Feedback-ID: ie3de48e3:Fastmail
Date: Sat, 31 Jan 2026 10:41:06 +0100
From: =?utf-8?Q?=C3=81lvaro?= Herrera <alvherre@kurilemu.de>
To: Pg Hackers <pgsql-hackers@lists.postgresql.org>
Subject: splitting pg_resetwal output strings
Message-ID: <202601310924.yoik5n3blgt4@alvherre.pgsql>
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="6po7oomtfoqj5cjo"
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
Archived-At: 
 <https://www.postgresql.org/message-id/202601310924.yoik5n3blgt4%40alvherre.pgsql>
Precedence: bulk


--6po7oomtfoqj5cjo
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit

Hello,

For a long time I've been annoyed that certain tools such as (but not
only) pg_resetwal have translatable strings full of whitespace that
translators have to be careful about so that things look nice.
For Spanish I have made the lines a bit wider so that everything fits,
which means that every time someone adds a new line that's not yet
translated, the output looks bad; and if I want to add one more space
to align a new longer string, then I have to edit every single one of
them.  This is horrible.

Here's a proposal.  The idea is to have a separate file (entries.h right
now but proposal for better names are welcome) which lists those
strings, together with the printf specifiers needed to actually print
them.  This way, we can measure the length of each exactly as they
translate before printing anything, and then line up everything to the
same output length.

One curious thing of note is that I had to add an internal_wcswidth()
function, to avoid having to link libpq just to be able to do
pg_wcswidth().

This is not complete.  It modifies PrintControlValues(), which is easy
because I just print each item in the entries.h file in the same order
they appear there.   But for PrintNewControlValues() I'll need to add a
symbolic identifier to each string, that the code can use to scan the
array and print just those elements.  I'll do that if there are no
objections to this idea here.  Also, pg_controldata could probably
something very similar or maybe the same entries.h file.

-- 
Álvaro Herrera               48°01'N 7°57'E  —  https://www.EnterpriseDB.com/
"If you want to have good ideas, you must have many ideas.  Most of them
will be wrong, and what you have to learn is which ones to throw away."
                                                         (Linus Pauling)

--6po7oomtfoqj5cjo
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment;
	filename="0001-Split-out-entry-names-in-pg_resetwal.patch"

From 59403690ca6253835ce7577f3eee7d04893b6950 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=81lvaro=20Herrera?= <alvherre@kurilemu.de>
Date: Fri, 14 Nov 2025 16:25:46 +0100
Subject: [PATCH] Split out entry names in pg_resetwal

---
 src/bin/pg_resetwal/entries.h     |  62 ++++++++++++++
 src/bin/pg_resetwal/nls.mk        |   4 +-
 src/bin/pg_resetwal/pg_resetwal.c | 132 ++++++++++++++++--------------
 3 files changed, 134 insertions(+), 64 deletions(-)
 create mode 100644 src/bin/pg_resetwal/entries.h

diff --git a/src/bin/pg_resetwal/entries.h b/src/bin/pg_resetwal/entries.h
new file mode 100644
index 00000000000..6b7686da83a
--- /dev/null
+++ b/src/bin/pg_resetwal/entries.h
@@ -0,0 +1,62 @@
+CONTROLDATA_LINE("pg_control version number",
+				 "%u", ControlFile.pg_control_version)
+CONTROLDATA_LINE("Catalog version number",
+				 "%u", ControlFile.catalog_version_no)
+CONTROLDATA_LINE("Database system identifier",
+				 "%" PRIu64, ControlFile.system_identifier)
+CONTROLDATA_LINE("Latest checkpoint's TimeLineID",
+				 "%u", ControlFile.checkPointCopy.ThisTimeLineID)
+CONTROLDATA_LINE("Latest checkpoint's full_page_writes",
+				 "%s", (ControlFile.checkPointCopy.fullPageWrites ? _("on") : _("off")))
+CONTROLDATA_LINE("Latest checkpoint's NextXID",
+				 "%u:%u", EpochFromFullTransactionId(ControlFile.checkPointCopy.nextXid), XidFromFullTransactionId(ControlFile.checkPointCopy.nextXid))
+CONTROLDATA_LINE("Latest checkpoint's NextOID",
+				 "%u", ControlFile.checkPointCopy.nextOid)
+CONTROLDATA_LINE("Latest checkpoint's NextMultiXactId",
+				 "%u", ControlFile.checkPointCopy.nextMulti)
+CONTROLDATA_LINE("Latest checkpoint's NextMultiOffset",
+				 "%" PRIu64, ControlFile.checkPointCopy.nextMultiOffset)
+CONTROLDATA_LINE("Latest checkpoint's oldestXID",
+				 "%u", ControlFile.checkPointCopy.oldestXid)
+CONTROLDATA_LINE("Latest checkpoint's oldestXID's DB",
+				 "%u", ControlFile.checkPointCopy.oldestXidDB)
+CONTROLDATA_LINE("Latest checkpoint's oldestActiveXID",
+				 "%u", ControlFile.checkPointCopy.oldestActiveXid)
+CONTROLDATA_LINE("Latest checkpoint's oldestMultiXid",
+				 "%u", ControlFile.checkPointCopy.oldestMulti)
+CONTROLDATA_LINE("Latest checkpoint's oldestMulti's DB",
+				 "%u", ControlFile.checkPointCopy.oldestMultiDB)
+CONTROLDATA_LINE("Latest checkpoint's oldestCommitTsXid",
+				 "%u", ControlFile.checkPointCopy.oldestCommitTsXid)
+CONTROLDATA_LINE("Latest checkpoint's newestCommitTsXid",
+				 "%u", ControlFile.checkPointCopy.newestCommitTsXid)
+CONTROLDATA_LINE("Maximum data alignment",
+				 "%u", ControlFile.maxAlign)
+CONTROLDATA_LINE("Database block size",
+				 "%u", ControlFile.blcksz)
+CONTROLDATA_LINE("Blocks per segment of large relation",
+				 "%u", ControlFile.relseg_size)
+CONTROLDATA_LINE("Pages per SLRU segment",
+				 "%u", ControlFile.slru_pages_per_segment)
+CONTROLDATA_LINE("WAL block size",
+				 "%u", ControlFile.xlog_blcksz)
+CONTROLDATA_LINE("Bytes per WAL segment",
+				 "%u", ControlFile.xlog_seg_size)
+CONTROLDATA_LINE("Maximum length of identifiers",
+				 "%u", ControlFile.nameDataLen)
+CONTROLDATA_LINE("Maximum columns in an index",
+				 "%u", ControlFile.indexMaxKeys)
+CONTROLDATA_LINE("Maximum size of a TOAST chunk",
+				 "%u", ControlFile.toast_max_chunk_size)
+CONTROLDATA_LINE("Size of a large-object chunk",
+				 "%u", ControlFile.loblksize)
+
+/* This is no longer configurable, but users may still expect to see it: */
+CONTROLDATA_LINE("Date/time type storage",
+				 "%s", _("64-bit integers"))
+CONTROLDATA_LINE("Float8 argument passing",
+				 "%s", ControlFile.float8ByVal ? _("by value") : _("by reference"))
+CONTROLDATA_LINE("Data page checksum version",
+				 "%u", ControlFile.data_checksum_version)
+CONTROLDATA_LINE("Default char data signedness",
+				 "%s", ControlFile.default_char_signedness ? _("signed") : _("unsigned"))
diff --git a/src/bin/pg_resetwal/nls.mk b/src/bin/pg_resetwal/nls.mk
index 694d5420a29..8dabee72bef 100644
--- a/src/bin/pg_resetwal/nls.mk
+++ b/src/bin/pg_resetwal/nls.mk
@@ -2,10 +2,12 @@
 CATALOG_NAME     = pg_resetwal
 GETTEXT_FILES    = $(FRONTEND_COMMON_GETTEXT_FILES) \
                    pg_resetwal.c \
+                   entries.h \
                    ../../common/controldata_utils.c \
                    ../../common/fe_memutils.c \
                    ../../common/file_utils.c \
                    ../../common/restricted_token.c \
                    ../../fe_utils/option_utils.c
-GETTEXT_TRIGGERS = $(FRONTEND_COMMON_GETTEXT_TRIGGERS)
+GETTEXT_TRIGGERS = $(FRONTEND_COMMON_GETTEXT_TRIGGERS) \
+				   CONTROLDATA_LINE:1
 GETTEXT_FLAGS    = $(FRONTEND_COMMON_GETTEXT_FLAGS)
diff --git a/src/bin/pg_resetwal/pg_resetwal.c b/src/bin/pg_resetwal/pg_resetwal.c
index 431b83a67da..fb17b6f80e0 100644
--- a/src/bin/pg_resetwal/pg_resetwal.c
+++ b/src/bin/pg_resetwal/pg_resetwal.c
@@ -57,6 +57,7 @@
 #include "fe_utils/option_utils.h"
 #include "fe_utils/version.h"
 #include "getopt_long.h"
+#include "mb/pg_wchar.h"
 #include "pg_getopt.h"
 #include "storage/large_object.h"
 
@@ -114,6 +115,7 @@ static void KillExistingArchiveStatus(void);
 static void KillExistingWALSummaries(void);
 static void WriteEmptyXLOG(void);
 static void usage(void);
+static int	internal_wcswidth(const char *pwcs, size_t len, int encoding);
 static uint32 strtouint32_strict(const char *restrict s, char **restrict endptr, int base);
 static uint64 strtouint64_strict(const char *restrict s, char **restrict endptr, int base);
 
@@ -753,74 +755,48 @@ GuessControlValues(void)
 static void
 PrintControlValues(bool guessed)
 {
+	int			encoding = pg_get_encoding_from_locale(NULL, true);
+	int			maxlen = 0;
+	int			thislen;
+
 	if (guessed)
 		printf(_("Guessed pg_control values:\n\n"));
 	else
 		printf(_("Current pg_control values:\n\n"));
 
-	printf(_("pg_control version number:            %u\n"),
-		   ControlFile.pg_control_version);
-	printf(_("Catalog version number:               %u\n"),
-		   ControlFile.catalog_version_no);
-	printf(_("Database system identifier:           %" PRIu64 "\n"),
-		   ControlFile.system_identifier);
-	printf(_("Latest checkpoint's TimeLineID:       %u\n"),
-		   ControlFile.checkPointCopy.ThisTimeLineID);
-	printf(_("Latest checkpoint's full_page_writes: %s\n"),
-		   ControlFile.checkPointCopy.fullPageWrites ? _("on") : _("off"));
-	printf(_("Latest checkpoint's NextXID:          %u:%u\n"),
-		   EpochFromFullTransactionId(ControlFile.checkPointCopy.nextXid),
-		   XidFromFullTransactionId(ControlFile.checkPointCopy.nextXid));
-	printf(_("Latest checkpoint's NextOID:          %u\n"),
-		   ControlFile.checkPointCopy.nextOid);
-	printf(_("Latest checkpoint's NextMultiXactId:  %u\n"),
-		   ControlFile.checkPointCopy.nextMulti);
-	printf(_("Latest checkpoint's NextMultiOffset:  %" PRIu64 "\n"),
-		   ControlFile.checkPointCopy.nextMultiOffset);
-	printf(_("Latest checkpoint's oldestXID:        %u\n"),
-		   ControlFile.checkPointCopy.oldestXid);
-	printf(_("Latest checkpoint's oldestXID's DB:   %u\n"),
-		   ControlFile.checkPointCopy.oldestXidDB);
-	printf(_("Latest checkpoint's oldestActiveXID:  %u\n"),
-		   ControlFile.checkPointCopy.oldestActiveXid);
-	printf(_("Latest checkpoint's oldestMultiXid:   %u\n"),
-		   ControlFile.checkPointCopy.oldestMulti);
-	printf(_("Latest checkpoint's oldestMulti's DB: %u\n"),
-		   ControlFile.checkPointCopy.oldestMultiDB);
-	printf(_("Latest checkpoint's oldestCommitTsXid:%u\n"),
-		   ControlFile.checkPointCopy.oldestCommitTsXid);
-	printf(_("Latest checkpoint's newestCommitTsXid:%u\n"),
-		   ControlFile.checkPointCopy.newestCommitTsXid);
-	printf(_("Maximum data alignment:               %u\n"),
-		   ControlFile.maxAlign);
-	/* we don't print floatFormat since can't say much useful about it */
-	printf(_("Database block size:                  %u\n"),
-		   ControlFile.blcksz);
-	printf(_("Blocks per segment of large relation: %u\n"),
-		   ControlFile.relseg_size);
-	printf(_("Pages per SLRU segment:               %u\n"),
-		   ControlFile.slru_pages_per_segment);
-	printf(_("WAL block size:                       %u\n"),
-		   ControlFile.xlog_blcksz);
-	printf(_("Bytes per WAL segment:                %u\n"),
-		   ControlFile.xlog_seg_size);
-	printf(_("Maximum length of identifiers:        %u\n"),
-		   ControlFile.nameDataLen);
-	printf(_("Maximum columns in an index:          %u\n"),
-		   ControlFile.indexMaxKeys);
-	printf(_("Maximum size of a TOAST chunk:        %u\n"),
-		   ControlFile.toast_max_chunk_size);
-	printf(_("Size of a large-object chunk:         %u\n"),
-		   ControlFile.loblksize);
-	/* This is no longer configurable, but users may still expect to see it: */
-	printf(_("Date/time type storage:               %s\n"),
-		   _("64-bit integers"));
-	printf(_("Float8 argument passing:              %s\n"),
-		   (ControlFile.float8ByVal ? _("by value") : _("by reference")));
-	printf(_("Data page checksum version:           %u\n"),
-		   ControlFile.data_checksum_version);
-	printf(_("Default char data signedness:         %s\n"),
-		   (ControlFile.default_char_signedness ? _("signed") : _("unsigned")));
+	/*
+	 * First, determine the maximum length of the description of all entries,
+	 * some or all of which might be translated.
+	 */
+#define CONTROLDATA_LINE(description, fmt, ...)			\
+	thislen = internal_wcswidth(_(description),			\
+								strlen(_(description)),	\
+								encoding);				\
+	if (thislen > maxlen)								\
+		maxlen = thislen;
+#include "entries.h"
+#undef CONTROLDATA_LINE
+
+	/*
+	 * Print each line: the possibly-translated description, then some padding
+	 * spaces according to its display width, then the value.
+	 */
+#define CONTROLDATA_LINE(description, fmt, ...)			\
+	{													\
+		int		thisstrlen;								\
+														\
+		thisstrlen = strlen(_(description));			\
+		thislen = internal_wcswidth(_(description),		\
+									thisstrlen,			\
+									encoding);			\
+		printf("%s:%*s" fmt "\n",						\
+			   _(description),							\
+			   maxlen - thislen + 2,					\
+			   " ",										\
+			   __VA_ARGS__);							\
+	}
+#include "entries.h"
+#undef CONTROLDATA_LINE
 }
 
 
@@ -1238,6 +1214,36 @@ usage(void)
 	printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
 }
 
+/*
+ * Measure the display length of a single-line string in the given encoding.
+ *
+ * Similar to pg_wcswidth, written without dependency on libpq.
+ */
+static int
+internal_wcswidth(const char *pwcs, size_t len, int encoding)
+{
+	int			width = 0;
+
+	while (len > 0)
+	{
+		int			chlen,
+					chwidth;
+
+		chlen = pg_encoding_mblen(encoding, pwcs);
+		if (len < (size_t) chlen)
+			break;				/* Invalid string */
+
+		chwidth = pg_encoding_dsplen(encoding, pwcs);
+		if (chwidth > 0)
+			width += chwidth;
+
+		pwcs += chlen;
+		len -= chlen;
+	}
+	return width;
+}
+
+
 /*
  * strtouint32_strict -- like strtoul(), but returns uint32 and doesn't accept
  * negative values
-- 
2.47.3


--6po7oomtfoqj5cjo--