Add GCRYMPI_FLAG_CONST and make use constants.

* src/gcrypt.h.in (GCRYMPI_FLAG_CONST): New.
* src/mpi.h (mpi_is_const, mpi_const): New.
(enum gcry_mpi_constants, MPI_NUMBER_OF_CONSTANTS): New.
* mpi/mpiutil.c (_gcry_mpi_init): New.
(constants): New.
(_gcry_mpi_free): Do not release a constant flagged MPI.
(gcry_mpi_copy): Clear the const and immutable flags.
(gcry_mpi_set_flag, gcry_mpi_clear_flag, gcry_mpi_get_flag): Support
GCRYMPI_FLAG_CONST.
(_gcry_mpi_const): New.
* src/global.c (global_init): Call _gcry_mpi_init.
* mpi/ec.c (mpi_ec_ctx_s): Remove fields one, two, three, four, and
eight.  Change all users to call mpi_const() instead.

* src/mpiutils.c (gcry_mpi_set_opaque): Check the immutable flag.
--

Allocating the trivial constants newly for every EC context is a waste
of memory and cpu cycles.  We instead provide a simple mechanism to
internally support such constants.  Using a new flag in THE API also
allows to mark an arbitrary MPI as constant.  The drawback of the
constants is the their memory will never be deallocated.  However,
that is what constants are about.

1 files changed, 1 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index 3a4ca4c0..c0a7e8e9 100644
--- a/NEWS
+++ b/NEWS
@@ -51,6 +51,7 @@ Noteworthy changes in version 1.6.0 (unreleased)
  gcry_mpi_ec_add                 NEW.
  gcry_mpi_ec_mul                 NEW.
  GCRYMPI_FLAG_IMMUTABLE          NEW.
+ GCRYMPI_FLAG_CONST              NEW.
 
 
 Noteworthy changes in version 1.5.0 (2011-06-29)