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From stef...@apache.org
Subject svn commit: r983430 [1/3] - in /subversion/branches/performance/subversion/libsvn_fs_fs: caching.c fs.h fs_fs.c temp_serializer.c temp_serializer.h
Date Sun, 08 Aug 2010 15:34:48 GMT
Author: stefan2
Date: Sun Aug  8 15:34:48 2010
New Revision: 983430

URL: http://svn.apache.org/viewvc?rev=983430&view=rev
Log:
Implement txdelta window caching. This will be used by svnadmin only
since fulltext caches are mainly ineffective during dump etc. The opposite
is true for server functions (get / set fulltext data).

The cache processing for txdelta windows is relatively straightforward 
but requires some auxiliary information. Thus, we wrap them in the
svn_fs_fs__txdelta_cached_window_t structure.

* subversion/libsvn_fs_fs/temp_serializer.h
  (svn_fs_fs__combine_number_and_string, svn_fs_fs__combine_two_numbers):
  declare key construction utility functions
  (svn_fs_fs__txdelta_cached_window_t): auxilliary struct used to represent cached txdelta
windows
  (svn_fs_fs__serialize_txdelta_window, svn_fs_fs__deserialize_txdelta_window):
  declare API to (de)serialize txdelta windows for caching
* subversion/libsvn_fs_fs/temp_serializer.c
* subversion/libsvn_fs_fs/fs_fs.c
  (rep_state): add a reference to the txdelta window cache to use
  (create_rep_state_body): init that reference
  (get_window_key, get_cached_window, set_cached_window):
  utility functions to get / set txdelta window objects from / to the cache
  (read_window): speed up using the window cache
* subversion/libsvn_fs_fs/fs.h
  (fs_fs_data_t): add txdelta_window_cache window
* subversion/libsvn_fs_fs/caching.c
  (svn_fs_fs__initialize_caches): add initialization of the txdelta window cache

Added:
    subversion/branches/performance/subversion/libsvn_fs_fs/temp_serializer.c   (contents,
props changed)
      - copied, changed from r982417, subversion/branches/performance/subversion/libsvn_fs_fs/fs_fs.c
    subversion/branches/performance/subversion/libsvn_fs_fs/temp_serializer.h   (contents,
props changed)
      - copied, changed from r982376, subversion/branches/performance/subversion/libsvn_fs_fs/fs_fs.h
Modified:
    subversion/branches/performance/subversion/libsvn_fs_fs/caching.c
    subversion/branches/performance/subversion/libsvn_fs_fs/fs.h
    subversion/branches/performance/subversion/libsvn_fs_fs/fs_fs.c

Modified: subversion/branches/performance/subversion/libsvn_fs_fs/caching.c
URL: http://svn.apache.org/viewvc/subversion/branches/performance/subversion/libsvn_fs_fs/caching.c?rev=983430&r1=983429&r2=983430&view=diff
==============================================================================
--- subversion/branches/performance/subversion/libsvn_fs_fs/caching.c (original)
+++ subversion/branches/performance/subversion/libsvn_fs_fs/caching.c Sun Aug  8 15:34:48
2010
@@ -195,7 +195,7 @@ warn_on_cache_errors(svn_error_t *err,
 static svn_fs_fs__cache_config_t cache_settings =
   {
     /* default configuration:
-      */
+     */
     0x8000000,   /* 128 MB for caches */
     16,          /* up to 16 files kept open */
     FALSE,       /* don't cache fulltexts */
@@ -416,5 +416,27 @@ svn_fs_fs__initialize_caches(svn_fs_t *f
   /* initialize file handle cache as configured */
   ffd->file_handle_cache = get_global_file_handle_cache();
 
+  /* if enabled, enable the txdelta window cache */
+  if (get_global_membuffer_cache() &&
+      svn_fs_fs__get_cache_config()->cache_txdeltas)
+    {
+      SVN_ERR(svn_cache__create_membuffer_cache
+                (&(ffd->txdelta_window_cache),
+                 get_global_membuffer_cache(),
+                 svn_fs_fs__serialize_txdelta_window,
+                 svn_fs_fs__deserialize_txdelta_window,
+                 APR_HASH_KEY_STRING,
+                 apr_pstrcat(pool, prefix, "TXDELTA_WINDOW", NULL),
+                 fs->pool));
+    }
+  else
+    {
+      ffd->txdelta_window_cache = NULL;
+    }
+
+  if (ffd->txdelta_window_cache && ! no_handler)
+    SVN_ERR(svn_cache__set_error_handler(ffd->txdelta_window_cache,
+                                         warn_on_cache_errors, fs, pool));
+
   return SVN_NO_ERROR;
 }

Modified: subversion/branches/performance/subversion/libsvn_fs_fs/fs.h
URL: http://svn.apache.org/viewvc/subversion/branches/performance/subversion/libsvn_fs_fs/fs.h?rev=983430&r1=983429&r2=983430&view=diff
==============================================================================
--- subversion/branches/performance/subversion/libsvn_fs_fs/fs.h (original)
+++ subversion/branches/performance/subversion/libsvn_fs_fs/fs.h Sun Aug  8 15:34:48 2010
@@ -244,6 +244,9 @@ typedef struct
   /* Reference to the process-global open file handle cache */
   svn_file_handle_cache_t *file_handle_cache;
 
+  /* Cache for txdelta_window_t objects; the key is (revFilePath, offset) */
+  svn_cache__t *txdelta_window_cache;
+
   /* Data shared between all svn_fs_t objects for a given filesystem. */
   fs_fs_shared_data_t *shared;
 

Modified: subversion/branches/performance/subversion/libsvn_fs_fs/fs_fs.c
URL: http://svn.apache.org/viewvc/subversion/branches/performance/subversion/libsvn_fs_fs/fs_fs.c?rev=983430&r1=983429&r2=983430&view=diff
==============================================================================
--- subversion/branches/performance/subversion/libsvn_fs_fs/fs_fs.c (original)
+++ subversion/branches/performance/subversion/libsvn_fs_fs/fs_fs.c Sun Aug  8 15:34:48 2010
@@ -47,6 +47,7 @@
 #include "svn_time.h"
 #include "svn_mergeinfo.h"
 #include "svn_config.h"
+#include "svn_ctype.h"
 
 #include "fs.h"
 #include "err.h"
@@ -56,6 +57,7 @@
 #include "fs_fs.h"
 #include "id.h"
 #include "rep-cache.h"
+#include "temp_serializer.h"
 
 #include "revprops-db.h"
 
@@ -2913,6 +2915,8 @@ struct rep_state
                     /* For convenience, store the APR file handle
                        along with the surrounding cached file handle. */
   apr_file_t *apr_file;
+                    /* The txdelta window cache to use or NULL. */
+  svn_cache__t *window_cache;
   apr_off_t start;  /* The starting offset for the raw
                        svndiff/plaintext data minus header. */
   apr_off_t off;    /* The current offset into the file. */
@@ -2929,12 +2933,14 @@ create_rep_state_body(struct rep_state *
                       svn_fs_t *fs,
                       apr_pool_t *pool)
 {
+  fs_fs_data_t *ffd = fs->fsap_data;
   struct rep_state *rs = apr_pcalloc(pool, sizeof(*rs));
   struct rep_args *ra;
   unsigned char buf[4];
 
   SVN_ERR(open_and_seek_representation(&rs->file, fs, rep, pool));
   rs->apr_file = svn_file_handle_cache__get_apr_handle(rs->file);
+  rs->window_cache = ffd->txdelta_window_cache;
 
   SVN_ERR(read_rep_line(&ra, rs->apr_file, pool));
   SVN_ERR(get_file_offset(&rs->start, rs->apr_file, pool));
@@ -3126,6 +3132,113 @@ rep_read_get_baton(struct rep_read_baton
   return SVN_NO_ERROR;
 }
 
+/* Combine the name of the rev file in RS with the given OFFSET to form
+ * a cache lookup key. Allocations will be made from POOL. */
+static const char*
+get_window_key(struct rep_state *rs, apr_off_t offset, apr_pool_t *pool)
+{
+  const char *name;
+  const char *last_part;
+  const char *name_last;
+
+  /* the rev file name containing the txdelta window.
+   * If this fails we are in serious trouble anyways. 
+   * And if nobody else detects the problems, the file content checksum
+   * comparison _will_ find them.
+   */
+  if (apr_file_name_get(&name, rs->apr_file))
+    return "";
+
+  /* We care about the file name only as it represents the start revision
+   * of this rev file.  Handle packed files as well. */
+  name_last = name + strlen(name) - 1;
+  while (! svn_ctype_isdigit(*name_last))
+    --name_last;
+
+  last_part = name_last;
+  while (svn_ctype_isdigit(*last_part))
+    --last_part;
+
+  /* copy one char MORE than the actual number to mark packed files,
+   * i.e. packed revision file content uses different key space then
+   * non-packed ones: keys for packed rev file content ends with a dot
+   * for non-packed rev files they end with a digit. */
+  name = apr_pstrndup(pool, last_part + 1, name_last - last_part);
+  return svn_fs_fs__combine_number_and_string(offset, name, pool);
+}
+
+/* Read the WINDOW_P for the rep state RS from the current FSFS session's 
+ * cache. This will be a no-op and IS_CACHED will be set to FALSE if no
+ * cache has been given. If a cache is available IS_CACHED will inform
+ * the caller about the success of the lookup. Allocations (of the window
+ * in particualar) will be made from POOL. 
+ *
+ * If the information could be found, put RS and the position within the 
+ * rev file into the same state as if the data had just been read from it.  
+ */
+static svn_error_t *
+get_cached_window(svn_txdelta_window_t **window_p,
+                  struct rep_state *rs,
+                  svn_boolean_t *is_cached,
+                  apr_pool_t *pool)
+{
+  if (! rs->window_cache)
+    {
+      /* txdelta window has not been enabled */
+      *is_cached = FALSE;
+    }
+  else
+    {
+      /* ask the cache for the desired txdelta window */
+      svn_fs_fs__txdelta_cached_window_t *cached_window;
+      SVN_ERR(svn_cache__get((void **) &cached_window,
+                             is_cached,
+                             rs->window_cache,
+                             get_window_key(rs, rs->off, pool),
+                             pool));
+
+      if (*is_cached)
+        {
+          /* found it. Pass it back to the caller. */
+          *window_p = cached_window->window;
+
+          /* manipulate the RS as if we just read the data */
+          rs->chunk_index++;
+          rs->off = cached_window->end_offset;
+
+          /* manipulate the rev file as if we just read from it */
+          SVN_ERR(svn_io_file_seek(rs->apr_file, APR_SET, &rs->off, pool));
+        }
+    }
+
+  return SVN_NO_ERROR;
+}
+
+/* Store the WINDOW read at OFFSET for the rep state RS in the current
+ * FSFS session's cache. This will be a no-op if no cache has been given. 
+ * Temporary allocations will be made from SCRATCH_POOL. */
+static svn_error_t *
+set_cached_window(svn_txdelta_window_t *window,
+                  struct rep_state *rs,
+                  apr_off_t offset,
+                  apr_pool_t *scratch_pool)
+{
+  if (rs->window_cache)
+    {
+      /* store the window and the first offset _past_ it */
+      svn_fs_fs__txdelta_cached_window_t cached_window = { window, rs->off };
+
+      /* but key it with the start offset because that is the known state
+       * when we will look it up */
+      return svn_cache__set(rs->window_cache,
+                            get_window_key(rs, offset, scratch_pool),
+                            &cached_window,
+                            scratch_pool);
+    }
+
+  return SVN_NO_ERROR;
+}
+
 /* Skip forwards to THIS_CHUNK in REP_STATE and then read the next delta
    window into *NWIN. */
 static svn_error_t *
@@ -3133,6 +3246,8 @@ read_window(svn_txdelta_window_t **nwin,
             apr_pool_t *pool)
 {
   svn_stream_t *stream;
+  svn_boolean_t is_cached;
+  apr_off_t old_offset;
 
   SVN_ERR_ASSERT(rs->chunk_index <= this_chunk);
 
@@ -3149,7 +3264,13 @@ read_window(svn_txdelta_window_t **nwin,
                                   "representation"));
     }
 
-  /* Read the next window. */
+  /* Read the next window. But first, try to find it in the cache. */
+  SVN_ERR(get_cached_window(nwin, rs, &is_cached, pool));
+  if (is_cached)
+    return SVN_NO_ERROR;
+
+  /* Actually read the next window. */
+  old_offset = rs->off;
   stream = svn_stream__from_cached_file_handle(rs->file, TRUE, pool);
   SVN_ERR(svn_txdelta_read_svndiff_window(nwin, stream, rs->ver, pool));
   rs->chunk_index++;
@@ -3160,7 +3281,9 @@ read_window(svn_txdelta_window_t **nwin,
                             _("Reading one svndiff window read beyond "
                               "the end of the representation"));
 
-  return SVN_NO_ERROR;
+  /* the window has not been cached before, thus cache it now
+   * (if caching is used for them at all) */
+  return set_cached_window(*nwin, rs, old_offset, pool);
 }
 
 /* Get one delta window that is a result of combining all but the last deltas



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