svn commit: r1148882 - /subversion/trunk/subversion/libsvn_client/merge.c

[st...@apache.org]

Author: stsp
Date: Wed Jul 20 18:34:43 2011
New Revision: 1148882

URL: http://svn.apache.org/viewvc?rev=1148882&view=rev
Log:
* subversion/libsvn_client/merge.c
  (log_noop_baton_t, log_noop_revs): Add comments explaining the
   unusual rules governing the pool member of log_noop_baton_t.

Modified:
    subversion/trunk/subversion/libsvn_client/merge.c

Modified: subversion/trunk/subversion/libsvn_client/merge.c
URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_client/merge.c?rev=1148882&r1=1148881&r2=1148882&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_client/merge.c (original)
+++ subversion/trunk/subversion/libsvn_client/merge.c Wed Jul 20 18:34:43 2011
@@ -7860,10 +7860,16 @@ typedef struct log_noop_baton_t
      being diffed. */
   const char *source_repos_abs;
 
-  /* Initially empty rangelists allocated in POOL. */
+  /* Initially empty rangelists allocated in POOL. The rangelists are
+   * populated across multiple invocations of the log_noop_revs(). */
   apr_array_header_t *operative_ranges;
   apr_array_header_t *merged_ranges;
 
+  /* Pool to store the rangelists. It stores the final result, as well
+   * as temporary copies of rangelists which get created while we compute
+   * the result across multiple invocations of log_noop_revs().
+   * This pool needs to be cleared periodically to prevent unbound
+   * growth of allocations. */
   apr_pool_t *pool;
 } log_noop_baton_t;
 
@@ -7894,7 +7900,10 @@ log_noop_revs(void *baton,
   apr_array_header_t *rangelist;
 
   /* The baton's pool is essentially an iterpool so we must clear it
-   * for each invocation of this function. */
+   * for each invocation of this function, preserving the result
+   * we computed during the previous invocation but discarding any
+   * data allocated before the previous invocation. (Note that
+   * svn_rangelist_merge() returns a newly allocated rangelist.) */
   rl1 = svn_rangelist_dup(log_gap_baton->operative_ranges, scratch_pool);
   rl2 = svn_rangelist_dup(log_gap_baton->merged_ranges, scratch_pool);
   svn_pool_clear(log_gap_baton->pool);