svn commit: r1335152 - /subversion/trunk/subversion/libsvn_delta/text_delta.c

[cm...@apache.org]

Author: cmpilato
Date: Mon May  7 17:48:16 2012
New Revision: 1335152

URL: http://svn.apache.org/viewvc?rev=1335152&view=rev
Log:
* subversion/libsvn_delta/text_delta.c
  (svn_txdelta_send_stream): Finish an old TODO item about doing
    straight window generation here instead of firing up the diff
    machinery just to diff aagainst the empty stream.

Suggested by: gstein

Modified:
    subversion/trunk/subversion/libsvn_delta/text_delta.c

Modified: subversion/trunk/subversion/libsvn_delta/text_delta.c
URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_delta/text_delta.c?rev=1335152&r1=1335151&r2=1335152&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_delta/text_delta.c (original)
+++ subversion/trunk/subversion/libsvn_delta/text_delta.c Mon May  7 17:48:16 2012
@@ -904,29 +904,54 @@ svn_error_t *svn_txdelta_send_stream(svn
                                      unsigned char *digest,
                                      apr_pool_t *pool)
 {
-  svn_txdelta_stream_t *txstream;
-  svn_error_t *err;
+  svn_txdelta_window_t delta_window = { 0 };
+  svn_txdelta_op_t delta_op;
+  svn_string_t window_data;
+  char read_buf[SVN__STREAM_CHUNK_SIZE + 1];
+  svn_checksum_ctx_t *md5_checksum_ctx;
 
-  /* ### this is a hack. we should simply read from the stream, construct
-     ### some windows, and pass those to the handler. there isn't any reason
-     ### to crank up a full "diff" algorithm just to copy a stream.
-     ###
-     ### will fix RSN. */
-
-  /* Create a delta stream which converts an *empty* bytestream into the
-     target bytestream. */
-  svn_txdelta(&txstream, svn_stream_empty(pool), stream, pool);
-  err = svn_txdelta_send_txstream(txstream, handler, handler_baton, pool);
+  if (digest)
+    md5_checksum_ctx = svn_checksum_ctx_create(svn_checksum_md5, pool);
 
-  if (digest && (! err))
+  while (1)
     {
-      const unsigned char *result_md5;
-      result_md5 = svn_txdelta_md5_digest(txstream);
-      /* Since err is null, result_md5 "cannot" be null. */
-      memcpy(digest, result_md5, APR_MD5_DIGESTSIZE);
+      apr_size_t read_len = SVN__STREAM_CHUNK_SIZE;
+      
+      SVN_ERR(svn_stream_read(stream, read_buf, &read_len));
+      if (read_len == 0)
+        break;
+      
+      window_data.data = read_buf;
+      window_data.len = read_len;
+      
+      delta_op.action_code = svn_txdelta_new;
+      delta_op.offset = 0;
+      delta_op.length = read_len;
+      
+      delta_window.tview_len = read_len;
+      delta_window.num_ops = 1;
+      delta_window.ops = &delta_op;
+      delta_window.new_data = &window_data;
+      
+      SVN_ERR(handler(&delta_window, handler_baton));
+
+      if (digest)
+        SVN_ERR(svn_checksum_update(md5_checksum_ctx, read_buf, read_len));
+      
+      if (read_len < SVN__STREAM_CHUNK_SIZE)
+        break;
     }
+  SVN_ERR(handler(NULL, handler_baton));
 
-  return err;
+  if (digest)
+    {
+      svn_checksum_t *md5_checksum;
+
+      SVN_ERR(svn_checksum_final(&md5_checksum, md5_checksum_ctx, pool));
+      memcpy(digest, md5_checksum->digest, APR_MD5_DIGESTSIZE);
+    }
+  
+  return SVN_NO_ERROR;
 }
 
 svn_error_t *svn_txdelta_send_txstream(svn_txdelta_stream_t *txstream,