Change gist stratnum function to use CompareType

This changes commit 7406ab623fe in that the gist strategy number
mapping support function is changed to use the CompareType enum as
input, instead of the "well-known" RT*StrategyNumber strategy numbers.

This is a bit cleaner, since you are not dealing with two sets of
strategy numbers.  Also, this will enable us to subsume this system
into a more general system of using CompareType to define operator
semantics across index methods.

Discussion: https://www.postgresql.org/message-id/flat/[email protected]

2 files changed, 13 insertions, 13 deletions

diff --git a/doc/src/sgml/gist.sgml b/doc/src/sgml/gist.sgml
index 638d912dc2d..99098ab2522 100644
--- a/doc/src/sgml/gist.sgml
+++ b/doc/src/sgml/gist.sgml
@@ -290,8 +290,8 @@ CREATE INDEX ON my_table USING GIST (my_inet_column inet_ops);
    The optional eleventh method <function>sortsupport</function> is used to
    speed up building a <acronym>GiST</acronym> index.
    The optional twelfth method <function>stratnum</function> is used to
-   translate well-known <literal>RT*StrategyNumber</literal>s (from
-   <filename>src/include/access/stratnum.h</filename>) into strategy numbers
+   translate compare types (from
+   <filename>src/include/nodes/primnodes.h</filename>) into strategy numbers
    used by the operator class.  This lets the core code look up operators for
    temporal constraint indexes.
  </para>
@@ -1173,8 +1173,8 @@ my_sortsupport(PG_FUNCTION_ARGS)
      <term><function>stratnum</function></term>
      <listitem>
       <para>
-       Given an <literal>RT*StrategyNumber</literal> value from
-       <filename>src/include/access/stratnum.h</filename>, returns a strategy
+       Given a <literal>CompareType</literal> value from
+       <filename>src/include/nodes/primnodes.h</filename>, returns a strategy
        number used by this operator class for matching functionality.  The
        function should return <literal>InvalidStrategy</literal> if the
        operator class has no matching strategy.
@@ -1184,7 +1184,7 @@ my_sortsupport(PG_FUNCTION_ARGS)
        This is used for temporal index constraints (i.e., <literal>PRIMARY
        KEY</literal> and <literal>UNIQUE</literal>).  If the operator class
        provides this function and it returns results for
-       <literal>RTEqualStrategyNumber</literal>, it can be used in the
+       <literal>COMPARE_EQ</literal>, it can be used in the
        non-<literal>WITHOUT OVERLAPS</literal> part(s) of an index constraint.
       </para>
 
@@ -1194,7 +1194,7 @@ my_sortsupport(PG_FUNCTION_ARGS)
 
 <programlisting>
 CREATE OR REPLACE FUNCTION my_stratnum(integer)
-RETURNS integer
+RETURNS smallint
 AS 'MODULE_PATHNAME'
 LANGUAGE C STRICT;
 </programlisting>
@@ -1209,12 +1209,12 @@ PG_FUNCTION_INFO_V1(my_stratnum);
 Datum
 my_stratnum(PG_FUNCTION_ARGS)
 {
-    StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(1);
+    CompareType cmptype = PG_GETARG_INT32(0);
     StrategyNumber ret = InvalidStrategy;
 
-    switch (strategy)
+    switch (cmptype)
     {
-        case RTEqualStrategyNumber:
+        case COMPARE_EQ:
             ret = BTEqualStrategyNumber;
     }
 
@@ -1226,9 +1226,9 @@ my_stratnum(PG_FUNCTION_ARGS)
       <para>
        One translation function is provided by
        <productname>PostgreSQL</productname>:
-       <literal>gist_stratnum_identity</literal> is for operator classes that
-       already use the <literal>RT*StrategyNumber</literal> constants.  It
-       returns whatever is passed to it.  The <literal>btree_gist</literal>
+       <literal>gist_stratnum_common</literal> is for operator classes that
+       use the <literal>RT*StrategyNumber</literal> constants.
+       The <literal>btree_gist</literal>
        extension defines a second translation function,
        <literal>gist_stratnum_btree</literal>, for operator classes that use
        the <literal>BT*StrategyNumber</literal> constants.
diff --git a/doc/src/sgml/xindex.sgml b/doc/src/sgml/xindex.sgml
index 3a19dab15e0..05361962495 100644
--- a/doc/src/sgml/xindex.sgml
+++ b/doc/src/sgml/xindex.sgml
@@ -592,7 +592,7 @@
       </row>
       <row>
        <entry><function>stratnum</function></entry>
-       <entry>translate well-known strategy numbers to ones
+       <entry>translate compare types to strategy numbers
         used by the operator class (optional)</entry>
        <entry>12</entry>
       </row>