Re: Cleaning up and speeding up string functions - Mailing list pgsql-hackers

ilmari@ilmari.org (Dagfinn Ilmari Mannsåker) writes:

> David Rowley <david.rowley@2ndquadrant.com> writes:
>
>> On Thu, 4 Jul 2019 at 13:51, David Rowley <david.rowley@2ndquadrant.com> wrote:
>>> Instead of having 0004, how about the attached?
>>>
>>> Most of the calls won't improve much performance-wise since they're so
>>> cheap anyway, but there is xmlconcat(), I imagine that should see some
>>> speedup.
>>
>> I've pushed this after having found a couple more places where the
>> length is known.
>
> I noticed a lot of these are appending one StringInfo onto another;
> would it make sense to introduce a helper funciton
> appendStringInfoStringInfo(StringInfo str, StringInfo str2) to avoid the
> `str.data, str2.len` repetition?

A bit of grepping only turned up 18 uses, but I was bored and whipped up
the attached anyway, in case we decide it's worth it.

- ilmari
-- 
"The surreality of the universe tends towards a maximum" -- Skud's Law
"Never formulate a law or axiom that you're not prepared to live with
 the consequences of."                              -- Skud's Meta-Law

From 1e68adae513425470cad10cd2a44f66bca61a5fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dagfinn=20Ilmari=20Manns=C3=A5ker?= <ilmari@ilmari.org>
Date: Mon, 22 Jul 2019 15:01:03 +0100
Subject: [PATCH] Add appendStringInfoStringInfo() function

This simplifies appending one StringInfo to another
---
 contrib/hstore/hstore_io.c          |  2 +-
 contrib/postgres_fdw/deparse.c      |  4 ++--
 src/backend/access/transam/xlog.c   |  2 +-
 src/backend/executor/execMain.c     |  2 +-
 src/backend/lib/stringinfo.c        | 12 ++++++++++++
 src/backend/storage/lmgr/deadlock.c |  2 +-
 src/backend/utils/adt/ri_triggers.c |  4 ++--
 src/backend/utils/adt/ruleutils.c   | 10 +++++-----
 src/backend/utils/adt/xml.c         | 12 +++++-------
 src/include/lib/stringinfo.h        |  7 +++++++
 10 files changed, 37 insertions(+), 20 deletions(-)

diff --git a/contrib/hstore/hstore_io.c b/contrib/hstore/hstore_io.c
index 745497c76f..58415ccaec 100644
--- a/contrib/hstore/hstore_io.c
+++ b/contrib/hstore/hstore_io.c
@@ -1309,7 +1309,7 @@ hstore_to_json_loose(PG_FUNCTION_ARGS)
             appendBinaryStringInfo(&tmp, HSTORE_VAL(entries, base, i),
                                    HSTORE_VALLEN(entries, i));
             if (IsValidJsonNumber(tmp.data, tmp.len))
-                appendBinaryStringInfo(&dst, tmp.data, tmp.len);
+                appendStringInfoStringInfo(&dst, &tmp);
             else
                 escape_json(&dst, tmp.data);
         }
diff --git a/contrib/postgres_fdw/deparse.c b/contrib/postgres_fdw/deparse.c
index 19f928ec59..510e034e8e 100644
--- a/contrib/postgres_fdw/deparse.c
+++ b/contrib/postgres_fdw/deparse.c
@@ -1531,7 +1531,7 @@ deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
             {
                 Assert(fpinfo->jointype == JOIN_INNER);
                 Assert(fpinfo->joinclauses == NIL);
-                appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
+                appendStringInfoStringInfo(buf, &join_sql_o);
                 return;
             }
         }
@@ -1552,7 +1552,7 @@ deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
             {
                 Assert(fpinfo->jointype == JOIN_INNER);
                 Assert(fpinfo->joinclauses == NIL);
-                appendBinaryStringInfo(buf, join_sql_i.data, join_sql_i.len);
+                appendStringInfoStringInfo(buf, &join_sql_i);
                 return;
             }
         }
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index da3d250986..e674c63056 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1192,7 +1192,7 @@ XLogInsertRecord(XLogRecData *rdata,
          */
         initStringInfo(&recordBuf);
         for (; rdata != NULL; rdata = rdata->next)
-            appendBinaryStringInfo(&recordBuf, rdata->data, rdata->len);
+            appendStringInfoStringInfo(&recordBuf, rdata);
 
         if (!debug_reader)
             debug_reader = XLogReaderAllocate(wal_segment_size, NULL, NULL);
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index dbd7dd9bcd..1969b36891 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -2309,7 +2309,7 @@ ExecBuildSlotValueDescription(Oid reloid,
     if (!table_perm)
     {
         appendStringInfoString(&collist, ") = ");
-        appendBinaryStringInfo(&collist, buf.data, buf.len);
+        appendStringInfoStringInfo(&collist, &buf);
 
         return collist.data;
     }
diff --git a/src/backend/lib/stringinfo.c b/src/backend/lib/stringinfo.c
index 99c83c1549..d25d122289 100644
--- a/src/backend/lib/stringinfo.c
+++ b/src/backend/lib/stringinfo.c
@@ -165,6 +165,18 @@ appendStringInfoString(StringInfo str, const char *s)
     appendBinaryStringInfo(str, s, strlen(s));
 }
 
+/*
+ * appendStringInfoStringInfo
+ *
+ * Append another StringInfo to str.
+ * Like appendBinaryStringInfo(str, str2->data, str2->len)
+ */
+void
+appendStringInfoStringInfo(StringInfo str, const StringInfo str2)
+{
+    appendBinaryStringInfo(str, str2->data, str2->len);
+}
+
 /*
  * appendStringInfoChar
  *
diff --git a/src/backend/storage/lmgr/deadlock.c b/src/backend/storage/lmgr/deadlock.c
index 990d48377d..14a47b9e66 100644
--- a/src/backend/storage/lmgr/deadlock.c
+++ b/src/backend/storage/lmgr/deadlock.c
@@ -1115,7 +1115,7 @@ DeadLockReport(void)
     }
 
     /* Duplicate all the above for the server ... */
-    appendBinaryStringInfo(&logbuf, clientbuf.data, clientbuf.len);
+    appendStringInfoStringInfo(&logbuf, &clientbuf);
 
     /* ... and add info about query strings */
     for (i = 0; i < nDeadlockDetails; i++)
diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c
index 8c895459c3..5b4872db09 100644
--- a/src/backend/utils/adt/ri_triggers.c
+++ b/src/backend/utils/adt/ri_triggers.c
@@ -927,7 +927,7 @@ RI_FKey_cascade_upd(PG_FUNCTION_ARGS)
             queryoids[i] = pk_type;
             queryoids[j] = pk_type;
         }
-        appendBinaryStringInfo(&querybuf, qualbuf.data, qualbuf.len);
+        appendStringInfoStringInfo(&querybuf, &qualbuf);
 
         /* Prepare and save the plan */
         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys * 2, queryoids,
@@ -1106,7 +1106,7 @@ ri_set(TriggerData *trigdata, bool is_set_null)
             qualsep = "AND";
             queryoids[i] = pk_type;
         }
-        appendBinaryStringInfo(&querybuf, qualbuf.data, qualbuf.len);
+        appendStringInfoStringInfo(&querybuf, &qualbuf);
 
         /* Prepare and save the plan */
         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 0c58f1f109..1801899ec1 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2804,9 +2804,9 @@ pg_get_functiondef(PG_FUNCTION_ARGS)
         appendStringInfoChar(&dq, 'x');
     appendStringInfoChar(&dq, '$');
 
-    appendBinaryStringInfo(&buf, dq.data, dq.len);
+    appendStringInfoStringInfo(&buf, &dq);
     appendStringInfoString(&buf, prosrc);
-    appendBinaryStringInfo(&buf, dq.data, dq.len);
+    appendStringInfoStringInfo(&buf, &dq);
 
     appendStringInfoChar(&buf, '\n');
 
@@ -2930,7 +2930,7 @@ print_function_rettype(StringInfo buf, HeapTuple proctup)
         appendStringInfoString(&rbuf, format_type_be(proc->prorettype));
     }
 
-    appendBinaryStringInfo(buf, rbuf.data, rbuf.len);
+    appendStringInfoStringInfo(buf, &rbuf);
 }
 
 /*
@@ -5682,7 +5682,7 @@ get_target_list(List *targetList, deparse_context *context,
         }
 
         /* Add the new field */
-        appendBinaryStringInfo(buf, targetbuf.data, targetbuf.len);
+        appendStringInfoStringInfo(buf, &targetbuf);
     }
 
     /* clean up */
@@ -9987,7 +9987,7 @@ get_from_clause(Query *query, const char *prefix, deparse_context *context)
             }
 
             /* Add the new item */
-            appendBinaryStringInfo(buf, itembuf.data, itembuf.len);
+            appendStringInfoStringInfo(buf, &itembuf);
 
             /* clean up */
             pfree(itembuf.data);
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 5e629d29ea..2a3f5403cf 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -559,7 +559,7 @@ xmlconcat(List *args)
                        0,
                        global_standalone);
 
-        appendBinaryStringInfo(&buf2, buf.data, buf.len);
+        appendStringInfoStringInfo(&buf2, &buf);
         buf = buf2;
     }
 
@@ -1879,8 +1879,7 @@ xml_errorHandler(void *data, xmlErrorPtr error)
     if (xmlerrcxt->strictness == PG_XML_STRICTNESS_LEGACY)
     {
         appendStringInfoLineSeparator(&xmlerrcxt->err_buf);
-        appendBinaryStringInfo(&xmlerrcxt->err_buf, errorBuf->data,
-                               errorBuf->len);
+        appendStringInfoStringInfo(&xmlerrcxt->err_buf, errorBuf);
 
         pfree(errorBuf->data);
         pfree(errorBuf);
@@ -1898,8 +1897,7 @@ xml_errorHandler(void *data, xmlErrorPtr error)
     if (level >= XML_ERR_ERROR)
     {
         appendStringInfoLineSeparator(&xmlerrcxt->err_buf);
-        appendBinaryStringInfo(&xmlerrcxt->err_buf, errorBuf->data,
-                               errorBuf->len);
+        appendStringInfoStringInfo(&xmlerrcxt->err_buf, errorBuf);
 
         xmlerrcxt->err_occurred = true;
     }
@@ -2876,7 +2874,7 @@ schema_to_xml_internal(Oid nspid, const char *xmlschema, bool nulls,
         subres = table_to_xml_internal(relid, NULL, nulls, tableforest,
                                        targetns, false);
 
-        appendBinaryStringInfo(result, subres->data, subres->len);
+        appendStringInfoStringInfo(result, subres);
         appendStringInfoChar(result, '\n');
     }
 
@@ -3051,7 +3049,7 @@ database_to_xml_internal(const char *xmlschema, bool nulls,
         subres = schema_to_xml_internal(nspid, NULL, nulls,
                                         tableforest, targetns, false);
 
-        appendBinaryStringInfo(result, subres->data, subres->len);
+        appendStringInfoStringInfo(result, subres);
         appendStringInfoChar(result, '\n');
     }
 
diff --git a/src/include/lib/stringinfo.h b/src/include/lib/stringinfo.h
index c4842778c5..8a6ffd7ce8 100644
--- a/src/include/lib/stringinfo.h
+++ b/src/include/lib/stringinfo.h
@@ -112,6 +112,13 @@ extern int    appendStringInfoVA(StringInfo str, const char *fmt, va_list args) pg_
  */
 extern void appendStringInfoString(StringInfo str, const char *s);
 
+/*------------------------
+ * appendStringInfoString
+ * Append another StringInfo to str.
+ * Like appendBinaryStringInfo(str, str2->data, str2->len)
+ */
+extern void appendStringInfoStringInfo(StringInfo str, const StringInfo str2);
+
 /*------------------------
  * appendStringInfoChar
  * Append a single byte to str.
-- 
2.20.1