_prefetch_cache_flush (this->private, 1);
-
-  STACK_WIND (frame,
-              stat_prefetch_chown_cbk,
-              FIRST_CHILD(this),
-              FIRST_CHILD(this)->fops->chown,
-              path,
-	      uid,
-	      gid);
-
-  return 0;
-}
-
-
-int32_t
-stat_prefetch_utimes_cbk (call_frame_t *frame,
-                          void *cookie,
-                          xlator_t *this,
-                          int32_t op_ret,
-                          int32_t op_errno,
-			  struct stat *buf)
-{
-  STACK_UNWIND (frame, op_ret, op_errno, buf);
-  return 0;
-}
-
-int32_t
-stat_prefetch_utimes (call_frame_t *frame,
-		      struct xlator *this,
-		      const char *path,
-		      struct timespec *tvp)
-{
-  stat_prefetch_cache_flush (this->private, 1);
-
-  STACK_WIND (frame,
-              stat_prefetch_utimes_cbk,
-              FIRST_CHILD(this),
-              FIRST_CHILD(this)->fops->utimes,
-              path,
-	      tvp);
-
-  return 0;
-}
-
-
-int32_t
-stat_prefetch_truncate_cbk (call_frame_t *frame,
-			    void *cookie,
-			    xlator_t *this,
-			    int32_t op_ret,
-			    int32_t op_errno,
-			    struct stat *buf)
-{
-  STACK_UNWIND (frame, op_ret, op_errno, buf);
-  return 0;
-}
-
-int32_t
-stat_prefetch_truncate (call_frame_t *frame,
-			struct xlator *this,
-			const char *path,
-			off_t offset)
-{
-  stat_prefetch_cache_flush (this->private, 1);
-
-  STACK_WIND (frame,
-              stat_prefetch_truncate_cbk,
-              FIRST_CHILD(this),
-              FIRST_CHILD(this)->fops->truncate,
-              path,
-	      offset);
-
-  return 0;
-}
-
-
-int32_t
-stat_prefetch_rename_cbk (call_frame_t *frame,
-                          void *cookie,
-                          xlator_t *this,
-                          int32_t op_ret,
-                          int32_t op_errno)
-{
-  STACK_UNWIND (frame, op_ret, op_errno);
-  return 0;
-}
-
-int32_t
-stat_prefetch_rename (call_frame_t *frame,
-                      struct xlator *this,
-                      const char *oldpath,
-		      const char *newpath)
-{
-  stat_prefetch_cache_flush (this->private, 1);
-
-  STACK_WIND (frame,
-              stat_prefetch_rename_cbk,
-              FIRST_CHILD(this),
-              FIRST_CHILD(this)->fops->rename,
-              oldpath,
-	      newpath);
-
-  return 0;
-}
 
 int32_t 
-init (struct xlator *this)
+init (xlator_t *this)
 {
-  struct sp_cache *cache;
-  dict_t *options = this->options;
+        int32_t ret = -1;
+        if (!this->children || this->children->next) {
+                gf_log ("stat-prefetch",
+                        GF_LOG_ERROR,
+                        "FATAL: translator %s does not have exactly one child "
+                        "node", this->name);
+                goto out;
+        }
 
-  if (!this->children || this->children->next) {
-    gf_log ("stat-prefetch",
-	    GF_LOG_ERROR,
-	    "FATAL: translator %s does not have exactly one child node",
-	    this->name);
-    return -1;
-  }
-
-  cache = (void *) CALLOC (1, sizeof (*cache));
-  ERR_ABORT (cache);
-  cache->next = cache->prev = cache;
-
-  cache->tv_time = 1 * 1000000;
-
-  if (dict_get (options, "cache-seconds")) {
-    cache->tv_time = (data_to_int64 (dict_get (options, "cache-seconds")) *
-		      1000000);
-  }
-
-  pthread_mutex_init (&cache->lock, NULL);
-
-  this->private = cache;
-  return 0;
+        ret = 0;
+out:
+        return ret;
 }
 
 void
-fini (struct xlator *this)
+fini (xlator_t *this)
 {
-  return;
+        return;
 }
 
 
 struct xlator_fops fops = {
-  .getattr     = stat_prefetch_getattr,
-  .readdir     = stat_prefetch_readdir,
-  .unlink      = stat_prefetch_unlink,
-  .chmod       = stat_prefetch_chmod,
-  .chown       = stat_prefetch_chown,
-  .rename      = stat_prefetch_rename,
-  .utimes      = stat_prefetch_utimes,
-  .truncate    = stat_prefetch_truncate,
 };
 
 struct xlator_mops mops = {
 };
+
+struct xlator_cbks cbks = {
+};
diff --git a/xlators/performance/stat-prefetch/src/stat-prefetch.h b/xlators/performance/stat-prefetch/src/stat-prefetch.h
index ef82952b0..bd8d9e7eb 100644
--- a/xlators/performance/stat-prefetch/src/stat-prefetch.h
+++ b/xlators/performance/stat-prefetch/src/stat-prefetch.h
@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2006-2009 Z RESEARCH, Inc. <http://www.zresearch.com>
+   Copyright (c) 2009-2010 Z RESEARCH, Inc. <http://www.zresearch.com>
    This file is part of GlusterFS.
 
    GlusterFS is free software; you can redistribute it and/or modify
@@ -17,16 +17,16 @@
    <http://www.gnu.org/licenses/>.
 */
 
-#ifndef _STAT_PREFETCH_H_
-#define _STAT_PREFETCH_H_
+#ifndef _STAT_PREFETCH_H
+#define _STAT_PREFETCH_H
 
 #ifndef _CONFIG_H
 #define _CONFIG_H
 #include "config.h"
 #endif
 
-#include <stdio.h>
-#include <sys/time.h>
+#include "glusterfs.h"
+#include "dict.h"
 #include "xlator.h"
 
-#endif /* _STAT_PREFETCH_H_ */
+#endif  /* #ifndef _STAT_PREFETCH_H */