Add support for building with ZSTD.

This commit doesn't actually add anything that uses ZSTD; that will be
done separately. It just puts the basic infrastructure into place.

Jeevan Ladhe, Robert Haas, and Michael Paquier. Reviewed by Justin
Pryzby and Andres Freund.

Discussion: http://postgr.es/m/CA+TgmoatQKGd+8SjcV+bzvw4XaoEwminHjU83yG12+NXtQzTTQ@mail.gmail.com

Author: robertmhaas

configure

@@ -650,6 +650,7 @@ CFLAGS_ARMV8_CRC32C
 CFLAGS_SSE42
 have_win32_dbghelp
 LIBOBJS
+ZSTD
 LZ4
 UUID_LIBS
 LDAP_LIBS_BE
@@ -700,6 +701,9 @@ with_gnu_ld
 LD
 LDFLAGS_SL
 LDFLAGS_EX
+ZSTD_LIBS
+ZSTD_CFLAGS
+with_zstd
 LZ4_LIBS
 LZ4_CFLAGS
 with_lz4
@@ -869,6 +873,7 @@ with_libxslt
 with_system_tzdata
 with_zlib
 with_lz4
+with_zstd
 with_gnu_ld
 with_ssl
 with_openssl
@@ -898,6 +903,8 @@ XML2_CFLAGS
 XML2_LIBS
 LZ4_CFLAGS
 LZ4_LIBS
+ZSTD_CFLAGS
+ZSTD_LIBS
 LDFLAGS_EX
 LDFLAGS_SL
 PERL
@@ -1577,6 +1584,7 @@ Optional Packages:
                           use system time zone data in DIR
   --without-zlib          do not use Zlib
   --with-lz4              build with LZ4 support
+  --with-zstd             build with ZSTD support
   --with-gnu-ld           assume the C compiler uses GNU ld [default=no]
   --with-ssl=LIB          use LIB for SSL/TLS support (openssl)
   --with-openssl          obsolete spelling of --with-ssl=openssl
@@ -1606,6 +1614,8 @@ Some influential environment variables:
   XML2_LIBS   linker flags for XML2, overriding pkg-config
   LZ4_CFLAGS  C compiler flags for LZ4, overriding pkg-config
   LZ4_LIBS    linker flags for LZ4, overriding pkg-config
+  ZSTD_CFLAGS C compiler flags for ZSTD, overriding pkg-config
+  ZSTD_LIBS   linker flags for ZSTD, overriding pkg-config
   LDFLAGS_EX  extra linker flags for linking executables only
   LDFLAGS_SL  extra linker flags for linking shared libraries only
   PERL        Perl program
@@ -9034,6 +9044,146 @@ fi
   done
 fi
 
+#
+# ZSTD
+#
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to build with ZSTD support" >&5
+$as_echo_n "checking whether to build with ZSTD support... " >&6; }
+
+
+
+# Check whether --with-zstd was given.
+if test "${with_zstd+set}" = set; then :
+  withval=$with_zstd;
+  case $withval in
+    yes)
+
+$as_echo "#define USE_ZSTD 1" >>confdefs.h
+
+      ;;
+    no)
+      :
+      ;;
+    *)
+      as_fn_error $? "no argument expected for --with-zstd option" "$LINENO" 5
+      ;;
+  esac
+
+else
+  with_zstd=no
+
+fi
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $with_zstd" >&5
+$as_echo "$with_zstd" >&6; }
+
+
+if test "$with_zstd" = yes; then
+
+pkg_failed=no
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for libzstd" >&5
+$as_echo_n "checking for libzstd... " >&6; }
+
+if test -n "$ZSTD_CFLAGS"; then
+    pkg_cv_ZSTD_CFLAGS="$ZSTD_CFLAGS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libzstd\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "libzstd") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_ZSTD_CFLAGS=`$PKG_CONFIG --cflags "libzstd" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+if test -n "$ZSTD_LIBS"; then
+    pkg_cv_ZSTD_LIBS="$ZSTD_LIBS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libzstd\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "libzstd") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_ZSTD_LIBS=`$PKG_CONFIG --libs "libzstd" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+
+
+
+if test $pkg_failed = yes; then
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+if $PKG_CONFIG --atleast-pkgconfig-version 0.20; then
+        _pkg_short_errors_supported=yes
+else
+        _pkg_short_errors_supported=no
+fi
+        if test $_pkg_short_errors_supported = yes; then
+	        ZSTD_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "libzstd" 2>&1`
+        else
+	        ZSTD_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "libzstd" 2>&1`
+        fi
+	# Put the nasty error message in config.log where it belongs
+	echo "$ZSTD_PKG_ERRORS" >&5
+
+	as_fn_error $? "Package requirements (libzstd) were not met:
+
+$ZSTD_PKG_ERRORS
+
+Consider adjusting the PKG_CONFIG_PATH environment variable if you
+installed software in a non-standard prefix.
+
+Alternatively, you may set the environment variables ZSTD_CFLAGS
+and ZSTD_LIBS to avoid the need to call pkg-config.
+See the pkg-config man page for more details." "$LINENO" 5
+elif test $pkg_failed = untried; then
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+	{ { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "The pkg-config script could not be found or is too old.  Make sure it
+is in your PATH or set the PKG_CONFIG environment variable to the full
+path to pkg-config.
+
+Alternatively, you may set the environment variables ZSTD_CFLAGS
+and ZSTD_LIBS to avoid the need to call pkg-config.
+See the pkg-config man page for more details.
+
+To get pkg-config, see <http://pkg-config.freedesktop.org/>.
+See \`config.log' for more details" "$LINENO" 5; }
+else
+	ZSTD_CFLAGS=$pkg_cv_ZSTD_CFLAGS
+	ZSTD_LIBS=$pkg_cv_ZSTD_LIBS
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+
+fi
+  # We only care about -I, -D, and -L switches;
+  # note that -lzstd will be added by AC_CHECK_LIB below.
+  for pgac_option in $ZSTD_CFLAGS; do
+    case $pgac_option in
+      -I*|-D*) CPPFLAGS="$CPPFLAGS $pgac_option";;
+    esac
+  done
+  for pgac_option in $ZSTD_LIBS; do
+    case $pgac_option in
+      -L*) LDFLAGS="$LDFLAGS $pgac_option";;
+    esac
+  done
+fi
 #
 # Assignments
 #
@@ -13130,6 +13280,56 @@ fi
 
 fi
 
+if test "$with_zstd" = yes ; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ZSTD_compress in -lzstd" >&5
+$as_echo_n "checking for ZSTD_compress in -lzstd... " >&6; }
+if ${ac_cv_lib_zstd_ZSTD_compress+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lzstd  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char ZSTD_compress ();
+int
+main ()
+{
+return ZSTD_compress ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_zstd_ZSTD_compress=yes
+else
+  ac_cv_lib_zstd_ZSTD_compress=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_zstd_ZSTD_compress" >&5
+$as_echo "$ac_cv_lib_zstd_ZSTD_compress" >&6; }
+if test "x$ac_cv_lib_zstd_ZSTD_compress" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBZSTD 1
+_ACEOF
+
+  LIBS="-lzstd $LIBS"
+
+else
+  as_fn_error $? "library 'zstd' is required for ZSTD support" "$LINENO" 5
+fi
+
+fi
+
 # Note: We can test for libldap_r only after we know PTHREAD_LIBS;
 # also, on AIX, we may need to have openssl in LIBS for this step.
 if test "$with_ldap" = yes ; then
@@ -13902,6 +14102,71 @@ fi
 
 done
 
+fi
+
+if test -z "$ZSTD"; then
+  for ac_prog in zstd
+do
+  # Extract the first word of "$ac_prog", so it can be a program name with args.
+set dummy $ac_prog; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_path_ZSTD+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $ZSTD in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_ZSTD="$ZSTD" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_path_ZSTD="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+ZSTD=$ac_cv_path_ZSTD
+if test -n "$ZSTD"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ZSTD" >&5
+$as_echo "$ZSTD" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+  test -n "$ZSTD" && break
+done
+
+else
+  # Report the value of ZSTD in configure's output in all cases.
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ZSTD" >&5
+$as_echo_n "checking for ZSTD... " >&6; }
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ZSTD" >&5
+$as_echo "$ZSTD" >&6; }
+fi
+
+if test "$with_zstd" = yes; then
+  ac_fn_c_check_header_mongrel "$LINENO" "zstd.h" "ac_cv_header_zstd_h" "$ac_includes_default"
+if test "x$ac_cv_header_zstd_h" = xyes; then :
+
+else
+  as_fn_error $? "zstd.h header file is required for ZSTD" "$LINENO" 5
+fi
+
+
 fi
 
 if test "$with_gssapi" = yes ; then

configure.ac

@@ -1056,6 +1056,30 @@ if test "$with_lz4" = yes; then
   done
 fi
 
+#
+# ZSTD
+#
+AC_MSG_CHECKING([whether to build with ZSTD support])
+PGAC_ARG_BOOL(with, zstd, no, [build with ZSTD support],
+              [AC_DEFINE([USE_ZSTD], 1, [Define to 1 to build with ZSTD support. (--with-zstd)])])
+AC_MSG_RESULT([$with_zstd])
+AC_SUBST(with_zstd)
+
+if test "$with_zstd" = yes; then
+  PKG_CHECK_MODULES(ZSTD, libzstd)
+  # We only care about -I, -D, and -L switches;
+  # note that -lzstd will be added by AC_CHECK_LIB below.
+  for pgac_option in $ZSTD_CFLAGS; do
+    case $pgac_option in
+      -I*|-D*) CPPFLAGS="$CPPFLAGS $pgac_option";;
+    esac
+  done
+  for pgac_option in $ZSTD_LIBS; do
+    case $pgac_option in
+      -L*) LDFLAGS="$LDFLAGS $pgac_option";;
+    esac
+  done
+fi
 #
 # Assignments
 #
@@ -1325,6 +1349,10 @@ if test "$with_lz4" = yes ; then
   AC_CHECK_LIB(lz4, LZ4_compress_default, [], [AC_MSG_ERROR([library 'lz4' is required for LZ4 support])])
 fi
 
+if test "$with_zstd" = yes ; then
+  AC_CHECK_LIB(zstd, ZSTD_compress, [], [AC_MSG_ERROR([library 'zstd' is required for ZSTD support])])
+fi
+
 # Note: We can test for libldap_r only after we know PTHREAD_LIBS;
 # also, on AIX, we may need to have openssl in LIBS for this step.
 if test "$with_ldap" = yes ; then
@@ -1490,6 +1518,11 @@ if test "$with_lz4" = yes; then
   AC_CHECK_HEADERS(lz4.h, [], [AC_MSG_ERROR([lz4.h header file is required for LZ4])])
 fi
 
+PGAC_PATH_PROGS(ZSTD, zstd)
+if test "$with_zstd" = yes; then
+  AC_CHECK_HEADER(zstd.h, [], [AC_MSG_ERROR([zstd.h header file is required for ZSTD])])
+fi
+
 if test "$with_gssapi" = yes ; then
   AC_CHECK_HEADERS(gssapi/gssapi.h, [],
 	[AC_CHECK_HEADERS(gssapi.h, [], [AC_MSG_ERROR([gssapi.h header file is required for GSSAPI])])])

doc/src/sgml/install-windows.sgml

@@ -307,6 +307,15 @@ $ENV{MSBFLAGS}="/m";
      </para></listitem>
     </varlistentry>
 
+    <varlistentry>
+     <term><productname>ZSTD</productname></term>
+     <listitem><para>
+      Required for supporting <productname>ZSTD</productname> compression
+      method. Binaries and source can be downloaded from
+      <ulink url="https://github.com/facebook/zstd/releases"></ulink>.
+     </para></listitem>
+    </varlistentry>
+
     <varlistentry>
      <term><productname>OpenSSL</productname></term>
      <listitem><para>