wrapper for zlib library

assume that zlib is available for linking. This is usually the case
(zlib is a stable standard library), but there is currently no check
that gives a nice error message or the possibility to use zlib from a
non-standard location

CMakeLists.txt

@@ -184,7 +184,7 @@ if (CMAKE_BUILD_TYPE STREQUAL "DEBUG")
 endif ()
 
 set (CMAKE_Fortran_FLAGS_${CMAKE_BUILD_TYPE}   "${CMAKE_Fortran_FLAGS_${CMAKE_BUILD_TYPE}} ${PETSC_INCLUDES} ${BUILDCMD_POST}")
-set (CMAKE_Fortran_LINK_EXECUTABLE             "${CMAKE_Fortran_LINK_EXECUTABLE} <OBJECTS> -o <TARGET> <LINK_LIBRARIES> ${PETSC_EXTERNAL_LIB} ${BUILDCMD_POST}")
+set (CMAKE_Fortran_LINK_EXECUTABLE             "${CMAKE_Fortran_LINK_EXECUTABLE} <OBJECTS> -o <TARGET> <LINK_LIBRARIES> ${PETSC_EXTERNAL_LIB} -lz ${BUILDCMD_POST}")
 
 message ("Fortran Compiler Flags:\n${CMAKE_Fortran_FLAGS_${CMAKE_BUILD_TYPE}}\n")
 message ("C Compiler Flags:\n${CMAKE_C_FLAGS_${CMAKE_BUILD_TYPE}}\n")

src/C_routines.c

@@ -6,6 +6,7 @@
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include "zlib.h"
 
 /* http://stackoverflow.com/questions/30279228/is-there-an-alternative-to-getcwd-in-fortran-2003-2008 */
 
@@ -57,3 +58,17 @@ void signalusr1_c(void (*handler)(int)){
 void signalusr2_c(void (*handler)(int)){
   signal(SIGUSR2, handler);
 }
+
+void inflate_c(const uLong *s_deflated, const uLong *s_inflated, const Byte deflated[], Byte inflated[]){
+  /* make writable copy, uncompress will write to it */
+  uLong s_inflated_;
+  s_inflated_ = *s_inflated;
+
+  if(uncompress((Bytef *)inflated, &s_inflated_, (Bytef *)deflated, *s_deflated) == Z_OK)
+    return;
+  else{
+    for(uLong i=0;i<*s_inflated;i++){
+      inflated[i] = 0;
+    }
+  }
+}

src/zlib.f90

@@ -0,0 +1,44 @@
+!--------------------------------------------------------------------------------------------------
+!> @author Martin Diehl, Max-Planck-Institut für Eisenforschung GmbH
+!> @brief  Inflate zlib compressed data
+!--------------------------------------------------------------------------------------------------
+module zlib
+  use prec
+
+  implicit none
+  private
+
+  public :: &
+    zlib_inflate
+
+  interface
+
+  subroutine inflate_C(s_deflated,s_inflated,deflated,inflated) bind(C)
+    use, intrinsic :: ISO_C_Binding, only: &
+      C_SIGNED_CHAR, C_INT64_T
+
+    integer(C_INT64_T),                            intent(in)  :: s_deflated,s_inflated
+    integer(C_SIGNED_CHAR), dimension(s_deflated), intent(in)  :: deflated
+    integer(C_SIGNED_CHAR), dimension(s_inflated), intent(out) :: inflated
+
+  end subroutine inflate_C
+
+  end interface
+
+contains
+
+!--------------------------------------------------------------------------------------------------
+!> @brief Inflate byte-wise representation
+!--------------------------------------------------------------------------------------------------
+function zlib_inflate(deflated,size_inflated)
+
+  integer(C_SIGNED_CHAR), dimension(:), intent(in) :: deflated
+  integer(pLongInt),                    intent(in) :: size_inflated
+
+  integer(C_SIGNED_CHAR), dimension(size_inflated) :: zlib_inflate
+
+  call inflate_C(size(deflated,kind=C_INT64_T),int(size_inflated,C_INT64_T),deflated,zlib_inflate)
+
+end function zlib_inflate
+
+end module zlib