From b0776fd0f8086ab272075262006358660a915024 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Sun, 10 May 2020 00:05:52 -0700
Subject: [PATCH] ircd::m::homeserver: Preliminary bootstrap from event vector.

---
 construct/construct.cc      |  3 ++
 include/ircd/m/homeserver.h |  6 +++
 matrix/homeserver.cc        | 75 ++++++++++++++++++++++++++++++++++++-
 3 files changed, 82 insertions(+), 2 deletions(-)

diff --git a/construct/construct.cc b/construct/construct.cc
index 4ff4f39aa..fd3a9ed9b 100644
--- a/construct/construct.cc
+++ b/construct/construct.cc
@@ -41,6 +41,7 @@ bool soft_assert;
 bool nomatrix;
 bool matrix {true}; // matrix server by default.
 bool defaults;
+const char *bootstrap;
 
 lgetopt opts[]
 {
@@ -70,6 +71,7 @@ lgetopt opts[]
 	{ "nomatrix",   &nomatrix,      lgetopt::BOOL,    "Prevent loading the matrix application module" },
 	{ "matrix",     &matrix,        lgetopt::BOOL,    "Allow loading the matrix application module" },
 	{ "defaults",   &defaults,      lgetopt::BOOL,    "Use configuration defaults without database load for this execution" },
+	{ "bootstrap",  &bootstrap,     lgetopt::STRING,  "Bootstrap fresh database from event vector" },
 	{ nullptr,      nullptr,        lgetopt::STRING,  nullptr },
 };
 
@@ -203,6 +205,7 @@ noexcept try
 			struct ircd::m::homeserver::opts opts;
 			opts.origin = origin;
 			opts.server_name = server_name;
+			opts.bootstrap_vector_path = bootstrap;
 			const ircd::custom_ptr<ircd::m::homeserver> homeserver
 			{
 				// 6.1
diff --git a/include/ircd/m/homeserver.h b/include/ircd/m/homeserver.h
index 72ea5f359..b41c34aaf 100644
--- a/include/ircd/m/homeserver.h
+++ b/include/ircd/m/homeserver.h
@@ -143,4 +143,10 @@ struct ircd::m::homeserver::opts
 	/// be the origin itself; otherwise, SRV/well-known indirection is required
 	/// to reach the servername starting from the origin.
 	string_view server_name;
+
+	/// When instantiating a homeserver with a fresh database, the file found
+	/// at this path can supplement for any initial bootstrapping. This vector
+	/// may contain additional events as well; the server will continue its
+	/// operation after having processed these events.
+	string_view bootstrap_vector_path;
 };
diff --git a/matrix/homeserver.cc b/matrix/homeserver.cc
index 06e10a683..71082d574 100644
--- a/matrix/homeserver.cc
+++ b/matrix/homeserver.cc
@@ -10,6 +10,7 @@
 
 namespace ircd::m
 {
+	static void bootstrap_event_vector(homeserver &);
 	static void bootstrap(homeserver &);
 	static void signon(homeserver &), signoff(homeserver &) noexcept;
 
@@ -260,7 +261,12 @@ try
 	}};
 
 	if(dbs::events && sequence(*dbs::events) == 0)
-		bootstrap(*this);
+	{
+		if(opts->bootstrap_vector_path)
+			bootstrap_event_vector(*this);
+		else
+			bootstrap(*this);
+	}
 
 	if(key && !key->verify_keys.empty())
 		m::keys::cache::set(key->verify_keys);
@@ -830,9 +836,74 @@ catch(...)
 }
 
 //
-// bootstrap
+// bootstrap_vector
 //
 
+void
+ircd::m::bootstrap_event_vector(homeserver &homeserver)
+try
+{
+	const string_view &path
+	{
+		homeserver.opts->bootstrap_vector_path
+	};
+
+	fs::fd::opts fileopts(std::ios::in);
+	fileopts.sequential = true;
+	const fs::fd file
+	{
+		path, fileopts
+	};
+
+	log::notice
+	{
+		log, "Bootstrapping database from event vector @ `%s'",
+		path,
+	};
+
+	const unique_mutable_buffer mb
+	{
+		512_KiB
+	};
+
+	size_t events(0);
+	const_buffer buf;
+	fs::read_opts ropts; do
+	{
+		buf = read(file, mb, ropts);
+
+
+		ropts.offset += size(buf);
+	}
+	while(!!buf);
+
+	log::info
+	{
+		log, "Bootstrapped %zu events in %zu bytes from `%s'",
+		events,
+		ropts.offset,
+		path,
+	};
+}
+catch(const std::exception &e)
+{
+	log::logf
+	{
+		log, log::level::CRITICAL,
+		"Failed to start server '%s' on network '%s'",
+		server_name(homeserver),
+		origin(homeserver),
+		e.what()
+	};
+
+	throw ircd::error
+	{
+		"bootstrap %s error :%s",
+		server_name(homeserver),
+		e.what()
+	};
+}
+
 void
 ircd::m::bootstrap(homeserver &homeserver)
 try