Make various variables const (read-only).

These changes should generally improve correctness/maintainability.
A nice side benefit is that several kilobytes move from initialized
data to text segment, allowing them to be shared across processes and
probably reducing copy-on-write overhead while forking a new backend.
Unfortunately this doesn't seem to help libpq in the same way (at least
not when it's compiled with -fpic on x86_64), but we can hope the linker
at least collects all nominally-const data together even if it's not
actually part of the text segment.

Also, make pg_encname_tbl[] static in encnames.c, since there seems
no very good reason for any other code to use it; per a suggestion
from Wim Lewis, who independently submitted a patch that was mostly
a subset of this one.

Oskari Saarenmaa, with some editorialization by me

1 files changed, 8 insertions, 8 deletions

diff --git a/src/backend/utils/adt/tsrank.c b/src/backend/utils/adt/tsrank.c
index a8e07e7fbc2..c9e71c9e21d 100644
--- a/src/backend/utils/adt/tsrank.c
+++ b/src/backend/utils/adt/tsrank.c
@@ -20,7 +20,7 @@
 #include "miscadmin.h"
 
 
-static float weights[] = {0.1f, 0.2f, 0.4f, 1.0f};
+static const float weights[] = {0.1f, 0.2f, 0.4f, 1.0f};
 
 #define wpos(wep)	( w[ WEP_GETWEIGHT(wep) ] )
 
@@ -33,8 +33,8 @@ static float weights[] = {0.1f, 0.2f, 0.4f, 1.0f};
 #define RANK_NORM_RDIVRPLUS1	0x20
 #define DEF_NORM_METHOD			RANK_NO_NORM
 
-static float calc_rank_or(float *w, TSVector t, TSQuery q);
-static float calc_rank_and(float *w, TSVector t, TSQuery q);
+static float calc_rank_or(const float *w, TSVector t, TSQuery q);
+static float calc_rank_and(const float *w, TSVector t, TSQuery q);
 
 /*
  * Returns a weight of a word collocation
@@ -202,7 +202,7 @@ static WordEntryPosVector POSNULL = {
 };
 
 static float
-calc_rank_and(float *w, TSVector t, TSQuery q)
+calc_rank_and(const float *w, TSVector t, TSQuery q)
 {
 	WordEntryPosVector **pos;
 	int			i,
@@ -278,7 +278,7 @@ calc_rank_and(float *w, TSVector t, TSQuery q)
 }
 
 static float
-calc_rank_or(float *w, TSVector t, TSQuery q)
+calc_rank_or(const float *w, TSVector t, TSQuery q)
 {
 	WordEntry  *entry,
 			   *firstentry;
@@ -347,7 +347,7 @@ calc_rank_or(float *w, TSVector t, TSQuery q)
 }
 
 static float
-calc_rank(float *w, TSVector t, TSQuery q, int32 method)
+calc_rank(const float *w, TSVector t, TSQuery q, int32 method)
 {
 	QueryItem  *item = GETQUERY(q);
 	float		res = 0.0;
@@ -387,7 +387,7 @@ calc_rank(float *w, TSVector t, TSQuery q, int32 method)
 	return res;
 }
 
-static float *
+static const float *
 getWeights(ArrayType *win)
 {
 	static float ws[lengthof(weights)];
@@ -723,7 +723,7 @@ get_docrep(TSVector txt, QueryRepresentation *qr, int *doclen)
 }
 
 static float4
-calc_rank_cd(float4 *arrdata, TSVector txt, TSQuery query, int method)
+calc_rank_cd(const float4 *arrdata, TSVector txt, TSQuery query, int method)
 {
 	DocRepresentation *doc;
 	int			len,