From f50fa46cca9a1e5bfd517f7f1d979ef4db55ce03 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 3 Oct 2016 16:40:06 -0400 Subject: [PATCH] Show a sensible value in pg_settings.unit for GUC_UNIT_XSEGS variables. Commit 88e982302 invented GUC_UNIT_XSEGS for min_wal_size and max_wal_size, but neglected to make it display sensibly in pg_settings.unit (by adding a case to the switch in GetConfigOptionByNum). Fix that, and adjust said switch to throw a run-time error the next time somebody forgets. In passing, avoid using a static buffer for the output string --- the rest of this function pstrdup's from a local buffer, and I see no very good reason why the units code should do it differently and less safely. Per report from Otar Shavadze. Back-patch to 9.5 where the new unit type was added. Report: --- src/backend/utils/misc/guc.c | 20 ++++++++++++++------ src/include/utils/guc.h | 4 ++-- 2 files changed, 16 insertions(+), 8 deletions(-) diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index f249b3906c..9e6c555622 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -7808,20 +7808,23 @@ GetConfigOptionByNum(int varnum, const char **values, bool *noshow) /* unit */ if (conf->vartype == PGC_INT) { - static char buf[8]; - switch (conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME)) { case GUC_UNIT_KB: values[2] = "kB"; break; case GUC_UNIT_BLOCKS: - snprintf(buf, sizeof(buf), "%dkB", BLCKSZ / 1024); - values[2] = buf; + snprintf(buffer, sizeof(buffer), "%dkB", BLCKSZ / 1024); + values[2] = pstrdup(buffer); break; case GUC_UNIT_XBLOCKS: - snprintf(buf, sizeof(buf), "%dkB", XLOG_BLCKSZ / 1024); - values[2] = buf; + snprintf(buffer, sizeof(buffer), "%dkB", XLOG_BLCKSZ / 1024); + values[2] = pstrdup(buffer); + break; + case GUC_UNIT_XSEGS: + snprintf(buffer, sizeof(buffer), "%dMB", + XLOG_SEG_SIZE / (1024 * 1024)); + values[2] = pstrdup(buffer); break; case GUC_UNIT_MS: values[2] = "ms"; @@ -7832,7 +7835,12 @@ GetConfigOptionByNum(int varnum, const char **values, bool *noshow) case GUC_UNIT_MIN: values[2] = "min"; break; + case 0: + values[2] = NULL; + break; default: + elog(ERROR, "unrecognized GUC units value: %d", + conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME)); values[2] = NULL; break; } diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h index 49ec3840af..03a5dd1c57 100644 --- a/src/include/utils/guc.h +++ b/src/include/utils/guc.h @@ -219,12 +219,12 @@ typedef enum #define GUC_UNIT_BLOCKS 0x2000 /* value is in blocks */ #define GUC_UNIT_XBLOCKS 0x3000 /* value is in xlog blocks */ #define GUC_UNIT_XSEGS 0x4000 /* value is in xlog segments */ -#define GUC_UNIT_MEMORY 0xF000 /* mask for KB, BLOCKS, XBLOCKS */ +#define GUC_UNIT_MEMORY 0xF000 /* mask for size-related units */ #define GUC_UNIT_MS 0x10000 /* value is in milliseconds */ #define GUC_UNIT_S 0x20000 /* value is in seconds */ #define GUC_UNIT_MIN 0x30000 /* value is in minutes */ -#define GUC_UNIT_TIME 0xF0000 /* mask for MS, S, MIN */ +#define GUC_UNIT_TIME 0xF0000 /* mask for time-related units */ #define GUC_UNIT (GUC_UNIT_MEMORY | GUC_UNIT_TIME)