Expose some mdbx statistics/metadata to ruby.

- Add anonymous structs for settings and state to the internal db instance struct. - Allow tweaking the max_readers setting on db open. - Allow altering database sizing/geometry values. - Start sketching out some transaction re-entrancy. - Refactor initialization slightly, just use the db struct instead of additional unnecessary vars. FossilOrigin-Name: 513f02946f7dc39001c402c1adf0697bb2852ba867685b35adbccaaaf43c6e15
2020-12-23 01:10:19 +00:00 · 2020-12-23 01:10:19 +00:00 · ceb92fad16
commit ceb92fad16
parent 770a931d77
4 changed files with 397 additions and 111 deletions
--- a/ext/mdbx_ext/stats.c
+++ b/ext/mdbx_ext/stats.c
@ -0,0 +1,192 @@
+/* vim: set noet sta sw=4 ts=4 :
+ *
+ * Expose a bunch of mdbx internals to ruby.
+ * This is all largely stolen from mdbx_stat.c.
+ *
+ * Entry point is rmdbx_stats() in database.c.
+ *
+ */
+
+#include "mdbx_ext.h"
+
+
+/*
+ * Metadata specific to the mdbx build.
+ */
+void
+rmdbx_gather_build_stats( VALUE stat )
+{
+	rb_hash_aset( stat, ID2SYM(rb_intern("build_compiler")),
+			rb_str_new_cstr(mdbx_build.compiler) );
+	rb_hash_aset( stat, ID2SYM(rb_intern("build_flags")),
+			rb_str_new_cstr(mdbx_build.flags) );
+	rb_hash_aset( stat, ID2SYM(rb_intern("build_options")),
+			rb_str_new_cstr(mdbx_build.options) );
+	rb_hash_aset( stat, ID2SYM(rb_intern("build_target")),
+			rb_str_new_cstr(mdbx_build.target) );
+	return;
+}
+
+
+/*
+ * Metadata for the database file.
+ */
+void
+rmdbx_gather_datafile_stats(
+	VALUE environ,
+	MDBX_stat mstat,
+	MDBX_envinfo menvinfo )
+{
+	VALUE datafile = rb_hash_new();
+	rb_hash_aset( environ, ID2SYM(rb_intern("datafile")), datafile );
+
+	rb_hash_aset( datafile, ID2SYM(rb_intern("size_current")),
+			INT2NUM(menvinfo.mi_geo.current) );
+	rb_hash_aset( datafile, ID2SYM(rb_intern("pages")),
+			INT2NUM(menvinfo.mi_geo.current / mstat.ms_psize) );
+
+	if ( menvinfo.mi_geo.lower != menvinfo.mi_geo.upper ) {
+		rb_hash_aset( datafile, ID2SYM(rb_intern("type")),
+			rb_str_new_cstr("dynamic") );
+		rb_hash_aset( datafile, ID2SYM(rb_intern("size_lower")),
+			INT2NUM( menvinfo.mi_geo.lower ) );
+		rb_hash_aset( datafile, ID2SYM(rb_intern("size_upper")),
+			LONG2FIX( menvinfo.mi_geo.upper ) );
+		rb_hash_aset( datafile, ID2SYM(rb_intern("growth_step")),
+			INT2NUM( menvinfo.mi_geo.grow ) );
+		rb_hash_aset( datafile, ID2SYM(rb_intern("shrink_threshold")),
+			INT2NUM( menvinfo.mi_geo.shrink ) );
+	}
+	else {
+		rb_hash_aset( datafile, ID2SYM(rb_intern("type")),
+			rb_str_new_cstr("fixed") );
+	}
+
+	return;
+}
+
+
+/*
+ * Metadata for the database environment.
+ */
+void
+rmdbx_gather_environment_stats(
+	VALUE stat,
+	MDBX_stat mstat,
+	MDBX_envinfo menvinfo )
+{
+	VALUE environ  = rb_hash_new();
+	rb_hash_aset( stat, ID2SYM(rb_intern("environment")), environ );
+
+	rb_hash_aset( environ, ID2SYM(rb_intern("pagesize")),
+			INT2NUM(mstat.ms_psize) );
+	rb_hash_aset( environ, ID2SYM(rb_intern("last_txnid")),
+			INT2NUM(menvinfo.mi_recent_txnid) );
+	rb_hash_aset( environ, ID2SYM(rb_intern("last_reader_txnid")),
+			INT2NUM(menvinfo.mi_latter_reader_txnid) );
+	rb_hash_aset( environ, ID2SYM(rb_intern("maximum_readers")),
+			INT2NUM(menvinfo.mi_maxreaders) );
+	rb_hash_aset( environ, ID2SYM(rb_intern("readers_in_use")),
+			INT2NUM(menvinfo.mi_numreaders) );
+
+	rmdbx_gather_datafile_stats( environ, mstat, menvinfo );
+
+	return;
+}
+
+
+/*
+ * Callback iterator for pulling each reader's current state.
+ * See: https://erthink.github.io/libmdbx/group__c__statinfo.html#gad1ab5cf54d4a9f7d4c2999078920e8b0
+ *
+ */
+int
+reader_list_callback(
+	void *ctx,
+	int num,
+	int slot,
+	mdbx_pid_t pid,
+	mdbx_tid_t thread,
+	uint64_t txnid,
+	uint64_t lag,
+	size_t bytes_used,
+	size_t bytes_retired )
+{
+	VALUE reader = rb_hash_new();
+
+	rb_hash_aset( reader, ID2SYM(rb_intern("slot")),
+			INT2NUM( slot ) );
+	rb_hash_aset( reader, ID2SYM(rb_intern("pid")),
+		   	LONG2FIX( pid ) );
+	rb_hash_aset( reader, ID2SYM(rb_intern("thread")),
+			LONG2FIX( thread ) );
+	rb_hash_aset( reader, ID2SYM(rb_intern("txnid")),
+			LONG2FIX( txnid ) );
+	rb_hash_aset( reader, ID2SYM(rb_intern("lag")),
+			LONG2FIX( lag ) );
+	rb_hash_aset( reader, ID2SYM(rb_intern("bytes_used")),
+			LONG2FIX( bytes_used ) );
+	rb_hash_aset( reader, ID2SYM(rb_intern("bytes_retired")),
+			LONG2FIX( bytes_retired ) );
+
+	rb_ary_push( (VALUE)ctx, reader );
+
+	return 0;
+}
+
+
+/*
+ * Metadata for current reader slots.
+ * Initialize an array and populate it with each reader's statistics.
+*/
+void
+rmdbx_gather_reader_stats(
+	rmdbx_db_t *db,
+	VALUE stat,
+	MDBX_stat mstat,
+	MDBX_envinfo menvinfo )
+{
+	VALUE readers = rb_ary_new();
+
+    mdbx_reader_list( db->env, reader_list_callback, (void*)readers );
+	rb_hash_aset( stat, ID2SYM(rb_intern("readers")), readers );
+
+	return;
+}
+
+
+/*
+ * Build and return a hash of various statistic/metadata
+ * for the open +db+ handle.
+ */
+VALUE
+rmdbx_gather_stats( rmdbx_db_t *db )
+{
+	VALUE stat = rb_hash_new();
+
+	int rc;
+	MDBX_stat mstat;
+	MDBX_envinfo menvinfo;
+
+	rmdbx_gather_build_stats( stat );
+
+	rmdbx_open_txn( db, MDBX_TXN_RDONLY );
+    rc = mdbx_env_info_ex( db->env, db->txn, &menvinfo, sizeof(menvinfo) );
+	if ( rc != MDBX_SUCCESS )
+		rb_raise( rmdbx_eDatabaseError, "mdbx_env_info_ex: (%d) %s", rc, mdbx_strerror(rc) );
+
+    rc = mdbx_env_stat_ex( db->env, db->txn, &mstat, sizeof(mstat) );
+	if ( rc != MDBX_SUCCESS )
+		rb_raise( rmdbx_eDatabaseError, "mdbx_env_stat_ex: (%d) %s", rc, mdbx_strerror(rc) );
+	rmdbx_close_txn( db, RMDBX_TXN_ROLLBACK );
+
+	rmdbx_gather_environment_stats( stat, mstat, menvinfo );
+	rmdbx_gather_reader_stats( db, stat, mstat, menvinfo );
+
+	/* database and subdatabases */
+
+
+	return stat;
+}
+
+