From b68b4d113a181fd193c28b387f49d1177eaef7e8 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Wed, 10 Jun 2020 04:29:12 -0700
Subject: [PATCH] ircd::db: Add conf item to disable automatic compactions.

construct: Add -nocompact program option.
---
 construct/construct.cc     |  5 +++++
 include/ircd/db/database.h |  1 +
 ircd/db.cc                 | 16 +++++++++++++++-
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/construct/construct.cc b/construct/construct.cc
index fd3a9ed9b..cf4bbf453 100644
--- a/construct/construct.cc
+++ b/construct/construct.cc
@@ -24,6 +24,7 @@ bool single;
 bool debugmode;
 bool nolisten;
 bool noautomod;
+bool nocompact;
 bool checkdb;
 bool pitrecdb;
 bool repairdb;
@@ -54,6 +55,7 @@ lgetopt opts[]
 	{ "execute",    &execute,       lgetopt::STRINGS, "Execute command lines immediately after startup" },
 	{ "nolisten",   &nolisten,      lgetopt::BOOL,    "Normal execution but without listening sockets" },
 	{ "noautomod",  &noautomod,     lgetopt::BOOL,    "Normal execution but without autoloading modules" },
+	{ "nocompact",  &nocompact,     lgetopt::BOOL,    "Disable automatic database compaction" },
 	{ "checkdb",    &checkdb,       lgetopt::BOOL,    "Perform complete checks of databases when opening" },
 	{ "pitrecdb",   &pitrecdb,      lgetopt::BOOL,    "Allow Point-In-Time-Recover if DB reports corruption after crash" },
 	{ "repairdb",   &repairdb,      lgetopt::BOOL,    "Perform full DB repair after deep block/file corruption" },
@@ -513,6 +515,9 @@ applyargs()
 	else
 		ircd::db::open_repair.set("false");
 
+	if(nocompact)
+		ircd::db::auto_compact.set("false");
+
 	if(nodirect)
 		ircd::fs::fd::opts::direct_io_enable.set("false");
 	else
diff --git a/include/ircd/db/database.h b/include/ircd/db/database.h
index 190f3d506..3da318774 100644
--- a/include/ircd/db/database.h
+++ b/include/ircd/db/database.h
@@ -19,6 +19,7 @@ namespace ircd::db
 	extern conf::item<bool> open_check;
 	extern conf::item<std::string> open_recover;
 	extern conf::item<bool> open_repair;
+	extern conf::item<bool> auto_compact;
 
 	// General information
 	const std::string &name(const database &);
diff --git a/ircd/db.cc b/ircd/db.cc
index a19f05baa..d91e741bf 100644
--- a/ircd/db.cc
+++ b/ircd/db.cc
@@ -442,6 +442,17 @@ ircd::db::open_repair
 	{ "persist",  false                  },
 };
 
+/// Conf item toggles whether automatic compaction is enabled or disabled for
+/// all databases upon opening. This is useful for developers, debugging and
+/// valgrind etc to prevent these background jobs from spawning when unwanted.
+decltype(ircd::db::auto_compact)
+ircd::db::auto_compact
+{
+	{ "name",     "ircd.db.compact.auto" },
+	{ "default",  true                   },
+	{ "persist",  false                  },
+};
+
 void
 ircd::db::sync(database &d)
 {
@@ -2014,6 +2025,10 @@ ircd::db::database::column::column(database &d,
 	this->options.min_write_buffer_number_to_merge = 4;
 	this->options.max_write_buffer_number_to_maintain = 0;
 
+	// Conf item can be set to disable automatic compactions. For developers
+	// and debugging; good for valgrind.
+	this->options.disable_auto_compactions = !bool(db::auto_compact);
+
 	// Set the compaction style; we don't override this in the descriptor yet.
 	//this->options.compaction_style = rocksdb::kCompactionStyleNone;
 	this->options.compaction_style = rocksdb::kCompactionStyleLevel;
@@ -2033,7 +2048,6 @@ ircd::db::database::column::column(database &d,
 
 	this->options.num_levels = 7;
 	this->options.level0_file_num_compaction_trigger = 2;
-	this->options.disable_auto_compactions = false;
 	this->options.level_compaction_dynamic_level_bytes = false;
 	this->options.ttl = 0;
 	#ifdef IRCD_DB_HAS_PERIODIC_COMPACTIONS