#include <tree-streamer.h>

Collaboration diagram for streamer_tree_cache_d:

Data Fields
hash_map< tree, unsigned > *	node_map

vec< tree >	nodes

vec< hashval_t >	hashes

unsigned	next_idx

Detailed Description

Data structures and functions for streaming trees.

   Copyright (C) 2011-2024 Free Software Foundation, Inc.
   Contributed by Diego Novillo <dnovillo@google.com>

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.

Cache of pickled nodes.  Used to avoid writing the same node more
than once.  The first time a tree node is streamed out, it is
entered in this cache.  Subsequent references to the same node are
resolved by looking it up in this cache.

This is used in two ways:

- On the writing side, the first time T is added to STREAMER_CACHE,
  a new reference index is created for T and T is emitted on the
  stream.  If T needs to be emitted again to the stream, instead of
  pickling it again, the reference index is emitted.

- On the reading side, the first time T is read from the stream, it
  is reconstructed in memory and a new reference index created for
  T.  The reconstructed T is inserted in some array so that when
  the reference index for T is found in the input stream, it can be
  used to look up into the array to get the reconstructed T.