From 2b2de01e951c4b9db01c93c640d3ad0cc0b43af6 Mon Sep 17 00:00:00 2001
From: Konstantin Isakov <ikm@users.berlios.de>
Date: Thu, 28 May 2009 12:26:16 +0000
Subject: [PATCH] *! Minimize the number of realloc()s done when reading zip
 cdir.    This should presumably make reading of large zip archives much
 faster.

---
 src/libzip/zip_open.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/libzip/zip_open.c b/src/libzip/zip_open.c
index 51430513..8b0cb4b2 100644
--- a/src/libzip/zip_open.c
+++ b/src/libzip/zip_open.c
@@ -232,14 +232,16 @@ _zip_readcdir(FILE *fp, unsigned char *buf, unsigned char *eocd, int buflen,
     }
 
   // Instead of using nentry, just read all entries until one can't be read.
-  // And we're not gonna use 
+
+  int allocated = nentry;
 
     for (i=0; ; i++)
     {
-      if ( i >= nentry )
+      if ( i >= allocated )
       {
         // The original array won't hold -- reallocate
-        cd->entry = realloc( cd->entry, ( i + 1 ) * sizeof(*(cd->entry)) );
+        allocated += 65536;
+        cd->entry = realloc( cd->entry, allocated * sizeof(*(cd->entry)) );
       }
       
 	if ((_zip_dirent_read(cd->entry+i, fp, bufp, eocd-cdp, 0,
@@ -248,6 +250,11 @@ _zip_readcdir(FILE *fp, unsigned char *buf, unsigned char *eocd, int buflen,
 	}
     }
 
+  // Deallocate the unneeded memory
+
+  if ( allocated != i )
+    cd->entry = realloc( cd->entry, i * sizeof(*(cd->entry)) );
+
   cd->nentry = i;
     
     return cd;