/*
 *  dump_editor.c: A svn_delta_editor_t editor used to dump revisions.
 *
 * ====================================================================
 *    Licensed to the Apache Software Foundation (ASF) under one
 *    or more contributor license agreements.  See the NOTICE file
 *    distributed with this work for additional information
 *    regarding copyright ownership.  The ASF licenses this file
 *    to you under the Apache License, Version 2.0 (the
 *    "License"); you may not use this file except in compliance
 *    with the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing,
 *    software distributed under the License is distributed on an
 *    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *    KIND, either express or implied.  See the License for the
 *    specific language governing permissions and limitations
 *    under the License.
 * ====================================================================
 */

#include "svn_repos.h"
#include "svn_hash.h"
#include "svn_pools.h"
#include "svn_path.h"
#include "svn_props.h"
#include "svn_subst.h"
#include "svn_dirent_uri.h"

#include "private/svn_repos_private.h"

#include <assert.h>

#define ARE_VALID_COPY_ARGS(p,r) ((p) && SVN_IS_VALID_REVNUM(r))


/* Normalize the line ending style of the values of properties in PROPS
 * that "need translation" (according to svn_prop_needs_translation(),
 * currently all svn:* props) so that they contain only LF (\n) line endings.
 *
 * Put the normalized props into NORMAL_PROPS, allocated in RESULT_POOL.
 */
static svn_error_t *
normalize_props(apr_hash_t **normal_props,
                apr_hash_t *props,
                apr_pool_t *result_pool)
{
  apr_hash_index_t *hi;
  apr_pool_t *iterpool;

  *normal_props = apr_hash_make(result_pool);

  iterpool = svn_pool_create(result_pool);
  for (hi = apr_hash_first(result_pool, props); hi; hi = apr_hash_next(hi))
    {
      const char *key = apr_hash_this_key(hi);
      const svn_string_t *value = apr_hash_this_val(hi);

      svn_pool_clear(iterpool);

      SVN_ERR(svn_repos__normalize_prop(&value, NULL, key, value,
                                        result_pool, iterpool));
      svn_hash_sets(*normal_props, key, value);
    }
  svn_pool_destroy(iterpool);

  return SVN_NO_ERROR;
}

/* A directory baton used by all directory-related callback functions
 * in the dump editor.  */
struct dir_baton
{
  struct dump_edit_baton *eb;

  /* Pool for per-directory allocations */
  apr_pool_t *pool;

  /* the path to this directory */
  const char *repos_relpath; /* a relpath */

  /* Copyfrom info for the node, if any. */
  const char *copyfrom_path; /* a relpath */
  svn_revnum_t copyfrom_rev;

  /* Headers accumulated so far for this directory */
  svn_repos__dumpfile_headers_t *headers;

  /* Properties which were modified during change_dir_prop. */
  apr_hash_t *props;

  /* Properties which were deleted during change_dir_prop. */
  apr_hash_t *deleted_props;

  /* Hash of paths that need to be deleted, though some -might- be
     replaced.  Maps const char * paths to this dir_baton. Note that
     they're full paths, because that's what the editor driver gives
     us, although they're all really within this directory. */
  apr_hash_t *deleted_entries;

  /* Flag to trigger dumping props. */
  svn_boolean_t dump_props;
};

/* A file baton used by all file-related callback functions in the dump
 * editor */
struct file_baton
{
  struct dump_edit_baton *eb;

  /* Pool for per-file allocations */
  apr_pool_t *pool;

  /* the path to this file */
  const char *repos_relpath; /* a relpath */

  /* Properties which were modified during change_file_prop. */
  apr_hash_t *props;

  /* Properties which were deleted during change_file_prop. */
  apr_hash_t *deleted_props;

  /* The checksum of the file the delta is being applied to */
  const char *base_checksum;

  /* Copy state and source information (if any). */
  svn_boolean_t is_copy;
  const char *copyfrom_path;
  svn_revnum_t copyfrom_rev;

  /* The action associate with this node. */
  enum svn_node_action action;

  /* Flags to trigger dumping props and text. */
  svn_boolean_t dump_text;
  svn_boolean_t dump_props;
};

/* The baton used by the dump editor. */
struct dump_edit_baton {
  /* The output stream we write the dumpfile to */
  svn_stream_t *stream;

  /* The repository relpath of the anchor of the editor when driven
     via the RA update mechanism; NULL otherwise. (When the editor is
     driven via the RA "replay" mechanism instead, the editor is
     always anchored at the repository, we don't need to prepend an
     anchor path to the dumped node paths, and open_root() doesn't
     need to manufacture directory additions.)  */
  const char *update_anchor_relpath;

  /* Pool for per-revision allocations */
  apr_pool_t *pool;

  /* Temporary file used for textdelta application along with its
     absolute path; these two variables should be allocated in the
     per-edit-session pool */
  const char *delta_abspath;
  apr_file_t *delta_file;

  /* The baton of the directory node whose block of
     dump stream data has not been fully completed; NULL if there's no
     such item. */
  struct dir_baton *pending_db;
};

/* Make a directory baton to represent the directory at PATH (relative
 * to the EDIT_BATON).
 *
 * COPYFROM_PATH/COPYFROM_REV are the path/revision against which this
 * directory should be compared for changes. If the copyfrom
 * information is valid, the directory will be compared against its
 * copy source.
 *
 * PB is the directory baton of this directory's parent, or NULL if
 * this is the top-level directory of the edit.
 *
 * Perform all allocations in POOL.  */
static struct dir_baton *
make_dir_baton(const char *path,
               const char *copyfrom_path,
               svn_revnum_t copyfrom_rev,
               void *edit_baton,
               struct dir_baton *pb,
               apr_pool_t *pool)
{
  struct dump_edit_baton *eb = edit_baton;
  struct dir_baton *new_db = apr_pcalloc(pool, sizeof(*new_db));
  const char *repos_relpath;

  /* Construct the full path of this node. */
  if (pb)
    repos_relpath = svn_relpath_canonicalize(path, pool);
  else
    repos_relpath = "";

  /* Strip leading slash from copyfrom_path so that the path is
     canonical and svn_relpath_join can be used */
  if (copyfrom_path)
    copyfrom_path = svn_relpath_canonicalize(copyfrom_path, pool);

  new_db->eb = eb;
  new_db->pool = pool;
  new_db->repos_relpath = repos_relpath;
  new_db->copyfrom_path = copyfrom_path
                            ? svn_relpath_canonicalize(copyfrom_path, pool)
                            : NULL;
  new_db->copyfrom_rev = copyfrom_rev;
  new_db->headers = NULL;
  new_db->props = apr_hash_make(pool);
  new_db->deleted_props = apr_hash_make(pool);
  new_db->deleted_entries = apr_hash_make(pool);

  return new_db;
}

/* Make a file baton to represent the directory at PATH (relative to
 * PB->eb).  PB is the directory baton of this directory's parent, or
 * NULL if this is the top-level directory of the edit.  Perform all
 * allocations in POOL.  */
static struct file_baton *
make_file_baton(const char *path,
                struct dir_baton *pb,
                apr_pool_t *pool)
{
  struct file_baton *new_fb = apr_pcalloc(pool, sizeof(*new_fb));

  new_fb->eb = pb->eb;
  new_fb->pool = pool;
  new_fb->repos_relpath = svn_relpath_canonicalize(path, pool);
  new_fb->props = apr_hash_make(pool);
  new_fb->deleted_props = apr_hash_make(pool);
  new_fb->is_copy = FALSE;
  new_fb->copyfrom_path = NULL;
  new_fb->copyfrom_rev = SVN_INVALID_REVNUM;
  new_fb->action = svn_node_action_change;

  return new_fb;
}

/* Append to HEADERS the required headers, and set *CONTENT to the property
 * content section, to represent the property delta of PROPS/DELETED_PROPS.
 */
static svn_error_t *
get_props_content(svn_repos__dumpfile_headers_t *headers,
                  svn_stringbuf_t **content,
                  apr_hash_t *props,
                  apr_hash_t *deleted_props,
                  apr_pool_t *result_pool,
                  apr_pool_t *scratch_pool)
{
  svn_stream_t *content_stream;
  apr_hash_t *normal_props;

  *content = svn_stringbuf_create_empty(result_pool);

  content_stream = svn_stream_from_stringbuf(*content, scratch_pool);

  SVN_ERR(normalize_props(&normal_props, props, scratch_pool));
  SVN_ERR(svn_hash_write_incremental(normal_props, deleted_props,
                                     content_stream, "PROPS-END",
                                     scratch_pool));
  SVN_ERR(svn_stream_close(content_stream));

  /* Prop-delta: true */
  svn_repos__dumpfile_header_push(
    headers, SVN_REPOS_DUMPFILE_PROP_DELTA, "true");

  return SVN_NO_ERROR;
}

/* A special case of dump_node(), for a delete record.
 *
 * The only thing special about this version is it only writes one blank
 * line, not two, after the headers. Why? Historical precedent for the
 * case where a delete record is used as part of a (delete + add-with-history)
 * in implementing a replacement.
 */
static svn_error_t *
dump_node_delete(svn_stream_t *stream,
                 const char *node_relpath,
                 apr_pool_t *pool)
{
  svn_repos__dumpfile_headers_t *headers
    = svn_repos__dumpfile_headers_create(pool);

  assert(svn_relpath_is_canonical(node_relpath));

  /* Node-path: ... */
  svn_repos__dumpfile_header_push(
    headers, SVN_REPOS_DUMPFILE_NODE_PATH, node_relpath);

  /* Node-action: delete */
  svn_repos__dumpfile_header_push(
    headers, SVN_REPOS_DUMPFILE_NODE_ACTION, "delete");

  SVN_ERR(svn_repos__dump_node_record(stream, headers,
                                      NULL, FALSE, 0,  /* props & text */
                                      FALSE /*content_length_always*/, pool));
  return SVN_NO_ERROR;
}

/* Set *HEADERS_P to contain some headers for the node at PATH of type KIND.
 *
 * ACTION describes what is happening to the node (see enum
 * svn_node_action).
 *
 * If the node was itself copied, IS_COPY is TRUE and the
 * path/revision of the copy source are in COPYFROM_PATH/COPYFROM_REV.
 * If IS_COPY is FALSE, yet COPYFROM_PATH/COPYFROM_REV are valid, this
 * node is part of a copied subtree.
 *
 * Iff ACTION is svn_node_action_replace and IS_COPY, then first write a
 * complete deletion record to the dump stream.
 *
 * If ACTION is svn_node_action_delete, then the node record will be
 * complete. (The caller may want to write two blank lines after the
 * header block.)
 */
static svn_error_t *
dump_node(svn_repos__dumpfile_headers_t **headers_p,
          struct dump_edit_baton *eb,
          const char *repos_relpath,
          struct dir_baton *db,
          struct file_baton *fb,
          enum svn_node_action action,
          svn_boolean_t is_copy,
          const char *copyfrom_path,
          svn_revnum_t copyfrom_rev,
          apr_pool_t *pool)
{
  const char *node_relpath = repos_relpath;
  svn_repos__dumpfile_headers_t *headers
    = svn_repos__dumpfile_headers_create(pool);

  assert(svn_relpath_is_canonical(repos_relpath));
  assert(!copyfrom_path || svn_relpath_is_canonical(copyfrom_path));
  assert(! (db && fb));

  /* Add the edit root relpath prefix if necessary. */
  if (eb->update_anchor_relpath)
    node_relpath = svn_relpath_join(eb->update_anchor_relpath,
                                    node_relpath, pool);

  /* Node-path: ... */
  svn_repos__dumpfile_header_push(
    headers, SVN_REPOS_DUMPFILE_NODE_PATH, node_relpath);

  /* Node-kind: "file" | "dir" */
  if (fb)
    svn_repos__dumpfile_header_push(
      headers, SVN_REPOS_DUMPFILE_NODE_KIND, "file");
  else if (db)
    svn_repos__dumpfile_header_push(
      headers, SVN_REPOS_DUMPFILE_NODE_KIND, "dir");


  /* Write the appropriate Node-action header */
  switch (action)
    {
    case svn_node_action_change:
      /* We are here after a change_file_prop or change_dir_prop. They
         set up whatever dump_props they needed to- nothing to
         do here but print node action information.

         Node-action: change.  */
      svn_repos__dumpfile_header_push(
        headers, SVN_REPOS_DUMPFILE_NODE_ACTION, "change");
      break;

    case svn_node_action_delete:
      /* Node-action: delete */
      svn_repos__dumpfile_header_push(
        headers, SVN_REPOS_DUMPFILE_NODE_ACTION, "delete");
      break;

    case svn_node_action_replace:
      if (! is_copy)
        {
          /* Node-action: replace */
          svn_repos__dumpfile_header_push(
            headers, SVN_REPOS_DUMPFILE_NODE_ACTION, "replace");

          /* Wait for a change_*_prop to be called before dumping
             anything */
          if (fb)
            fb->dump_props = TRUE;
          else if (db)
            db->dump_props = TRUE;
          break;
        }
      else
        {
          /* More complex case: is_copy is true, and copyfrom_path/
             copyfrom_rev are present: delete the original, and then re-add
             it */
          /* ### Why not write a 'replace' record? Don't know. */

          /* ### Unusually, we end this 'delete' node record with only a single
                 blank line after the header block -- no extra blank line. */
          SVN_ERR(dump_node_delete(eb->stream, repos_relpath, pool));

          /* The remaining action is a non-replacing add-with-history */
          /* action = svn_node_action_add; */
        }
      /* FALL THROUGH to 'add' */

    case svn_node_action_add:
      /* Node-action: add */
      svn_repos__dumpfile_header_push(
        headers, SVN_REPOS_DUMPFILE_NODE_ACTION, "add");

      if (is_copy)
        {
          /* Node-copyfrom-rev / Node-copyfrom-path */
          svn_repos__dumpfile_header_pushf(
            headers, SVN_REPOS_DUMPFILE_NODE_COPYFROM_REV, "%ld", copyfrom_rev);
          svn_repos__dumpfile_header_push(
            headers, SVN_REPOS_DUMPFILE_NODE_COPYFROM_PATH, copyfrom_path);
        }
      else
        {
          /* fb->dump_props (for files) is handled in close_file()
             which is called immediately.

             However, directories are not closed until all the work
             inside them has been done; db->dump_props (for directories)
             is handled (via dump_pending()) in all the functions that
             can possibly be called after add_directory():

               - add_directory()
               - open_directory()
               - delete_entry()
               - close_directory()
               - add_file()
               - open_file()

             change_dir_prop() is a special case. */
          if (fb)
            fb->dump_props = TRUE;
          else if (db)
            db->dump_props = TRUE;
        }

      break;
    }

  /* Return the headers so far. We don't necessarily have all the headers
     yet -- there may be property-related and content length headers to
     come, if this was not a 'delete' record. */
  *headers_p = headers;
  return SVN_NO_ERROR;
}

static svn_error_t *
dump_mkdir(struct dump_edit_baton *eb,
           const char *repos_relpath,
           apr_pool_t *pool)
{
  svn_stringbuf_t *prop_content;
  svn_repos__dumpfile_headers_t *headers
    = svn_repos__dumpfile_headers_create(pool);

  /* Node-path: ... */
  svn_repos__dumpfile_header_push(
    headers, SVN_REPOS_DUMPFILE_NODE_PATH, repos_relpath);

  /* Node-kind: dir */
  svn_repos__dumpfile_header_push(
    headers, SVN_REPOS_DUMPFILE_NODE_KIND, "dir");

  /* Node-action: add */
  svn_repos__dumpfile_header_push(
    headers, SVN_REPOS_DUMPFILE_NODE_ACTION, "add");

  /* Dump the (empty) property block. */
  SVN_ERR(get_props_content(headers, &prop_content,
                            apr_hash_make(pool), apr_hash_make(pool),
                            pool, pool));
  SVN_ERR(svn_repos__dump_node_record(eb->stream, headers, prop_content,
                                      FALSE, 0, FALSE /*content_length_always*/,
                                      pool));

  /* Newlines to tie it all off. */
  SVN_ERR(svn_stream_puts(eb->stream, "\n\n"));

  return SVN_NO_ERROR;
}

/* Dump pending headers and properties for the directory EB->pending_db (if
 * not null), to allow starting the dump of a child node */
static svn_error_t *
dump_pending_dir(struct dump_edit_baton *eb,
                 apr_pool_t *scratch_pool)
{
  struct dir_baton *db = eb->pending_db;
  svn_stringbuf_t *prop_content = NULL;

  if (! db)
    return SVN_NO_ERROR;

  /* Some pending properties to dump? */
  if (db->dump_props)
    {
      SVN_ERR(get_props_content(db->headers, &prop_content,
                                db->props, db->deleted_props,
                                scratch_pool, scratch_pool));
    }
  SVN_ERR(svn_repos__dump_node_record(eb->stream, db->headers, prop_content,
                                      FALSE, 0, FALSE /*content_length_always*/,
                                      scratch_pool));

  /* No text is going to be dumped. Write a couple of newlines and
       wait for the next node/ revision. */
  SVN_ERR(svn_stream_puts(eb->stream, "\n\n"));

  if (db->dump_props)
    {
      /* Cleanup so that data is never dumped twice. */
      apr_hash_clear(db->props);
      apr_hash_clear(db->deleted_props);
      db->dump_props = FALSE;
    }

  /* Anything that was pending is pending no longer. */
  eb->pending_db = NULL;

  return SVN_NO_ERROR;
}



/*** Editor Function Implementations ***/

static svn_error_t *
open_root(void *edit_baton,
          svn_revnum_t base_revision,
          apr_pool_t *pool,
          void **root_baton)
{
  struct dump_edit_baton *eb = edit_baton;
  struct dir_baton *new_db = NULL;

  /* Clear the per-revision pool after each revision */
  svn_pool_clear(eb->pool);

  if (eb->update_anchor_relpath)
    {
      int i;
      const char *parent_path = eb->update_anchor_relpath;
      apr_array_header_t *dirs_to_add =
        apr_array_make(pool, 4, sizeof(const char *));
      apr_pool_t *iterpool = svn_pool_create(pool);

      while (! svn_path_is_empty(parent_path))
        {
          APR_ARRAY_PUSH(dirs_to_add, const char *) = parent_path;
          parent_path = svn_relpath_dirname(parent_path, pool);
        }

      for (i = dirs_to_add->nelts; i; --i)
        {
          const char *dir_to_add =
            APR_ARRAY_IDX(dirs_to_add, i - 1, const char *);

          svn_pool_clear(iterpool);

          /* For parents of the source directory, we just manufacture
             the adds ourselves. */
          if (i > 1)
            {
              SVN_ERR(dump_mkdir(eb, dir_to_add, iterpool));
            }
          else
            {
              /* ... but for the source directory itself, we'll defer
                 to letting the typical plumbing handle this task. */
              new_db = make_dir_baton(NULL, NULL, SVN_INVALID_REVNUM,
                                      edit_baton, NULL, pool);
              SVN_ERR(dump_node(&new_db->headers,
                                eb, new_db->repos_relpath, new_db,
                                NULL, svn_node_action_add, FALSE,
                                NULL, SVN_INVALID_REVNUM, pool));

              /* Remember that we've started but not yet finished
                 handling this directory. */
              eb->pending_db = new_db;
            }
        }
      svn_pool_destroy(iterpool);
    }

  if (! new_db)
    {
      new_db = make_dir_baton(NULL, NULL, SVN_INVALID_REVNUM,
                              edit_baton, NULL, pool);
    }

  *root_baton = new_db;
  return SVN_NO_ERROR;
}

static svn_error_t *
delete_entry(const char *path,
             svn_revnum_t revision,
             void *parent_baton,
             apr_pool_t *pool)
{
  struct dir_baton *pb = parent_baton;

  SVN_ERR(dump_pending_dir(pb->eb, pool));

  /* We don't dump this deletion immediate.  Rather, we add this path
     to the deleted_entries of the parent directory baton.  That way,
     we can tell (later) an addition from a replacement.  All the real
     deletions get handled in close_directory().  */
  svn_hash_sets(pb->deleted_entries, apr_pstrdup(pb->pool, path), pb);

  return SVN_NO_ERROR;
}

static svn_error_t *
add_directory(const char *path,
              void *parent_baton,
              const char *copyfrom_path,
              svn_revnum_t copyfrom_rev,
              apr_pool_t *pool,
              void **child_baton)
{
  struct dir_baton *pb = parent_baton;
  void *was_deleted;
  struct dir_baton *new_db;
  svn_boolean_t is_copy;

  SVN_ERR(dump_pending_dir(pb->eb, pool));

  new_db = make_dir_baton(path, copyfrom_path, copyfrom_rev, pb->eb,
                          pb, pb->pool);

  /* This might be a replacement -- is the path already deleted? */
  was_deleted = svn_hash_gets(pb->deleted_entries, path);

  /* Detect an add-with-history */
  is_copy = ARE_VALID_COPY_ARGS(copyfrom_path, copyfrom_rev);

  /* Dump the node */
  SVN_ERR(dump_node(&new_db->headers,
                    pb->eb, new_db->repos_relpath, new_db, NULL,
                    was_deleted ? svn_node_action_replace : svn_node_action_add,
                    is_copy,
                    is_copy ? new_db->copyfrom_path : NULL,
                    is_copy ? copyfrom_rev : SVN_INVALID_REVNUM,
                    pool));

  if (was_deleted)
    /* Delete the path, it's now been dumped */
    svn_hash_sets(pb->deleted_entries, path, NULL);

  /* Remember that we've started, but not yet finished handling this
     directory. */
  pb->eb->pending_db = new_db;

  *child_baton = new_db;
  return SVN_NO_ERROR;
}

static svn_error_t *
open_directory(const char *path,
               void *parent_baton,
               svn_revnum_t base_revision,
               apr_pool_t *pool,
               void **child_baton)
{
  struct dir_baton *pb = parent_baton;
  struct dir_baton *new_db;
  const char *copyfrom_path = NULL;
  svn_revnum_t copyfrom_rev = SVN_INVALID_REVNUM;

  SVN_ERR(dump_pending_dir(pb->eb, pool));

  /* If the parent directory has explicit comparison path and rev,
     record the same for this one. */
  if (ARE_VALID_COPY_ARGS(pb->copyfrom_path, pb->copyfrom_rev))
    {
      copyfrom_path = svn_relpath_join(pb->copyfrom_path,
                                       svn_relpath_basename(path, NULL),
                                       pb->pool);
      copyfrom_rev = pb->copyfrom_rev;
    }

  new_db = make_dir_baton(path, copyfrom_path, copyfrom_rev, pb->eb, pb,
                          pb->pool);

  *child_baton = new_db;
  return SVN_NO_ERROR;
}

static svn_error_t *
close_directory(void *dir_baton,
                apr_pool_t *pool)
{
  struct dir_baton *db = dir_baton;
  apr_hash_index_t *hi;
  svn_boolean_t this_pending;

  /* Remember if this directory is the one currently pending. */
  this_pending = (db->eb->pending_db == db);

  SVN_ERR(dump_pending_dir(db->eb, pool));

  /* If this directory was pending, then dump_pending() should have
     taken care of all the props and such.  Of course, the only way
     that would be the case is if this directory was added/replaced.

     Otherwise, if stuff for this directory has already been written
     out (at some point in the past, prior to our handling other
     nodes), we might need to generate a second "change" record just
     to carry the information we've since learned about the
     directory. */
  if ((! this_pending) && (db->dump_props))
    {
      SVN_ERR(dump_node(&db->headers,
                        db->eb, db->repos_relpath, db, NULL,
                        svn_node_action_change, FALSE,
                        NULL, SVN_INVALID_REVNUM, pool));
      db->eb->pending_db = db;
      SVN_ERR(dump_pending_dir(db->eb, pool));
    }

  /* Dump the deleted directory entries */
  for (hi = apr_hash_first(pool, db->deleted_entries); hi;
       hi = apr_hash_next(hi))
    {
      const char *path = apr_hash_this_key(hi);

      SVN_ERR(dump_node_delete(db->eb->stream, path, pool));
      /* This deletion record is complete -- write an extra newline */
      SVN_ERR(svn_stream_puts(db->eb->stream, "\n"));
    }

  /* ### should be unnecessary */
  apr_hash_clear(db->deleted_entries);

  return SVN_NO_ERROR;
}

static svn_error_t *
add_file(const char *path,
         void *parent_baton,
         const char *copyfrom_path,
         svn_revnum_t copyfrom_rev,
         apr_pool_t *pool,
         void **file_baton)
{
  struct dir_baton *pb = parent_baton;
  struct file_baton *fb;
  void *was_deleted;

  SVN_ERR(dump_pending_dir(pb->eb, pool));

  /* Make the file baton. */
  fb = make_file_baton(path, pb, pool);

  /* This might be a replacement -- is the path already deleted? */
  was_deleted = svn_hash_gets(pb->deleted_entries, path);

  /* Detect add-with-history. */
  if (ARE_VALID_COPY_ARGS(copyfrom_path, copyfrom_rev))
    {
      fb->copyfrom_path = svn_relpath_canonicalize(copyfrom_path, fb->pool);
      fb->copyfrom_rev = copyfrom_rev;
      fb->is_copy = TRUE;
    }
  fb->action = was_deleted ? svn_node_action_replace : svn_node_action_add;

  /* Delete the path, it's now been dumped. */
  if (was_deleted)
    svn_hash_sets(pb->deleted_entries, path, NULL);

  *file_baton = fb;
  return SVN_NO_ERROR;
}

static svn_error_t *
open_file(const char *path,
          void *parent_baton,
          svn_revnum_t ancestor_revision,
          apr_pool_t *pool,
          void **file_baton)
{
  struct dir_baton *pb = parent_baton;
  struct file_baton *fb;

  SVN_ERR(dump_pending_dir(pb->eb, pool));

  /* Make the file baton. */
  fb = make_file_baton(path, pb, pool);

  /* If the parent directory has explicit copyfrom path and rev,
     record the same for this one. */
  if (ARE_VALID_COPY_ARGS(pb->copyfrom_path, pb->copyfrom_rev))
    {
      fb->copyfrom_path = svn_relpath_join(pb->copyfrom_path,
                                           svn_relpath_basename(path, NULL),
                                           pb->pool);
      fb->copyfrom_rev = pb->copyfrom_rev;
    }

  *file_baton = fb;
  return SVN_NO_ERROR;
}

static svn_error_t *
change_dir_prop(void *parent_baton,
                const char *name,
                const svn_string_t *value,
                apr_pool_t *pool)
{
  struct dir_baton *db = parent_baton;
  svn_boolean_t this_pending;

  /* This directory is not pending, but something else is, so handle
     the "something else".  */
  this_pending = (db->eb->pending_db == db);
  if (! this_pending)
    SVN_ERR(dump_pending_dir(db->eb, pool));

  if (svn_property_kind2(name) != svn_prop_regular_kind)
    return SVN_NO_ERROR;

  if (value)
    svn_hash_sets(db->props,
                  apr_pstrdup(db->pool, name),
                  svn_string_dup(value, db->pool));
  else
    svn_hash_sets(db->deleted_props, apr_pstrdup(db->pool, name), "");

  /* Make sure we eventually output the props */
  db->dump_props = TRUE;

  return SVN_NO_ERROR;
}

static svn_error_t *
change_file_prop(void *file_baton,
                 const char *name,
                 const svn_string_t *value,
                 apr_pool_t *pool)
{
  struct file_baton *fb = file_baton;

  if (svn_property_kind2(name) != svn_prop_regular_kind)
    return SVN_NO_ERROR;

  if (value)
    svn_hash_sets(fb->props,
                  apr_pstrdup(fb->pool, name),
                  svn_string_dup(value, fb->pool));
  else
    svn_hash_sets(fb->deleted_props, apr_pstrdup(fb->pool, name), "");

  /* Dump the property headers and wait; close_file might need
     to write text headers too depending on whether
     apply_textdelta is called */
  fb->dump_props = TRUE;

  return SVN_NO_ERROR;
}

static svn_error_t *
apply_textdelta(void *file_baton, const char *base_checksum,
                apr_pool_t *pool,
                svn_txdelta_window_handler_t *handler,
                void **handler_baton)
{
  struct file_baton *fb = file_baton;
  struct dump_edit_baton *eb = fb->eb;
  svn_stream_t *delta_filestream;

  /* Use a temporary file to measure the Text-content-length */
  delta_filestream = svn_stream_from_aprfile2(eb->delta_file, TRUE, pool);

  /* Prepare to write the delta to the delta_filestream */
  svn_txdelta_to_svndiff3(handler, handler_baton,
                          delta_filestream, 0,
                          SVN_DELTA_COMPRESSION_LEVEL_DEFAULT, pool);

  /* Record that there's text to be dumped, and its base checksum. */
  fb->dump_text = TRUE;
  fb->base_checksum = apr_pstrdup(fb->pool, base_checksum);

  return SVN_NO_ERROR;
}

static svn_error_t *
close_file(void *file_baton,
           const char *text_checksum,
           apr_pool_t *pool)
{
  struct file_baton *fb = file_baton;
  struct dump_edit_baton *eb = fb->eb;
  svn_filesize_t text_content_length = 0;
  svn_stringbuf_t *propstring = NULL;
  svn_repos__dumpfile_headers_t *headers;

  SVN_ERR(dump_pending_dir(eb, pool));

  /* Start dumping this node, by collecting some basic headers for it. */
  SVN_ERR(dump_node(&headers, eb, fb->repos_relpath, NULL, fb,
                    fb->action, fb->is_copy, fb->copyfrom_path,
                    fb->copyfrom_rev, pool));

  /* Some pending properties to dump?  We'll dump just the headers for
     now, then dump the actual propchange content only after dumping
     the text headers too (if present). */
  if (fb->dump_props)
    {
      SVN_ERR(get_props_content(headers, &propstring,
                                fb->props, fb->deleted_props,
                                pool, pool));
    }

  /* Dump the text headers */
  if (fb->dump_text)
    {
      /* Text-delta: true */
      svn_repos__dumpfile_header_push(
        headers, SVN_REPOS_DUMPFILE_TEXT_DELTA, "true");

      SVN_ERR(svn_io_file_size_get(&text_content_length, eb->delta_file,
                                   pool));

      if (fb->base_checksum)
        /* Text-delta-base-md5: */
        svn_repos__dumpfile_header_push(
          headers, SVN_REPOS_DUMPFILE_TEXT_DELTA_BASE_MD5, fb->base_checksum);

      /* Text-content-md5: 82705804337e04dcd0e586bfa2389a7f */
      svn_repos__dumpfile_header_push(
        headers, SVN_REPOS_DUMPFILE_TEXT_CONTENT_MD5, text_checksum);
    }

  /* Dump the headers and props now */
  SVN_ERR(svn_repos__dump_node_record(eb->stream, headers, propstring,
                                      fb->dump_text, text_content_length,
                                      FALSE /*content_length_always*/,
                                      pool));

  if (fb->dump_props)
    {
      /* Cleanup */
      fb->dump_props = FALSE;
      apr_hash_clear(fb->props);
      apr_hash_clear(fb->deleted_props);
    }

  /* Dump the text */
  if (fb->dump_text)
    {
      /* Seek to the beginning of the delta file, map it to a stream,
         and copy the stream to eb->stream. Then close the stream and
         truncate the file so we can reuse it for the next textdelta
         application. Note that the file isn't created, opened or
         closed here */
      svn_stream_t *delta_filestream;
      apr_off_t offset = 0;

      SVN_ERR(svn_io_file_seek(eb->delta_file, APR_SET, &offset, pool));
      delta_filestream = svn_stream_from_aprfile2(eb->delta_file, TRUE, pool);
      SVN_ERR(svn_stream_copy3(delta_filestream, eb->stream, NULL, NULL, pool));

      /* Cleanup */
      SVN_ERR(svn_stream_close(delta_filestream));
      SVN_ERR(svn_io_file_trunc(eb->delta_file, 0, pool));
    }

  /* Write a couple of blank lines for matching output with `svnadmin
     dump` */
  SVN_ERR(svn_stream_puts(eb->stream, "\n\n"));

  return SVN_NO_ERROR;
}

static svn_error_t *
close_edit(void *edit_baton, apr_pool_t *pool)
{
  return SVN_NO_ERROR;
}

svn_error_t *
svn_repos__get_dump_editor(const svn_delta_editor_t **editor,
                           void **edit_baton,
                           svn_stream_t *stream,
                           const char *update_anchor_relpath,
                           apr_pool_t *pool)
{
  struct dump_edit_baton *eb;
  svn_delta_editor_t *de;

  eb = apr_pcalloc(pool, sizeof(struct dump_edit_baton));
  eb->stream = stream;
  eb->update_anchor_relpath = update_anchor_relpath;
  eb->pending_db = NULL;

  /* Create a special per-revision pool */
  eb->pool = svn_pool_create(pool);

  /* Open a unique temporary file for all textdelta applications in
     this edit session. The file is automatically closed and cleaned
     up when the edit session is done. */
  SVN_ERR(svn_io_open_unique_file3(&(eb->delta_file), &(eb->delta_abspath),
                                   NULL, svn_io_file_del_on_close, pool, pool));

  de = svn_delta_default_editor(pool);
  de->open_root = open_root;
  de->delete_entry = delete_entry;
  de->add_directory = add_directory;
  de->open_directory = open_directory;
  de->close_directory = close_directory;
  de->change_dir_prop = change_dir_prop;
  de->change_file_prop = change_file_prop;
  de->apply_textdelta = apply_textdelta;
  de->add_file = add_file;
  de->open_file = open_file;
  de->close_file = close_file;
  de->close_edit = close_edit;

  /* Set the edit_baton and editor. */
  *edit_baton = eb;
  *editor = de;

  return SVN_NO_ERROR;
}
